1// This is CodeMirror (http://codemirror.net), a code editor
2// implemented in JavaScript on top of the browser's DOM.
3//
4// You can find some technical background for some of the code below
5// at http://marijnhaverbeke.nl/blog/#cm-internals .
6
7(function(mod) {
8  if (typeof exports == "object" && typeof module == "object") // CommonJS
9    module.exports = mod();
10  else if (typeof define == "function" && define.amd) // AMD
11    return define([], mod);
12  else // Plain browser env
13    this.CodeMirror = mod();
14})(function() {
15  "use strict";
16
17  // BROWSER SNIFFING
18
19  // Kludges for bugs and behavior differences that can't be feature
20  // detected are enabled based on userAgent etc sniffing.
21
22  var gecko = /gecko\/\d/i.test(navigator.userAgent);
23  // ie_uptoN means Internet Explorer version N or lower
24  var ie_upto10 = /MSIE \d/.test(navigator.userAgent);
25  var ie_upto7 = ie_upto10 && (document.documentMode == null || document.documentMode < 8);
26  var ie_upto8 = ie_upto10 && (document.documentMode == null || document.documentMode < 9);
27  var ie_upto9 = ie_upto10 && (document.documentMode == null || document.documentMode < 10);
28  var ie_11up = /Trident\/([7-9]|\d{2,})\./.test(navigator.userAgent);
29  var ie = ie_upto10 || ie_11up;
30  var webkit = /WebKit\//.test(navigator.userAgent);
31  var qtwebkit = webkit && /Qt\/\d+\.\d+/.test(navigator.userAgent);
32  var chrome = /Chrome\//.test(navigator.userAgent);
33  var presto = /Opera\//.test(navigator.userAgent);
34  var safari = /Apple Computer/.test(navigator.vendor);
35  var khtml = /KHTML\//.test(navigator.userAgent);
36  var mac_geMountainLion = /Mac OS X 1\d\D([8-9]|\d\d)\D/.test(navigator.userAgent);
37  var phantom = /PhantomJS/.test(navigator.userAgent);
38
39  var ios = /AppleWebKit/.test(navigator.userAgent) && /Mobile\/\w+/.test(navigator.userAgent);
40  // This is woefully incomplete. Suggestions for alternative methods welcome.
41  var mobile = ios || /Android|webOS|BlackBerry|Opera Mini|Opera Mobi|IEMobile/i.test(navigator.userAgent);
42  var mac = ios || /Mac/.test(navigator.platform);
43  var windows = /win/i.test(navigator.platform);
44
45  var presto_version = presto && navigator.userAgent.match(/Version\/(\d*\.\d*)/);
46  if (presto_version) presto_version = Number(presto_version[1]);
47  if (presto_version && presto_version >= 15) { presto = false; webkit = true; }
48  // Some browsers use the wrong event properties to signal cmd/ctrl on OS X
49  var flipCtrlCmd = mac && (qtwebkit || presto && (presto_version == null || presto_version < 12.11));
50  var captureRightClick = gecko || (ie && !ie_upto8);
51
52  // Optimize some code when these features are not used.
53  var sawReadOnlySpans = false, sawCollapsedSpans = false;
54
55  // EDITOR CONSTRUCTOR
56
57  // A CodeMirror instance represents an editor. This is the object
58  // that user code is usually dealing with.
59
60  function CodeMirror(place, options) {
61    if (!(this instanceof CodeMirror)) return new CodeMirror(place, options);
62
63    this.options = options = options || {};
64    // Determine effective options based on given values and defaults.
65    copyObj(defaults, options, false);
66    setGuttersForLineNumbers(options);
67
68    var doc = options.value;
69    if (typeof doc == "string") doc = new Doc(doc, options.mode);
70    this.doc = doc;
71
72    var display = this.display = new Display(place, doc);
73    display.wrapper.CodeMirror = this;
74    updateGutters(this);
75    themeChanged(this);
76    if (options.lineWrapping)
77      this.display.wrapper.className += " CodeMirror-wrap";
78    if (options.autofocus && !mobile) focusInput(this);
79
80    this.state = {
81      keyMaps: [],  // stores maps added by addKeyMap
82      overlays: [], // highlighting overlays, as added by addOverlay
83      modeGen: 0,   // bumped when mode/overlay changes, used to invalidate highlighting info
84      overwrite: false, focused: false,
85      suppressEdits: false, // used to disable editing during key handlers when in readOnly mode
86      pasteIncoming: false, cutIncoming: false, // help recognize paste/cut edits in readInput
87      draggingText: false,
88      highlight: new Delayed() // stores highlight worker timeout
89    };
90
91    // Override magic textarea content restore that IE sometimes does
92    // on our hidden textarea on reload
93    if (ie_upto10) setTimeout(bind(resetInput, this, true), 20);
94
95    registerEventHandlers(this);
96
97    var cm = this;
98    runInOp(this, function() {
99      cm.curOp.forceUpdate = true;
100      attachDoc(cm, doc);
101
102      if ((options.autofocus && !mobile) || activeElt() == display.input)
103        setTimeout(bind(onFocus, cm), 20);
104      else
105        onBlur(cm);
106
107      for (var opt in optionHandlers) if (optionHandlers.hasOwnProperty(opt))
108        optionHandlers[opt](cm, options[opt], Init);
109      for (var i = 0; i < initHooks.length; ++i) initHooks[i](cm);
110    });
111  }
112
113  // DISPLAY CONSTRUCTOR
114
115  // The display handles the DOM integration, both for input reading
116  // and content drawing. It holds references to DOM nodes and
117  // display-related state.
118
119  function Display(place, doc) {
120    var d = this;
121
122    // The semihidden textarea that is focused when the editor is
123    // focused, and receives input.
124    var input = d.input = elt("textarea", null, null, "position: absolute; padding: 0; width: 1px; height: 1em; outline: none");
125    // The textarea is kept positioned near the cursor to prevent the
126    // fact that it'll be scrolled into view on input from scrolling
127    // our fake cursor out of view. On webkit, when wrap=off, paste is
128    // very slow. So make the area wide instead.
129    if (webkit) input.style.width = "1000px";
130    else input.setAttribute("wrap", "off");
131    // If border: 0; -- iOS fails to open keyboard (issue #1287)
132    if (ios) input.style.border = "1px solid black";
133    input.setAttribute("autocorrect", "off"); input.setAttribute("autocapitalize", "off"); input.setAttribute("spellcheck", "false");
134
135    // Wraps and hides input textarea
136    d.inputDiv = elt("div", [input], null, "overflow: hidden; position: relative; width: 3px; height: 0px;");
137    // The fake scrollbar elements.
138    d.scrollbarH = elt("div", [elt("div", null, null, "height: 100%; min-height: 1px")], "CodeMirror-hscrollbar");
139    d.scrollbarV = elt("div", [elt("div", null, null, "min-width: 1px")], "CodeMirror-vscrollbar");
140    // Covers bottom-right square when both scrollbars are present.
141    d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler");
142    // Covers bottom of gutter when coverGutterNextToScrollbar is on
143    // and h scrollbar is present.
144    d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler");
145    // Will contain the actual code, positioned to cover the viewport.
146    d.lineDiv = elt("div", null, "CodeMirror-code");
147    // Elements are added to these to represent selection and cursors.
148    d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1");
149    d.cursorDiv = elt("div", null, "CodeMirror-cursors");
150    // A visibility: hidden element used to find the size of things.
151    d.measure = elt("div", null, "CodeMirror-measure");
152    // When lines outside of the viewport are measured, they are drawn in this.
153    d.lineMeasure = elt("div", null, "CodeMirror-measure");
154    // Wraps everything that needs to exist inside the vertically-padded coordinate system
155    d.lineSpace = elt("div", [d.measure, d.lineMeasure, d.selectionDiv, d.cursorDiv, d.lineDiv],
156                      null, "position: relative; outline: none");
157    // Moved around its parent to cover visible view.
158    d.mover = elt("div", [elt("div", [d.lineSpace], "CodeMirror-lines")], null, "position: relative");
159    // Set to the height of the document, allowing scrolling.
160    d.sizer = elt("div", [d.mover], "CodeMirror-sizer");
161    // Behavior of elts with overflow: auto and padding is
162    // inconsistent across browsers. This is used to ensure the
163    // scrollable area is big enough.
164    d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerCutOff + "px; width: 1px;");
165    // Will contain the gutters, if any.
166    d.gutters = elt("div", null, "CodeMirror-gutters");
167    d.lineGutter = null;
168    // Actual scrollable element.
169    d.scroller = elt("div", [d.sizer, d.heightForcer, d.gutters], "CodeMirror-scroll");
170    d.scroller.setAttribute("tabIndex", "-1");
171    // The element in which the editor lives.
172    d.wrapper = elt("div", [d.inputDiv, d.scrollbarH, d.scrollbarV,
173                            d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror");
174
175    // Work around IE7 z-index bug (not perfect, hence IE7 not really being supported)
176    if (ie_upto7) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0; }
177    // Needed to hide big blue blinking cursor on Mobile Safari
178    if (ios) input.style.width = "0px";
179    if (!webkit) d.scroller.draggable = true;
180    // Needed to handle Tab key in KHTML
181    if (khtml) { d.inputDiv.style.height = "1px"; d.inputDiv.style.position = "absolute"; }
182    // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
183    if (ie_upto7) d.scrollbarH.style.minHeight = d.scrollbarV.style.minWidth = "18px";
184
185    if (place.appendChild) place.appendChild(d.wrapper);
186    else place(d.wrapper);
187
188    // Current rendered range (may be bigger than the view window).
189    d.viewFrom = d.viewTo = doc.first;
190    // Information about the rendered lines.
191    d.view = [];
192    // Holds info about a single rendered line when it was rendered
193    // for measurement, while not in view.
194    d.externalMeasured = null;
195    // Empty space (in pixels) above the view
196    d.viewOffset = 0;
197    d.lastSizeC = 0;
198    d.updateLineNumbers = null;
199
200    // Used to only resize the line number gutter when necessary (when
201    // the amount of lines crosses a boundary that makes its width change)
202    d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null;
203    // See readInput and resetInput
204    d.prevInput = "";
205    // Set to true when a non-horizontal-scrolling line widget is
206    // added. As an optimization, line widget aligning is skipped when
207    // this is false.
208    d.alignWidgets = false;
209    // Flag that indicates whether we expect input to appear real soon
210    // now (after some event like 'keypress' or 'input') and are
211    // polling intensively.
212    d.pollingFast = false;
213    // Self-resetting timeout for the poller
214    d.poll = new Delayed();
215
216    d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
217
218    // Tracks when resetInput has punted to just putting a short
219    // string into the textarea instead of the full selection.
220    d.inaccurateSelection = false;
221
222    // Tracks the maximum line length so that the horizontal scrollbar
223    // can be kept static when scrolling.
224    d.maxLine = null;
225    d.maxLineLength = 0;
226    d.maxLineChanged = false;
227
228    // Used for measuring wheel scrolling granularity
229    d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null;
230
231    // True when shift is held down.
232    d.shift = false;
233  }
234
235  // STATE UPDATES
236
237  // Used to get the editor into a consistent state again when options change.
238
239  function loadMode(cm) {
240    cm.doc.mode = CodeMirror.getMode(cm.options, cm.doc.modeOption);
241    resetModeState(cm);
242  }
243
244  function resetModeState(cm) {
245    cm.doc.iter(function(line) {
246      if (line.stateAfter) line.stateAfter = null;
247      if (line.styles) line.styles = null;
248    });
249    cm.doc.frontier = cm.doc.first;
250    startWorker(cm, 100);
251    cm.state.modeGen++;
252    if (cm.curOp) regChange(cm);
253  }
254
255  function wrappingChanged(cm) {
256    if (cm.options.lineWrapping) {
257      addClass(cm.display.wrapper, "CodeMirror-wrap");
258      cm.display.sizer.style.minWidth = "";
259    } else {
260      rmClass(cm.display.wrapper, "CodeMirror-wrap");
261      findMaxLine(cm);
262    }
263    estimateLineHeights(cm);
264    regChange(cm);
265    clearCaches(cm);
266    setTimeout(function(){updateScrollbars(cm);}, 100);
267  }
268
269  // Returns a function that estimates the height of a line, to use as
270  // first approximation until the line becomes visible (and is thus
271  // properly measurable).
272  function estimateHeight(cm) {
273    var th = textHeight(cm.display), wrapping = cm.options.lineWrapping;
274    var perLine = wrapping && Math.max(5, cm.display.scroller.clientWidth / charWidth(cm.display) - 3);
275    return function(line) {
276      if (lineIsHidden(cm.doc, line)) return 0;
277
278      var widgetsHeight = 0;
279      if (line.widgets) for (var i = 0; i < line.widgets.length; i++) {
280        if (line.widgets[i].height) widgetsHeight += line.widgets[i].height;
281      }
282
283      if (wrapping)
284        return widgetsHeight + (Math.ceil(line.text.length / perLine) || 1) * th;
285      else
286        return widgetsHeight + th;
287    };
288  }
289
290  function estimateLineHeights(cm) {
291    var doc = cm.doc, est = estimateHeight(cm);
292    doc.iter(function(line) {
293      var estHeight = est(line);
294      if (estHeight != line.height) updateLineHeight(line, estHeight);
295    });
296  }
297
298  function keyMapChanged(cm) {
299    var map = keyMap[cm.options.keyMap], style = map.style;
300    cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-keymap-\S+/g, "") +
301      (style ? " cm-keymap-" + style : "");
302  }
303
304  function themeChanged(cm) {
305    cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-s-\S+/g, "") +
306      cm.options.theme.replace(/(^|\s)\s*/g, " cm-s-");
307    clearCaches(cm);
308  }
309
310  function guttersChanged(cm) {
311    updateGutters(cm);
312    regChange(cm);
313    setTimeout(function(){alignHorizontally(cm);}, 20);
314  }
315
316  // Rebuild the gutter elements, ensure the margin to the left of the
317  // code matches their width.
318  function updateGutters(cm) {
319    var gutters = cm.display.gutters, specs = cm.options.gutters;
320    removeChildren(gutters);
321    for (var i = 0; i < specs.length; ++i) {
322      var gutterClass = specs[i];
323      var gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + gutterClass));
324      if (gutterClass == "CodeMirror-linenumbers") {
325        cm.display.lineGutter = gElt;
326        gElt.style.width = (cm.display.lineNumWidth || 1) + "px";
327      }
328    }
329    gutters.style.display = i ? "" : "none";
330    updateGutterSpace(cm);
331  }
332
333  function updateGutterSpace(cm) {
334    var width = cm.display.gutters.offsetWidth;
335    cm.display.sizer.style.marginLeft = width + "px";
336    cm.display.scrollbarH.style.left = cm.options.fixedGutter ? width + "px" : 0;
337  }
338
339  // Compute the character length of a line, taking into account
340  // collapsed ranges (see markText) that might hide parts, and join
341  // other lines onto it.
342  function lineLength(line) {
343    if (line.height == 0) return 0;
344    var len = line.text.length, merged, cur = line;
345    while (merged = collapsedSpanAtStart(cur)) {
346      var found = merged.find(0, true);
347      cur = found.from.line;
348      len += found.from.ch - found.to.ch;
349    }
350    cur = line;
351    while (merged = collapsedSpanAtEnd(cur)) {
352      var found = merged.find(0, true);
353      len -= cur.text.length - found.from.ch;
354      cur = found.to.line;
355      len += cur.text.length - found.to.ch;
356    }
357    return len;
358  }
359
360  // Find the longest line in the document.
361  function findMaxLine(cm) {
362    var d = cm.display, doc = cm.doc;
363    d.maxLine = getLine(doc, doc.first);
364    d.maxLineLength = lineLength(d.maxLine);
365    d.maxLineChanged = true;
366    doc.iter(function(line) {
367      var len = lineLength(line);
368      if (len > d.maxLineLength) {
369        d.maxLineLength = len;
370        d.maxLine = line;
371      }
372    });
373  }
374
375  // Make sure the gutters options contains the element
376  // "CodeMirror-linenumbers" when the lineNumbers option is true.
377  function setGuttersForLineNumbers(options) {
378    var found = indexOf(options.gutters, "CodeMirror-linenumbers");
379    if (found == -1 && options.lineNumbers) {
380      options.gutters = options.gutters.concat(["CodeMirror-linenumbers"]);
381    } else if (found > -1 && !options.lineNumbers) {
382      options.gutters = options.gutters.slice(0);
383      options.gutters.splice(found, 1);
384    }
385  }
386
387  // SCROLLBARS
388
389  // Prepare DOM reads needed to update the scrollbars. Done in one
390  // shot to minimize update/measure roundtrips.
391  function measureForScrollbars(cm) {
392    var scroll = cm.display.scroller;
393    return {
394      clientHeight: scroll.clientHeight,
395      barHeight: cm.display.scrollbarV.clientHeight,
396      scrollWidth: scroll.scrollWidth, clientWidth: scroll.clientWidth,
397      barWidth: cm.display.scrollbarH.clientWidth,
398      docHeight: Math.round(cm.doc.height + paddingVert(cm.display))
399    };
400  }
401
402  // Re-synchronize the fake scrollbars with the actual size of the
403  // content.
404  function updateScrollbars(cm, measure) {
405    if (!measure) measure = measureForScrollbars(cm);
406    var d = cm.display;
407    var scrollHeight = measure.docHeight + scrollerCutOff;
408    var needsH = measure.scrollWidth > measure.clientWidth;
409    var needsV = scrollHeight > measure.clientHeight;
410    if (needsV) {
411      d.scrollbarV.style.display = "block";
412      d.scrollbarV.style.bottom = needsH ? scrollbarWidth(d.measure) + "px" : "0";
413      // A bug in IE8 can cause this value to be negative, so guard it.
414      d.scrollbarV.firstChild.style.height =
415        Math.max(0, scrollHeight - measure.clientHeight + (measure.barHeight || d.scrollbarV.clientHeight)) + "px";
416    } else {
417      d.scrollbarV.style.display = "";
418      d.scrollbarV.firstChild.style.height = "0";
419    }
420    if (needsH) {
421      d.scrollbarH.style.display = "block";
422      d.scrollbarH.style.right = needsV ? scrollbarWidth(d.measure) + "px" : "0";
423      d.scrollbarH.firstChild.style.width =
424        (measure.scrollWidth - measure.clientWidth + (measure.barWidth || d.scrollbarH.clientWidth)) + "px";
425    } else {
426      d.scrollbarH.style.display = "";
427      d.scrollbarH.firstChild.style.width = "0";
428    }
429    if (needsH && needsV) {
430      d.scrollbarFiller.style.display = "block";
431      d.scrollbarFiller.style.height = d.scrollbarFiller.style.width = scrollbarWidth(d.measure) + "px";
432    } else d.scrollbarFiller.style.display = "";
433    if (needsH && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {
434      d.gutterFiller.style.display = "block";
435      d.gutterFiller.style.height = scrollbarWidth(d.measure) + "px";
436      d.gutterFiller.style.width = d.gutters.offsetWidth + "px";
437    } else d.gutterFiller.style.display = "";
438
439    if (!cm.state.checkedOverlayScrollbar && measure.clientHeight > 0) {
440      if (scrollbarWidth(d.measure) === 0) {
441        var w = mac && !mac_geMountainLion ? "12px" : "18px";
442        d.scrollbarV.style.minWidth = d.scrollbarH.style.minHeight = w;
443        var barMouseDown = function(e) {
444          if (e_target(e) != d.scrollbarV && e_target(e) != d.scrollbarH)
445            operation(cm, onMouseDown)(e);
446        };
447        on(d.scrollbarV, "mousedown", barMouseDown);
448        on(d.scrollbarH, "mousedown", barMouseDown);
449      }
450      cm.state.checkedOverlayScrollbar = true;
451    }
452  }
453
454  // Compute the lines that are visible in a given viewport (defaults
455  // the the current scroll position). viewPort may contain top,
456  // height, and ensure (see op.scrollToPos) properties.
457  function visibleLines(display, doc, viewPort) {
458    var top = viewPort && viewPort.top != null ? viewPort.top : display.scroller.scrollTop;
459    top = Math.floor(top - paddingTop(display));
460    var bottom = viewPort && viewPort.bottom != null ? viewPort.bottom : top + display.wrapper.clientHeight;
461
462    var from = lineAtHeight(doc, top), to = lineAtHeight(doc, bottom);
463    // Ensure is a {from: {line, ch}, to: {line, ch}} object, and
464    // forces those lines into the viewport (if possible).
465    if (viewPort && viewPort.ensure) {
466      var ensureFrom = viewPort.ensure.from.line, ensureTo = viewPort.ensure.to.line;
467      if (ensureFrom < from)
468        return {from: ensureFrom,
469                to: lineAtHeight(doc, heightAtLine(getLine(doc, ensureFrom)) + display.wrapper.clientHeight)};
470      if (Math.min(ensureTo, doc.lastLine()) >= to)
471        return {from: lineAtHeight(doc, heightAtLine(getLine(doc, ensureTo)) - display.wrapper.clientHeight),
472                to: ensureTo};
473    }
474    return {from: from, to: to};
475  }
476
477  // LINE NUMBERS
478
479  // Re-align line numbers and gutter marks to compensate for
480  // horizontal scrolling.
481  function alignHorizontally(cm) {
482    var display = cm.display, view = display.view;
483    if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) return;
484    var comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft;
485    var gutterW = display.gutters.offsetWidth, left = comp + "px";
486    for (var i = 0; i < view.length; i++) if (!view[i].hidden) {
487      if (cm.options.fixedGutter && view[i].gutter)
488        view[i].gutter.style.left = left;
489      var align = view[i].alignable;
490      if (align) for (var j = 0; j < align.length; j++)
491        align[j].style.left = left;
492    }
493    if (cm.options.fixedGutter)
494      display.gutters.style.left = (comp + gutterW) + "px";
495  }
496
497  // Used to ensure that the line number gutter is still the right
498  // size for the current document size. Returns true when an update
499  // is needed.
500  function maybeUpdateLineNumberWidth(cm) {
501    if (!cm.options.lineNumbers) return false;
502    var doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display;
503    if (last.length != display.lineNumChars) {
504      var test = display.measure.appendChild(elt("div", [elt("div", last)],
505                                                 "CodeMirror-linenumber CodeMirror-gutter-elt"));
506      var innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW;
507      display.lineGutter.style.width = "";
508      display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding);
509      display.lineNumWidth = display.lineNumInnerWidth + padding;
510      display.lineNumChars = display.lineNumInnerWidth ? last.length : -1;
511      display.lineGutter.style.width = display.lineNumWidth + "px";
512      updateGutterSpace(cm);
513      return true;
514    }
515    return false;
516  }
517
518  function lineNumberFor(options, i) {
519    return String(options.lineNumberFormatter(i + options.firstLineNumber));
520  }
521
522  // Computes display.scroller.scrollLeft + display.gutters.offsetWidth,
523  // but using getBoundingClientRect to get a sub-pixel-accurate
524  // result.
525  function compensateForHScroll(display) {
526    return display.scroller.getBoundingClientRect().left - display.sizer.getBoundingClientRect().left;
527  }
528
529  // DISPLAY DRAWING
530
531  // Updates the display, selection, and scrollbars, using the
532  // information in display.view to find out which nodes are no longer
533  // up-to-date. Tries to bail out early when no changes are needed,
534  // unless forced is true.
535  // Returns true if an actual update happened, false otherwise.
536  function updateDisplay(cm, viewPort, forced) {
537    var oldFrom = cm.display.viewFrom, oldTo = cm.display.viewTo, updated;
538    var visible = visibleLines(cm.display, cm.doc, viewPort);
539    for (var first = true;; first = false) {
540      var oldWidth = cm.display.scroller.clientWidth;
541      if (!updateDisplayInner(cm, visible, forced)) break;
542      updated = true;
543
544      // If the max line changed since it was last measured, measure it,
545      // and ensure the document's width matches it.
546      if (cm.display.maxLineChanged && !cm.options.lineWrapping)
547        adjustContentWidth(cm);
548
549      var barMeasure = measureForScrollbars(cm);
550      updateSelection(cm);
551      setDocumentHeight(cm, barMeasure);
552      updateScrollbars(cm, barMeasure);
553      if (webkit && cm.options.lineWrapping)
554        checkForWebkitWidthBug(cm, barMeasure); // (Issue #2420)
555      if (first && cm.options.lineWrapping && oldWidth != cm.display.scroller.clientWidth) {
556        forced = true;
557        continue;
558      }
559      forced = false;
560
561      // Clip forced viewport to actual scrollable area.
562      if (viewPort && viewPort.top != null)
563        viewPort = {top: Math.min(barMeasure.docHeight - scrollerCutOff - barMeasure.clientHeight, viewPort.top)};
564      // Updated line heights might result in the drawn area not
565      // actually covering the viewport. Keep looping until it does.
566      visible = visibleLines(cm.display, cm.doc, viewPort);
567      if (visible.from >= cm.display.viewFrom && visible.to <= cm.display.viewTo)
568        break;
569    }
570
571    cm.display.updateLineNumbers = null;
572    if (updated) {
573      signalLater(cm, "update", cm);
574      if (cm.display.viewFrom != oldFrom || cm.display.viewTo != oldTo)
575        signalLater(cm, "viewportChange", cm, cm.display.viewFrom, cm.display.viewTo);
576    }
577    return updated;
578  }
579
580  // Does the actual updating of the line display. Bails out
581  // (returning false) when there is nothing to be done and forced is
582  // false.
583  function updateDisplayInner(cm, visible, forced) {
584    var display = cm.display, doc = cm.doc;
585    if (!display.wrapper.offsetWidth) {
586      resetView(cm);
587      return;
588    }
589
590    // Bail out if the visible area is already rendered and nothing changed.
591    if (!forced && visible.from >= display.viewFrom && visible.to <= display.viewTo &&
592        countDirtyView(cm) == 0)
593      return;
594
595    if (maybeUpdateLineNumberWidth(cm))
596      resetView(cm);
597    var dims = getDimensions(cm);
598
599    // Compute a suitable new viewport (from & to)
600    var end = doc.first + doc.size;
601    var from = Math.max(visible.from - cm.options.viewportMargin, doc.first);
602    var to = Math.min(end, visible.to + cm.options.viewportMargin);
603    if (display.viewFrom < from && from - display.viewFrom < 20) from = Math.max(doc.first, display.viewFrom);
604    if (display.viewTo > to && display.viewTo - to < 20) to = Math.min(end, display.viewTo);
605    if (sawCollapsedSpans) {
606      from = visualLineNo(cm.doc, from);
607      to = visualLineEndNo(cm.doc, to);
608    }
609
610    var different = from != display.viewFrom || to != display.viewTo ||
611      display.lastSizeC != display.wrapper.clientHeight;
612    adjustView(cm, from, to);
613
614    display.viewOffset = heightAtLine(getLine(cm.doc, display.viewFrom));
615    // Position the mover div to align with the current scroll position
616    cm.display.mover.style.top = display.viewOffset + "px";
617
618    var toUpdate = countDirtyView(cm);
619    if (!different && toUpdate == 0 && !forced) return;
620
621    // For big changes, we hide the enclosing element during the
622    // update, since that speeds up the operations on most browsers.
623    var focused = activeElt();
624    if (toUpdate > 4) display.lineDiv.style.display = "none";
625    patchDisplay(cm, display.updateLineNumbers, dims);
626    if (toUpdate > 4) display.lineDiv.style.display = "";
627    // There might have been a widget with a focused element that got
628    // hidden or updated, if so re-focus it.
629    if (focused && activeElt() != focused && focused.offsetHeight) focused.focus();
630
631    // Prevent selection and cursors from interfering with the scroll
632    // width.
633    removeChildren(display.cursorDiv);
634    removeChildren(display.selectionDiv);
635
636    if (different) {
637      display.lastSizeC = display.wrapper.clientHeight;
638      startWorker(cm, 400);
639    }
640
641    updateHeightsInViewport(cm);
642
643    return true;
644  }
645
646  function adjustContentWidth(cm) {
647    var display = cm.display;
648    var width = measureChar(cm, display.maxLine, display.maxLine.text.length).left;
649    display.maxLineChanged = false;
650    var minWidth = Math.max(0, width + 3);
651    var maxScrollLeft = Math.max(0, display.sizer.offsetLeft + minWidth + scrollerCutOff - display.scroller.clientWidth);
652    display.sizer.style.minWidth = minWidth + "px";
653    if (maxScrollLeft < cm.doc.scrollLeft)
654      setScrollLeft(cm, Math.min(display.scroller.scrollLeft, maxScrollLeft), true);
655  }
656
657  function setDocumentHeight(cm, measure) {
658    cm.display.sizer.style.minHeight = cm.display.heightForcer.style.top = measure.docHeight + "px";
659    cm.display.gutters.style.height = Math.max(measure.docHeight, measure.clientHeight - scrollerCutOff) + "px";
660  }
661
662
663  function checkForWebkitWidthBug(cm, measure) {
664    // Work around Webkit bug where it sometimes reserves space for a
665    // non-existing phantom scrollbar in the scroller (Issue #2420)
666    if (cm.display.sizer.offsetWidth + cm.display.gutters.offsetWidth < cm.display.scroller.clientWidth - 1) {
667      cm.display.sizer.style.minHeight = cm.display.heightForcer.style.top = "0px";
668      cm.display.gutters.style.height = measure.docHeight + "px";
669    }
670  }
671
672  // Read the actual heights of the rendered lines, and update their
673  // stored heights to match.
674  function updateHeightsInViewport(cm) {
675    var display = cm.display;
676    var prevBottom = display.lineDiv.offsetTop;
677    for (var i = 0; i < display.view.length; i++) {
678      var cur = display.view[i], height;
679      if (cur.hidden) continue;
680      if (ie_upto7) {
681        var bot = cur.node.offsetTop + cur.node.offsetHeight;
682        height = bot - prevBottom;
683        prevBottom = bot;
684      } else {
685        var box = cur.node.getBoundingClientRect();
686        height = box.bottom - box.top;
687      }
688      var diff = cur.line.height - height;
689      if (height < 2) height = textHeight(display);
690      if (diff > .001 || diff < -.001) {
691        updateLineHeight(cur.line, height);
692        updateWidgetHeight(cur.line);
693        if (cur.rest) for (var j = 0; j < cur.rest.length; j++)
694          updateWidgetHeight(cur.rest[j]);
695      }
696    }
697  }
698
699  // Read and store the height of line widgets associated with the
700  // given line.
701  function updateWidgetHeight(line) {
702    if (line.widgets) for (var i = 0; i < line.widgets.length; ++i)
703      line.widgets[i].height = line.widgets[i].node.offsetHeight;
704  }
705
706  // Do a bulk-read of the DOM positions and sizes needed to draw the
707  // view, so that we don't interleave reading and writing to the DOM.
708  function getDimensions(cm) {
709    var d = cm.display, left = {}, width = {};
710    for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {
711      left[cm.options.gutters[i]] = n.offsetLeft;
712      width[cm.options.gutters[i]] = n.offsetWidth;
713    }
714    return {fixedPos: compensateForHScroll(d),
715            gutterTotalWidth: d.gutters.offsetWidth,
716            gutterLeft: left,
717            gutterWidth: width,
718            wrapperWidth: d.wrapper.clientWidth};
719  }
720
721  // Sync the actual display DOM structure with display.view, removing
722  // nodes for lines that are no longer in view, and creating the ones
723  // that are not there yet, and updating the ones that are out of
724  // date.
725  function patchDisplay(cm, updateNumbersFrom, dims) {
726    var display = cm.display, lineNumbers = cm.options.lineNumbers;
727    var container = display.lineDiv, cur = container.firstChild;
728
729    function rm(node) {
730      var next = node.nextSibling;
731      // Works around a throw-scroll bug in OS X Webkit
732      if (webkit && mac && cm.display.currentWheelTarget == node)
733        node.style.display = "none";
734      else
735        node.parentNode.removeChild(node);
736      return next;
737    }
738
739    var view = display.view, lineN = display.viewFrom;
740    // Loop over the elements in the view, syncing cur (the DOM nodes
741    // in display.lineDiv) with the view as we go.
742    for (var i = 0; i < view.length; i++) {
743      var lineView = view[i];
744      if (lineView.hidden) {
745      } else if (!lineView.node) { // Not drawn yet
746        var node = buildLineElement(cm, lineView, lineN, dims);
747        container.insertBefore(node, cur);
748      } else { // Already drawn
749        while (cur != lineView.node) cur = rm(cur);
750        var updateNumber = lineNumbers && updateNumbersFrom != null &&
751          updateNumbersFrom <= lineN && lineView.lineNumber;
752        if (lineView.changes) {
753          if (indexOf(lineView.changes, "gutter") > -1) updateNumber = false;
754          updateLineForChanges(cm, lineView, lineN, dims);
755        }
756        if (updateNumber) {
757          removeChildren(lineView.lineNumber);
758          lineView.lineNumber.appendChild(document.createTextNode(lineNumberFor(cm.options, lineN)));
759        }
760        cur = lineView.node.nextSibling;
761      }
762      lineN += lineView.size;
763    }
764    while (cur) cur = rm(cur);
765  }
766
767  // When an aspect of a line changes, a string is added to
768  // lineView.changes. This updates the relevant part of the line's
769  // DOM structure.
770  function updateLineForChanges(cm, lineView, lineN, dims) {
771    for (var j = 0; j < lineView.changes.length; j++) {
772      var type = lineView.changes[j];
773      if (type == "text") updateLineText(cm, lineView);
774      else if (type == "gutter") updateLineGutter(cm, lineView, lineN, dims);
775      else if (type == "class") updateLineClasses(lineView);
776      else if (type == "widget") updateLineWidgets(lineView, dims);
777    }
778    lineView.changes = null;
779  }
780
781  // Lines with gutter elements, widgets or a background class need to
782  // be wrapped, and have the extra elements added to the wrapper div
783  function ensureLineWrapped(lineView) {
784    if (lineView.node == lineView.text) {
785      lineView.node = elt("div", null, null, "position: relative");
786      if (lineView.text.parentNode)
787        lineView.text.parentNode.replaceChild(lineView.node, lineView.text);
788      lineView.node.appendChild(lineView.text);
789      if (ie_upto7) lineView.node.style.zIndex = 2;
790    }
791    return lineView.node;
792  }
793
794  function updateLineBackground(lineView) {
795    var cls = lineView.bgClass ? lineView.bgClass + " " + (lineView.line.bgClass || "") : lineView.line.bgClass;
796    if (cls) cls += " CodeMirror-linebackground";
797    if (lineView.background) {
798      if (cls) lineView.background.className = cls;
799      else { lineView.background.parentNode.removeChild(lineView.background); lineView.background = null; }
800    } else if (cls) {
801      var wrap = ensureLineWrapped(lineView);
802      lineView.background = wrap.insertBefore(elt("div", null, cls), wrap.firstChild);
803    }
804  }
805
806  // Wrapper around buildLineContent which will reuse the structure
807  // in display.externalMeasured when possible.
808  function getLineContent(cm, lineView) {
809    var ext = cm.display.externalMeasured;
810    if (ext && ext.line == lineView.line) {
811      cm.display.externalMeasured = null;
812      lineView.measure = ext.measure;
813      return ext.built;
814    }
815    return buildLineContent(cm, lineView);
816  }
817
818  // Redraw the line's text. Interacts with the background and text
819  // classes because the mode may output tokens that influence these
820  // classes.
821  function updateLineText(cm, lineView) {
822    var cls = lineView.text.className;
823    var built = getLineContent(cm, lineView);
824    if (lineView.text == lineView.node) lineView.node = built.pre;
825    lineView.text.parentNode.replaceChild(built.pre, lineView.text);
826    lineView.text = built.pre;
827    if (built.bgClass != lineView.bgClass || built.textClass != lineView.textClass) {
828      lineView.bgClass = built.bgClass;
829      lineView.textClass = built.textClass;
830      updateLineClasses(lineView);
831    } else if (cls) {
832      lineView.text.className = cls;
833    }
834  }
835
836  function updateLineClasses(lineView) {
837    updateLineBackground(lineView);
838    if (lineView.line.wrapClass)
839      ensureLineWrapped(lineView).className = lineView.line.wrapClass;
840    else if (lineView.node != lineView.text)
841      lineView.node.className = "";
842    var textClass = lineView.textClass ? lineView.textClass + " " + (lineView.line.textClass || "") : lineView.line.textClass;
843    lineView.text.className = textClass || "";
844  }
845
846  function updateLineGutter(cm, lineView, lineN, dims) {
847    if (lineView.gutter) {
848      lineView.node.removeChild(lineView.gutter);
849      lineView.gutter = null;
850    }
851    var markers = lineView.line.gutterMarkers;
852    if (cm.options.lineNumbers || markers) {
853      var wrap = ensureLineWrapped(lineView);
854      var gutterWrap = lineView.gutter =
855        wrap.insertBefore(elt("div", null, "CodeMirror-gutter-wrapper", "position: absolute; left: " +
856                              (cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + "px"),
857                          lineView.text);
858      if (cm.options.lineNumbers && (!markers || !markers["CodeMirror-linenumbers"]))
859        lineView.lineNumber = gutterWrap.appendChild(
860          elt("div", lineNumberFor(cm.options, lineN),
861              "CodeMirror-linenumber CodeMirror-gutter-elt",
862              "left: " + dims.gutterLeft["CodeMirror-linenumbers"] + "px; width: "
863              + cm.display.lineNumInnerWidth + "px"));
864      if (markers) for (var k = 0; k < cm.options.gutters.length; ++k) {
865        var id = cm.options.gutters[k], found = markers.hasOwnProperty(id) && markers[id];
866        if (found)
867          gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt", "left: " +
868                                     dims.gutterLeft[id] + "px; width: " + dims.gutterWidth[id] + "px"));
869      }
870    }
871  }
872
873  function updateLineWidgets(lineView, dims) {
874    if (lineView.alignable) lineView.alignable = null;
875    for (var node = lineView.node.firstChild, next; node; node = next) {
876      var next = node.nextSibling;
877      if (node.className == "CodeMirror-linewidget")
878        lineView.node.removeChild(node);
879    }
880    insertLineWidgets(lineView, dims);
881  }
882
883  // Build a line's DOM representation from scratch
884  function buildLineElement(cm, lineView, lineN, dims) {
885    var built = getLineContent(cm, lineView);
886    lineView.text = lineView.node = built.pre;
887    if (built.bgClass) lineView.bgClass = built.bgClass;
888    if (built.textClass) lineView.textClass = built.textClass;
889
890    updateLineClasses(lineView);
891    updateLineGutter(cm, lineView, lineN, dims);
892    insertLineWidgets(lineView, dims);
893    return lineView.node;
894  }
895
896  // A lineView may contain multiple logical lines (when merged by
897  // collapsed spans). The widgets for all of them need to be drawn.
898  function insertLineWidgets(lineView, dims) {
899    insertLineWidgetsFor(lineView.line, lineView, dims, true);
900    if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)
901      insertLineWidgetsFor(lineView.rest[i], lineView, dims, false);
902  }
903
904  function insertLineWidgetsFor(line, lineView, dims, allowAbove) {
905    if (!line.widgets) return;
906    var wrap = ensureLineWrapped(lineView);
907    for (var i = 0, ws = line.widgets; i < ws.length; ++i) {
908      var widget = ws[i], node = elt("div", [widget.node], "CodeMirror-linewidget");
909      if (!widget.handleMouseEvents) node.ignoreEvents = true;
910      positionLineWidget(widget, node, lineView, dims);
911      if (allowAbove && widget.above)
912        wrap.insertBefore(node, lineView.gutter || lineView.text);
913      else
914        wrap.appendChild(node);
915      signalLater(widget, "redraw");
916    }
917  }
918
919  function positionLineWidget(widget, node, lineView, dims) {
920    if (widget.noHScroll) {
921      (lineView.alignable || (lineView.alignable = [])).push(node);
922      var width = dims.wrapperWidth;
923      node.style.left = dims.fixedPos + "px";
924      if (!widget.coverGutter) {
925        width -= dims.gutterTotalWidth;
926        node.style.paddingLeft = dims.gutterTotalWidth + "px";
927      }
928      node.style.width = width + "px";
929    }
930    if (widget.coverGutter) {
931      node.style.zIndex = 5;
932      node.style.position = "relative";
933      if (!widget.noHScroll) node.style.marginLeft = -dims.gutterTotalWidth + "px";
934    }
935  }
936
937  // POSITION OBJECT
938
939  // A Pos instance represents a position within the text.
940  var Pos = CodeMirror.Pos = function(line, ch) {
941    if (!(this instanceof Pos)) return new Pos(line, ch);
942    this.line = line; this.ch = ch;
943  };
944
945  // Compare two positions, return 0 if they are the same, a negative
946  // number when a is less, and a positive number otherwise.
947  var cmp = CodeMirror.cmpPos = function(a, b) { return a.line - b.line || a.ch - b.ch; };
948
949  function copyPos(x) {return Pos(x.line, x.ch);}
950  function maxPos(a, b) { return cmp(a, b) < 0 ? b : a; }
951  function minPos(a, b) { return cmp(a, b) < 0 ? a : b; }
952
953  // SELECTION / CURSOR
954
955  // Selection objects are immutable. A new one is created every time
956  // the selection changes. A selection is one or more non-overlapping
957  // (and non-touching) ranges, sorted, and an integer that indicates
958  // which one is the primary selection (the one that's scrolled into
959  // view, that getCursor returns, etc).
960  function Selection(ranges, primIndex) {
961    this.ranges = ranges;
962    this.primIndex = primIndex;
963  }
964
965  Selection.prototype = {
966    primary: function() { return this.ranges[this.primIndex]; },
967    equals: function(other) {
968      if (other == this) return true;
969      if (other.primIndex != this.primIndex || other.ranges.length != this.ranges.length) return false;
970      for (var i = 0; i < this.ranges.length; i++) {
971        var here = this.ranges[i], there = other.ranges[i];
972        if (cmp(here.anchor, there.anchor) != 0 || cmp(here.head, there.head) != 0) return false;
973      }
974      return true;
975    },
976    deepCopy: function() {
977      for (var out = [], i = 0; i < this.ranges.length; i++)
978        out[i] = new Range(copyPos(this.ranges[i].anchor), copyPos(this.ranges[i].head));
979      return new Selection(out, this.primIndex);
980    },
981    somethingSelected: function() {
982      for (var i = 0; i < this.ranges.length; i++)
983        if (!this.ranges[i].empty()) return true;
984      return false;
985    },
986    contains: function(pos, end) {
987      if (!end) end = pos;
988      for (var i = 0; i < this.ranges.length; i++) {
989        var range = this.ranges[i];
990        if (cmp(end, range.from()) >= 0 && cmp(pos, range.to()) <= 0)
991          return i;
992      }
993      return -1;
994    }
995  };
996
997  function Range(anchor, head) {
998    this.anchor = anchor; this.head = head;
999  }
1000
1001  Range.prototype = {
1002    from: function() { return minPos(this.anchor, this.head); },
1003    to: function() { return maxPos(this.anchor, this.head); },
1004    empty: function() {
1005      return this.head.line == this.anchor.line && this.head.ch == this.anchor.ch;
1006    }
1007  };
1008
1009  // Take an unsorted, potentially overlapping set of ranges, and
1010  // build a selection out of it. 'Consumes' ranges array (modifying
1011  // it).
1012  function normalizeSelection(ranges, primIndex) {
1013    var prim = ranges[primIndex];
1014    ranges.sort(function(a, b) { return cmp(a.from(), b.from()); });
1015    primIndex = indexOf(ranges, prim);
1016    for (var i = 1; i < ranges.length; i++) {
1017      var cur = ranges[i], prev = ranges[i - 1];
1018      if (cmp(prev.to(), cur.from()) >= 0) {
1019        var from = minPos(prev.from(), cur.from()), to = maxPos(prev.to(), cur.to());
1020        var inv = prev.empty() ? cur.from() == cur.head : prev.from() == prev.head;
1021        if (i <= primIndex) --primIndex;
1022        ranges.splice(--i, 2, new Range(inv ? to : from, inv ? from : to));
1023      }
1024    }
1025    return new Selection(ranges, primIndex);
1026  }
1027
1028  function simpleSelection(anchor, head) {
1029    return new Selection([new Range(anchor, head || anchor)], 0);
1030  }
1031
1032  // Most of the external API clips given positions to make sure they
1033  // actually exist within the document.
1034  function clipLine(doc, n) {return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1));}
1035  function clipPos(doc, pos) {
1036    if (pos.line < doc.first) return Pos(doc.first, 0);
1037    var last = doc.first + doc.size - 1;
1038    if (pos.line > last) return Pos(last, getLine(doc, last).text.length);
1039    return clipToLen(pos, getLine(doc, pos.line).text.length);
1040  }
1041  function clipToLen(pos, linelen) {
1042    var ch = pos.ch;
1043    if (ch == null || ch > linelen) return Pos(pos.line, linelen);
1044    else if (ch < 0) return Pos(pos.line, 0);
1045    else return pos;
1046  }
1047  function isLine(doc, l) {return l >= doc.first && l < doc.first + doc.size;}
1048  function clipPosArray(doc, array) {
1049    for (var out = [], i = 0; i < array.length; i++) out[i] = clipPos(doc, array[i]);
1050    return out;
1051  }
1052
1053  // SELECTION UPDATES
1054
1055  // The 'scroll' parameter given to many of these indicated whether
1056  // the new cursor position should be scrolled into view after
1057  // modifying the selection.
1058
1059  // If shift is held or the extend flag is set, extends a range to
1060  // include a given position (and optionally a second position).
1061  // Otherwise, simply returns the range between the given positions.
1062  // Used for cursor motion and such.
1063  function extendRange(doc, range, head, other) {
1064    if (doc.cm && doc.cm.display.shift || doc.extend) {
1065      var anchor = range.anchor;
1066      if (other) {
1067        var posBefore = cmp(head, anchor) < 0;
1068        if (posBefore != (cmp(other, anchor) < 0)) {
1069          anchor = head;
1070          head = other;
1071        } else if (posBefore != (cmp(head, other) < 0)) {
1072          head = other;
1073        }
1074      }
1075      return new Range(anchor, head);
1076    } else {
1077      return new Range(other || head, head);
1078    }
1079  }
1080
1081  // Extend the primary selection range, discard the rest.
1082  function extendSelection(doc, head, other, options) {
1083    setSelection(doc, new Selection([extendRange(doc, doc.sel.primary(), head, other)], 0), options);
1084  }
1085
1086  // Extend all selections (pos is an array of selections with length
1087  // equal the number of selections)
1088  function extendSelections(doc, heads, options) {
1089    for (var out = [], i = 0; i < doc.sel.ranges.length; i++)
1090      out[i] = extendRange(doc, doc.sel.ranges[i], heads[i], null);
1091    var newSel = normalizeSelection(out, doc.sel.primIndex);
1092    setSelection(doc, newSel, options);
1093  }
1094
1095  // Updates a single range in the selection.
1096  function replaceOneSelection(doc, i, range, options) {
1097    var ranges = doc.sel.ranges.slice(0);
1098    ranges[i] = range;
1099    setSelection(doc, normalizeSelection(ranges, doc.sel.primIndex), options);
1100  }
1101
1102  // Reset the selection to a single range.
1103  function setSimpleSelection(doc, anchor, head, options) {
1104    setSelection(doc, simpleSelection(anchor, head), options);
1105  }
1106
1107  // Give beforeSelectionChange handlers a change to influence a
1108  // selection update.
1109  function filterSelectionChange(doc, sel) {
1110    var obj = {
1111      ranges: sel.ranges,
1112      update: function(ranges) {
1113        this.ranges = [];
1114        for (var i = 0; i < ranges.length; i++)
1115          this.ranges[i] = new Range(clipPos(doc, ranges[i].anchor),
1116                                     clipPos(doc, ranges[i].head));
1117      }
1118    };
1119    signal(doc, "beforeSelectionChange", doc, obj);
1120    if (doc.cm) signal(doc.cm, "beforeSelectionChange", doc.cm, obj);
1121    if (obj.ranges != sel.ranges) return normalizeSelection(obj.ranges, obj.ranges.length - 1);
1122    else return sel;
1123  }
1124
1125  function setSelectionReplaceHistory(doc, sel, options) {
1126    var done = doc.history.done, last = lst(done);
1127    if (last && last.ranges) {
1128      done[done.length - 1] = sel;
1129      setSelectionNoUndo(doc, sel, options);
1130    } else {
1131      setSelection(doc, sel, options);
1132    }
1133  }
1134
1135  // Set a new selection.
1136  function setSelection(doc, sel, options) {
1137    setSelectionNoUndo(doc, sel, options);
1138    addSelectionToHistory(doc, doc.sel, doc.cm ? doc.cm.curOp.id : NaN, options);
1139  }
1140
1141  function setSelectionNoUndo(doc, sel, options) {
1142    if (hasHandler(doc, "beforeSelectionChange") || doc.cm && hasHandler(doc.cm, "beforeSelectionChange"))
1143      sel = filterSelectionChange(doc, sel);
1144
1145    var bias = cmp(sel.primary().head, doc.sel.primary().head) < 0 ? -1 : 1;
1146    setSelectionInner(doc, skipAtomicInSelection(doc, sel, bias, true));
1147
1148    if (!(options && options.scroll === false) && doc.cm)
1149      ensureCursorVisible(doc.cm);
1150  }
1151
1152  function setSelectionInner(doc, sel) {
1153    if (sel.equals(doc.sel)) return;
1154
1155    doc.sel = sel;
1156
1157    if (doc.cm) {
1158      doc.cm.curOp.updateInput = doc.cm.curOp.selectionChanged = true;
1159      signalCursorActivity(doc.cm);
1160    }
1161    signalLater(doc, "cursorActivity", doc);
1162  }
1163
1164  // Verify that the selection does not partially select any atomic
1165  // marked ranges.
1166  function reCheckSelection(doc) {
1167    setSelectionInner(doc, skipAtomicInSelection(doc, doc.sel, null, false), sel_dontScroll);
1168  }
1169
1170  // Return a selection that does not partially select any atomic
1171  // ranges.
1172  function skipAtomicInSelection(doc, sel, bias, mayClear) {
1173    var out;
1174    for (var i = 0; i < sel.ranges.length; i++) {
1175      var range = sel.ranges[i];
1176      var newAnchor = skipAtomic(doc, range.anchor, bias, mayClear);
1177      var newHead = skipAtomic(doc, range.head, bias, mayClear);
1178      if (out || newAnchor != range.anchor || newHead != range.head) {
1179        if (!out) out = sel.ranges.slice(0, i);
1180        out[i] = new Range(newAnchor, newHead);
1181      }
1182    }
1183    return out ? normalizeSelection(out, sel.primIndex) : sel;
1184  }
1185
1186  // Ensure a given position is not inside an atomic range.
1187  function skipAtomic(doc, pos, bias, mayClear) {
1188    var flipped = false, curPos = pos;
1189    var dir = bias || 1;
1190    doc.cantEdit = false;
1191    search: for (;;) {
1192      var line = getLine(doc, curPos.line);
1193      if (line.markedSpans) {
1194        for (var i = 0; i < line.markedSpans.length; ++i) {
1195          var sp = line.markedSpans[i], m = sp.marker;
1196          if ((sp.from == null || (m.inclusiveLeft ? sp.from <= curPos.ch : sp.from < curPos.ch)) &&
1197              (sp.to == null || (m.inclusiveRight ? sp.to >= curPos.ch : sp.to > curPos.ch))) {
1198            if (mayClear) {
1199              signal(m, "beforeCursorEnter");
1200              if (m.explicitlyCleared) {
1201                if (!line.markedSpans) break;
1202                else {--i; continue;}
1203              }
1204            }
1205            if (!m.atomic) continue;
1206            var newPos = m.find(dir < 0 ? -1 : 1);
1207            if (cmp(newPos, curPos) == 0) {
1208              newPos.ch += dir;
1209              if (newPos.ch < 0) {
1210                if (newPos.line > doc.first) newPos = clipPos(doc, Pos(newPos.line - 1));
1211                else newPos = null;
1212              } else if (newPos.ch > line.text.length) {
1213                if (newPos.line < doc.first + doc.size - 1) newPos = Pos(newPos.line + 1, 0);
1214                else newPos = null;
1215              }
1216              if (!newPos) {
1217                if (flipped) {
1218                  // Driven in a corner -- no valid cursor position found at all
1219                  // -- try again *with* clearing, if we didn't already
1220                  if (!mayClear) return skipAtomic(doc, pos, bias, true);
1221                  // Otherwise, turn off editing until further notice, and return the start of the doc
1222                  doc.cantEdit = true;
1223                  return Pos(doc.first, 0);
1224                }
1225                flipped = true; newPos = pos; dir = -dir;
1226              }
1227            }
1228            curPos = newPos;
1229            continue search;
1230          }
1231        }
1232      }
1233      return curPos;
1234    }
1235  }
1236
1237  // SELECTION DRAWING
1238
1239  // Redraw the selection and/or cursor
1240  function updateSelection(cm) {
1241    var display = cm.display, doc = cm.doc;
1242    var curFragment = document.createDocumentFragment();
1243    var selFragment = document.createDocumentFragment();
1244
1245    for (var i = 0; i < doc.sel.ranges.length; i++) {
1246      var range = doc.sel.ranges[i];
1247      var collapsed = range.empty();
1248      if (collapsed || cm.options.showCursorWhenSelecting)
1249        drawSelectionCursor(cm, range, curFragment);
1250      if (!collapsed)
1251        drawSelectionRange(cm, range, selFragment);
1252    }
1253
1254    // Move the hidden textarea near the cursor to prevent scrolling artifacts
1255    if (cm.options.moveInputWithCursor) {
1256      var headPos = cursorCoords(cm, doc.sel.primary().head, "div");
1257      var wrapOff = display.wrapper.getBoundingClientRect(), lineOff = display.lineDiv.getBoundingClientRect();
1258      var top = Math.max(0, Math.min(display.wrapper.clientHeight - 10,
1259                                     headPos.top + lineOff.top - wrapOff.top));
1260      var left = Math.max(0, Math.min(display.wrapper.clientWidth - 10,
1261                                      headPos.left + lineOff.left - wrapOff.left));
1262      display.inputDiv.style.top = top + "px";
1263      display.inputDiv.style.left = left + "px";
1264    }
1265
1266    removeChildrenAndAdd(display.cursorDiv, curFragment);
1267    removeChildrenAndAdd(display.selectionDiv, selFragment);
1268  }
1269
1270  // Draws a cursor for the given range
1271  function drawSelectionCursor(cm, range, output) {
1272    var pos = cursorCoords(cm, range.head, "div");
1273
1274    var cursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor"));
1275    cursor.style.left = pos.left + "px";
1276    cursor.style.top = pos.top + "px";
1277    cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + "px";
1278
1279    if (pos.other) {
1280      // Secondary cursor, shown when on a 'jump' in bi-directional text
1281      var otherCursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor CodeMirror-secondarycursor"));
1282      otherCursor.style.display = "";
1283      otherCursor.style.left = pos.other.left + "px";
1284      otherCursor.style.top = pos.other.top + "px";
1285      otherCursor.style.height = (pos.other.bottom - pos.other.top) * .85 + "px";
1286    }
1287  }
1288
1289  // Draws the given range as a highlighted selection
1290  function drawSelectionRange(cm, range, output) {
1291    var display = cm.display, doc = cm.doc;
1292    var fragment = document.createDocumentFragment();
1293    var padding = paddingH(cm.display), leftSide = padding.left, rightSide = display.lineSpace.offsetWidth - padding.right;
1294
1295    function add(left, top, width, bottom) {
1296      if (top < 0) top = 0;
1297      top = Math.round(top);
1298      bottom = Math.round(bottom);
1299      fragment.appendChild(elt("div", null, "CodeMirror-selected", "position: absolute; left: " + left +
1300                               "px; top: " + top + "px; width: " + (width == null ? rightSide - left : width) +
1301                               "px; height: " + (bottom - top) + "px"));
1302    }
1303
1304    function drawForLine(line, fromArg, toArg) {
1305      var lineObj = getLine(doc, line);
1306      var lineLen = lineObj.text.length;
1307      var start, end;
1308      function coords(ch, bias) {
1309        return charCoords(cm, Pos(line, ch), "div", lineObj, bias);
1310      }
1311
1312      iterateBidiSections(getOrder(lineObj), fromArg || 0, toArg == null ? lineLen : toArg, function(from, to, dir) {
1313        var leftPos = coords(from, "left"), rightPos, left, right;
1314        if (from == to) {
1315          rightPos = leftPos;
1316          left = right = leftPos.left;
1317        } else {
1318          rightPos = coords(to - 1, "right");
1319          if (dir == "rtl") { var tmp = leftPos; leftPos = rightPos; rightPos = tmp; }
1320          left = leftPos.left;
1321          right = rightPos.right;
1322        }
1323        if (fromArg == null && from == 0) left = leftSide;
1324        if (rightPos.top - leftPos.top > 3) { // Different lines, draw top part
1325          add(left, leftPos.top, null, leftPos.bottom);
1326          left = leftSide;
1327          if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, null, rightPos.top);
1328        }
1329        if (toArg == null && to == lineLen) right = rightSide;
1330        if (!start || leftPos.top < start.top || leftPos.top == start.top && leftPos.left < start.left)
1331          start = leftPos;
1332        if (!end || rightPos.bottom > end.bottom || rightPos.bottom == end.bottom && rightPos.right > end.right)
1333          end = rightPos;
1334        if (left < leftSide + 1) left = leftSide;
1335        add(left, rightPos.top, right - left, rightPos.bottom);
1336      });
1337      return {start: start, end: end};
1338    }
1339
1340    var sFrom = range.from(), sTo = range.to();
1341    if (sFrom.line == sTo.line) {
1342      drawForLine(sFrom.line, sFrom.ch, sTo.ch);
1343    } else {
1344      var fromLine = getLine(doc, sFrom.line), toLine = getLine(doc, sTo.line);
1345      var singleVLine = visualLine(fromLine) == visualLine(toLine);
1346      var leftEnd = drawForLine(sFrom.line, sFrom.ch, singleVLine ? fromLine.text.length + 1 : null).end;
1347      var rightStart = drawForLine(sTo.line, singleVLine ? 0 : null, sTo.ch).start;
1348      if (singleVLine) {
1349        if (leftEnd.top < rightStart.top - 2) {
1350          add(leftEnd.right, leftEnd.top, null, leftEnd.bottom);
1351          add(leftSide, rightStart.top, rightStart.left, rightStart.bottom);
1352        } else {
1353          add(leftEnd.right, leftEnd.top, rightStart.left - leftEnd.right, leftEnd.bottom);
1354        }
1355      }
1356      if (leftEnd.bottom < rightStart.top)
1357        add(leftSide, leftEnd.bottom, null, rightStart.top);
1358    }
1359
1360    output.appendChild(fragment);
1361  }
1362
1363  // Cursor-blinking
1364  function restartBlink(cm) {
1365    if (!cm.state.focused) return;
1366    var display = cm.display;
1367    clearInterval(display.blinker);
1368    var on = true;
1369    display.cursorDiv.style.visibility = "";
1370    if (cm.options.cursorBlinkRate > 0)
1371      display.blinker = setInterval(function() {
1372        display.cursorDiv.style.visibility = (on = !on) ? "" : "hidden";
1373      }, cm.options.cursorBlinkRate);
1374  }
1375
1376  // HIGHLIGHT WORKER
1377
1378  function startWorker(cm, time) {
1379    if (cm.doc.mode.startState && cm.doc.frontier < cm.display.viewTo)
1380      cm.state.highlight.set(time, bind(highlightWorker, cm));
1381  }
1382
1383  function highlightWorker(cm) {
1384    var doc = cm.doc;
1385    if (doc.frontier < doc.first) doc.frontier = doc.first;
1386    if (doc.frontier >= cm.display.viewTo) return;
1387    var end = +new Date + cm.options.workTime;
1388    var state = copyState(doc.mode, getStateBefore(cm, doc.frontier));
1389
1390    runInOp(cm, function() {
1391    doc.iter(doc.frontier, Math.min(doc.first + doc.size, cm.display.viewTo + 500), function(line) {
1392      if (doc.frontier >= cm.display.viewFrom) { // Visible
1393        var oldStyles = line.styles;
1394        var highlighted = highlightLine(cm, line, state, true);
1395        line.styles = highlighted.styles;
1396        if (highlighted.classes) line.styleClasses = highlighted.classes;
1397        else if (line.styleClasses) line.styleClasses = null;
1398        var ischange = !oldStyles || oldStyles.length != line.styles.length;
1399        for (var i = 0; !ischange && i < oldStyles.length; ++i) ischange = oldStyles[i] != line.styles[i];
1400        if (ischange) regLineChange(cm, doc.frontier, "text");
1401        line.stateAfter = copyState(doc.mode, state);
1402      } else {
1403        processLine(cm, line.text, state);
1404        line.stateAfter = doc.frontier % 5 == 0 ? copyState(doc.mode, state) : null;
1405      }
1406      ++doc.frontier;
1407      if (+new Date > end) {
1408        startWorker(cm, cm.options.workDelay);
1409        return true;
1410      }
1411    });
1412    });
1413  }
1414
1415  // Finds the line to start with when starting a parse. Tries to
1416  // find a line with a stateAfter, so that it can start with a
1417  // valid state. If that fails, it returns the line with the
1418  // smallest indentation, which tends to need the least context to
1419  // parse correctly.
1420  function findStartLine(cm, n, precise) {
1421    var minindent, minline, doc = cm.doc;
1422    var lim = precise ? -1 : n - (cm.doc.mode.innerMode ? 1000 : 100);
1423    for (var search = n; search > lim; --search) {
1424      if (search <= doc.first) return doc.first;
1425      var line = getLine(doc, search - 1);
1426      if (line.stateAfter && (!precise || search <= doc.frontier)) return search;
1427      var indented = countColumn(line.text, null, cm.options.tabSize);
1428      if (minline == null || minindent > indented) {
1429        minline = search - 1;
1430        minindent = indented;
1431      }
1432    }
1433    return minline;
1434  }
1435
1436  function getStateBefore(cm, n, precise) {
1437    var doc = cm.doc, display = cm.display;
1438    if (!doc.mode.startState) return true;
1439    var pos = findStartLine(cm, n, precise), state = pos > doc.first && getLine(doc, pos-1).stateAfter;
1440    if (!state) state = startState(doc.mode);
1441    else state = copyState(doc.mode, state);
1442    doc.iter(pos, n, function(line) {
1443      processLine(cm, line.text, state);
1444      var save = pos == n - 1 || pos % 5 == 0 || pos >= display.viewFrom && pos < display.viewTo;
1445      line.stateAfter = save ? copyState(doc.mode, state) : null;
1446      ++pos;
1447    });
1448    if (precise) doc.frontier = pos;
1449    return state;
1450  }
1451
1452  // POSITION MEASUREMENT
1453
1454  function paddingTop(display) {return display.lineSpace.offsetTop;}
1455  function paddingVert(display) {return display.mover.offsetHeight - display.lineSpace.offsetHeight;}
1456  function paddingH(display) {
1457    if (display.cachedPaddingH) return display.cachedPaddingH;
1458    var e = removeChildrenAndAdd(display.measure, elt("pre", "x"));
1459    var style = window.getComputedStyle ? window.getComputedStyle(e) : e.currentStyle;
1460    var data = {left: parseInt(style.paddingLeft), right: parseInt(style.paddingRight)};
1461    if (!isNaN(data.left) && !isNaN(data.right)) display.cachedPaddingH = data;
1462    return data;
1463  }
1464
1465  // Ensure the lineView.wrapping.heights array is populated. This is
1466  // an array of bottom offsets for the lines that make up a drawn
1467  // line. When lineWrapping is on, there might be more than one
1468  // height.
1469  function ensureLineHeights(cm, lineView, rect) {
1470    var wrapping = cm.options.lineWrapping;
1471    var curWidth = wrapping && cm.display.scroller.clientWidth;
1472    if (!lineView.measure.heights || wrapping && lineView.measure.width != curWidth) {
1473      var heights = lineView.measure.heights = [];
1474      if (wrapping) {
1475        lineView.measure.width = curWidth;
1476        var rects = lineView.text.firstChild.getClientRects();
1477        for (var i = 0; i < rects.length - 1; i++) {
1478          var cur = rects[i], next = rects[i + 1];
1479          if (Math.abs(cur.bottom - next.bottom) > 2)
1480            heights.push((cur.bottom + next.top) / 2 - rect.top);
1481        }
1482      }
1483      heights.push(rect.bottom - rect.top);
1484    }
1485  }
1486
1487  // Find a line map (mapping character offsets to text nodes) and a
1488  // measurement cache for the given line number. (A line view might
1489  // contain multiple lines when collapsed ranges are present.)
1490  function mapFromLineView(lineView, line, lineN) {
1491    if (lineView.line == line)
1492      return {map: lineView.measure.map, cache: lineView.measure.cache};
1493    for (var i = 0; i < lineView.rest.length; i++)
1494      if (lineView.rest[i] == line)
1495        return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i]};
1496    for (var i = 0; i < lineView.rest.length; i++)
1497      if (lineNo(lineView.rest[i]) > lineN)
1498        return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i], before: true};
1499  }
1500
1501  // Render a line into the hidden node display.externalMeasured. Used
1502  // when measurement is needed for a line that's not in the viewport.
1503  function updateExternalMeasurement(cm, line) {
1504    line = visualLine(line);
1505    var lineN = lineNo(line);
1506    var view = cm.display.externalMeasured = new LineView(cm.doc, line, lineN);
1507    view.lineN = lineN;
1508    var built = view.built = buildLineContent(cm, view);
1509    view.text = built.pre;
1510    removeChildrenAndAdd(cm.display.lineMeasure, built.pre);
1511    return view;
1512  }
1513
1514  // Get a {top, bottom, left, right} box (in line-local coordinates)
1515  // for a given character.
1516  function measureChar(cm, line, ch, bias) {
1517    return measureCharPrepared(cm, prepareMeasureForLine(cm, line), ch, bias);
1518  }
1519
1520  // Find a line view that corresponds to the given line number.
1521  function findViewForLine(cm, lineN) {
1522    if (lineN >= cm.display.viewFrom && lineN < cm.display.viewTo)
1523      return cm.display.view[findViewIndex(cm, lineN)];
1524    var ext = cm.display.externalMeasured;
1525    if (ext && lineN >= ext.lineN && lineN < ext.lineN + ext.size)
1526      return ext;
1527  }
1528
1529  // Measurement can be split in two steps, the set-up work that
1530  // applies to the whole line, and the measurement of the actual
1531  // character. Functions like coordsChar, that need to do a lot of
1532  // measurements in a row, can thus ensure that the set-up work is
1533  // only done once.
1534  function prepareMeasureForLine(cm, line) {
1535    var lineN = lineNo(line);
1536    var view = findViewForLine(cm, lineN);
1537    if (view && !view.text)
1538      view = null;
1539    else if (view && view.changes)
1540      updateLineForChanges(cm, view, lineN, getDimensions(cm));
1541    if (!view)
1542      view = updateExternalMeasurement(cm, line);
1543
1544    var info = mapFromLineView(view, line, lineN);
1545    return {
1546      line: line, view: view, rect: null,
1547      map: info.map, cache: info.cache, before: info.before,
1548      hasHeights: false
1549    };
1550  }
1551
1552  // Given a prepared measurement object, measures the position of an
1553  // actual character (or fetches it from the cache).
1554  function measureCharPrepared(cm, prepared, ch, bias) {
1555    if (prepared.before) ch = -1;
1556    var key = ch + (bias || ""), found;
1557    if (prepared.cache.hasOwnProperty(key)) {
1558      found = prepared.cache[key];
1559    } else {
1560      if (!prepared.rect)
1561        prepared.rect = prepared.view.text.getBoundingClientRect();
1562      if (!prepared.hasHeights) {
1563        ensureLineHeights(cm, prepared.view, prepared.rect);
1564        prepared.hasHeights = true;
1565      }
1566      found = measureCharInner(cm, prepared, ch, bias);
1567      if (!found.bogus) prepared.cache[key] = found;
1568    }
1569    return {left: found.left, right: found.right, top: found.top, bottom: found.bottom};
1570  }
1571
1572  var nullRect = {left: 0, right: 0, top: 0, bottom: 0};
1573
1574  function measureCharInner(cm, prepared, ch, bias) {
1575    var map = prepared.map;
1576
1577    var node, start, end, collapse;
1578    // First, search the line map for the text node corresponding to,
1579    // or closest to, the target character.
1580    for (var i = 0; i < map.length; i += 3) {
1581      var mStart = map[i], mEnd = map[i + 1];
1582      if (ch < mStart) {
1583        start = 0; end = 1;
1584        collapse = "left";
1585      } else if (ch < mEnd) {
1586        start = ch - mStart;
1587        end = start + 1;
1588      } else if (i == map.length - 3 || ch == mEnd && map[i + 3] > ch) {
1589        end = mEnd - mStart;
1590        start = end - 1;
1591        if (ch >= mEnd) collapse = "right";
1592      }
1593      if (start != null) {
1594        node = map[i + 2];
1595        if (mStart == mEnd && bias == (node.insertLeft ? "left" : "right"))
1596          collapse = bias;
1597        if (bias == "left" && start == 0)
1598          while (i && map[i - 2] == map[i - 3] && map[i - 1].insertLeft) {
1599            node = map[(i -= 3) + 2];
1600            collapse = "left";
1601          }
1602        if (bias == "right" && start == mEnd - mStart)
1603          while (i < map.length - 3 && map[i + 3] == map[i + 4] && !map[i + 5].insertLeft) {
1604            node = map[(i += 3) + 2];
1605            collapse = "right";
1606          }
1607        break;
1608      }
1609    }
1610
1611    var rect;
1612    if (node.nodeType == 3) { // If it is a text node, use a range to retrieve the coordinates.
1613      while (start && isExtendingChar(prepared.line.text.charAt(mStart + start))) --start;
1614      while (mStart + end < mEnd && isExtendingChar(prepared.line.text.charAt(mStart + end))) ++end;
1615      if (ie_upto8 && start == 0 && end == mEnd - mStart) {
1616        rect = node.parentNode.getBoundingClientRect();
1617      } else if (ie && cm.options.lineWrapping) {
1618        var rects = range(node, start, end).getClientRects();
1619        if (rects.length)
1620          rect = rects[bias == "right" ? rects.length - 1 : 0];
1621        else
1622          rect = nullRect;
1623      } else {
1624        rect = range(node, start, end).getBoundingClientRect();
1625      }
1626    } else { // If it is a widget, simply get the box for the whole widget.
1627      if (start > 0) collapse = bias = "right";
1628      var rects;
1629      if (cm.options.lineWrapping && (rects = node.getClientRects()).length > 1)
1630        rect = rects[bias == "right" ? rects.length - 1 : 0];
1631      else
1632        rect = node.getBoundingClientRect();
1633    }
1634    if (ie_upto8 && !start && (!rect || !rect.left && !rect.right)) {
1635      var rSpan = node.parentNode.getClientRects()[0];
1636      if (rSpan)
1637        rect = {left: rSpan.left, right: rSpan.left + charWidth(cm.display), top: rSpan.top, bottom: rSpan.bottom};
1638      else
1639        rect = nullRect;
1640    }
1641
1642    var top, bot = (rect.bottom + rect.top) / 2 - prepared.rect.top;
1643    var heights = prepared.view.measure.heights;
1644    for (var i = 0; i < heights.length - 1; i++)
1645      if (bot < heights[i]) break;
1646    top = i ? heights[i - 1] : 0; bot = heights[i];
1647    var result = {left: (collapse == "right" ? rect.right : rect.left) - prepared.rect.left,
1648                  right: (collapse == "left" ? rect.left : rect.right) - prepared.rect.left,
1649                  top: top, bottom: bot};
1650    if (!rect.left && !rect.right) result.bogus = true;
1651    return result;
1652  }
1653
1654  function clearLineMeasurementCacheFor(lineView) {
1655    if (lineView.measure) {
1656      lineView.measure.cache = {};
1657      lineView.measure.heights = null;
1658      if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)
1659        lineView.measure.caches[i] = {};
1660    }
1661  }
1662
1663  function clearLineMeasurementCache(cm) {
1664    cm.display.externalMeasure = null;
1665    removeChildren(cm.display.lineMeasure);
1666    for (var i = 0; i < cm.display.view.length; i++)
1667      clearLineMeasurementCacheFor(cm.display.view[i]);
1668  }
1669
1670  function clearCaches(cm) {
1671    clearLineMeasurementCache(cm);
1672    cm.display.cachedCharWidth = cm.display.cachedTextHeight = cm.display.cachedPaddingH = null;
1673    if (!cm.options.lineWrapping) cm.display.maxLineChanged = true;
1674    cm.display.lineNumChars = null;
1675  }
1676
1677  function pageScrollX() { return window.pageXOffset || (document.documentElement || document.body).scrollLeft; }
1678  function pageScrollY() { return window.pageYOffset || (document.documentElement || document.body).scrollTop; }
1679
1680  // Converts a {top, bottom, left, right} box from line-local
1681  // coordinates into another coordinate system. Context may be one of
1682  // "line", "div" (display.lineDiv), "local"/null (editor), or "page".
1683  function intoCoordSystem(cm, lineObj, rect, context) {
1684    if (lineObj.widgets) for (var i = 0; i < lineObj.widgets.length; ++i) if (lineObj.widgets[i].above) {
1685      var size = widgetHeight(lineObj.widgets[i]);
1686      rect.top += size; rect.bottom += size;
1687    }
1688    if (context == "line") return rect;
1689    if (!context) context = "local";
1690    var yOff = heightAtLine(lineObj);
1691    if (context == "local") yOff += paddingTop(cm.display);
1692    else yOff -= cm.display.viewOffset;
1693    if (context == "page" || context == "window") {
1694      var lOff = cm.display.lineSpace.getBoundingClientRect();
1695      yOff += lOff.top + (context == "window" ? 0 : pageScrollY());
1696      var xOff = lOff.left + (context == "window" ? 0 : pageScrollX());
1697      rect.left += xOff; rect.right += xOff;
1698    }
1699    rect.top += yOff; rect.bottom += yOff;
1700    return rect;
1701  }
1702
1703  // Coverts a box from "div" coords to another coordinate system.
1704  // Context may be "window", "page", "div", or "local"/null.
1705  function fromCoordSystem(cm, coords, context) {
1706    if (context == "div") return coords;
1707    var left = coords.left, top = coords.top;
1708    // First move into "page" coordinate system
1709    if (context == "page") {
1710      left -= pageScrollX();
1711      top -= pageScrollY();
1712    } else if (context == "local" || !context) {
1713      var localBox = cm.display.sizer.getBoundingClientRect();
1714      left += localBox.left;
1715      top += localBox.top;
1716    }
1717
1718    var lineSpaceBox = cm.display.lineSpace.getBoundingClientRect();
1719    return {left: left - lineSpaceBox.left, top: top - lineSpaceBox.top};
1720  }
1721
1722  function charCoords(cm, pos, context, lineObj, bias) {
1723    if (!lineObj) lineObj = getLine(cm.doc, pos.line);
1724    return intoCoordSystem(cm, lineObj, measureChar(cm, lineObj, pos.ch, bias), context);
1725  }
1726
1727  // Returns a box for a given cursor position, which may have an
1728  // 'other' property containing the position of the secondary cursor
1729  // on a bidi boundary.
1730  function cursorCoords(cm, pos, context, lineObj, preparedMeasure) {
1731    lineObj = lineObj || getLine(cm.doc, pos.line);
1732    if (!preparedMeasure) preparedMeasure = prepareMeasureForLine(cm, lineObj);
1733    function get(ch, right) {
1734      var m = measureCharPrepared(cm, preparedMeasure, ch, right ? "right" : "left");
1735      if (right) m.left = m.right; else m.right = m.left;
1736      return intoCoordSystem(cm, lineObj, m, context);
1737    }
1738    function getBidi(ch, partPos) {
1739      var part = order[partPos], right = part.level % 2;
1740      if (ch == bidiLeft(part) && partPos && part.level < order[partPos - 1].level) {
1741        part = order[--partPos];
1742        ch = bidiRight(part) - (part.level % 2 ? 0 : 1);
1743        right = true;
1744      } else if (ch == bidiRight(part) && partPos < order.length - 1 && part.level < order[partPos + 1].level) {
1745        part = order[++partPos];
1746        ch = bidiLeft(part) - part.level % 2;
1747        right = false;
1748      }
1749      if (right && ch == part.to && ch > part.from) return get(ch - 1);
1750      return get(ch, right);
1751    }
1752    var order = getOrder(lineObj), ch = pos.ch;
1753    if (!order) return get(ch);
1754    var partPos = getBidiPartAt(order, ch);
1755    var val = getBidi(ch, partPos);
1756    if (bidiOther != null) val.other = getBidi(ch, bidiOther);
1757    return val;
1758  }
1759
1760  // Used to cheaply estimate the coordinates for a position. Used for
1761  // intermediate scroll updates.
1762  function estimateCoords(cm, pos) {
1763    var left = 0, pos = clipPos(cm.doc, pos);
1764    if (!cm.options.lineWrapping) left = charWidth(cm.display) * pos.ch;
1765    var lineObj = getLine(cm.doc, pos.line);
1766    var top = heightAtLine(lineObj) + paddingTop(cm.display);
1767    return {left: left, right: left, top: top, bottom: top + lineObj.height};
1768  }
1769
1770  // Positions returned by coordsChar contain some extra information.
1771  // xRel is the relative x position of the input coordinates compared
1772  // to the found position (so xRel > 0 means the coordinates are to
1773  // the right of the character position, for example). When outside
1774  // is true, that means the coordinates lie outside the line's
1775  // vertical range.
1776  function PosWithInfo(line, ch, outside, xRel) {
1777    var pos = Pos(line, ch);
1778    pos.xRel = xRel;
1779    if (outside) pos.outside = true;
1780    return pos;
1781  }
1782
1783  // Compute the character position closest to the given coordinates.
1784  // Input must be lineSpace-local ("div" coordinate system).
1785  function coordsChar(cm, x, y) {
1786    var doc = cm.doc;
1787    y += cm.display.viewOffset;
1788    if (y < 0) return PosWithInfo(doc.first, 0, true, -1);
1789    var lineN = lineAtHeight(doc, y), last = doc.first + doc.size - 1;
1790    if (lineN > last)
1791      return PosWithInfo(doc.first + doc.size - 1, getLine(doc, last).text.length, true, 1);
1792    if (x < 0) x = 0;
1793
1794    var lineObj = getLine(doc, lineN);
1795    for (;;) {
1796      var found = coordsCharInner(cm, lineObj, lineN, x, y);
1797      var merged = collapsedSpanAtEnd(lineObj);
1798      var mergedPos = merged && merged.find(0, true);
1799      if (merged && (found.ch > mergedPos.from.ch || found.ch == mergedPos.from.ch && found.xRel > 0))
1800        lineN = lineNo(lineObj = mergedPos.to.line);
1801      else
1802        return found;
1803    }
1804  }
1805
1806  function coordsCharInner(cm, lineObj, lineNo, x, y) {
1807    var innerOff = y - heightAtLine(lineObj);
1808    var wrongLine = false, adjust = 2 * cm.display.wrapper.clientWidth;
1809    var preparedMeasure = prepareMeasureForLine(cm, lineObj);
1810
1811    function getX(ch) {
1812      var sp = cursorCoords(cm, Pos(lineNo, ch), "line", lineObj, preparedMeasure);
1813      wrongLine = true;
1814      if (innerOff > sp.bottom) return sp.left - adjust;
1815      else if (innerOff < sp.top) return sp.left + adjust;
1816      else wrongLine = false;
1817      return sp.left;
1818    }
1819
1820    var bidi = getOrder(lineObj), dist = lineObj.text.length;
1821    var from = lineLeft(lineObj), to = lineRight(lineObj);
1822    var fromX = getX(from), fromOutside = wrongLine, toX = getX(to), toOutside = wrongLine;
1823
1824    if (x > toX) return PosWithInfo(lineNo, to, toOutside, 1);
1825    // Do a binary search between these bounds.
1826    for (;;) {
1827      if (bidi ? to == from || to == moveVisually(lineObj, from, 1) : to - from <= 1) {
1828        var ch = x < fromX || x - fromX <= toX - x ? from : to;
1829        var xDiff = x - (ch == from ? fromX : toX);
1830        while (isExtendingChar(lineObj.text.charAt(ch))) ++ch;
1831        var pos = PosWithInfo(lineNo, ch, ch == from ? fromOutside : toOutside,
1832                              xDiff < -1 ? -1 : xDiff > 1 ? 1 : 0);
1833        return pos;
1834      }
1835      var step = Math.ceil(dist / 2), middle = from + step;
1836      if (bidi) {
1837        middle = from;
1838        for (var i = 0; i < step; ++i) middle = moveVisually(lineObj, middle, 1);
1839      }
1840      var middleX = getX(middle);
1841      if (middleX > x) {to = middle; toX = middleX; if (toOutside = wrongLine) toX += 1000; dist = step;}
1842      else {from = middle; fromX = middleX; fromOutside = wrongLine; dist -= step;}
1843    }
1844  }
1845
1846  var measureText;
1847  // Compute the default text height.
1848  function textHeight(display) {
1849    if (display.cachedTextHeight != null) return display.cachedTextHeight;
1850    if (measureText == null) {
1851      measureText = elt("pre");
1852      // Measure a bunch of lines, for browsers that compute
1853      // fractional heights.
1854      for (var i = 0; i < 49; ++i) {
1855        measureText.appendChild(document.createTextNode("x"));
1856        measureText.appendChild(elt("br"));
1857      }
1858      measureText.appendChild(document.createTextNode("x"));
1859    }
1860    removeChildrenAndAdd(display.measure, measureText);
1861    var height = measureText.offsetHeight / 50;
1862    if (height > 3) display.cachedTextHeight = height;
1863    removeChildren(display.measure);
1864    return height || 1;
1865  }
1866
1867  // Compute the default character width.
1868  function charWidth(display) {
1869    if (display.cachedCharWidth != null) return display.cachedCharWidth;
1870    var anchor = elt("span", "xxxxxxxxxx");
1871    var pre = elt("pre", [anchor]);
1872    removeChildrenAndAdd(display.measure, pre);
1873    var rect = anchor.getBoundingClientRect(), width = (rect.right - rect.left) / 10;
1874    if (width > 2) display.cachedCharWidth = width;
1875    return width || 10;
1876  }
1877
1878  // OPERATIONS
1879
1880  // Operations are used to wrap a series of changes to the editor
1881  // state in such a way that each change won't have to update the
1882  // cursor and display (which would be awkward, slow, and
1883  // error-prone). Instead, display updates are batched and then all
1884  // combined and executed at once.
1885
1886  var nextOpId = 0;
1887  // Start a new operation.
1888  function startOperation(cm) {
1889    cm.curOp = {
1890      viewChanged: false,      // Flag that indicates that lines might need to be redrawn
1891      startHeight: cm.doc.height, // Used to detect need to update scrollbar
1892      forceUpdate: false,      // Used to force a redraw
1893      updateInput: null,       // Whether to reset the input textarea
1894      typing: false,           // Whether this reset should be careful to leave existing text (for compositing)
1895      changeObjs: null,        // Accumulated changes, for firing change events
1896      cursorActivityHandlers: null, // Set of handlers to fire cursorActivity on
1897      selectionChanged: false, // Whether the selection needs to be redrawn
1898      updateMaxLine: false,    // Set when the widest line needs to be determined anew
1899      scrollLeft: null, scrollTop: null, // Intermediate scroll position, not pushed to DOM yet
1900      scrollToPos: null,       // Used to scroll to a specific position
1901      id: ++nextOpId           // Unique ID
1902    };
1903    if (!delayedCallbackDepth++) delayedCallbacks = [];
1904  }
1905
1906  // Finish an operation, updating the display and signalling delayed events
1907  function endOperation(cm) {
1908    var op = cm.curOp, doc = cm.doc, display = cm.display;
1909    cm.curOp = null;
1910
1911    if (op.updateMaxLine) findMaxLine(cm);
1912
1913    // If it looks like an update might be needed, call updateDisplay
1914    if (op.viewChanged || op.forceUpdate || op.scrollTop != null ||
1915        op.scrollToPos && (op.scrollToPos.from.line < display.viewFrom ||
1916                           op.scrollToPos.to.line >= display.viewTo) ||
1917        display.maxLineChanged && cm.options.lineWrapping) {
1918      var updated = updateDisplay(cm, {top: op.scrollTop, ensure: op.scrollToPos}, op.forceUpdate);
1919      if (cm.display.scroller.offsetHeight) cm.doc.scrollTop = cm.display.scroller.scrollTop;
1920    }
1921    // If no update was run, but the selection changed, redraw that.
1922    if (!updated && op.selectionChanged) updateSelection(cm);
1923    if (!updated && op.startHeight != cm.doc.height) updateScrollbars(cm);
1924
1925    // Propagate the scroll position to the actual DOM scroller
1926    if (op.scrollTop != null && display.scroller.scrollTop != op.scrollTop) {
1927      var top = Math.max(0, Math.min(display.scroller.scrollHeight - display.scroller.clientHeight, op.scrollTop));
1928      display.scroller.scrollTop = display.scrollbarV.scrollTop = doc.scrollTop = top;
1929    }
1930    if (op.scrollLeft != null && display.scroller.scrollLeft != op.scrollLeft) {
1931      var left = Math.max(0, Math.min(display.scroller.scrollWidth - display.scroller.clientWidth, op.scrollLeft));
1932      display.scroller.scrollLeft = display.scrollbarH.scrollLeft = doc.scrollLeft = left;
1933      alignHorizontally(cm);
1934    }
1935    // If we need to scroll a specific position into view, do so.
1936    if (op.scrollToPos) {
1937      var coords = scrollPosIntoView(cm, clipPos(cm.doc, op.scrollToPos.from),
1938                                     clipPos(cm.doc, op.scrollToPos.to), op.scrollToPos.margin);
1939      if (op.scrollToPos.isCursor && cm.state.focused) maybeScrollWindow(cm, coords);
1940    }
1941
1942    if (op.selectionChanged) restartBlink(cm);
1943
1944    if (cm.state.focused && op.updateInput)
1945      resetInput(cm, op.typing);
1946
1947    // Fire events for markers that are hidden/unidden by editing or
1948    // undoing
1949    var hidden = op.maybeHiddenMarkers, unhidden = op.maybeUnhiddenMarkers;
1950    if (hidden) for (var i = 0; i < hidden.length; ++i)
1951      if (!hidden[i].lines.length) signal(hidden[i], "hide");
1952    if (unhidden) for (var i = 0; i < unhidden.length; ++i)
1953      if (unhidden[i].lines.length) signal(unhidden[i], "unhide");
1954
1955    var delayed;
1956    if (!--delayedCallbackDepth) {
1957      delayed = delayedCallbacks;
1958      delayedCallbacks = null;
1959    }
1960    // Fire change events, and delayed event handlers
1961    if (op.changeObjs)
1962      signal(cm, "changes", cm, op.changeObjs);
1963    if (delayed) for (var i = 0; i < delayed.length; ++i) delayed[i]();
1964    if (op.cursorActivityHandlers)
1965      for (var i = 0; i < op.cursorActivityHandlers.length; i++)
1966        op.cursorActivityHandlers[i](cm);
1967  }
1968
1969  // Run the given function in an operation
1970  function runInOp(cm, f) {
1971    if (cm.curOp) return f();
1972    startOperation(cm);
1973    try { return f(); }
1974    finally { endOperation(cm); }
1975  }
1976  // Wraps a function in an operation. Returns the wrapped function.
1977  function operation(cm, f) {
1978    return function() {
1979      if (cm.curOp) return f.apply(cm, arguments);
1980      startOperation(cm);
1981      try { return f.apply(cm, arguments); }
1982      finally { endOperation(cm); }
1983    };
1984  }
1985  // Used to add methods to editor and doc instances, wrapping them in
1986  // operations.
1987  function methodOp(f) {
1988    return function() {
1989      if (this.curOp) return f.apply(this, arguments);
1990      startOperation(this);
1991      try { return f.apply(this, arguments); }
1992      finally { endOperation(this); }
1993    };
1994  }
1995  function docMethodOp(f) {
1996    return function() {
1997      var cm = this.cm;
1998      if (!cm || cm.curOp) return f.apply(this, arguments);
1999      startOperation(cm);
2000      try { return f.apply(this, arguments); }
2001      finally { endOperation(cm); }
2002    };
2003  }
2004
2005  // VIEW TRACKING
2006
2007  // These objects are used to represent the visible (currently drawn)
2008  // part of the document. A LineView may correspond to multiple
2009  // logical lines, if those are connected by collapsed ranges.
2010  function LineView(doc, line, lineN) {
2011    // The starting line
2012    this.line = line;
2013    // Continuing lines, if any
2014    this.rest = visualLineContinued(line);
2015    // Number of logical lines in this visual line
2016    this.size = this.rest ? lineNo(lst(this.rest)) - lineN + 1 : 1;
2017    this.node = this.text = null;
2018    this.hidden = lineIsHidden(doc, line);
2019  }
2020
2021  // Create a range of LineView objects for the given lines.
2022  function buildViewArray(cm, from, to) {
2023    var array = [], nextPos;
2024    for (var pos = from; pos < to; pos = nextPos) {
2025      var view = new LineView(cm.doc, getLine(cm.doc, pos), pos);
2026      nextPos = pos + view.size;
2027      array.push(view);
2028    }
2029    return array;
2030  }
2031
2032  // Updates the display.view data structure for a given change to the
2033  // document. From and to are in pre-change coordinates. Lendiff is
2034  // the amount of lines added or subtracted by the change. This is
2035  // used for changes that span multiple lines, or change the way
2036  // lines are divided into visual lines. regLineChange (below)
2037  // registers single-line changes.
2038  function regChange(cm, from, to, lendiff) {
2039    if (from == null) from = cm.doc.first;
2040    if (to == null) to = cm.doc.first + cm.doc.size;
2041    if (!lendiff) lendiff = 0;
2042
2043    var display = cm.display;
2044    if (lendiff && to < display.viewTo &&
2045        (display.updateLineNumbers == null || display.updateLineNumbers > from))
2046      display.updateLineNumbers = from;
2047
2048    cm.curOp.viewChanged = true;
2049
2050    if (from >= display.viewTo) { // Change after
2051      if (sawCollapsedSpans && visualLineNo(cm.doc, from) < display.viewTo)
2052        resetView(cm);
2053    } else if (to <= display.viewFrom) { // Change before
2054      if (sawCollapsedSpans && visualLineEndNo(cm.doc, to + lendiff) > display.viewFrom) {
2055        resetView(cm);
2056      } else {
2057        display.viewFrom += lendiff;
2058        display.viewTo += lendiff;
2059      }
2060    } else if (from <= display.viewFrom && to >= display.viewTo) { // Full overlap
2061      resetView(cm);
2062    } else if (from <= display.viewFrom) { // Top overlap
2063      var cut = viewCuttingPoint(cm, to, to + lendiff, 1);
2064      if (cut) {
2065        display.view = display.view.slice(cut.index);
2066        display.viewFrom = cut.lineN;
2067        display.viewTo += lendiff;
2068      } else {
2069        resetView(cm);
2070      }
2071    } else if (to >= display.viewTo) { // Bottom overlap
2072      var cut = viewCuttingPoint(cm, from, from, -1);
2073      if (cut) {
2074        display.view = display.view.slice(0, cut.index);
2075        display.viewTo = cut.lineN;
2076      } else {
2077        resetView(cm);
2078      }
2079    } else { // Gap in the middle
2080      var cutTop = viewCuttingPoint(cm, from, from, -1);
2081      var cutBot = viewCuttingPoint(cm, to, to + lendiff, 1);
2082      if (cutTop && cutBot) {
2083        display.view = display.view.slice(0, cutTop.index)
2084          .concat(buildViewArray(cm, cutTop.lineN, cutBot.lineN))
2085          .concat(display.view.slice(cutBot.index));
2086        display.viewTo += lendiff;
2087      } else {
2088        resetView(cm);
2089      }
2090    }
2091
2092    var ext = display.externalMeasured;
2093    if (ext) {
2094      if (to < ext.lineN)
2095        ext.lineN += lendiff;
2096      else if (from < ext.lineN + ext.size)
2097        display.externalMeasured = null;
2098    }
2099  }
2100
2101  // Register a change to a single line. Type must be one of "text",
2102  // "gutter", "class", "widget"
2103  function regLineChange(cm, line, type) {
2104    cm.curOp.viewChanged = true;
2105    var display = cm.display, ext = cm.display.externalMeasured;
2106    if (ext && line >= ext.lineN && line < ext.lineN + ext.size)
2107      display.externalMeasured = null;
2108
2109    if (line < display.viewFrom || line >= display.viewTo) return;
2110    var lineView = display.view[findViewIndex(cm, line)];
2111    if (lineView.node == null) return;
2112    var arr = lineView.changes || (lineView.changes = []);
2113    if (indexOf(arr, type) == -1) arr.push(type);
2114  }
2115
2116  // Clear the view.
2117  function resetView(cm) {
2118    cm.display.viewFrom = cm.display.viewTo = cm.doc.first;
2119    cm.display.view = [];
2120    cm.display.viewOffset = 0;
2121  }
2122
2123  // Find the view element corresponding to a given line. Return null
2124  // when the line isn't visible.
2125  function findViewIndex(cm, n) {
2126    if (n >= cm.display.viewTo) return null;
2127    n -= cm.display.viewFrom;
2128    if (n < 0) return null;
2129    var view = cm.display.view;
2130    for (var i = 0; i < view.length; i++) {
2131      n -= view[i].size;
2132      if (n < 0) return i;
2133    }
2134  }
2135
2136  function viewCuttingPoint(cm, oldN, newN, dir) {
2137    var index = findViewIndex(cm, oldN), diff, view = cm.display.view;
2138    if (!sawCollapsedSpans) return {index: index, lineN: newN};
2139    for (var i = 0, n = cm.display.viewFrom; i < index; i++)
2140      n += view[i].size;
2141    if (n != oldN) {
2142      if (dir > 0) {
2143        if (index == view.length - 1) return null;
2144        diff = (n + view[index].size) - oldN;
2145        index++;
2146      } else {
2147        diff = n - oldN;
2148      }
2149      oldN += diff; newN += diff;
2150    }
2151    while (visualLineNo(cm.doc, newN) != newN) {
2152      if (index == (dir < 0 ? 0 : view.length - 1)) return null;
2153      newN += dir * view[index - (dir < 0 ? 1 : 0)].size;
2154      index += dir;
2155    }
2156    return {index: index, lineN: newN};
2157  }
2158
2159  // Force the view to cover a given range, adding empty view element
2160  // or clipping off existing ones as needed.
2161  function adjustView(cm, from, to) {
2162    var display = cm.display, view = display.view;
2163    if (view.length == 0 || from >= display.viewTo || to <= display.viewFrom) {
2164      display.view = buildViewArray(cm, from, to);
2165      display.viewFrom = from;
2166    } else {
2167      if (display.viewFrom > from)
2168        display.view = buildViewArray(cm, from, display.viewFrom).concat(display.view);
2169      else if (display.viewFrom < from)
2170        display.view = display.view.slice(findViewIndex(cm, from));
2171      display.viewFrom = from;
2172      if (display.viewTo < to)
2173        display.view = display.view.concat(buildViewArray(cm, display.viewTo, to));
2174      else if (display.viewTo > to)
2175        display.view = display.view.slice(0, findViewIndex(cm, to));
2176    }
2177    display.viewTo = to;
2178  }
2179
2180  // Count the number of lines in the view whose DOM representation is
2181  // out of date (or nonexistent).
2182  function countDirtyView(cm) {
2183    var view = cm.display.view, dirty = 0;
2184    for (var i = 0; i < view.length; i++) {
2185      var lineView = view[i];
2186      if (!lineView.hidden && (!lineView.node || lineView.changes)) ++dirty;
2187    }
2188    return dirty;
2189  }
2190
2191  // INPUT HANDLING
2192
2193  // Poll for input changes, using the normal rate of polling. This
2194  // runs as long as the editor is focused.
2195  function slowPoll(cm) {
2196    if (cm.display.pollingFast) return;
2197    cm.display.poll.set(cm.options.pollInterval, function() {
2198      readInput(cm);
2199      if (cm.state.focused) slowPoll(cm);
2200    });
2201  }
2202
2203  // When an event has just come in that is likely to add or change
2204  // something in the input textarea, we poll faster, to ensure that
2205  // the change appears on the screen quickly.
2206  function fastPoll(cm) {
2207    var missed = false;
2208    cm.display.pollingFast = true;
2209    function p() {
2210      var changed = readInput(cm);
2211      if (!changed && !missed) {missed = true; cm.display.poll.set(60, p);}
2212      else {cm.display.pollingFast = false; slowPoll(cm);}
2213    }
2214    cm.display.poll.set(20, p);
2215  }
2216
2217  // Read input from the textarea, and update the document to match.
2218  // When something is selected, it is present in the textarea, and
2219  // selected (unless it is huge, in which case a placeholder is
2220  // used). When nothing is selected, the cursor sits after previously
2221  // seen text (can be empty), which is stored in prevInput (we must
2222  // not reset the textarea when typing, because that breaks IME).
2223  function readInput(cm) {
2224    var input = cm.display.input, prevInput = cm.display.prevInput, doc = cm.doc;
2225    // Since this is called a *lot*, try to bail out as cheaply as
2226    // possible when it is clear that nothing happened. hasSelection
2227    // will be the case when there is a lot of text in the textarea,
2228    // in which case reading its value would be expensive.
2229    if (!cm.state.focused || (hasSelection(input) && !prevInput) || isReadOnly(cm) || cm.options.disableInput)
2230      return false;
2231    // See paste handler for more on the fakedLastChar kludge
2232    if (cm.state.pasteIncoming && cm.state.fakedLastChar) {
2233      input.value = input.value.substring(0, input.value.length - 1);
2234      cm.state.fakedLastChar = false;
2235    }
2236    var text = input.value;
2237    // If nothing changed, bail.
2238    if (text == prevInput && !cm.somethingSelected()) return false;
2239    // Work around nonsensical selection resetting in IE9/10
2240    if (ie && !ie_upto8 && cm.display.inputHasSelection === text) {
2241      resetInput(cm);
2242      return false;
2243    }
2244
2245    var withOp = !cm.curOp;
2246    if (withOp) startOperation(cm);
2247    cm.display.shift = false;
2248
2249    // Find the part of the input that is actually new
2250    var same = 0, l = Math.min(prevInput.length, text.length);
2251    while (same < l && prevInput.charCodeAt(same) == text.charCodeAt(same)) ++same;
2252    var inserted = text.slice(same), textLines = splitLines(inserted);
2253
2254    // When pasing N lines into N selections, insert one line per selection
2255    var multiPaste = cm.state.pasteIncoming && textLines.length > 1 && doc.sel.ranges.length == textLines.length;
2256
2257    // Normal behavior is to insert the new text into every selection
2258    for (var i = doc.sel.ranges.length - 1; i >= 0; i--) {
2259      var range = doc.sel.ranges[i];
2260      var from = range.from(), to = range.to();
2261      // Handle deletion
2262      if (same < prevInput.length)
2263        from = Pos(from.line, from.ch - (prevInput.length - same));
2264      // Handle overwrite
2265      else if (cm.state.overwrite && range.empty() && !cm.state.pasteIncoming)
2266        to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + lst(textLines).length));
2267      var updateInput = cm.curOp.updateInput;
2268      var changeEvent = {from: from, to: to, text: multiPaste ? [textLines[i]] : textLines,
2269                         origin: cm.state.pasteIncoming ? "paste" : cm.state.cutIncoming ? "cut" : "+input"};
2270      makeChange(cm.doc, changeEvent);
2271      signalLater(cm, "inputRead", cm, changeEvent);
2272      // When an 'electric' character is inserted, immediately trigger a reindent
2273      if (inserted && !cm.state.pasteIncoming && cm.options.electricChars &&
2274          cm.options.smartIndent && range.head.ch < 100 &&
2275          (!i || doc.sel.ranges[i - 1].head.line != range.head.line)) {
2276        var mode = cm.getModeAt(range.head);
2277        if (mode.electricChars) {
2278          for (var j = 0; j < mode.electricChars.length; j++)
2279            if (inserted.indexOf(mode.electricChars.charAt(j)) > -1) {
2280              indentLine(cm, range.head.line, "smart");
2281              break;
2282            }
2283        } else if (mode.electricInput) {
2284          var end = changeEnd(changeEvent);
2285          if (mode.electricInput.test(getLine(doc, end.line).text.slice(0, end.ch)))
2286            indentLine(cm, range.head.line, "smart");
2287        }
2288      }
2289    }
2290    ensureCursorVisible(cm);
2291    cm.curOp.updateInput = updateInput;
2292    cm.curOp.typing = true;
2293
2294    // Don't leave long text in the textarea, since it makes further polling slow
2295    if (text.length > 1000 || text.indexOf("\n") > -1) input.value = cm.display.prevInput = "";
2296    else cm.display.prevInput = text;
2297    if (withOp) endOperation(cm);
2298    cm.state.pasteIncoming = cm.state.cutIncoming = false;
2299    return true;
2300  }
2301
2302  // Reset the input to correspond to the selection (or to be empty,
2303  // when not typing and nothing is selected)
2304  function resetInput(cm, typing) {
2305    var minimal, selected, doc = cm.doc;
2306    if (cm.somethingSelected()) {
2307      cm.display.prevInput = "";
2308      var range = doc.sel.primary();
2309      minimal = hasCopyEvent &&
2310        (range.to().line - range.from().line > 100 || (selected = cm.getSelection()).length > 1000);
2311      var content = minimal ? "-" : selected || cm.getSelection();
2312      cm.display.input.value = content;
2313      if (cm.state.focused) selectInput(cm.display.input);
2314      if (ie && !ie_upto8) cm.display.inputHasSelection = content;
2315    } else if (!typing) {
2316      cm.display.prevInput = cm.display.input.value = "";
2317      if (ie && !ie_upto8) cm.display.inputHasSelection = null;
2318    }
2319    cm.display.inaccurateSelection = minimal;
2320  }
2321
2322  function focusInput(cm) {
2323    if (cm.options.readOnly != "nocursor" && (!mobile || activeElt() != cm.display.input))
2324      cm.display.input.focus();
2325  }
2326
2327  function ensureFocus(cm) {
2328    if (!cm.state.focused) { focusInput(cm); onFocus(cm); }
2329  }
2330
2331  function isReadOnly(cm) {
2332    return cm.options.readOnly || cm.doc.cantEdit;
2333  }
2334
2335  // EVENT HANDLERS
2336
2337  // Attach the necessary event handlers when initializing the editor
2338  function registerEventHandlers(cm) {
2339    var d = cm.display;
2340    on(d.scroller, "mousedown", operation(cm, onMouseDown));
2341    // Older IE's will not fire a second mousedown for a double click
2342    if (ie_upto10)
2343      on(d.scroller, "dblclick", operation(cm, function(e) {
2344        if (signalDOMEvent(cm, e)) return;
2345        var pos = posFromMouse(cm, e);
2346        if (!pos || clickInGutter(cm, e) || eventInWidget(cm.display, e)) return;
2347        e_preventDefault(e);
2348        var word = findWordAt(cm.doc, pos);
2349        extendSelection(cm.doc, word.anchor, word.head);
2350      }));
2351    else
2352      on(d.scroller, "dblclick", function(e) { signalDOMEvent(cm, e) || e_preventDefault(e); });
2353    // Prevent normal selection in the editor (we handle our own)
2354    on(d.lineSpace, "selectstart", function(e) {
2355      if (!eventInWidget(d, e)) e_preventDefault(e);
2356    });
2357    // Some browsers fire contextmenu *after* opening the menu, at
2358    // which point we can't mess with it anymore. Context menu is
2359    // handled in onMouseDown for these browsers.
2360    if (!captureRightClick) on(d.scroller, "contextmenu", function(e) {onContextMenu(cm, e);});
2361
2362    // Sync scrolling between fake scrollbars and real scrollable
2363    // area, ensure viewport is updated when scrolling.
2364    on(d.scroller, "scroll", function() {
2365      if (d.scroller.clientHeight) {
2366        setScrollTop(cm, d.scroller.scrollTop);
2367        setScrollLeft(cm, d.scroller.scrollLeft, true);
2368        signal(cm, "scroll", cm);
2369      }
2370    });
2371    on(d.scrollbarV, "scroll", function() {
2372      if (d.scroller.clientHeight) setScrollTop(cm, d.scrollbarV.scrollTop);
2373    });
2374    on(d.scrollbarH, "scroll", function() {
2375      if (d.scroller.clientHeight) setScrollLeft(cm, d.scrollbarH.scrollLeft);
2376    });
2377
2378    // Listen to wheel events in order to try and update the viewport on time.
2379    on(d.scroller, "mousewheel", function(e){onScrollWheel(cm, e);});
2380    on(d.scroller, "DOMMouseScroll", function(e){onScrollWheel(cm, e);});
2381
2382    // Prevent clicks in the scrollbars from killing focus
2383    function reFocus() { if (cm.state.focused) setTimeout(bind(focusInput, cm), 0); }
2384    on(d.scrollbarH, "mousedown", reFocus);
2385    on(d.scrollbarV, "mousedown", reFocus);
2386    // Prevent wrapper from ever scrolling
2387    on(d.wrapper, "scroll", function() { d.wrapper.scrollTop = d.wrapper.scrollLeft = 0; });
2388
2389    // When the window resizes, we need to refresh active editors.
2390    var resizeTimer;
2391    function onResize() {
2392      if (resizeTimer == null) resizeTimer = setTimeout(function() {
2393        resizeTimer = null;
2394        // Might be a text scaling operation, clear size caches.
2395        d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = knownScrollbarWidth = null;
2396        cm.setSize();
2397      }, 100);
2398    }
2399    on(window, "resize", onResize);
2400    // The above handler holds on to the editor and its data
2401    // structures. Here we poll to unregister it when the editor is no
2402    // longer in the document, so that it can be garbage-collected.
2403    function unregister() {
2404      if (contains(document.body, d.wrapper)) setTimeout(unregister, 5000);
2405      else off(window, "resize", onResize);
2406    }
2407    setTimeout(unregister, 5000);
2408
2409    on(d.input, "keyup", operation(cm, onKeyUp));
2410    on(d.input, "input", function() {
2411      if (ie && !ie_upto8 && cm.display.inputHasSelection) cm.display.inputHasSelection = null;
2412      fastPoll(cm);
2413    });
2414    on(d.input, "keydown", operation(cm, onKeyDown));
2415    on(d.input, "keypress", operation(cm, onKeyPress));
2416    on(d.input, "focus", bind(onFocus, cm));
2417    on(d.input, "blur", bind(onBlur, cm));
2418
2419    function drag_(e) {
2420      if (!signalDOMEvent(cm, e)) e_stop(e);
2421    }
2422    if (cm.options.dragDrop) {
2423      on(d.scroller, "dragstart", function(e){onDragStart(cm, e);});
2424      on(d.scroller, "dragenter", drag_);
2425      on(d.scroller, "dragover", drag_);
2426      on(d.scroller, "drop", operation(cm, onDrop));
2427    }
2428    on(d.scroller, "paste", function(e) {
2429      if (eventInWidget(d, e)) return;
2430      cm.state.pasteIncoming = true;
2431      focusInput(cm);
2432      fastPoll(cm);
2433    });
2434    on(d.input, "paste", function() {
2435      // Workaround for webkit bug https://bugs.webkit.org/show_bug.cgi?id=90206
2436      // Add a char to the end of textarea before paste occur so that
2437      // selection doesn't span to the end of textarea.
2438      if (webkit && !cm.state.fakedLastChar && !(new Date - cm.state.lastMiddleDown < 200)) {
2439        var start = d.input.selectionStart, end = d.input.selectionEnd;
2440        d.input.value += "$";
2441        d.input.selectionStart = start;
2442        d.input.selectionEnd = end;
2443        cm.state.fakedLastChar = true;
2444      }
2445      cm.state.pasteIncoming = true;
2446      fastPoll(cm);
2447    });
2448
2449    function prepareCopyCut(e) {
2450      if (cm.somethingSelected()) {
2451        if (d.inaccurateSelection) {
2452          d.prevInput = "";
2453          d.inaccurateSelection = false;
2454          d.input.value = cm.getSelection();
2455          selectInput(d.input);
2456        }
2457      } else {
2458        var text = "", ranges = [];
2459        for (var i = 0; i < cm.doc.sel.ranges.length; i++) {
2460          var line = cm.doc.sel.ranges[i].head.line;
2461          var lineRange = {anchor: Pos(line, 0), head: Pos(line + 1, 0)};
2462          ranges.push(lineRange);
2463          text += cm.getRange(lineRange.anchor, lineRange.head);
2464        }
2465        if (e.type == "cut") {
2466          cm.setSelections(ranges, null, sel_dontScroll);
2467        } else {
2468          d.prevInput = "";
2469          d.input.value = text;
2470          selectInput(d.input);
2471        }
2472      }
2473      if (e.type == "cut") cm.state.cutIncoming = true;
2474    }
2475    on(d.input, "cut", prepareCopyCut);
2476    on(d.input, "copy", prepareCopyCut);
2477
2478    // Needed to handle Tab key in KHTML
2479    if (khtml) on(d.sizer, "mouseup", function() {
2480      if (activeElt() == d.input) d.input.blur();
2481      focusInput(cm);
2482    });
2483  }
2484
2485  // MOUSE EVENTS
2486
2487  // Return true when the given mouse event happened in a widget
2488  function eventInWidget(display, e) {
2489    for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {
2490      if (!n || n.ignoreEvents || n.parentNode == display.sizer && n != display.mover) return true;
2491    }
2492  }
2493
2494  // Given a mouse event, find the corresponding position. If liberal
2495  // is false, it checks whether a gutter or scrollbar was clicked,
2496  // and returns null if it was. forRect is used by rectangular
2497  // selections, and tries to estimate a character position even for
2498  // coordinates beyond the right of the text.
2499  function posFromMouse(cm, e, liberal, forRect) {
2500    var display = cm.display;
2501    if (!liberal) {
2502      var target = e_target(e);
2503      if (target == display.scrollbarH || target == display.scrollbarV ||
2504          target == display.scrollbarFiller || target == display.gutterFiller) return null;
2505    }
2506    var x, y, space = display.lineSpace.getBoundingClientRect();
2507    // Fails unpredictably on IE[67] when mouse is dragged around quickly.
2508    try { x = e.clientX - space.left; y = e.clientY - space.top; }
2509    catch (e) { return null; }
2510    var coords = coordsChar(cm, x, y), line;
2511    if (forRect && coords.xRel == 1 && (line = getLine(cm.doc, coords.line).text).length == coords.ch) {
2512      var colDiff = countColumn(line, line.length, cm.options.tabSize) - line.length;
2513      coords = Pos(coords.line, Math.max(0, Math.round((x - paddingH(cm.display).left) / charWidth(cm.display)) - colDiff));
2514    }
2515    return coords;
2516  }
2517
2518  // A mouse down can be a single click, double click, triple click,
2519  // start of selection drag, start of text drag, new cursor
2520  // (ctrl-click), rectangle drag (alt-drag), or xwin
2521  // middle-click-paste. Or it might be a click on something we should
2522  // not interfere with, such as a scrollbar or widget.
2523  function onMouseDown(e) {
2524    if (signalDOMEvent(this, e)) return;
2525    var cm = this, display = cm.display;
2526    display.shift = e.shiftKey;
2527
2528    if (eventInWidget(display, e)) {
2529      if (!webkit) {
2530        // Briefly turn off draggability, to allow widgets to do
2531        // normal dragging things.
2532        display.scroller.draggable = false;
2533        setTimeout(function(){display.scroller.draggable = true;}, 100);
2534      }
2535      return;
2536    }
2537    if (clickInGutter(cm, e)) return;
2538    var start = posFromMouse(cm, e);
2539    window.focus();
2540
2541    switch (e_button(e)) {
2542    case 1:
2543      if (start)
2544        leftButtonDown(cm, e, start);
2545      else if (e_target(e) == display.scroller)
2546        e_preventDefault(e);
2547      break;
2548    case 2:
2549      if (webkit) cm.state.lastMiddleDown = +new Date;
2550      if (start) extendSelection(cm.doc, start);
2551      setTimeout(bind(focusInput, cm), 20);
2552      e_preventDefault(e);
2553      break;
2554    case 3:
2555      if (captureRightClick) onContextMenu(cm, e);
2556      break;
2557    }
2558  }
2559
2560  var lastClick, lastDoubleClick;
2561  function leftButtonDown(cm, e, start) {
2562    setTimeout(bind(ensureFocus, cm), 0);
2563
2564    var now = +new Date, type;
2565    if (lastDoubleClick && lastDoubleClick.time > now - 400 && cmp(lastDoubleClick.pos, start) == 0) {
2566      type = "triple";
2567    } else if (lastClick && lastClick.time > now - 400 && cmp(lastClick.pos, start) == 0) {
2568      type = "double";
2569      lastDoubleClick = {time: now, pos: start};
2570    } else {
2571      type = "single";
2572      lastClick = {time: now, pos: start};
2573    }
2574
2575    var sel = cm.doc.sel, addNew = mac ? e.metaKey : e.ctrlKey;
2576    if (cm.options.dragDrop && dragAndDrop && !addNew && !isReadOnly(cm) &&
2577        type == "single" && sel.contains(start) > -1 && sel.somethingSelected())
2578      leftButtonStartDrag(cm, e, start);
2579    else
2580      leftButtonSelect(cm, e, start, type, addNew);
2581  }
2582
2583  // Start a text drag. When it ends, see if any dragging actually
2584  // happen, and treat as a click if it didn't.
2585  function leftButtonStartDrag(cm, e, start) {
2586    var display = cm.display;
2587    var dragEnd = operation(cm, function(e2) {
2588      if (webkit) display.scroller.draggable = false;
2589      cm.state.draggingText = false;
2590      off(document, "mouseup", dragEnd);
2591      off(display.scroller, "drop", dragEnd);
2592      if (Math.abs(e.clientX - e2.clientX) + Math.abs(e.clientY - e2.clientY) < 10) {
2593        e_preventDefault(e2);
2594        extendSelection(cm.doc, start);
2595        focusInput(cm);
2596        // Work around unexplainable focus problem in IE9 (#2127)
2597        if (ie_upto10 && !ie_upto8)
2598          setTimeout(function() {document.body.focus(); focusInput(cm);}, 20);
2599      }
2600    });
2601    // Let the drag handler handle this.
2602    if (webkit) display.scroller.draggable = true;
2603    cm.state.draggingText = dragEnd;
2604    // IE's approach to draggable
2605    if (display.scroller.dragDrop) display.scroller.dragDrop();
2606    on(document, "mouseup", dragEnd);
2607    on(display.scroller, "drop", dragEnd);
2608  }
2609
2610  // Normal selection, as opposed to text dragging.
2611  function leftButtonSelect(cm, e, start, type, addNew) {
2612    var display = cm.display, doc = cm.doc;
2613    e_preventDefault(e);
2614
2615    var ourRange, ourIndex, startSel = doc.sel;
2616    if (addNew && !e.shiftKey) {
2617      ourIndex = doc.sel.contains(start);
2618      if (ourIndex > -1)
2619        ourRange = doc.sel.ranges[ourIndex];
2620      else
2621        ourRange = new Range(start, start);
2622    } else {
2623      ourRange = doc.sel.primary();
2624    }
2625
2626    if (e.altKey) {
2627      type = "rect";
2628      if (!addNew) ourRange = new Range(start, start);
2629      start = posFromMouse(cm, e, true, true);
2630      ourIndex = -1;
2631    } else if (type == "double") {
2632      var word = findWordAt(doc, start);
2633      if (cm.display.shift || doc.extend)
2634        ourRange = extendRange(doc, ourRange, word.anchor, word.head);
2635      else
2636        ourRange = word;
2637    } else if (type == "triple") {
2638      var line = new Range(Pos(start.line, 0), clipPos(doc, Pos(start.line + 1, 0)));
2639      if (cm.display.shift || doc.extend)
2640        ourRange = extendRange(doc, ourRange, line.anchor, line.head);
2641      else
2642        ourRange = line;
2643    } else {
2644      ourRange = extendRange(doc, ourRange, start);
2645    }
2646
2647    if (!addNew) {
2648      ourIndex = 0;
2649      setSelection(doc, new Selection([ourRange], 0), sel_mouse);
2650      startSel = doc.sel;
2651    } else if (ourIndex > -1) {
2652      replaceOneSelection(doc, ourIndex, ourRange, sel_mouse);
2653    } else {
2654      ourIndex = doc.sel.ranges.length;
2655      setSelection(doc, normalizeSelection(doc.sel.ranges.concat([ourRange]), ourIndex),
2656                   {scroll: false, origin: "*mouse"});
2657    }
2658
2659    var lastPos = start;
2660    function extendTo(pos) {
2661      if (cmp(lastPos, pos) == 0) return;
2662      lastPos = pos;
2663
2664      if (type == "rect") {
2665        var ranges = [], tabSize = cm.options.tabSize;
2666        var startCol = countColumn(getLine(doc, start.line).text, start.ch, tabSize);
2667        var posCol = countColumn(getLine(doc, pos.line).text, pos.ch, tabSize);
2668        var left = Math.min(startCol, posCol), right = Math.max(startCol, posCol);
2669        for (var line = Math.min(start.line, pos.line), end = Math.min(cm.lastLine(), Math.max(start.line, pos.line));
2670             line <= end; line++) {
2671          var text = getLine(doc, line).text, leftPos = findColumn(text, left, tabSize);
2672          if (left == right)
2673            ranges.push(new Range(Pos(line, leftPos), Pos(line, leftPos)));
2674          else if (text.length > leftPos)
2675            ranges.push(new Range(Pos(line, leftPos), Pos(line, findColumn(text, right, tabSize))));
2676        }
2677        if (!ranges.length) ranges.push(new Range(start, start));
2678        setSelection(doc, normalizeSelection(startSel.ranges.slice(0, ourIndex).concat(ranges), ourIndex), sel_mouse);
2679      } else {
2680        var oldRange = ourRange;
2681        var anchor = oldRange.anchor, head = pos;
2682        if (type != "single") {
2683          if (type == "double")
2684            var range = findWordAt(doc, pos);
2685          else
2686            var range = new Range(Pos(pos.line, 0), clipPos(doc, Pos(pos.line + 1, 0)));
2687          if (cmp(range.anchor, anchor) > 0) {
2688            head = range.head;
2689            anchor = minPos(oldRange.from(), range.anchor);
2690          } else {
2691            head = range.anchor;
2692            anchor = maxPos(oldRange.to(), range.head);
2693          }
2694        }
2695        var ranges = startSel.ranges.slice(0);
2696        ranges[ourIndex] = new Range(clipPos(doc, anchor), head);
2697        setSelection(doc, normalizeSelection(ranges, ourIndex), sel_mouse);
2698      }
2699    }
2700
2701    var editorSize = display.wrapper.getBoundingClientRect();
2702    // Used to ensure timeout re-tries don't fire when another extend
2703    // happened in the meantime (clearTimeout isn't reliable -- at
2704    // least on Chrome, the timeouts still happen even when cleared,
2705    // if the clear happens after their scheduled firing time).
2706    var counter = 0;
2707
2708    function extend(e) {
2709      var curCount = ++counter;
2710      var cur = posFromMouse(cm, e, true, type == "rect");
2711      if (!cur) return;
2712      if (cmp(cur, lastPos) != 0) {
2713        ensureFocus(cm);
2714        extendTo(cur);
2715        var visible = visibleLines(display, doc);
2716        if (cur.line >= visible.to || cur.line < visible.from)
2717          setTimeout(operation(cm, function(){if (counter == curCount) extend(e);}), 150);
2718      } else {
2719        var outside = e.clientY < editorSize.top ? -20 : e.clientY > editorSize.bottom ? 20 : 0;
2720        if (outside) setTimeout(operation(cm, function() {
2721          if (counter != curCount) return;
2722          display.scroller.scrollTop += outside;
2723          extend(e);
2724        }), 50);
2725      }
2726    }
2727
2728    function done(e) {
2729      counter = Infinity;
2730      e_preventDefault(e);
2731      focusInput(cm);
2732      off(document, "mousemove", move);
2733      off(document, "mouseup", up);
2734      doc.history.lastSelOrigin = null;
2735    }
2736
2737    var move = operation(cm, function(e) {
2738      if ((ie && !ie_upto9) ?  !e.buttons : !e_button(e)) done(e);
2739      else extend(e);
2740    });
2741    var up = operation(cm, done);
2742    on(document, "mousemove", move);
2743    on(document, "mouseup", up);
2744  }
2745
2746  // Determines whether an event happened in the gutter, and fires the
2747  // handlers for the corresponding event.
2748  function gutterEvent(cm, e, type, prevent, signalfn) {
2749    try { var mX = e.clientX, mY = e.clientY; }
2750    catch(e) { return false; }
2751    if (mX >= Math.floor(cm.display.gutters.getBoundingClientRect().right)) return false;
2752    if (prevent) e_preventDefault(e);
2753
2754    var display = cm.display;
2755    var lineBox = display.lineDiv.getBoundingClientRect();
2756
2757    if (mY > lineBox.bottom || !hasHandler(cm, type)) return e_defaultPrevented(e);
2758    mY -= lineBox.top - display.viewOffset;
2759
2760    for (var i = 0; i < cm.options.gutters.length; ++i) {
2761      var g = display.gutters.childNodes[i];
2762      if (g && g.getBoundingClientRect().right >= mX) {
2763        var line = lineAtHeight(cm.doc, mY);
2764        var gutter = cm.options.gutters[i];
2765        signalfn(cm, type, cm, line, gutter, e);
2766        return e_defaultPrevented(e);
2767      }
2768    }
2769  }
2770
2771  function clickInGutter(cm, e) {
2772    return gutterEvent(cm, e, "gutterClick", true, signalLater);
2773  }
2774
2775  // Kludge to work around strange IE behavior where it'll sometimes
2776  // re-fire a series of drag-related events right after the drop (#1551)
2777  var lastDrop = 0;
2778
2779  function onDrop(e) {
2780    var cm = this;
2781    if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e))
2782      return;
2783    e_preventDefault(e);
2784    if (ie) lastDrop = +new Date;
2785    var pos = posFromMouse(cm, e, true), files = e.dataTransfer.files;
2786    if (!pos || isReadOnly(cm)) return;
2787    // Might be a file drop, in which case we simply extract the text
2788    // and insert it.
2789    if (files && files.length && window.FileReader && window.File) {
2790      var n = files.length, text = Array(n), read = 0;
2791      var loadFile = function(file, i) {
2792        var reader = new FileReader;
2793        reader.onload = operation(cm, function() {
2794          text[i] = reader.result;
2795          if (++read == n) {
2796            pos = clipPos(cm.doc, pos);
2797            var change = {from: pos, to: pos, text: splitLines(text.join("\n")), origin: "paste"};
2798            makeChange(cm.doc, change);
2799            setSelectionReplaceHistory(cm.doc, simpleSelection(pos, changeEnd(change)));
2800          }
2801        });
2802        reader.readAsText(file);
2803      };
2804      for (var i = 0; i < n; ++i) loadFile(files[i], i);
2805    } else { // Normal drop
2806      // Don't do a replace if the drop happened inside of the selected text.
2807      if (cm.state.draggingText && cm.doc.sel.contains(pos) > -1) {
2808        cm.state.draggingText(e);
2809        // Ensure the editor is re-focused
2810        setTimeout(bind(focusInput, cm), 20);
2811        return;
2812      }
2813      try {
2814        var text = e.dataTransfer.getData("Text");
2815        if (text) {
2816          var selected = cm.state.draggingText && cm.listSelections();
2817          setSelectionNoUndo(cm.doc, simpleSelection(pos, pos));
2818          if (selected) for (var i = 0; i < selected.length; ++i)
2819            replaceRange(cm.doc, "", selected[i].anchor, selected[i].head, "drag");
2820          cm.replaceSelection(text, "around", "paste");
2821          focusInput(cm);
2822        }
2823      }
2824      catch(e){}
2825    }
2826  }
2827
2828  function onDragStart(cm, e) {
2829    if (ie && (!cm.state.draggingText || +new Date - lastDrop < 100)) { e_stop(e); return; }
2830    if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) return;
2831
2832    e.dataTransfer.setData("Text", cm.getSelection());
2833
2834    // Use dummy image instead of default browsers image.
2835    // Recent Safari (~6.0.2) have a tendency to segfault when this happens, so we don't do it there.
2836    if (e.dataTransfer.setDragImage && !safari) {
2837      var img = elt("img", null, null, "position: fixed; left: 0; top: 0;");
2838      img.src = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";
2839      if (presto) {
2840        img.width = img.height = 1;
2841        cm.display.wrapper.appendChild(img);
2842        // Force a relayout, or Opera won't use our image for some obscure reason
2843        img._top = img.offsetTop;
2844      }
2845      e.dataTransfer.setDragImage(img, 0, 0);
2846      if (presto) img.parentNode.removeChild(img);
2847    }
2848  }
2849
2850  // SCROLL EVENTS
2851
2852  // Sync the scrollable area and scrollbars, ensure the viewport
2853  // covers the visible area.
2854  function setScrollTop(cm, val) {
2855    if (Math.abs(cm.doc.scrollTop - val) < 2) return;
2856    cm.doc.scrollTop = val;
2857    if (!gecko) updateDisplay(cm, {top: val});
2858    if (cm.display.scroller.scrollTop != val) cm.display.scroller.scrollTop = val;
2859    if (cm.display.scrollbarV.scrollTop != val) cm.display.scrollbarV.scrollTop = val;
2860    if (gecko) updateDisplay(cm);
2861    startWorker(cm, 100);
2862  }
2863  // Sync scroller and scrollbar, ensure the gutter elements are
2864  // aligned.
2865  function setScrollLeft(cm, val, isScroller) {
2866    if (isScroller ? val == cm.doc.scrollLeft : Math.abs(cm.doc.scrollLeft - val) < 2) return;
2867    val = Math.min(val, cm.display.scroller.scrollWidth - cm.display.scroller.clientWidth);
2868    cm.doc.scrollLeft = val;
2869    alignHorizontally(cm);
2870    if (cm.display.scroller.scrollLeft != val) cm.display.scroller.scrollLeft = val;
2871    if (cm.display.scrollbarH.scrollLeft != val) cm.display.scrollbarH.scrollLeft = val;
2872  }
2873
2874  // Since the delta values reported on mouse wheel events are
2875  // unstandardized between browsers and even browser versions, and
2876  // generally horribly unpredictable, this code starts by measuring
2877  // the scroll effect that the first few mouse wheel events have,
2878  // and, from that, detects the way it can convert deltas to pixel
2879  // offsets afterwards.
2880  //
2881  // The reason we want to know the amount a wheel event will scroll
2882  // is that it gives us a chance to update the display before the
2883  // actual scrolling happens, reducing flickering.
2884
2885  var wheelSamples = 0, wheelPixelsPerUnit = null;
2886  // Fill in a browser-detected starting value on browsers where we
2887  // know one. These don't have to be accurate -- the result of them
2888  // being wrong would just be a slight flicker on the first wheel
2889  // scroll (if it is large enough).
2890  if (ie) wheelPixelsPerUnit = -.53;
2891  else if (gecko) wheelPixelsPerUnit = 15;
2892  else if (chrome) wheelPixelsPerUnit = -.7;
2893  else if (safari) wheelPixelsPerUnit = -1/3;
2894
2895  function onScrollWheel(cm, e) {
2896    var dx = e.wheelDeltaX, dy = e.wheelDeltaY;
2897    if (dx == null && e.detail && e.axis == e.HORIZONTAL_AXIS) dx = e.detail;
2898    if (dy == null && e.detail && e.axis == e.VERTICAL_AXIS) dy = e.detail;
2899    else if (dy == null) dy = e.wheelDelta;
2900
2901    var display = cm.display, scroll = display.scroller;
2902    // Quit if there's nothing to scroll here
2903    if (!(dx && scroll.scrollWidth > scroll.clientWidth ||
2904          dy && scroll.scrollHeight > scroll.clientHeight)) return;
2905
2906    // Webkit browsers on OS X abort momentum scrolls when the target
2907    // of the scroll event is removed from the scrollable element.
2908    // This hack (see related code in patchDisplay) makes sure the
2909    // element is kept around.
2910    if (dy && mac && webkit) {
2911      outer: for (var cur = e.target, view = display.view; cur != scroll; cur = cur.parentNode) {
2912        for (var i = 0; i < view.length; i++) {
2913          if (view[i].node == cur) {
2914            cm.display.currentWheelTarget = cur;
2915            break outer;
2916          }
2917        }
2918      }
2919    }
2920
2921    // On some browsers, horizontal scrolling will cause redraws to
2922    // happen before the gutter has been realigned, causing it to
2923    // wriggle around in a most unseemly way. When we have an
2924    // estimated pixels/delta value, we just handle horizontal
2925    // scrolling entirely here. It'll be slightly off from native, but
2926    // better than glitching out.
2927    if (dx && !gecko && !presto && wheelPixelsPerUnit != null) {
2928      if (dy)
2929        setScrollTop(cm, Math.max(0, Math.min(scroll.scrollTop + dy * wheelPixelsPerUnit, scroll.scrollHeight - scroll.clientHeight)));
2930      setScrollLeft(cm, Math.max(0, Math.min(scroll.scrollLeft + dx * wheelPixelsPerUnit, scroll.scrollWidth - scroll.clientWidth)));
2931      e_preventDefault(e);
2932      display.wheelStartX = null; // Abort measurement, if in progress
2933      return;
2934    }
2935
2936    // 'Project' the visible viewport to cover the area that is being
2937    // scrolled into view (if we know enough to estimate it).
2938    if (dy && wheelPixelsPerUnit != null) {
2939      var pixels = dy * wheelPixelsPerUnit;
2940      var top = cm.doc.scrollTop, bot = top + display.wrapper.clientHeight;
2941      if (pixels < 0) top = Math.max(0, top + pixels - 50);
2942      else bot = Math.min(cm.doc.height, bot + pixels + 50);
2943      updateDisplay(cm, {top: top, bottom: bot});
2944    }
2945
2946    if (wheelSamples < 20) {
2947      if (display.wheelStartX == null) {
2948        display.wheelStartX = scroll.scrollLeft; display.wheelStartY = scroll.scrollTop;
2949        display.wheelDX = dx; display.wheelDY = dy;
2950        setTimeout(function() {
2951          if (display.wheelStartX == null) return;
2952          var movedX = scroll.scrollLeft - display.wheelStartX;
2953          var movedY = scroll.scrollTop - display.wheelStartY;
2954          var sample = (movedY && display.wheelDY && movedY / display.wheelDY) ||
2955            (movedX && display.wheelDX && movedX / display.wheelDX);
2956          display.wheelStartX = display.wheelStartY = null;
2957          if (!sample) return;
2958          wheelPixelsPerUnit = (wheelPixelsPerUnit * wheelSamples + sample) / (wheelSamples + 1);
2959          ++wheelSamples;
2960        }, 200);
2961      } else {
2962        display.wheelDX += dx; display.wheelDY += dy;
2963      }
2964    }
2965  }
2966
2967  // KEY EVENTS
2968
2969  // Run a handler that was bound to a key.
2970  function doHandleBinding(cm, bound, dropShift) {
2971    if (typeof bound == "string") {
2972      bound = commands[bound];
2973      if (!bound) return false;
2974    }
2975    // Ensure previous input has been read, so that the handler sees a
2976    // consistent view of the document
2977    if (cm.display.pollingFast && readInput(cm)) cm.display.pollingFast = false;
2978    var prevShift = cm.display.shift, done = false;
2979    try {
2980      if (isReadOnly(cm)) cm.state.suppressEdits = true;
2981      if (dropShift) cm.display.shift = false;
2982      done = bound(cm) != Pass;
2983    } finally {
2984      cm.display.shift = prevShift;
2985      cm.state.suppressEdits = false;
2986    }
2987    return done;
2988  }
2989
2990  // Collect the currently active keymaps.
2991  function allKeyMaps(cm) {
2992    var maps = cm.state.keyMaps.slice(0);
2993    if (cm.options.extraKeys) maps.push(cm.options.extraKeys);
2994    maps.push(cm.options.keyMap);
2995    return maps;
2996  }
2997
2998  var maybeTransition;
2999  // Handle a key from the keydown event.
3000  function handleKeyBinding(cm, e) {
3001    // Handle automatic keymap transitions
3002    var startMap = getKeyMap(cm.options.keyMap), next = startMap.auto;
3003    clearTimeout(maybeTransition);
3004    if (next && !isModifierKey(e)) maybeTransition = setTimeout(function() {
3005      if (getKeyMap(cm.options.keyMap) == startMap) {
3006        cm.options.keyMap = (next.call ? next.call(null, cm) : next);
3007        keyMapChanged(cm);
3008      }
3009    }, 50);
3010
3011    var name = keyName(e, true), handled = false;
3012    if (!name) return false;
3013    var keymaps = allKeyMaps(cm);
3014
3015    if (e.shiftKey) {
3016      // First try to resolve full name (including 'Shift-'). Failing
3017      // that, see if there is a cursor-motion command (starting with
3018      // 'go') bound to the keyname without 'Shift-'.
3019      handled = lookupKey("Shift-" + name, keymaps, function(b) {return doHandleBinding(cm, b, true);})
3020             || lookupKey(name, keymaps, function(b) {
3021                  if (typeof b == "string" ? /^go[A-Z]/.test(b) : b.motion)
3022                    return doHandleBinding(cm, b);
3023                });
3024    } else {
3025      handled = lookupKey(name, keymaps, function(b) { return doHandleBinding(cm, b); });
3026    }
3027
3028    if (handled) {
3029      e_preventDefault(e);
3030      restartBlink(cm);
3031      signalLater(cm, "keyHandled", cm, name, e);
3032    }
3033    return handled;
3034  }
3035
3036  // Handle a key from the keypress event
3037  function handleCharBinding(cm, e, ch) {
3038    var handled = lookupKey("'" + ch + "'", allKeyMaps(cm),
3039                            function(b) { return doHandleBinding(cm, b, true); });
3040    if (handled) {
3041      e_preventDefault(e);
3042      restartBlink(cm);
3043      signalLater(cm, "keyHandled", cm, "'" + ch + "'", e);
3044    }
3045    return handled;
3046  }
3047
3048  var lastStoppedKey = null;
3049  function onKeyDown(e) {
3050    var cm = this;
3051    ensureFocus(cm);
3052    if (signalDOMEvent(cm, e)) return;
3053    // IE does strange things with escape.
3054    if (ie_upto10 && e.keyCode == 27) e.returnValue = false;
3055    var code = e.keyCode;
3056    cm.display.shift = code == 16 || e.shiftKey;
3057    var handled = handleKeyBinding(cm, e);
3058    if (presto) {
3059      lastStoppedKey = handled ? code : null;
3060      // Opera has no cut event... we try to at least catch the key combo
3061      if (!handled && code == 88 && !hasCopyEvent && (mac ? e.metaKey : e.ctrlKey))
3062        cm.replaceSelection("", null, "cut");
3063    }
3064
3065    // Turn mouse into crosshair when Alt is held on Mac.
3066    if (code == 18 && !/\bCodeMirror-crosshair\b/.test(cm.display.lineDiv.className))
3067      showCrossHair(cm);
3068  }
3069
3070  function showCrossHair(cm) {
3071    var lineDiv = cm.display.lineDiv;
3072    addClass(lineDiv, "CodeMirror-crosshair");
3073
3074    function up(e) {
3075      if (e.keyCode == 18 || !e.altKey) {
3076        rmClass(lineDiv, "CodeMirror-crosshair");
3077        off(document, "keyup", up);
3078        off(document, "mouseover", up);
3079      }
3080    }
3081    on(document, "keyup", up);
3082    on(document, "mouseover", up);
3083  }
3084
3085  function onKeyUp(e) {
3086    if (signalDOMEvent(this, e)) return;
3087    if (e.keyCode == 16) this.doc.sel.shift = false;
3088  }
3089
3090  function onKeyPress(e) {
3091    var cm = this;
3092    if (signalDOMEvent(cm, e)) return;
3093    var keyCode = e.keyCode, charCode = e.charCode;
3094    if (presto && keyCode == lastStoppedKey) {lastStoppedKey = null; e_preventDefault(e); return;}
3095    if (((presto && (!e.which || e.which < 10)) || khtml) && handleKeyBinding(cm, e)) return;
3096    var ch = String.fromCharCode(charCode == null ? keyCode : charCode);
3097    if (handleCharBinding(cm, e, ch)) return;
3098    if (ie && !ie_upto8) cm.display.inputHasSelection = null;
3099    fastPoll(cm);
3100  }
3101
3102  // FOCUS/BLUR EVENTS
3103
3104  function onFocus(cm) {
3105    if (cm.options.readOnly == "nocursor") return;
3106    if (!cm.state.focused) {
3107      signal(cm, "focus", cm);
3108      cm.state.focused = true;
3109      addClass(cm.display.wrapper, "CodeMirror-focused");
3110      // The prevInput test prevents this from firing when a context
3111      // menu is closed (since the resetInput would kill the
3112      // select-all detection hack)
3113      if (!cm.curOp && cm.display.selForContextMenu == cm.doc.sel) {
3114        resetInput(cm);
3115        if (webkit) setTimeout(bind(resetInput, cm, true), 0); // Issue #1730
3116      }
3117    }
3118    slowPoll(cm);
3119    restartBlink(cm);
3120  }
3121  function onBlur(cm) {
3122    if (cm.state.focused) {
3123      signal(cm, "blur", cm);
3124      cm.state.focused = false;
3125      rmClass(cm.display.wrapper, "CodeMirror-focused");
3126    }
3127    clearInterval(cm.display.blinker);
3128    setTimeout(function() {if (!cm.state.focused) cm.display.shift = false;}, 150);
3129  }
3130
3131  // CONTEXT MENU HANDLING
3132
3133  var detectingSelectAll;
3134  // To make the context menu work, we need to briefly unhide the
3135  // textarea (making it as unobtrusive as possible) to let the
3136  // right-click take effect on it.
3137  function onContextMenu(cm, e) {
3138    if (signalDOMEvent(cm, e, "contextmenu")) return;
3139    var display = cm.display;
3140    if (eventInWidget(display, e) || contextMenuInGutter(cm, e)) return;
3141
3142    var pos = posFromMouse(cm, e), scrollPos = display.scroller.scrollTop;
3143    if (!pos || presto) return; // Opera is difficult.
3144
3145    // Reset the current text selection only if the click is done outside of the selection
3146    // and 'resetSelectionOnContextMenu' option is true.
3147    var reset = cm.options.resetSelectionOnContextMenu;
3148    if (reset && cm.doc.sel.contains(pos) == -1)
3149      operation(cm, setSelection)(cm.doc, simpleSelection(pos), sel_dontScroll);
3150
3151    var oldCSS = display.input.style.cssText;
3152    display.inputDiv.style.position = "absolute";
3153    display.input.style.cssText = "position: fixed; width: 30px; height: 30px; top: " + (e.clientY - 5) +
3154      "px; left: " + (e.clientX - 5) + "px; z-index: 1000; background: " +
3155      (ie ? "rgba(255, 255, 255, .05)" : "transparent") +
3156      "; outline: none; border-width: 0; outline: none; overflow: hidden; opacity: .05; filter: alpha(opacity=5);";
3157    focusInput(cm);
3158    resetInput(cm);
3159    // Adds "Select all" to context menu in FF
3160    if (!cm.somethingSelected()) display.input.value = display.prevInput = " ";
3161    display.selForContextMenu = cm.doc.sel;
3162
3163    // Select-all will be greyed out if there's nothing to select, so
3164    // this adds a zero-width space so that we can later check whether
3165    // it got selected.
3166    function prepareSelectAllHack() {
3167      if (display.input.selectionStart != null) {
3168        var selected = cm.somethingSelected();
3169        var extval = display.input.value = "\u200b" + (selected ? display.input.value : "");
3170        display.prevInput = selected ? "" : "\u200b";
3171        display.input.selectionStart = 1; display.input.selectionEnd = extval.length;
3172      }
3173    }
3174    function rehide() {
3175      display.inputDiv.style.position = "relative";
3176      display.input.style.cssText = oldCSS;
3177      if (ie_upto8) display.scrollbarV.scrollTop = display.scroller.scrollTop = scrollPos;
3178      slowPoll(cm);
3179
3180      // Try to detect the user choosing select-all
3181      if (display.input.selectionStart != null) {
3182        if (!ie || ie_upto8) prepareSelectAllHack();
3183        clearTimeout(detectingSelectAll);
3184        var i = 0, poll = function() {
3185          if (display.selForContextMenu == cm.doc.sel && display.input.selectionStart == 0)
3186            operation(cm, commands.selectAll)(cm);
3187          else if (i++ < 10) detectingSelectAll = setTimeout(poll, 500);
3188          else resetInput(cm);
3189        };
3190        detectingSelectAll = setTimeout(poll, 200);
3191      }
3192    }
3193
3194    if (ie && !ie_upto8) prepareSelectAllHack();
3195    if (captureRightClick) {
3196      e_stop(e);
3197      var mouseup = function() {
3198        off(window, "mouseup", mouseup);
3199        setTimeout(rehide, 20);
3200      };
3201      on(window, "mouseup", mouseup);
3202    } else {
3203      setTimeout(rehide, 50);
3204    }
3205  }
3206
3207  function contextMenuInGutter(cm, e) {
3208    if (!hasHandler(cm, "gutterContextMenu")) return false;
3209    return gutterEvent(cm, e, "gutterContextMenu", false, signal);
3210  }
3211
3212  // UPDATING
3213
3214  // Compute the position of the end of a change (its 'to' property
3215  // refers to the pre-change end).
3216  var changeEnd = CodeMirror.changeEnd = function(change) {
3217    if (!change.text) return change.to;
3218    return Pos(change.from.line + change.text.length - 1,
3219               lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0));
3220  };
3221
3222  // Adjust a position to refer to the post-change position of the
3223  // same text, or the end of the change if the change covers it.
3224  function adjustForChange(pos, change) {
3225    if (cmp(pos, change.from) < 0) return pos;
3226    if (cmp(pos, change.to) <= 0) return changeEnd(change);
3227
3228    var line = pos.line + change.text.length - (change.to.line - change.from.line) - 1, ch = pos.ch;
3229    if (pos.line == change.to.line) ch += changeEnd(change).ch - change.to.ch;
3230    return Pos(line, ch);
3231  }
3232
3233  function computeSelAfterChange(doc, change) {
3234    var out = [];
3235    for (var i = 0; i < doc.sel.ranges.length; i++) {
3236      var range = doc.sel.ranges[i];
3237      out.push(new Range(adjustForChange(range.anchor, change),
3238                         adjustForChange(range.head, change)));
3239    }
3240    return normalizeSelection(out, doc.sel.primIndex);
3241  }
3242
3243  function offsetPos(pos, old, nw) {
3244    if (pos.line == old.line)
3245      return Pos(nw.line, pos.ch - old.ch + nw.ch);
3246    else
3247      return Pos(nw.line + (pos.line - old.line), pos.ch);
3248  }
3249
3250  // Used by replaceSelections to allow moving the selection to the
3251  // start or around the replaced test. Hint may be "start" or "around".
3252  function computeReplacedSel(doc, changes, hint) {
3253    var out = [];
3254    var oldPrev = Pos(doc.first, 0), newPrev = oldPrev;
3255    for (var i = 0; i < changes.length; i++) {
3256      var change = changes[i];
3257      var from = offsetPos(change.from, oldPrev, newPrev);
3258      var to = offsetPos(changeEnd(change), oldPrev, newPrev);
3259      oldPrev = change.to;
3260      newPrev = to;
3261      if (hint == "around") {
3262        var range = doc.sel.ranges[i], inv = cmp(range.head, range.anchor) < 0;
3263        out[i] = new Range(inv ? to : from, inv ? from : to);
3264      } else {
3265        out[i] = new Range(from, from);
3266      }
3267    }
3268    return new Selection(out, doc.sel.primIndex);
3269  }
3270
3271  // Allow "beforeChange" event handlers to influence a change
3272  function filterChange(doc, change, update) {
3273    var obj = {
3274      canceled: false,
3275      from: change.from,
3276      to: change.to,
3277      text: change.text,
3278      origin: change.origin,
3279      cancel: function() { this.canceled = true; }
3280    };
3281    if (update) obj.update = function(from, to, text, origin) {
3282      if (from) this.from = clipPos(doc, from);
3283      if (to) this.to = clipPos(doc, to);
3284      if (text) this.text = text;
3285      if (origin !== undefined) this.origin = origin;
3286    };
3287    signal(doc, "beforeChange", doc, obj);
3288    if (doc.cm) signal(doc.cm, "beforeChange", doc.cm, obj);
3289
3290    if (obj.canceled) return null;
3291    return {from: obj.from, to: obj.to, text: obj.text, origin: obj.origin};
3292  }
3293
3294  // Apply a change to a document, and add it to the document's
3295  // history, and propagating it to all linked documents.
3296  function makeChange(doc, change, ignoreReadOnly) {
3297    if (doc.cm) {
3298      if (!doc.cm.curOp) return operation(doc.cm, makeChange)(doc, change, ignoreReadOnly);
3299      if (doc.cm.state.suppressEdits) return;
3300    }
3301
3302    if (hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange")) {
3303      change = filterChange(doc, change, true);
3304      if (!change) return;
3305    }
3306
3307    // Possibly split or suppress the update based on the presence
3308    // of read-only spans in its range.
3309    var split = sawReadOnlySpans && !ignoreReadOnly && removeReadOnlyRanges(doc, change.from, change.to);
3310    if (split) {
3311      for (var i = split.length - 1; i >= 0; --i)
3312        makeChangeInner(doc, {from: split[i].from, to: split[i].to, text: i ? [""] : change.text});
3313    } else {
3314      makeChangeInner(doc, change);
3315    }
3316  }
3317
3318  function makeChangeInner(doc, change) {
3319    if (change.text.length == 1 && change.text[0] == "" && cmp(change.from, change.to) == 0) return;
3320    var selAfter = computeSelAfterChange(doc, change);
3321    addChangeToHistory(doc, change, selAfter, doc.cm ? doc.cm.curOp.id : NaN);
3322
3323    makeChangeSingleDoc(doc, change, selAfter, stretchSpansOverChange(doc, change));
3324    var rebased = [];
3325
3326    linkedDocs(doc, function(doc, sharedHist) {
3327      if (!sharedHist && indexOf(rebased, doc.history) == -1) {
3328        rebaseHist(doc.history, change);
3329        rebased.push(doc.history);
3330      }
3331      makeChangeSingleDoc(doc, change, null, stretchSpansOverChange(doc, change));
3332    });
3333  }
3334
3335  // Revert a change stored in a document's history.
3336  function makeChangeFromHistory(doc, type, allowSelectionOnly) {
3337    if (doc.cm && doc.cm.state.suppressEdits) return;
3338
3339    var hist = doc.history, event, selAfter = doc.sel;
3340    var source = type == "undo" ? hist.done : hist.undone, dest = type == "undo" ? hist.undone : hist.done;
3341
3342    // Verify that there is a useable event (so that ctrl-z won't
3343    // needlessly clear selection events)
3344    for (var i = 0; i < source.length; i++) {
3345      event = source[i];
3346      if (allowSelectionOnly ? event.ranges && !event.equals(doc.sel) : !event.ranges)
3347        break;
3348    }
3349    if (i == source.length) return;
3350    hist.lastOrigin = hist.lastSelOrigin = null;
3351
3352    for (;;) {
3353      event = source.pop();
3354      if (event.ranges) {
3355        pushSelectionToHistory(event, dest);
3356        if (allowSelectionOnly && !event.equals(doc.sel)) {
3357          setSelection(doc, event, {clearRedo: false});
3358          return;
3359        }
3360        selAfter = event;
3361      }
3362      else break;
3363    }
3364
3365    // Build up a reverse change object to add to the opposite history
3366    // stack (redo when undoing, and vice versa).
3367    var antiChanges = [];
3368    pushSelectionToHistory(selAfter, dest);
3369    dest.push({changes: antiChanges, generation: hist.generation});
3370    hist.generation = event.generation || ++hist.maxGeneration;
3371
3372    var filter = hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange");
3373
3374    for (var i = event.changes.length - 1; i >= 0; --i) {
3375      var change = event.changes[i];
3376      change.origin = type;
3377      if (filter && !filterChange(doc, change, false)) {
3378        source.length = 0;
3379        return;
3380      }
3381
3382      antiChanges.push(historyChangeFromChange(doc, change));
3383
3384      var after = i ? computeSelAfterChange(doc, change, null) : lst(source);
3385      makeChangeSingleDoc(doc, change, after, mergeOldSpans(doc, change));
3386      if (doc.cm) ensureCursorVisible(doc.cm);
3387      var rebased = [];
3388
3389      // Propagate to the linked documents
3390      linkedDocs(doc, function(doc, sharedHist) {
3391        if (!sharedHist && indexOf(rebased, doc.history) == -1) {
3392          rebaseHist(doc.history, change);
3393          rebased.push(doc.history);
3394        }
3395        makeChangeSingleDoc(doc, change, null, mergeOldSpans(doc, change));
3396      });
3397    }
3398  }
3399
3400  // Sub-views need their line numbers shifted when text is added
3401  // above or below them in the parent document.
3402  function shiftDoc(doc, distance) {
3403    doc.first += distance;
3404    doc.sel = new Selection(map(doc.sel.ranges, function(range) {
3405      return new Range(Pos(range.anchor.line + distance, range.anchor.ch),
3406                       Pos(range.head.line + distance, range.head.ch));
3407    }), doc.sel.primIndex);
3408    if (doc.cm) regChange(doc.cm, doc.first, doc.first - distance, distance);
3409  }
3410
3411  // More lower-level change function, handling only a single document
3412  // (not linked ones).
3413  function makeChangeSingleDoc(doc, change, selAfter, spans) {
3414    if (doc.cm && !doc.cm.curOp)
3415      return operation(doc.cm, makeChangeSingleDoc)(doc, change, selAfter, spans);
3416
3417    if (change.to.line < doc.first) {
3418      shiftDoc(doc, change.text.length - 1 - (change.to.line - change.from.line));
3419      return;
3420    }
3421    if (change.from.line > doc.lastLine()) return;
3422
3423    // Clip the change to the size of this doc
3424    if (change.from.line < doc.first) {
3425      var shift = change.text.length - 1 - (doc.first - change.from.line);
3426      shiftDoc(doc, shift);
3427      change = {from: Pos(doc.first, 0), to: Pos(change.to.line + shift, change.to.ch),
3428                text: [lst(change.text)], origin: change.origin};
3429    }
3430    var last = doc.lastLine();
3431    if (change.to.line > last) {
3432      change = {from: change.from, to: Pos(last, getLine(doc, last).text.length),
3433                text: [change.text[0]], origin: change.origin};
3434    }
3435
3436    change.removed = getBetween(doc, change.from, change.to);
3437
3438    if (!selAfter) selAfter = computeSelAfterChange(doc, change, null);
3439    if (doc.cm) makeChangeSingleDocInEditor(doc.cm, change, spans);
3440    else updateDoc(doc, change, spans);
3441    setSelectionNoUndo(doc, selAfter, sel_dontScroll);
3442  }
3443
3444  // Handle the interaction of a change to a document with the editor
3445  // that this document is part of.
3446  function makeChangeSingleDocInEditor(cm, change, spans) {
3447    var doc = cm.doc, display = cm.display, from = change.from, to = change.to;
3448
3449    var recomputeMaxLength = false, checkWidthStart = from.line;
3450    if (!cm.options.lineWrapping) {
3451      checkWidthStart = lineNo(visualLine(getLine(doc, from.line)));
3452      doc.iter(checkWidthStart, to.line + 1, function(line) {
3453        if (line == display.maxLine) {
3454          recomputeMaxLength = true;
3455          return true;
3456        }
3457      });
3458    }
3459
3460    if (doc.sel.contains(change.from, change.to) > -1)
3461      signalCursorActivity(cm);
3462
3463    updateDoc(doc, change, spans, estimateHeight(cm));
3464
3465    if (!cm.options.lineWrapping) {
3466      doc.iter(checkWidthStart, from.line + change.text.length, function(line) {
3467        var len = lineLength(line);
3468        if (len > display.maxLineLength) {
3469          display.maxLine = line;
3470          display.maxLineLength = len;
3471          display.maxLineChanged = true;
3472          recomputeMaxLength = false;
3473        }
3474      });
3475      if (recomputeMaxLength) cm.curOp.updateMaxLine = true;
3476    }
3477
3478    // Adjust frontier, schedule worker
3479    doc.frontier = Math.min(doc.frontier, from.line);
3480    startWorker(cm, 400);
3481
3482    var lendiff = change.text.length - (to.line - from.line) - 1;
3483    // Remember that these lines changed, for updating the display
3484    if (from.line == to.line && change.text.length == 1 && !isWholeLineUpdate(cm.doc, change))
3485      regLineChange(cm, from.line, "text");
3486    else
3487      regChange(cm, from.line, to.line + 1, lendiff);
3488
3489    var changesHandler = hasHandler(cm, "changes"), changeHandler = hasHandler(cm, "change");
3490    if (changeHandler || changesHandler) {
3491      var obj = {
3492        from: from, to: to,
3493        text: change.text,
3494        removed: change.removed,
3495        origin: change.origin
3496      };
3497      if (changeHandler) signalLater(cm, "change", cm, obj);
3498      if (changesHandler) (cm.curOp.changeObjs || (cm.curOp.changeObjs = [])).push(obj);
3499    }
3500  }
3501
3502  function replaceRange(doc, code, from, to, origin) {
3503    if (!to) to = from;
3504    if (cmp(to, from) < 0) { var tmp = to; to = from; from = tmp; }
3505    if (typeof code == "string") code = splitLines(code);
3506    makeChange(doc, {from: from, to: to, text: code, origin: origin});
3507  }
3508
3509  // SCROLLING THINGS INTO VIEW
3510
3511  // If an editor sits on the top or bottom of the window, partially
3512  // scrolled out of view, this ensures that the cursor is visible.
3513  function maybeScrollWindow(cm, coords) {
3514    var display = cm.display, box = display.sizer.getBoundingClientRect(), doScroll = null;
3515    if (coords.top + box.top < 0) doScroll = true;
3516    else if (coords.bottom + box.top > (window.innerHeight || document.documentElement.clientHeight)) doScroll = false;
3517    if (doScroll != null && !phantom) {
3518      var scrollNode = elt("div", "\u200b", null, "position: absolute; top: " +
3519                           (coords.top - display.viewOffset - paddingTop(cm.display)) + "px; height: " +
3520                           (coords.bottom - coords.top + scrollerCutOff) + "px; left: " +
3521                           coords.left + "px; width: 2px;");
3522      cm.display.lineSpace.appendChild(scrollNode);
3523      scrollNode.scrollIntoView(doScroll);
3524      cm.display.lineSpace.removeChild(scrollNode);
3525    }
3526  }
3527
3528  // Scroll a given position into view (immediately), verifying that
3529  // it actually became visible (as line heights are accurately
3530  // measured, the position of something may 'drift' during drawing).
3531  function scrollPosIntoView(cm, pos, end, margin) {
3532    if (margin == null) margin = 0;
3533    for (;;) {
3534      var changed = false, coords = cursorCoords(cm, pos);
3535      var endCoords = !end || end == pos ? coords : cursorCoords(cm, end);
3536      var scrollPos = calculateScrollPos(cm, Math.min(coords.left, endCoords.left),
3537                                         Math.min(coords.top, endCoords.top) - margin,
3538                                         Math.max(coords.left, endCoords.left),
3539                                         Math.max(coords.bottom, endCoords.bottom) + margin);
3540      var startTop = cm.doc.scrollTop, startLeft = cm.doc.scrollLeft;
3541      if (scrollPos.scrollTop != null) {
3542        setScrollTop(cm, scrollPos.scrollTop);
3543        if (Math.abs(cm.doc.scrollTop - startTop) > 1) changed = true;
3544      }
3545      if (scrollPos.scrollLeft != null) {
3546        setScrollLeft(cm, scrollPos.scrollLeft);
3547        if (Math.abs(cm.doc.scrollLeft - startLeft) > 1) changed = true;
3548      }
3549      if (!changed) return coords;
3550    }
3551  }
3552
3553  // Scroll a given set of coordinates into view (immediately).
3554  function scrollIntoView(cm, x1, y1, x2, y2) {
3555    var scrollPos = calculateScrollPos(cm, x1, y1, x2, y2);
3556    if (scrollPos.scrollTop != null) setScrollTop(cm, scrollPos.scrollTop);
3557    if (scrollPos.scrollLeft != null) setScrollLeft(cm, scrollPos.scrollLeft);
3558  }
3559
3560  // Calculate a new scroll position needed to scroll the given
3561  // rectangle into view. Returns an object with scrollTop and
3562  // scrollLeft properties. When these are undefined, the
3563  // vertical/horizontal position does not need to be adjusted.
3564  function calculateScrollPos(cm, x1, y1, x2, y2) {
3565    var display = cm.display, snapMargin = textHeight(cm.display);
3566    if (y1 < 0) y1 = 0;
3567    var screentop = cm.curOp && cm.curOp.scrollTop != null ? cm.curOp.scrollTop : display.scroller.scrollTop;
3568    var screen = display.scroller.clientHeight - scrollerCutOff, result = {};
3569    var docBottom = cm.doc.height + paddingVert(display);
3570    var atTop = y1 < snapMargin, atBottom = y2 > docBottom - snapMargin;
3571    if (y1 < screentop) {
3572      result.scrollTop = atTop ? 0 : y1;
3573    } else if (y2 > screentop + screen) {
3574      var newTop = Math.min(y1, (atBottom ? docBottom : y2) - screen);
3575      if (newTop != screentop) result.scrollTop = newTop;
3576    }
3577
3578    var screenleft = cm.curOp && cm.curOp.scrollLeft != null ? cm.curOp.scrollLeft : display.scroller.scrollLeft;
3579    var screenw = display.scroller.clientWidth - scrollerCutOff;
3580    x1 += display.gutters.offsetWidth; x2 += display.gutters.offsetWidth;
3581    var gutterw = display.gutters.offsetWidth;
3582    var atLeft = x1 < gutterw + 10;
3583    if (x1 < screenleft + gutterw || atLeft) {
3584      if (atLeft) x1 = 0;
3585      result.scrollLeft = Math.max(0, x1 - 10 - gutterw);
3586    } else if (x2 > screenw + screenleft - 3) {
3587      result.scrollLeft = x2 + 10 - screenw;
3588    }
3589    return result;
3590  }
3591
3592  // Store a relative adjustment to the scroll position in the current
3593  // operation (to be applied when the operation finishes).
3594  function addToScrollPos(cm, left, top) {
3595    if (left != null || top != null) resolveScrollToPos(cm);
3596    if (left != null)
3597      cm.curOp.scrollLeft = (cm.curOp.scrollLeft == null ? cm.doc.scrollLeft : cm.curOp.scrollLeft) + left;
3598    if (top != null)
3599      cm.curOp.scrollTop = (cm.curOp.scrollTop == null ? cm.doc.scrollTop : cm.curOp.scrollTop) + top;
3600  }
3601
3602  // Make sure that at the end of the operation the current cursor is
3603  // shown.
3604  function ensureCursorVisible(cm) {
3605    resolveScrollToPos(cm);
3606    var cur = cm.getCursor(), from = cur, to = cur;
3607    if (!cm.options.lineWrapping) {
3608      from = cur.ch ? Pos(cur.line, cur.ch - 1) : cur;
3609      to = Pos(cur.line, cur.ch + 1);
3610    }
3611    cm.curOp.scrollToPos = {from: from, to: to, margin: cm.options.cursorScrollMargin, isCursor: true};
3612  }
3613
3614  // When an operation has its scrollToPos property set, and another
3615  // scroll action is applied before the end of the operation, this
3616  // 'simulates' scrolling that position into view in a cheap way, so
3617  // that the effect of intermediate scroll commands is not ignored.
3618  function resolveScrollToPos(cm) {
3619    var range = cm.curOp.scrollToPos;
3620    if (range) {
3621      cm.curOp.scrollToPos = null;
3622      var from = estimateCoords(cm, range.from), to = estimateCoords(cm, range.to);
3623      var sPos = calculateScrollPos(cm, Math.min(from.left, to.left),
3624                                    Math.min(from.top, to.top) - range.margin,
3625                                    Math.max(from.right, to.right),
3626                                    Math.max(from.bottom, to.bottom) + range.margin);
3627      cm.scrollTo(sPos.scrollLeft, sPos.scrollTop);
3628    }
3629  }
3630
3631  // API UTILITIES
3632
3633  // Indent the given line. The how parameter can be "smart",
3634  // "add"/null, "subtract", or "prev". When aggressive is false
3635  // (typically set to true for forced single-line indents), empty
3636  // lines are not indented, and places where the mode returns Pass
3637  // are left alone.
3638  function indentLine(cm, n, how, aggressive) {
3639    var doc = cm.doc, state;
3640    if (how == null) how = "add";
3641    if (how == "smart") {
3642      // Fall back to "prev" when the mode doesn't have an indentation
3643      // method.
3644      if (!cm.doc.mode.indent) how = "prev";
3645      else state = getStateBefore(cm, n);
3646    }
3647
3648    var tabSize = cm.options.tabSize;
3649    var line = getLine(doc, n), curSpace = countColumn(line.text, null, tabSize);
3650    if (line.stateAfter) line.stateAfter = null;
3651    var curSpaceString = line.text.match(/^\s*/)[0], indentation;
3652    if (!aggressive && !/\S/.test(line.text)) {
3653      indentation = 0;
3654      how = "not";
3655    } else if (how == "smart") {
3656      indentation = cm.doc.mode.indent(state, line.text.slice(curSpaceString.length), line.text);
3657      if (indentation == Pass) {
3658        if (!aggressive) return;
3659        how = "prev";
3660      }
3661    }
3662    if (how == "prev") {
3663      if (n > doc.first) indentation = countColumn(getLine(doc, n-1).text, null, tabSize);
3664      else indentation = 0;
3665    } else if (how == "add") {
3666      indentation = curSpace + cm.options.indentUnit;
3667    } else if (how == "subtract") {
3668      indentation = curSpace - cm.options.indentUnit;
3669    } else if (typeof how == "number") {
3670      indentation = curSpace + how;
3671    }
3672    indentation = Math.max(0, indentation);
3673
3674    var indentString = "", pos = 0;
3675    if (cm.options.indentWithTabs)
3676      for (var i = Math.floor(indentation / tabSize); i; --i) {pos += tabSize; indentString += "\t";}
3677    if (pos < indentation) indentString += spaceStr(indentation - pos);
3678
3679    if (indentString != curSpaceString) {
3680      replaceRange(cm.doc, indentString, Pos(n, 0), Pos(n, curSpaceString.length), "+input");
3681    } else {
3682      // Ensure that, if the cursor was in the whitespace at the start
3683      // of the line, it is moved to the end of that space.
3684      for (var i = 0; i < doc.sel.ranges.length; i++) {
3685        var range = doc.sel.ranges[i];
3686        if (range.head.line == n && range.head.ch < curSpaceString.length) {
3687          var pos = Pos(n, curSpaceString.length);
3688          replaceOneSelection(doc, i, new Range(pos, pos));
3689          break;
3690        }
3691      }
3692    }
3693    line.stateAfter = null;
3694  }
3695
3696  // Utility for applying a change to a line by handle or number,
3697  // returning the number and optionally registering the line as
3698  // changed.
3699  function changeLine(cm, handle, changeType, op) {
3700    var no = handle, line = handle, doc = cm.doc;
3701    if (typeof handle == "number") line = getLine(doc, clipLine(doc, handle));
3702    else no = lineNo(handle);
3703    if (no == null) return null;
3704    if (op(line, no)) regLineChange(cm, no, changeType);
3705    return line;
3706  }
3707
3708  // Helper for deleting text near the selection(s), used to implement
3709  // backspace, delete, and similar functionality.
3710  function deleteNearSelection(cm, compute) {
3711    var ranges = cm.doc.sel.ranges, kill = [];
3712    // Build up a set of ranges to kill first, merging overlapping
3713    // ranges.
3714    for (var i = 0; i < ranges.length; i++) {
3715      var toKill = compute(ranges[i]);
3716      while (kill.length && cmp(toKill.from, lst(kill).to) <= 0) {
3717        var replaced = kill.pop();
3718        if (cmp(replaced.from, toKill.from) < 0) {
3719          toKill.from = replaced.from;
3720          break;
3721        }
3722      }
3723      kill.push(toKill);
3724    }
3725    // Next, remove those actual ranges.
3726    runInOp(cm, function() {
3727      for (var i = kill.length - 1; i >= 0; i--)
3728        replaceRange(cm.doc, "", kill[i].from, kill[i].to, "+delete");
3729      ensureCursorVisible(cm);
3730    });
3731  }
3732
3733  // Used for horizontal relative motion. Dir is -1 or 1 (left or
3734  // right), unit can be "char", "column" (like char, but doesn't
3735  // cross line boundaries), "word" (across next word), or "group" (to
3736  // the start of next group of word or non-word-non-whitespace
3737  // chars). The visually param controls whether, in right-to-left
3738  // text, direction 1 means to move towards the next index in the
3739  // string, or towards the character to the right of the current
3740  // position. The resulting position will have a hitSide=true
3741  // property if it reached the end of the document.
3742  function findPosH(doc, pos, dir, unit, visually) {
3743    var line = pos.line, ch = pos.ch, origDir = dir;
3744    var lineObj = getLine(doc, line);
3745    var possible = true;
3746    function findNextLine() {
3747      var l = line + dir;
3748      if (l < doc.first || l >= doc.first + doc.size) return (possible = false);
3749      line = l;
3750      return lineObj = getLine(doc, l);
3751    }
3752    function moveOnce(boundToLine) {
3753      var next = (visually ? moveVisually : moveLogically)(lineObj, ch, dir, true);
3754      if (next == null) {
3755        if (!boundToLine && findNextLine()) {
3756          if (visually) ch = (dir < 0 ? lineRight : lineLeft)(lineObj);
3757          else ch = dir < 0 ? lineObj.text.length : 0;
3758        } else return (possible = false);
3759      } else ch = next;
3760      return true;
3761    }
3762
3763    if (unit == "char") moveOnce();
3764    else if (unit == "column") moveOnce(true);
3765    else if (unit == "word" || unit == "group") {
3766      var sawType = null, group = unit == "group";
3767      for (var first = true;; first = false) {
3768        if (dir < 0 && !moveOnce(!first)) break;
3769        var cur = lineObj.text.charAt(ch) || "\n";
3770        var type = isWordChar(cur) ? "w"
3771          : group && cur == "\n" ? "n"
3772          : !group || /\s/.test(cur) ? null
3773          : "p";
3774        if (group && !first && !type) type = "s";
3775        if (sawType && sawType != type) {
3776          if (dir < 0) {dir = 1; moveOnce();}
3777          break;
3778        }
3779
3780        if (type) sawType = type;
3781        if (dir > 0 && !moveOnce(!first)) break;
3782      }
3783    }
3784    var result = skipAtomic(doc, Pos(line, ch), origDir, true);
3785    if (!possible) result.hitSide = true;
3786    return result;
3787  }
3788
3789  // For relative vertical movement. Dir may be -1 or 1. Unit can be
3790  // "page" or "line". The resulting position will have a hitSide=true
3791  // property if it reached the end of the document.
3792  function findPosV(cm, pos, dir, unit) {
3793    var doc = cm.doc, x = pos.left, y;
3794    if (unit == "page") {
3795      var pageSize = Math.min(cm.display.wrapper.clientHeight, window.innerHeight || document.documentElement.clientHeight);
3796      y = pos.top + dir * (pageSize - (dir < 0 ? 1.5 : .5) * textHeight(cm.display));
3797    } else if (unit == "line") {
3798      y = dir > 0 ? pos.bottom + 3 : pos.top - 3;
3799    }
3800    for (;;) {
3801      var target = coordsChar(cm, x, y);
3802      if (!target.outside) break;
3803      if (dir < 0 ? y <= 0 : y >= doc.height) { target.hitSide = true; break; }
3804      y += dir * 5;
3805    }
3806    return target;
3807  }
3808
3809  // Find the word at the given position (as returned by coordsChar).
3810  function findWordAt(doc, pos) {
3811    var line = getLine(doc, pos.line).text;
3812    var start = pos.ch, end = pos.ch;
3813    if (line) {
3814      if ((pos.xRel < 0 || end == line.length) && start) --start; else ++end;
3815      var startChar = line.charAt(start);
3816      var check = isWordChar(startChar) ? isWordChar
3817        : /\s/.test(startChar) ? function(ch) {return /\s/.test(ch);}
3818        : function(ch) {return !/\s/.test(ch) && !isWordChar(ch);};
3819      while (start > 0 && check(line.charAt(start - 1))) --start;
3820      while (end < line.length && check(line.charAt(end))) ++end;
3821    }
3822    return new Range(Pos(pos.line, start), Pos(pos.line, end));
3823  }
3824
3825  // EDITOR METHODS
3826
3827  // The publicly visible API. Note that methodOp(f) means
3828  // 'wrap f in an operation, performed on its `this` parameter'.
3829
3830  // This is not the complete set of editor methods. Most of the
3831  // methods defined on the Doc type are also injected into
3832  // CodeMirror.prototype, for backwards compatibility and
3833  // convenience.
3834
3835  CodeMirror.prototype = {
3836    constructor: CodeMirror,
3837    focus: function(){window.focus(); focusInput(this); fastPoll(this);},
3838
3839    setOption: function(option, value) {
3840      var options = this.options, old = options[option];
3841      if (options[option] == value && option != "mode") return;
3842      options[option] = value;
3843      if (optionHandlers.hasOwnProperty(option))
3844        operation(this, optionHandlers[option])(this, value, old);
3845    },
3846
3847    getOption: function(option) {return this.options[option];},
3848    getDoc: function() {return this.doc;},
3849
3850    addKeyMap: function(map, bottom) {
3851      this.state.keyMaps[bottom ? "push" : "unshift"](map);
3852    },
3853    removeKeyMap: function(map) {
3854      var maps = this.state.keyMaps;
3855      for (var i = 0; i < maps.length; ++i)
3856        if (maps[i] == map || (typeof maps[i] != "string" && maps[i].name == map)) {
3857          maps.splice(i, 1);
3858          return true;
3859        }
3860    },
3861
3862    addOverlay: methodOp(function(spec, options) {
3863      var mode = spec.token ? spec : CodeMirror.getMode(this.options, spec);
3864      if (mode.startState) throw new Error("Overlays may not be stateful.");
3865      this.state.overlays.push({mode: mode, modeSpec: spec, opaque: options && options.opaque});
3866      this.state.modeGen++;
3867      regChange(this);
3868    }),
3869    removeOverlay: methodOp(function(spec) {
3870      var overlays = this.state.overlays;
3871      for (var i = 0; i < overlays.length; ++i) {
3872        var cur = overlays[i].modeSpec;
3873        if (cur == spec || typeof spec == "string" && cur.name == spec) {
3874          overlays.splice(i, 1);
3875          this.state.modeGen++;
3876          regChange(this);
3877          return;
3878        }
3879      }
3880    }),
3881
3882    indentLine: methodOp(function(n, dir, aggressive) {
3883      if (typeof dir != "string" && typeof dir != "number") {
3884        if (dir == null) dir = this.options.smartIndent ? "smart" : "prev";
3885        else dir = dir ? "add" : "subtract";
3886      }
3887      if (isLine(this.doc, n)) indentLine(this, n, dir, aggressive);
3888    }),
3889    indentSelection: methodOp(function(how) {
3890      var ranges = this.doc.sel.ranges, end = -1;
3891      for (var i = 0; i < ranges.length; i++) {
3892        var range = ranges[i];
3893        if (!range.empty()) {
3894          var start = Math.max(end, range.from().line);
3895          var to = range.to();
3896          end = Math.min(this.lastLine(), to.line - (to.ch ? 0 : 1)) + 1;
3897          for (var j = start; j < end; ++j)
3898            indentLine(this, j, how);
3899        } else if (range.head.line > end) {
3900          indentLine(this, range.head.line, how, true);
3901          end = range.head.line;
3902          if (i == this.doc.sel.primIndex) ensureCursorVisible(this);
3903        }
3904      }
3905    }),
3906
3907    // Fetch the parser token for a given character. Useful for hacks
3908    // that want to inspect the mode state (say, for completion).
3909    getTokenAt: function(pos, precise) {
3910      var doc = this.doc;
3911      pos = clipPos(doc, pos);
3912      var state = getStateBefore(this, pos.line, precise), mode = this.doc.mode;
3913      var line = getLine(doc, pos.line);
3914      var stream = new StringStream(line.text, this.options.tabSize);
3915      while (stream.pos < pos.ch && !stream.eol()) {
3916        stream.start = stream.pos;
3917        var style = readToken(mode, stream, state);
3918      }
3919      return {start: stream.start,
3920              end: stream.pos,
3921              string: stream.current(),
3922              type: style || null,
3923              state: state};
3924    },
3925
3926    getTokenTypeAt: function(pos) {
3927      pos = clipPos(this.doc, pos);
3928      var styles = getLineStyles(this, getLine(this.doc, pos.line));
3929      var before = 0, after = (styles.length - 1) / 2, ch = pos.ch;
3930      var type;
3931      if (ch == 0) type = styles[2];
3932      else for (;;) {
3933        var mid = (before + after) >> 1;
3934        if ((mid ? styles[mid * 2 - 1] : 0) >= ch) after = mid;
3935        else if (styles[mid * 2 + 1] < ch) before = mid + 1;
3936        else { type = styles[mid * 2 + 2]; break; }
3937      }
3938      var cut = type ? type.indexOf("cm-overlay ") : -1;
3939      return cut < 0 ? type : cut == 0 ? null : type.slice(0, cut - 1);
3940    },
3941
3942    getModeAt: function(pos) {
3943      var mode = this.doc.mode;
3944      if (!mode.innerMode) return mode;
3945      return CodeMirror.innerMode(mode, this.getTokenAt(pos).state).mode;
3946    },
3947
3948    getHelper: function(pos, type) {
3949      return this.getHelpers(pos, type)[0];
3950    },
3951
3952    getHelpers: function(pos, type) {
3953      var found = [];
3954      if (!helpers.hasOwnProperty(type)) return helpers;
3955      var help = helpers[type], mode = this.getModeAt(pos);
3956      if (typeof mode[type] == "string") {
3957        if (help[mode[type]]) found.push(help[mode[type]]);
3958      } else if (mode[type]) {
3959        for (var i = 0; i < mode[type].length; i++) {
3960          var val = help[mode[type][i]];
3961          if (val) found.push(val);
3962        }
3963      } else if (mode.helperType && help[mode.helperType]) {
3964        found.push(help[mode.helperType]);
3965      } else if (help[mode.name]) {
3966        found.push(help[mode.name]);
3967      }
3968      for (var i = 0; i < help._global.length; i++) {
3969        var cur = help._global[i];
3970        if (cur.pred(mode, this) && indexOf(found, cur.val) == -1)
3971          found.push(cur.val);
3972      }
3973      return found;
3974    },
3975
3976    getStateAfter: function(line, precise) {
3977      var doc = this.doc;
3978      line = clipLine(doc, line == null ? doc.first + doc.size - 1: line);
3979      return getStateBefore(this, line + 1, precise);
3980    },
3981
3982    cursorCoords: function(start, mode) {
3983      var pos, range = this.doc.sel.primary();
3984      if (start == null) pos = range.head;
3985      else if (typeof start == "object") pos = clipPos(this.doc, start);
3986      else pos = start ? range.from() : range.to();
3987      return cursorCoords(this, pos, mode || "page");
3988    },
3989
3990    charCoords: function(pos, mode) {
3991      return charCoords(this, clipPos(this.doc, pos), mode || "page");
3992    },
3993
3994    coordsChar: function(coords, mode) {
3995      coords = fromCoordSystem(this, coords, mode || "page");
3996      return coordsChar(this, coords.left, coords.top);
3997    },
3998
3999    lineAtHeight: function(height, mode) {
4000      height = fromCoordSystem(this, {top: height, left: 0}, mode || "page").top;
4001      return lineAtHeight(this.doc, height + this.display.viewOffset);
4002    },
4003    heightAtLine: function(line, mode) {
4004      var end = false, last = this.doc.first + this.doc.size - 1;
4005      if (line < this.doc.first) line = this.doc.first;
4006      else if (line > last) { line = last; end = true; }
4007      var lineObj = getLine(this.doc, line);
4008      return intoCoordSystem(this, lineObj, {top: 0, left: 0}, mode || "page").top +
4009        (end ? this.doc.height - heightAtLine(lineObj) : 0);
4010    },
4011
4012    defaultTextHeight: function() { return textHeight(this.display); },
4013    defaultCharWidth: function() { return charWidth(this.display); },
4014
4015    setGutterMarker: methodOp(function(line, gutterID, value) {
4016      return changeLine(this, line, "gutter", function(line) {
4017        var markers = line.gutterMarkers || (line.gutterMarkers = {});
4018        markers[gutterID] = value;
4019        if (!value && isEmpty(markers)) line.gutterMarkers = null;
4020        return true;
4021      });
4022    }),
4023
4024    clearGutter: methodOp(function(gutterID) {
4025      var cm = this, doc = cm.doc, i = doc.first;
4026      doc.iter(function(line) {
4027        if (line.gutterMarkers && line.gutterMarkers[gutterID]) {
4028          line.gutterMarkers[gutterID] = null;
4029          regLineChange(cm, i, "gutter");
4030          if (isEmpty(line.gutterMarkers)) line.gutterMarkers = null;
4031        }
4032        ++i;
4033      });
4034    }),
4035
4036    addLineClass: methodOp(function(handle, where, cls) {
4037      return changeLine(this, handle, "class", function(line) {
4038        var prop = where == "text" ? "textClass" : where == "background" ? "bgClass" : "wrapClass";
4039        if (!line[prop]) line[prop] = cls;
4040        else if (new RegExp("(?:^|\\s)" + cls + "(?:$|\\s)").test(line[prop])) return false;
4041        else line[prop] += " " + cls;
4042        return true;
4043      });
4044    }),
4045
4046    removeLineClass: methodOp(function(handle, where, cls) {
4047      return changeLine(this, handle, "class", function(line) {
4048        var prop = where == "text" ? "textClass" : where == "background" ? "bgClass" : "wrapClass";
4049        var cur = line[prop];
4050        if (!cur) return false;
4051        else if (cls == null) line[prop] = null;
4052        else {
4053          var found = cur.match(new RegExp("(?:^|\\s+)" + cls + "(?:$|\\s+)"));
4054          if (!found) return false;
4055          var end = found.index + found[0].length;
4056          line[prop] = cur.slice(0, found.index) + (!found.index || end == cur.length ? "" : " ") + cur.slice(end) || null;
4057        }
4058        return true;
4059      });
4060    }),
4061
4062    addLineWidget: methodOp(function(handle, node, options) {
4063      return addLineWidget(this, handle, node, options);
4064    }),
4065
4066    removeLineWidget: function(widget) { widget.clear(); },
4067
4068    lineInfo: function(line) {
4069      if (typeof line == "number") {
4070        if (!isLine(this.doc, line)) return null;
4071        var n = line;
4072        line = getLine(this.doc, line);
4073        if (!line) return null;
4074      } else {
4075        var n = lineNo(line);
4076        if (n == null) return null;
4077      }
4078      return {line: n, handle: line, text: line.text, gutterMarkers: line.gutterMarkers,
4079              textClass: line.textClass, bgClass: line.bgClass, wrapClass: line.wrapClass,
4080              widgets: line.widgets};
4081    },
4082
4083    getViewport: function() { return {from: this.display.viewFrom, to: this.display.viewTo};},
4084
4085    addWidget: function(pos, node, scroll, vert, horiz) {
4086      var display = this.display;
4087      pos = cursorCoords(this, clipPos(this.doc, pos));
4088      var top = pos.bottom, left = pos.left;
4089      node.style.position = "absolute";
4090      display.sizer.appendChild(node);
4091      if (vert == "over") {
4092        top = pos.top;
4093      } else if (vert == "above" || vert == "near") {
4094        var vspace = Math.max(display.wrapper.clientHeight, this.doc.height),
4095        hspace = Math.max(display.sizer.clientWidth, display.lineSpace.clientWidth);
4096        // Default to positioning above (if specified and possible); otherwise default to positioning below
4097        if ((vert == 'above' || pos.bottom + node.offsetHeight > vspace) && pos.top > node.offsetHeight)
4098          top = pos.top - node.offsetHeight;
4099        else if (pos.bottom + node.offsetHeight <= vspace)
4100          top = pos.bottom;
4101        if (left + node.offsetWidth > hspace)
4102          left = hspace - node.offsetWidth;
4103      }
4104      node.style.top = top + "px";
4105      node.style.left = node.style.right = "";
4106      if (horiz == "right") {
4107        left = display.sizer.clientWidth - node.offsetWidth;
4108        node.style.right = "0px";
4109      } else {
4110        if (horiz == "left") left = 0;
4111        else if (horiz == "middle") left = (display.sizer.clientWidth - node.offsetWidth) / 2;
4112        node.style.left = left + "px";
4113      }
4114      if (scroll)
4115        scrollIntoView(this, left, top, left + node.offsetWidth, top + node.offsetHeight);
4116    },
4117
4118    triggerOnKeyDown: methodOp(onKeyDown),
4119    triggerOnKeyPress: methodOp(onKeyPress),
4120    triggerOnKeyUp: methodOp(onKeyUp),
4121
4122    execCommand: function(cmd) {
4123      if (commands.hasOwnProperty(cmd))
4124        return commands[cmd](this);
4125    },
4126
4127    findPosH: function(from, amount, unit, visually) {
4128      var dir = 1;
4129      if (amount < 0) { dir = -1; amount = -amount; }
4130      for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {
4131        cur = findPosH(this.doc, cur, dir, unit, visually);
4132        if (cur.hitSide) break;
4133      }
4134      return cur;
4135    },
4136
4137    moveH: methodOp(function(dir, unit) {
4138      var cm = this;
4139      cm.extendSelectionsBy(function(range) {
4140        if (cm.display.shift || cm.doc.extend || range.empty())
4141          return findPosH(cm.doc, range.head, dir, unit, cm.options.rtlMoveVisually);
4142        else
4143          return dir < 0 ? range.from() : range.to();
4144      }, sel_move);
4145    }),
4146
4147    deleteH: methodOp(function(dir, unit) {
4148      var sel = this.doc.sel, doc = this.doc;
4149      if (sel.somethingSelected())
4150        doc.replaceSelection("", null, "+delete");
4151      else
4152        deleteNearSelection(this, function(range) {
4153          var other = findPosH(doc, range.head, dir, unit, false);
4154          return dir < 0 ? {from: other, to: range.head} : {from: range.head, to: other};
4155        });
4156    }),
4157
4158    findPosV: function(from, amount, unit, goalColumn) {
4159      var dir = 1, x = goalColumn;
4160      if (amount < 0) { dir = -1; amount = -amount; }
4161      for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {
4162        var coords = cursorCoords(this, cur, "div");
4163        if (x == null) x = coords.left;
4164        else coords.left = x;
4165        cur = findPosV(this, coords, dir, unit);
4166        if (cur.hitSide) break;
4167      }
4168      return cur;
4169    },
4170
4171    moveV: methodOp(function(dir, unit) {
4172      var cm = this, doc = this.doc, goals = [];
4173      var collapse = !cm.display.shift && !doc.extend && doc.sel.somethingSelected();
4174      doc.extendSelectionsBy(function(range) {
4175        if (collapse)
4176          return dir < 0 ? range.from() : range.to();
4177        var headPos = cursorCoords(cm, range.head, "div");
4178        if (range.goalColumn != null) headPos.left = range.goalColumn;
4179        goals.push(headPos.left);
4180        var pos = findPosV(cm, headPos, dir, unit);
4181        if (unit == "page" && range == doc.sel.primary())
4182          addToScrollPos(cm, null, charCoords(cm, pos, "div").top - headPos.top);
4183        return pos;
4184      }, sel_move);
4185      if (goals.length) for (var i = 0; i < doc.sel.ranges.length; i++)
4186        doc.sel.ranges[i].goalColumn = goals[i];
4187    }),
4188
4189    toggleOverwrite: function(value) {
4190      if (value != null && value == this.state.overwrite) return;
4191      if (this.state.overwrite = !this.state.overwrite)
4192        addClass(this.display.cursorDiv, "CodeMirror-overwrite");
4193      else
4194        rmClass(this.display.cursorDiv, "CodeMirror-overwrite");
4195
4196      signal(this, "overwriteToggle", this, this.state.overwrite);
4197    },
4198    hasFocus: function() { return activeElt() == this.display.input; },
4199
4200    scrollTo: methodOp(function(x, y) {
4201      if (x != null || y != null) resolveScrollToPos(this);
4202      if (x != null) this.curOp.scrollLeft = x;
4203      if (y != null) this.curOp.scrollTop = y;
4204    }),
4205    getScrollInfo: function() {
4206      var scroller = this.display.scroller, co = scrollerCutOff;
4207      return {left: scroller.scrollLeft, top: scroller.scrollTop,
4208              height: scroller.scrollHeight - co, width: scroller.scrollWidth - co,
4209              clientHeight: scroller.clientHeight - co, clientWidth: scroller.clientWidth - co};
4210    },
4211
4212    scrollIntoView: methodOp(function(range, margin) {
4213      if (range == null) {
4214        range = {from: this.doc.sel.primary().head, to: null};
4215        if (margin == null) margin = this.options.cursorScrollMargin;
4216      } else if (typeof range == "number") {
4217        range = {from: Pos(range, 0), to: null};
4218      } else if (range.from == null) {
4219        range = {from: range, to: null};
4220      }
4221      if (!range.to) range.to = range.from;
4222      range.margin = margin || 0;
4223
4224      if (range.from.line != null) {
4225        resolveScrollToPos(this);
4226        this.curOp.scrollToPos = range;
4227      } else {
4228        var sPos = calculateScrollPos(this, Math.min(range.from.left, range.to.left),
4229                                      Math.min(range.from.top, range.to.top) - range.margin,
4230                                      Math.max(range.from.right, range.to.right),
4231                                      Math.max(range.from.bottom, range.to.bottom) + range.margin);
4232        this.scrollTo(sPos.scrollLeft, sPos.scrollTop);
4233      }
4234    }),
4235
4236    setSize: methodOp(function(width, height) {
4237      function interpret(val) {
4238        return typeof val == "number" || /^\d+$/.test(String(val)) ? val + "px" : val;
4239      }
4240      if (width != null) this.display.wrapper.style.width = interpret(width);
4241      if (height != null) this.display.wrapper.style.height = interpret(height);
4242      if (this.options.lineWrapping) clearLineMeasurementCache(this);
4243      this.curOp.forceUpdate = true;
4244      signal(this, "refresh", this);
4245    }),
4246
4247    operation: function(f){return runInOp(this, f);},
4248
4249    refresh: methodOp(function() {
4250      var oldHeight = this.display.cachedTextHeight;
4251      regChange(this);
4252      this.curOp.forceUpdate = true;
4253      clearCaches(this);
4254      this.scrollTo(this.doc.scrollLeft, this.doc.scrollTop);
4255      updateGutterSpace(this);
4256      if (oldHeight == null || Math.abs(oldHeight - textHeight(this.display)) > .5)
4257        estimateLineHeights(this);
4258      signal(this, "refresh", this);
4259    }),
4260
4261    swapDoc: methodOp(function(doc) {
4262      var old = this.doc;
4263      old.cm = null;
4264      attachDoc(this, doc);
4265      clearCaches(this);
4266      resetInput(this);
4267      this.scrollTo(doc.scrollLeft, doc.scrollTop);
4268      signalLater(this, "swapDoc", this, old);
4269      return old;
4270    }),
4271
4272    getInputField: function(){return this.display.input;},
4273    getWrapperElement: function(){return this.display.wrapper;},
4274    getScrollerElement: function(){return this.display.scroller;},
4275    getGutterElement: function(){return this.display.gutters;}
4276  };
4277  eventMixin(CodeMirror);
4278
4279  // OPTION DEFAULTS
4280
4281  // The default configuration options.
4282  var defaults = CodeMirror.defaults = {};
4283  // Functions to run when options are changed.
4284  var optionHandlers = CodeMirror.optionHandlers = {};
4285
4286  function option(name, deflt, handle, notOnInit) {
4287    CodeMirror.defaults[name] = deflt;
4288    if (handle) optionHandlers[name] =
4289      notOnInit ? function(cm, val, old) {if (old != Init) handle(cm, val, old);} : handle;
4290  }
4291
4292  // Passed to option handlers when there is no old value.
4293  var Init = CodeMirror.Init = {toString: function(){return "CodeMirror.Init";}};
4294
4295  // These two are, on init, called from the constructor because they
4296  // have to be initialized before the editor can start at all.
4297  option("value", "", function(cm, val) {
4298    cm.setValue(val);
4299  }, true);
4300  option("mode", null, function(cm, val) {
4301    cm.doc.modeOption = val;
4302    loadMode(cm);
4303  }, true);
4304
4305  option("indentUnit", 2, loadMode, true);
4306  option("indentWithTabs", false);
4307  option("smartIndent", true);
4308  option("tabSize", 4, function(cm) {
4309    resetModeState(cm);
4310    clearCaches(cm);
4311    regChange(cm);
4312  }, true);
4313  option("specialChars", /[\t\u0000-\u0019\u00ad\u200b\u2028\u2029\ufeff]/g, function(cm, val) {
4314    cm.options.specialChars = new RegExp(val.source + (val.test("\t") ? "" : "|\t"), "g");
4315    cm.refresh();
4316  }, true);
4317  option("specialCharPlaceholder", defaultSpecialCharPlaceholder, function(cm) {cm.refresh();}, true);
4318  option("electricChars", true);
4319  option("rtlMoveVisually", !windows);
4320  option("wholeLineUpdateBefore", true);
4321
4322  option("theme", "default", function(cm) {
4323    themeChanged(cm);
4324    guttersChanged(cm);
4325  }, true);
4326  option("keyMap", "default", keyMapChanged);
4327  option("extraKeys", null);
4328
4329  option("lineWrapping", false, wrappingChanged, true);
4330  option("gutters", [], function(cm) {
4331    setGuttersForLineNumbers(cm.options);
4332    guttersChanged(cm);
4333  }, true);
4334  option("fixedGutter", true, function(cm, val) {
4335    cm.display.gutters.style.left = val ? compensateForHScroll(cm.display) + "px" : "0";
4336    cm.refresh();
4337  }, true);
4338  option("coverGutterNextToScrollbar", false, updateScrollbars, true);
4339  option("lineNumbers", false, function(cm) {
4340    setGuttersForLineNumbers(cm.options);
4341    guttersChanged(cm);
4342  }, true);
4343  option("firstLineNumber", 1, guttersChanged, true);
4344  option("lineNumberFormatter", function(integer) {return integer;}, guttersChanged, true);
4345  option("showCursorWhenSelecting", false, updateSelection, true);
4346
4347  option("resetSelectionOnContextMenu", true);
4348
4349  option("readOnly", false, function(cm, val) {
4350    if (val == "nocursor") {
4351      onBlur(cm);
4352      cm.display.input.blur();
4353      cm.display.disabled = true;
4354    } else {
4355      cm.display.disabled = false;
4356      if (!val) resetInput(cm);
4357    }
4358  });
4359  option("disableInput", false, function(cm, val) {if (!val) resetInput(cm);}, true);
4360  option("dragDrop", true);
4361
4362  option("cursorBlinkRate", 530);
4363  option("cursorScrollMargin", 0);
4364  option("cursorHeight", 1);
4365  option("workTime", 100);
4366  option("workDelay", 100);
4367  option("flattenSpans", true, resetModeState, true);
4368  option("addModeClass", false, resetModeState, true);
4369  option("pollInterval", 100);
4370  option("undoDepth", 200, function(cm, val){cm.doc.history.undoDepth = val;});
4371  option("historyEventDelay", 1250);
4372  option("viewportMargin", 10, function(cm){cm.refresh();}, true);
4373  option("maxHighlightLength", 10000, resetModeState, true);
4374  option("moveInputWithCursor", true, function(cm, val) {
4375    if (!val) cm.display.inputDiv.style.top = cm.display.inputDiv.style.left = 0;
4376  });
4377
4378  option("tabindex", null, function(cm, val) {
4379    cm.display.input.tabIndex = val || "";
4380  });
4381  option("autofocus", null);
4382
4383  // MODE DEFINITION AND QUERYING
4384
4385  // Known modes, by name and by MIME
4386  var modes = CodeMirror.modes = {}, mimeModes = CodeMirror.mimeModes = {};
4387
4388  // Extra arguments are stored as the mode's dependencies, which is
4389  // used by (legacy) mechanisms like loadmode.js to automatically
4390  // load a mode. (Preferred mechanism is the require/define calls.)
4391  CodeMirror.defineMode = function(name, mode) {
4392    if (!CodeMirror.defaults.mode && name != "null") CodeMirror.defaults.mode = name;
4393    if (arguments.length > 2) {
4394      mode.dependencies = [];
4395      for (var i = 2; i < arguments.length; ++i) mode.dependencies.push(arguments[i]);
4396    }
4397    modes[name] = mode;
4398  };
4399
4400  CodeMirror.defineMIME = function(mime, spec) {
4401    mimeModes[mime] = spec;
4402  };
4403
4404  // Given a MIME type, a {name, ...options} config object, or a name
4405  // string, return a mode config object.
4406  CodeMirror.resolveMode = function(spec) {
4407    if (typeof spec == "string" && mimeModes.hasOwnProperty(spec)) {
4408      spec = mimeModes[spec];
4409    } else if (spec && typeof spec.name == "string" && mimeModes.hasOwnProperty(spec.name)) {
4410      var found = mimeModes[spec.name];
4411      if (typeof found == "string") found = {name: found};
4412      spec = createObj(found, spec);
4413      spec.name = found.name;
4414    } else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+xml$/.test(spec)) {
4415      return CodeMirror.resolveMode("application/xml");
4416    }
4417    if (typeof spec == "string") return {name: spec};
4418    else return spec || {name: "null"};
4419  };
4420
4421  // Given a mode spec (anything that resolveMode accepts), find and
4422  // initialize an actual mode object.
4423  CodeMirror.getMode = function(options, spec) {
4424    var spec = CodeMirror.resolveMode(spec);
4425    var mfactory = modes[spec.name];
4426    if (!mfactory) return CodeMirror.getMode(options, "text/plain");
4427    var modeObj = mfactory(options, spec);
4428    if (modeExtensions.hasOwnProperty(spec.name)) {
4429      var exts = modeExtensions[spec.name];
4430      for (var prop in exts) {
4431        if (!exts.hasOwnProperty(prop)) continue;
4432        if (modeObj.hasOwnProperty(prop)) modeObj["_" + prop] = modeObj[prop];
4433        modeObj[prop] = exts[prop];
4434      }
4435    }
4436    modeObj.name = spec.name;
4437    if (spec.helperType) modeObj.helperType = spec.helperType;
4438    if (spec.modeProps) for (var prop in spec.modeProps)
4439      modeObj[prop] = spec.modeProps[prop];
4440
4441    return modeObj;
4442  };
4443
4444  // Minimal default mode.
4445  CodeMirror.defineMode("null", function() {
4446    return {token: function(stream) {stream.skipToEnd();}};
4447  });
4448  CodeMirror.defineMIME("text/plain", "null");
4449
4450  // This can be used to attach properties to mode objects from
4451  // outside the actual mode definition.
4452  var modeExtensions = CodeMirror.modeExtensions = {};
4453  CodeMirror.extendMode = function(mode, properties) {
4454    var exts = modeExtensions.hasOwnProperty(mode) ? modeExtensions[mode] : (modeExtensions[mode] = {});
4455    copyObj(properties, exts);
4456  };
4457
4458  // EXTENSIONS
4459
4460  CodeMirror.defineExtension = function(name, func) {
4461    CodeMirror.prototype[name] = func;
4462  };
4463  CodeMirror.defineDocExtension = function(name, func) {
4464    Doc.prototype[name] = func;
4465  };
4466  CodeMirror.defineOption = option;
4467
4468  var initHooks = [];
4469  CodeMirror.defineInitHook = function(f) {initHooks.push(f);};
4470
4471  var helpers = CodeMirror.helpers = {};
4472  CodeMirror.registerHelper = function(type, name, value) {
4473    if (!helpers.hasOwnProperty(type)) helpers[type] = CodeMirror[type] = {_global: []};
4474    helpers[type][name] = value;
4475  };
4476  CodeMirror.registerGlobalHelper = function(type, name, predicate, value) {
4477    CodeMirror.registerHelper(type, name, value);
4478    helpers[type]._global.push({pred: predicate, val: value});
4479  };
4480
4481  // MODE STATE HANDLING
4482
4483  // Utility functions for working with state. Exported because nested
4484  // modes need to do this for their inner modes.
4485
4486  var copyState = CodeMirror.copyState = function(mode, state) {
4487    if (state === true) return state;
4488    if (mode.copyState) return mode.copyState(state);
4489    var nstate = {};
4490    for (var n in state) {
4491      var val = state[n];
4492      if (val instanceof Array) val = val.concat([]);
4493      nstate[n] = val;
4494    }
4495    return nstate;
4496  };
4497
4498  var startState = CodeMirror.startState = function(mode, a1, a2) {
4499    return mode.startState ? mode.startState(a1, a2) : true;
4500  };
4501
4502  // Given a mode and a state (for that mode), find the inner mode and
4503  // state at the position that the state refers to.
4504  CodeMirror.innerMode = function(mode, state) {
4505    while (mode.innerMode) {
4506      var info = mode.innerMode(state);
4507      if (!info || info.mode == mode) break;
4508      state = info.state;
4509      mode = info.mode;
4510    }
4511    return info || {mode: mode, state: state};
4512  };
4513
4514  // STANDARD COMMANDS
4515
4516  // Commands are parameter-less actions that can be performed on an
4517  // editor, mostly used for keybindings.
4518  var commands = CodeMirror.commands = {
4519    selectAll: function(cm) {cm.setSelection(Pos(cm.firstLine(), 0), Pos(cm.lastLine()), sel_dontScroll);},
4520    singleSelection: function(cm) {
4521      cm.setSelection(cm.getCursor("anchor"), cm.getCursor("head"), sel_dontScroll);
4522    },
4523    killLine: function(cm) {
4524      deleteNearSelection(cm, function(range) {
4525        if (range.empty()) {
4526          var len = getLine(cm.doc, range.head.line).text.length;
4527          if (range.head.ch == len && range.head.line < cm.lastLine())
4528            return {from: range.head, to: Pos(range.head.line + 1, 0)};
4529          else
4530            return {from: range.head, to: Pos(range.head.line, len)};
4531        } else {
4532          return {from: range.from(), to: range.to()};
4533        }
4534      });
4535    },
4536    deleteLine: function(cm) {
4537      deleteNearSelection(cm, function(range) {
4538        return {from: Pos(range.from().line, 0),
4539                to: clipPos(cm.doc, Pos(range.to().line + 1, 0))};
4540      });
4541    },
4542    delLineLeft: function(cm) {
4543      deleteNearSelection(cm, function(range) {
4544        return {from: Pos(range.from().line, 0), to: range.from()};
4545      });
4546    },
4547    undo: function(cm) {cm.undo();},
4548    redo: function(cm) {cm.redo();},
4549    undoSelection: function(cm) {cm.undoSelection();},
4550    redoSelection: function(cm) {cm.redoSelection();},
4551    goDocStart: function(cm) {cm.extendSelection(Pos(cm.firstLine(), 0));},
4552    goDocEnd: function(cm) {cm.extendSelection(Pos(cm.lastLine()));},
4553    goLineStart: function(cm) {
4554      cm.extendSelectionsBy(function(range) { return lineStart(cm, range.head.line); }, sel_move);
4555    },
4556    goLineStartSmart: function(cm) {
4557      cm.extendSelectionsBy(function(range) {
4558        var start = lineStart(cm, range.head.line);
4559        var line = cm.getLineHandle(start.line);
4560        var order = getOrder(line);
4561        if (!order || order[0].level == 0) {
4562          var firstNonWS = Math.max(0, line.text.search(/\S/));
4563          var inWS = range.head.line == start.line && range.head.ch <= firstNonWS && range.head.ch;
4564          return Pos(start.line, inWS ? 0 : firstNonWS);
4565        }
4566        return start;
4567      }, sel_move);
4568    },
4569    goLineEnd: function(cm) {
4570      cm.extendSelectionsBy(function(range) { return lineEnd(cm, range.head.line); }, sel_move);
4571    },
4572    goLineRight: function(cm) {
4573      cm.extendSelectionsBy(function(range) {
4574        var top = cm.charCoords(range.head, "div").top + 5;
4575        return cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div");
4576      }, sel_move);
4577    },
4578    goLineLeft: function(cm) {
4579      cm.extendSelectionsBy(function(range) {
4580        var top = cm.charCoords(range.head, "div").top + 5;
4581        return cm.coordsChar({left: 0, top: top}, "div");
4582      }, sel_move);
4583    },
4584    goLineUp: function(cm) {cm.moveV(-1, "line");},
4585    goLineDown: function(cm) {cm.moveV(1, "line");},
4586    goPageUp: function(cm) {cm.moveV(-1, "page");},
4587    goPageDown: function(cm) {cm.moveV(1, "page");},
4588    goCharLeft: function(cm) {cm.moveH(-1, "char");},
4589    goCharRight: function(cm) {cm.moveH(1, "char");},
4590    goColumnLeft: function(cm) {cm.moveH(-1, "column");},
4591    goColumnRight: function(cm) {cm.moveH(1, "column");},
4592    goWordLeft: function(cm) {cm.moveH(-1, "word");},
4593    goGroupRight: function(cm) {cm.moveH(1, "group");},
4594    goGroupLeft: function(cm) {cm.moveH(-1, "group");},
4595    goWordRight: function(cm) {cm.moveH(1, "word");},
4596    delCharBefore: function(cm) {cm.deleteH(-1, "char");},
4597    delCharAfter: function(cm) {cm.deleteH(1, "char");},
4598    delWordBefore: function(cm) {cm.deleteH(-1, "word");},
4599    delWordAfter: function(cm) {cm.deleteH(1, "word");},
4600    delGroupBefore: function(cm) {cm.deleteH(-1, "group");},
4601    delGroupAfter: function(cm) {cm.deleteH(1, "group");},
4602    indentAuto: function(cm) {cm.indentSelection("smart");},
4603    indentMore: function(cm) {cm.indentSelection("add");},
4604    indentLess: function(cm) {cm.indentSelection("subtract");},
4605    insertTab: function(cm) {cm.replaceSelection("\t");},
4606    insertSoftTab: function(cm) {
4607      var spaces = [], ranges = cm.listSelections(), tabSize = cm.options.tabSize;
4608      for (var i = 0; i < ranges.length; i++) {
4609        var pos = ranges[i].from();
4610        var col = countColumn(cm.getLine(pos.line), pos.ch, tabSize);
4611        spaces.push(new Array(tabSize - col % tabSize + 1).join(" "));
4612      }
4613      cm.replaceSelections(spaces);
4614    },
4615    defaultTab: function(cm) {
4616      if (cm.somethingSelected()) cm.indentSelection("add");
4617      else cm.execCommand("insertTab");
4618    },
4619    transposeChars: function(cm) {
4620      runInOp(cm, function() {
4621        var ranges = cm.listSelections();
4622        for (var i = 0; i < ranges.length; i++) {
4623          var cur = ranges[i].head, line = getLine(cm.doc, cur.line).text;
4624          if (cur.ch > 0 && cur.ch < line.length - 1)
4625            cm.replaceRange(line.charAt(cur.ch) + line.charAt(cur.ch - 1),
4626                            Pos(cur.line, cur.ch - 1), Pos(cur.line, cur.ch + 1));
4627        }
4628      });
4629    },
4630    newlineAndIndent: function(cm) {
4631      runInOp(cm, function() {
4632        var len = cm.listSelections().length;
4633        for (var i = 0; i < len; i++) {
4634          var range = cm.listSelections()[i];
4635          cm.replaceRange("\n", range.anchor, range.head, "+input");
4636          cm.indentLine(range.from().line + 1, null, true);
4637          ensureCursorVisible(cm);
4638        }
4639      });
4640    },
4641    toggleOverwrite: function(cm) {cm.toggleOverwrite();}
4642  };
4643
4644  // STANDARD KEYMAPS
4645
4646  var keyMap = CodeMirror.keyMap = {};
4647  keyMap.basic = {
4648    "Left": "goCharLeft", "Right": "goCharRight", "Up": "goLineUp", "Down": "goLineDown",
4649    "End": "goLineEnd", "Home": "goLineStartSmart", "PageUp": "goPageUp", "PageDown": "goPageDown",
4650    "Delete": "delCharAfter", "Backspace": "delCharBefore", "Shift-Backspace": "delCharBefore",
4651    "Tab": "defaultTab", "Shift-Tab": "indentAuto",
4652    "Enter": "newlineAndIndent", "Insert": "toggleOverwrite",
4653    "Esc": "singleSelection"
4654  };
4655  // Note that the save and find-related commands aren't defined by
4656  // default. User code or addons can define them. Unknown commands
4657  // are simply ignored.
4658  keyMap.pcDefault = {
4659    "Ctrl-A": "selectAll", "Ctrl-D": "deleteLine", "Ctrl-Z": "undo", "Shift-Ctrl-Z": "redo", "Ctrl-Y": "redo",
4660    "Ctrl-Home": "goDocStart", "Ctrl-Up": "goDocStart", "Ctrl-End": "goDocEnd", "Ctrl-Down": "goDocEnd",
4661    "Ctrl-Left": "goGroupLeft", "Ctrl-Right": "goGroupRight", "Alt-Left": "goLineStart", "Alt-Right": "goLineEnd",
4662    "Ctrl-Backspace": "delGroupBefore", "Ctrl-Delete": "delGroupAfter", "Ctrl-S": "save", "Ctrl-F": "find",
4663    "Ctrl-G": "findNext", "Shift-Ctrl-G": "findPrev", "Shift-Ctrl-F": "replace", "Shift-Ctrl-R": "replaceAll",
4664    "Ctrl-[": "indentLess", "Ctrl-]": "indentMore",
4665    "Ctrl-U": "undoSelection", "Shift-Ctrl-U": "redoSelection", "Alt-U": "redoSelection",
4666    fallthrough: "basic"
4667  };
4668  keyMap.macDefault = {
4669    "Cmd-A": "selectAll", "Cmd-D": "deleteLine", "Cmd-Z": "undo", "Shift-Cmd-Z": "redo", "Cmd-Y": "redo",
4670    "Cmd-Up": "goDocStart", "Cmd-End": "goDocEnd", "Cmd-Down": "goDocEnd", "Alt-Left": "goGroupLeft",
4671    "Alt-Right": "goGroupRight", "Cmd-Left": "goLineStart", "Cmd-Right": "goLineEnd", "Alt-Backspace": "delGroupBefore",
4672    "Ctrl-Alt-Backspace": "delGroupAfter", "Alt-Delete": "delGroupAfter", "Cmd-S": "save", "Cmd-F": "find",
4673    "Cmd-G": "findNext", "Shift-Cmd-G": "findPrev", "Cmd-Alt-F": "replace", "Shift-Cmd-Alt-F": "replaceAll",
4674    "Cmd-[": "indentLess", "Cmd-]": "indentMore", "Cmd-Backspace": "delLineLeft",
4675    "Cmd-U": "undoSelection", "Shift-Cmd-U": "redoSelection",
4676    fallthrough: ["basic", "emacsy"]
4677  };
4678  // Very basic readline/emacs-style bindings, which are standard on Mac.
4679  keyMap.emacsy = {
4680    "Ctrl-F": "goCharRight", "Ctrl-B": "goCharLeft", "Ctrl-P": "goLineUp", "Ctrl-N": "goLineDown",
4681    "Alt-F": "goWordRight", "Alt-B": "goWordLeft", "Ctrl-A": "goLineStart", "Ctrl-E": "goLineEnd",
4682    "Ctrl-V": "goPageDown", "Shift-Ctrl-V": "goPageUp", "Ctrl-D": "delCharAfter", "Ctrl-H": "delCharBefore",
4683    "Alt-D": "delWordAfter", "Alt-Backspace": "delWordBefore", "Ctrl-K": "killLine", "Ctrl-T": "transposeChars"
4684  };
4685  keyMap["default"] = mac ? keyMap.macDefault : keyMap.pcDefault;
4686
4687  // KEYMAP DISPATCH
4688
4689  function getKeyMap(val) {
4690    if (typeof val == "string") return keyMap[val];
4691    else return val;
4692  }
4693
4694  // Given an array of keymaps and a key name, call handle on any
4695  // bindings found, until that returns a truthy value, at which point
4696  // we consider the key handled. Implements things like binding a key
4697  // to false stopping further handling and keymap fallthrough.
4698  var lookupKey = CodeMirror.lookupKey = function(name, maps, handle) {
4699    function lookup(map) {
4700      map = getKeyMap(map);
4701      var found = map[name];
4702      if (found === false) return "stop";
4703      if (found != null && handle(found)) return true;
4704      if (map.nofallthrough) return "stop";
4705
4706      var fallthrough = map.fallthrough;
4707      if (fallthrough == null) return false;
4708      if (Object.prototype.toString.call(fallthrough) != "[object Array]")
4709        return lookup(fallthrough);
4710      for (var i = 0; i < fallthrough.length; ++i) {
4711        var done = lookup(fallthrough[i]);
4712        if (done) return done;
4713      }
4714      return false;
4715    }
4716
4717    for (var i = 0; i < maps.length; ++i) {
4718      var done = lookup(maps[i]);
4719      if (done) return done != "stop";
4720    }
4721  };
4722
4723  // Modifier key presses don't count as 'real' key presses for the
4724  // purpose of keymap fallthrough.
4725  var isModifierKey = CodeMirror.isModifierKey = function(event) {
4726    var name = keyNames[event.keyCode];
4727    return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod";
4728  };
4729
4730  // Look up the name of a key as indicated by an event object.
4731  var keyName = CodeMirror.keyName = function(event, noShift) {
4732    if (presto && event.keyCode == 34 && event["char"]) return false;
4733    var name = keyNames[event.keyCode];
4734    if (name == null || event.altGraphKey) return false;
4735    if (event.altKey) name = "Alt-" + name;
4736    if (flipCtrlCmd ? event.metaKey : event.ctrlKey) name = "Ctrl-" + name;
4737    if (flipCtrlCmd ? event.ctrlKey : event.metaKey) name = "Cmd-" + name;
4738    if (!noShift && event.shiftKey) name = "Shift-" + name;
4739    return name;
4740  };
4741
4742  // FROMTEXTAREA
4743
4744  CodeMirror.fromTextArea = function(textarea, options) {
4745    if (!options) options = {};
4746    options.value = textarea.value;
4747    if (!options.tabindex && textarea.tabindex)
4748      options.tabindex = textarea.tabindex;
4749    if (!options.placeholder && textarea.placeholder)
4750      options.placeholder = textarea.placeholder;
4751    // Set autofocus to true if this textarea is focused, or if it has
4752    // autofocus and no other element is focused.
4753    if (options.autofocus == null) {
4754      var hasFocus = activeElt();
4755      options.autofocus = hasFocus == textarea ||
4756        textarea.getAttribute("autofocus") != null && hasFocus == document.body;
4757    }
4758
4759    function save() {textarea.value = cm.getValue();}
4760    if (textarea.form) {
4761      on(textarea.form, "submit", save);
4762      // Deplorable hack to make the submit method do the right thing.
4763      if (!options.leaveSubmitMethodAlone) {
4764        var form = textarea.form, realSubmit = form.submit;
4765        try {
4766          var wrappedSubmit = form.submit = function() {
4767            save();
4768            form.submit = realSubmit;
4769            form.submit();
4770            form.submit = wrappedSubmit;
4771          };
4772        } catch(e) {}
4773      }
4774    }
4775
4776    textarea.style.display = "none";
4777    var cm = CodeMirror(function(node) {
4778      textarea.parentNode.insertBefore(node, textarea.nextSibling);
4779    }, options);
4780    cm.save = save;
4781    cm.getTextArea = function() { return textarea; };
4782    cm.toTextArea = function() {
4783      save();
4784      textarea.parentNode.removeChild(cm.getWrapperElement());
4785      textarea.style.display = "";
4786      if (textarea.form) {
4787        off(textarea.form, "submit", save);
4788        if (typeof textarea.form.submit == "function")
4789          textarea.form.submit = realSubmit;
4790      }
4791    };
4792    return cm;
4793  };
4794
4795  // STRING STREAM
4796
4797  // Fed to the mode parsers, provides helper functions to make
4798  // parsers more succinct.
4799
4800  var StringStream = CodeMirror.StringStream = function(string, tabSize) {
4801    this.pos = this.start = 0;
4802    this.string = string;
4803    this.tabSize = tabSize || 8;
4804    this.lastColumnPos = this.lastColumnValue = 0;
4805    this.lineStart = 0;
4806  };
4807
4808  StringStream.prototype = {
4809    eol: function() {return this.pos >= this.string.length;},
4810    sol: function() {return this.pos == this.lineStart;},
4811    peek: function() {return this.string.charAt(this.pos) || undefined;},
4812    next: function() {
4813      if (this.pos < this.string.length)
4814        return this.string.charAt(this.pos++);
4815    },
4816    eat: function(match) {
4817      var ch = this.string.charAt(this.pos);
4818      if (typeof match == "string") var ok = ch == match;
4819      else var ok = ch && (match.test ? match.test(ch) : match(ch));
4820      if (ok) {++this.pos; return ch;}
4821    },
4822    eatWhile: function(match) {
4823      var start = this.pos;
4824      while (this.eat(match)){}
4825      return this.pos > start;
4826    },
4827    eatSpace: function() {
4828      var start = this.pos;
4829      while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) ++this.pos;
4830      return this.pos > start;
4831    },
4832    skipToEnd: function() {this.pos = this.string.length;},
4833    skipTo: function(ch) {
4834      var found = this.string.indexOf(ch, this.pos);
4835      if (found > -1) {this.pos = found; return true;}
4836    },
4837    backUp: function(n) {this.pos -= n;},
4838    column: function() {
4839      if (this.lastColumnPos < this.start) {
4840        this.lastColumnValue = countColumn(this.string, this.start, this.tabSize, this.lastColumnPos, this.lastColumnValue);
4841        this.lastColumnPos = this.start;
4842      }
4843      return this.lastColumnValue - (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0);
4844    },
4845    indentation: function() {
4846      return countColumn(this.string, null, this.tabSize) -
4847        (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0);
4848    },
4849    match: function(pattern, consume, caseInsensitive) {
4850      if (typeof pattern == "string") {
4851        var cased = function(str) {return caseInsensitive ? str.toLowerCase() : str;};
4852        var substr = this.string.substr(this.pos, pattern.length);
4853        if (cased(substr) == cased(pattern)) {
4854          if (consume !== false) this.pos += pattern.length;
4855          return true;
4856        }
4857      } else {
4858        var match = this.string.slice(this.pos).match(pattern);
4859        if (match && match.index > 0) return null;
4860        if (match && consume !== false) this.pos += match[0].length;
4861        return match;
4862      }
4863    },
4864    current: function(){return this.string.slice(this.start, this.pos);},
4865    hideFirstChars: function(n, inner) {
4866      this.lineStart += n;
4867      try { return inner(); }
4868      finally { this.lineStart -= n; }
4869    }
4870  };
4871
4872  // TEXTMARKERS
4873
4874  // Created with markText and setBookmark methods. A TextMarker is a
4875  // handle that can be used to clear or find a marked position in the
4876  // document. Line objects hold arrays (markedSpans) containing
4877  // {from, to, marker} object pointing to such marker objects, and
4878  // indicating that such a marker is present on that line. Multiple
4879  // lines may point to the same marker when it spans across lines.
4880  // The spans will have null for their from/to properties when the
4881  // marker continues beyond the start/end of the line. Markers have
4882  // links back to the lines they currently touch.
4883
4884  var TextMarker = CodeMirror.TextMarker = function(doc, type) {
4885    this.lines = [];
4886    this.type = type;
4887    this.doc = doc;
4888  };
4889  eventMixin(TextMarker);
4890
4891  // Clear the marker.
4892  TextMarker.prototype.clear = function() {
4893    if (this.explicitlyCleared) return;
4894    var cm = this.doc.cm, withOp = cm && !cm.curOp;
4895    if (withOp) startOperation(cm);
4896    if (hasHandler(this, "clear")) {
4897      var found = this.find();
4898      if (found) signalLater(this, "clear", found.from, found.to);
4899    }
4900    var min = null, max = null;
4901    for (var i = 0; i < this.lines.length; ++i) {
4902      var line = this.lines[i];
4903      var span = getMarkedSpanFor(line.markedSpans, this);
4904      if (cm && !this.collapsed) regLineChange(cm, lineNo(line), "text");
4905      else if (cm) {
4906        if (span.to != null) max = lineNo(line);
4907        if (span.from != null) min = lineNo(line);
4908      }
4909      line.markedSpans = removeMarkedSpan(line.markedSpans, span);
4910      if (span.from == null && this.collapsed && !lineIsHidden(this.doc, line) && cm)
4911        updateLineHeight(line, textHeight(cm.display));
4912    }
4913    if (cm && this.collapsed && !cm.options.lineWrapping) for (var i = 0; i < this.lines.length; ++i) {
4914      var visual = visualLine(this.lines[i]), len = lineLength(visual);
4915      if (len > cm.display.maxLineLength) {
4916        cm.display.maxLine = visual;
4917        cm.display.maxLineLength = len;
4918        cm.display.maxLineChanged = true;
4919      }
4920    }
4921
4922    if (min != null && cm && this.collapsed) regChange(cm, min, max + 1);
4923    this.lines.length = 0;
4924    this.explicitlyCleared = true;
4925    if (this.atomic && this.doc.cantEdit) {
4926      this.doc.cantEdit = false;
4927      if (cm) reCheckSelection(cm.doc);
4928    }
4929    if (cm) signalLater(cm, "markerCleared", cm, this);
4930    if (withOp) endOperation(cm);
4931    if (this.parent) this.parent.clear();
4932  };
4933
4934  // Find the position of the marker in the document. Returns a {from,
4935  // to} object by default. Side can be passed to get a specific side
4936  // -- 0 (both), -1 (left), or 1 (right). When lineObj is true, the
4937  // Pos objects returned contain a line object, rather than a line
4938  // number (used to prevent looking up the same line twice).
4939  TextMarker.prototype.find = function(side, lineObj) {
4940    if (side == null && this.type == "bookmark") side = 1;
4941    var from, to;
4942    for (var i = 0; i < this.lines.length; ++i) {
4943      var line = this.lines[i];
4944      var span = getMarkedSpanFor(line.markedSpans, this);
4945      if (span.from != null) {
4946        from = Pos(lineObj ? line : lineNo(line), span.from);
4947        if (side == -1) return from;
4948      }
4949      if (span.to != null) {
4950        to = Pos(lineObj ? line : lineNo(line), span.to);
4951        if (side == 1) return to;
4952      }
4953    }
4954    return from && {from: from, to: to};
4955  };
4956
4957  // Signals that the marker's widget changed, and surrounding layout
4958  // should be recomputed.
4959  TextMarker.prototype.changed = function() {
4960    var pos = this.find(-1, true), widget = this, cm = this.doc.cm;
4961    if (!pos || !cm) return;
4962    runInOp(cm, function() {
4963      var line = pos.line, lineN = lineNo(pos.line);
4964      var view = findViewForLine(cm, lineN);
4965      if (view) {
4966        clearLineMeasurementCacheFor(view);
4967        cm.curOp.selectionChanged = cm.curOp.forceUpdate = true;
4968      }
4969      cm.curOp.updateMaxLine = true;
4970      if (!lineIsHidden(widget.doc, line) && widget.height != null) {
4971        var oldHeight = widget.height;
4972        widget.height = null;
4973        var dHeight = widgetHeight(widget) - oldHeight;
4974        if (dHeight)
4975          updateLineHeight(line, line.height + dHeight);
4976      }
4977    });
4978  };
4979
4980  TextMarker.prototype.attachLine = function(line) {
4981    if (!this.lines.length && this.doc.cm) {
4982      var op = this.doc.cm.curOp;
4983      if (!op.maybeHiddenMarkers || indexOf(op.maybeHiddenMarkers, this) == -1)
4984        (op.maybeUnhiddenMarkers || (op.maybeUnhiddenMarkers = [])).push(this);
4985    }
4986    this.lines.push(line);
4987  };
4988  TextMarker.prototype.detachLine = function(line) {
4989    this.lines.splice(indexOf(this.lines, line), 1);
4990    if (!this.lines.length && this.doc.cm) {
4991      var op = this.doc.cm.curOp;
4992      (op.maybeHiddenMarkers || (op.maybeHiddenMarkers = [])).push(this);
4993    }
4994  };
4995
4996  // Collapsed markers have unique ids, in order to be able to order
4997  // them, which is needed for uniquely determining an outer marker
4998  // when they overlap (they may nest, but not partially overlap).
4999  var nextMarkerId = 0;
5000
5001  // Create a marker, wire it up to the right lines, and
5002  function markText(doc, from, to, options, type) {
5003    // Shared markers (across linked documents) are handled separately
5004    // (markTextShared will call out to this again, once per
5005    // document).
5006    if (options && options.shared) return markTextShared(doc, from, to, options, type);
5007    // Ensure we are in an operation.
5008    if (doc.cm && !doc.cm.curOp) return operation(doc.cm, markText)(doc, from, to, options, type);
5009
5010    var marker = new TextMarker(doc, type), diff = cmp(from, to);
5011    if (options) copyObj(options, marker, false);
5012    // Don't connect empty markers unless clearWhenEmpty is false
5013    if (diff > 0 || diff == 0 && marker.clearWhenEmpty !== false)
5014      return marker;
5015    if (marker.replacedWith) {
5016      // Showing up as a widget implies collapsed (widget replaces text)
5017      marker.collapsed = true;
5018      marker.widgetNode = elt("span", [marker.replacedWith], "CodeMirror-widget");
5019      if (!options.handleMouseEvents) marker.widgetNode.ignoreEvents = true;
5020      if (options.insertLeft) marker.widgetNode.insertLeft = true;
5021    }
5022    if (marker.collapsed) {
5023      if (conflictingCollapsedRange(doc, from.line, from, to, marker) ||
5024          from.line != to.line && conflictingCollapsedRange(doc, to.line, from, to, marker))
5025        throw new Error("Inserting collapsed marker partially overlapping an existing one");
5026      sawCollapsedSpans = true;
5027    }
5028
5029    if (marker.addToHistory)
5030      addChangeToHistory(doc, {from: from, to: to, origin: "markText"}, doc.sel, NaN);
5031
5032    var curLine = from.line, cm = doc.cm, updateMaxLine;
5033    doc.iter(curLine, to.line + 1, function(line) {
5034      if (cm && marker.collapsed && !cm.options.lineWrapping && visualLine(line) == cm.display.maxLine)
5035        updateMaxLine = true;
5036      if (marker.collapsed && curLine != from.line) updateLineHeight(line, 0);
5037      addMarkedSpan(line, new MarkedSpan(marker,
5038                                         curLine == from.line ? from.ch : null,
5039                                         curLine == to.line ? to.ch : null));
5040      ++curLine;
5041    });
5042    // lineIsHidden depends on the presence of the spans, so needs a second pass
5043    if (marker.collapsed) doc.iter(from.line, to.line + 1, function(line) {
5044      if (lineIsHidden(doc, line)) updateLineHeight(line, 0);
5045    });
5046
5047    if (marker.clearOnEnter) on(marker, "beforeCursorEnter", function() { marker.clear(); });
5048
5049    if (marker.readOnly) {
5050      sawReadOnlySpans = true;
5051      if (doc.history.done.length || doc.history.undone.length)
5052        doc.clearHistory();
5053    }
5054    if (marker.collapsed) {
5055      marker.id = ++nextMarkerId;
5056      marker.atomic = true;
5057    }
5058    if (cm) {
5059      // Sync editor state
5060      if (updateMaxLine) cm.curOp.updateMaxLine = true;
5061      if (marker.collapsed)
5062        regChange(cm, from.line, to.line + 1);
5063      else if (marker.className || marker.title || marker.startStyle || marker.endStyle)
5064        for (var i = from.line; i <= to.line; i++) regLineChange(cm, i, "text");
5065      if (marker.atomic) reCheckSelection(cm.doc);
5066      signalLater(cm, "markerAdded", cm, marker);
5067    }
5068    return marker;
5069  }
5070
5071  // SHARED TEXTMARKERS
5072
5073  // A shared marker spans multiple linked documents. It is
5074  // implemented as a meta-marker-object controlling multiple normal
5075  // markers.
5076  var SharedTextMarker = CodeMirror.SharedTextMarker = function(markers, primary) {
5077    this.markers = markers;
5078    this.primary = primary;
5079    for (var i = 0; i < markers.length; ++i)
5080      markers[i].parent = this;
5081  };
5082  eventMixin(SharedTextMarker);
5083
5084  SharedTextMarker.prototype.clear = function() {
5085    if (this.explicitlyCleared) return;
5086    this.explicitlyCleared = true;
5087    for (var i = 0; i < this.markers.length; ++i)
5088      this.markers[i].clear();
5089    signalLater(this, "clear");
5090  };
5091  SharedTextMarker.prototype.find = function(side, lineObj) {
5092    return this.primary.find(side, lineObj);
5093  };
5094
5095  function markTextShared(doc, from, to, options, type) {
5096    options = copyObj(options);
5097    options.shared = false;
5098    var markers = [markText(doc, from, to, options, type)], primary = markers[0];
5099    var widget = options.widgetNode;
5100    linkedDocs(doc, function(doc) {
5101      if (widget) options.widgetNode = widget.cloneNode(true);
5102      markers.push(markText(doc, clipPos(doc, from), clipPos(doc, to), options, type));
5103      for (var i = 0; i < doc.linked.length; ++i)
5104        if (doc.linked[i].isParent) return;
5105      primary = lst(markers);
5106    });
5107    return new SharedTextMarker(markers, primary);
5108  }
5109
5110  function findSharedMarkers(doc) {
5111    return doc.findMarks(Pos(doc.first, 0), doc.clipPos(Pos(doc.lastLine())),
5112                         function(m) { return m.parent; });
5113  }
5114
5115  function copySharedMarkers(doc, markers) {
5116    for (var i = 0; i < markers.length; i++) {
5117      var marker = markers[i], pos = marker.find();
5118      var mFrom = doc.clipPos(pos.from), mTo = doc.clipPos(pos.to);
5119      if (cmp(mFrom, mTo)) {
5120        var subMark = markText(doc, mFrom, mTo, marker.primary, marker.primary.type);
5121        marker.markers.push(subMark);
5122        subMark.parent = marker;
5123      }
5124    }
5125  }
5126
5127  function detachSharedMarkers(markers) {
5128    for (var i = 0; i < markers.length; i++) {
5129      var marker = markers[i], linked = [marker.primary.doc];;
5130      linkedDocs(marker.primary.doc, function(d) { linked.push(d); });
5131      for (var j = 0; j < marker.markers.length; j++) {
5132        var subMarker = marker.markers[j];
5133        if (indexOf(linked, subMarker.doc) == -1) {
5134          subMarker.parent = null;
5135          marker.markers.splice(j--, 1);
5136        }
5137      }
5138    }
5139  }
5140
5141  // TEXTMARKER SPANS
5142
5143  function MarkedSpan(marker, from, to) {
5144    this.marker = marker;
5145    this.from = from; this.to = to;
5146  }
5147
5148  // Search an array of spans for a span matching the given marker.
5149  function getMarkedSpanFor(spans, marker) {
5150    if (spans) for (var i = 0; i < spans.length; ++i) {
5151      var span = spans[i];
5152      if (span.marker == marker) return span;
5153    }
5154  }
5155  // Remove a span from an array, returning undefined if no spans are
5156  // left (we don't store arrays for lines without spans).
5157  function removeMarkedSpan(spans, span) {
5158    for (var r, i = 0; i < spans.length; ++i)
5159      if (spans[i] != span) (r || (r = [])).push(spans[i]);
5160    return r;
5161  }
5162  // Add a span to a line.
5163  function addMarkedSpan(line, span) {
5164    line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span];
5165    span.marker.attachLine(line);
5166  }
5167
5168  // Used for the algorithm that adjusts markers for a change in the
5169  // document. These functions cut an array of spans at a given
5170  // character position, returning an array of remaining chunks (or
5171  // undefined if nothing remains).
5172  function markedSpansBefore(old, startCh, isInsert) {
5173    if (old) for (var i = 0, nw; i < old.length; ++i) {
5174      var span = old[i], marker = span.marker;
5175      var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= startCh : span.from < startCh);
5176      if (startsBefore || span.from == startCh && marker.type == "bookmark" && (!isInsert || !span.marker.insertLeft)) {
5177        var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= startCh : span.to > startCh);
5178        (nw || (nw = [])).push(new MarkedSpan(marker, span.from, endsAfter ? null : span.to));
5179      }
5180    }
5181    return nw;
5182  }
5183  function markedSpansAfter(old, endCh, isInsert) {
5184    if (old) for (var i = 0, nw; i < old.length; ++i) {
5185      var span = old[i], marker = span.marker;
5186      var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= endCh : span.to > endCh);
5187      if (endsAfter || span.from == endCh && marker.type == "bookmark" && (!isInsert || span.marker.insertLeft)) {
5188        var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= endCh : span.from < endCh);
5189        (nw || (nw = [])).push(new MarkedSpan(marker, startsBefore ? null : span.from - endCh,
5190                                              span.to == null ? null : span.to - endCh));
5191      }
5192    }
5193    return nw;
5194  }
5195
5196  // Given a change object, compute the new set of marker spans that
5197  // cover the line in which the change took place. Removes spans
5198  // entirely within the change, reconnects spans belonging to the
5199  // same marker that appear on both sides of the change, and cuts off
5200  // spans partially within the change. Returns an array of span
5201  // arrays with one element for each line in (after) the change.
5202  function stretchSpansOverChange(doc, change) {
5203    var oldFirst = isLine(doc, change.from.line) && getLine(doc, change.from.line).markedSpans;
5204    var oldLast = isLine(doc, change.to.line) && getLine(doc, change.to.line).markedSpans;
5205    if (!oldFirst && !oldLast) return null;
5206
5207    var startCh = change.from.ch, endCh = change.to.ch, isInsert = cmp(change.from, change.to) == 0;
5208    // Get the spans that 'stick out' on both sides
5209    var first = markedSpansBefore(oldFirst, startCh, isInsert);
5210    var last = markedSpansAfter(oldLast, endCh, isInsert);
5211
5212    // Next, merge those two ends
5213    var sameLine = change.text.length == 1, offset = lst(change.text).length + (sameLine ? startCh : 0);
5214    if (first) {
5215      // Fix up .to properties of first
5216      for (var i = 0; i < first.length; ++i) {
5217        var span = first[i];
5218        if (span.to == null) {
5219          var found = getMarkedSpanFor(last, span.marker);
5220          if (!found) span.to = startCh;
5221          else if (sameLine) span.to = found.to == null ? null : found.to + offset;
5222        }
5223      }
5224    }
5225    if (last) {
5226      // Fix up .from in last (or move them into first in case of sameLine)
5227      for (var i = 0; i < last.length; ++i) {
5228        var span = last[i];
5229        if (span.to != null) span.to += offset;
5230        if (span.from == null) {
5231          var found = getMarkedSpanFor(first, span.marker);
5232          if (!found) {
5233            span.from = offset;
5234            if (sameLine) (first || (first = [])).push(span);
5235          }
5236        } else {
5237          span.from += offset;
5238          if (sameLine) (first || (first = [])).push(span);
5239        }
5240      }
5241    }
5242    // Make sure we didn't create any zero-length spans
5243    if (first) first = clearEmptySpans(first);
5244    if (last && last != first) last = clearEmptySpans(last);
5245
5246    var newMarkers = [first];
5247    if (!sameLine) {
5248      // Fill gap with whole-line-spans
5249      var gap = change.text.length - 2, gapMarkers;
5250      if (gap > 0 && first)
5251        for (var i = 0; i < first.length; ++i)
5252          if (first[i].to == null)
5253            (gapMarkers || (gapMarkers = [])).push(new MarkedSpan(first[i].marker, null, null));
5254      for (var i = 0; i < gap; ++i)
5255        newMarkers.push(gapMarkers);
5256      newMarkers.push(last);
5257    }
5258    return newMarkers;
5259  }
5260
5261  // Remove spans that are empty and don't have a clearWhenEmpty
5262  // option of false.
5263  function clearEmptySpans(spans) {
5264    for (var i = 0; i < spans.length; ++i) {
5265      var span = spans[i];
5266      if (span.from != null && span.from == span.to && span.marker.clearWhenEmpty !== false)
5267        spans.splice(i--, 1);
5268    }
5269    if (!spans.length) return null;
5270    return spans;
5271  }
5272
5273  // Used for un/re-doing changes from the history. Combines the
5274  // result of computing the existing spans with the set of spans that
5275  // existed in the history (so that deleting around a span and then
5276  // undoing brings back the span).
5277  function mergeOldSpans(doc, change) {
5278    var old = getOldSpans(doc, change);
5279    var stretched = stretchSpansOverChange(doc, change);
5280    if (!old) return stretched;
5281    if (!stretched) return old;
5282
5283    for (var i = 0; i < old.length; ++i) {
5284      var oldCur = old[i], stretchCur = stretched[i];
5285      if (oldCur && stretchCur) {
5286        spans: for (var j = 0; j < stretchCur.length; ++j) {
5287          var span = stretchCur[j];
5288          for (var k = 0; k < oldCur.length; ++k)
5289            if (oldCur[k].marker == span.marker) continue spans;
5290          oldCur.push(span);
5291        }
5292      } else if (stretchCur) {
5293        old[i] = stretchCur;
5294      }
5295    }
5296    return old;
5297  }
5298
5299  // Used to 'clip' out readOnly ranges when making a change.
5300  function removeReadOnlyRanges(doc, from, to) {
5301    var markers = null;
5302    doc.iter(from.line, to.line + 1, function(line) {
5303      if (line.markedSpans) for (var i = 0; i < line.markedSpans.length; ++i) {
5304        var mark = line.markedSpans[i].marker;
5305        if (mark.readOnly && (!markers || indexOf(markers, mark) == -1))
5306          (markers || (markers = [])).push(mark);
5307      }
5308    });
5309    if (!markers) return null;
5310    var parts = [{from: from, to: to}];
5311    for (var i = 0; i < markers.length; ++i) {
5312      var mk = markers[i], m = mk.find(0);
5313      for (var j = 0; j < parts.length; ++j) {
5314        var p = parts[j];
5315        if (cmp(p.to, m.from) < 0 || cmp(p.from, m.to) > 0) continue;
5316        var newParts = [j, 1], dfrom = cmp(p.from, m.from), dto = cmp(p.to, m.to);
5317        if (dfrom < 0 || !mk.inclusiveLeft && !dfrom)
5318          newParts.push({from: p.from, to: m.from});
5319        if (dto > 0 || !mk.inclusiveRight && !dto)
5320          newParts.push({from: m.to, to: p.to});
5321        parts.splice.apply(parts, newParts);
5322        j += newParts.length - 1;
5323      }
5324    }
5325    return parts;
5326  }
5327
5328  // Connect or disconnect spans from a line.
5329  function detachMarkedSpans(line) {
5330    var spans = line.markedSpans;
5331    if (!spans) return;
5332    for (var i = 0; i < spans.length; ++i)
5333      spans[i].marker.detachLine(line);
5334    line.markedSpans = null;
5335  }
5336  function attachMarkedSpans(line, spans) {
5337    if (!spans) return;
5338    for (var i = 0; i < spans.length; ++i)
5339      spans[i].marker.attachLine(line);
5340    line.markedSpans = spans;
5341  }
5342
5343  // Helpers used when computing which overlapping collapsed span
5344  // counts as the larger one.
5345  function extraLeft(marker) { return marker.inclusiveLeft ? -1 : 0; }
5346  function extraRight(marker) { return marker.inclusiveRight ? 1 : 0; }
5347
5348  // Returns a number indicating which of two overlapping collapsed
5349  // spans is larger (and thus includes the other). Falls back to
5350  // comparing ids when the spans cover exactly the same range.
5351  function compareCollapsedMarkers(a, b) {
5352    var lenDiff = a.lines.length - b.lines.length;
5353    if (lenDiff != 0) return lenDiff;
5354    var aPos = a.find(), bPos = b.find();
5355    var fromCmp = cmp(aPos.from, bPos.from) || extraLeft(a) - extraLeft(b);
5356    if (fromCmp) return -fromCmp;
5357    var toCmp = cmp(aPos.to, bPos.to) || extraRight(a) - extraRight(b);
5358    if (toCmp) return toCmp;
5359    return b.id - a.id;
5360  }
5361
5362  // Find out whether a line ends or starts in a collapsed span. If
5363  // so, return the marker for that span.
5364  function collapsedSpanAtSide(line, start) {
5365    var sps = sawCollapsedSpans && line.markedSpans, found;
5366    if (sps) for (var sp, i = 0; i < sps.length; ++i) {
5367      sp = sps[i];
5368      if (sp.marker.collapsed && (start ? sp.from : sp.to) == null &&
5369          (!found || compareCollapsedMarkers(found, sp.marker) < 0))
5370        found = sp.marker;
5371    }
5372    return found;
5373  }
5374  function collapsedSpanAtStart(line) { return collapsedSpanAtSide(line, true); }
5375  function collapsedSpanAtEnd(line) { return collapsedSpanAtSide(line, false); }
5376
5377  // Test whether there exists a collapsed span that partially
5378  // overlaps (covers the start or end, but not both) of a new span.
5379  // Such overlap is not allowed.
5380  function conflictingCollapsedRange(doc, lineNo, from, to, marker) {
5381    var line = getLine(doc, lineNo);
5382    var sps = sawCollapsedSpans && line.markedSpans;
5383    if (sps) for (var i = 0; i < sps.length; ++i) {
5384      var sp = sps[i];
5385      if (!sp.marker.collapsed) continue;
5386      var found = sp.marker.find(0);
5387      var fromCmp = cmp(found.from, from) || extraLeft(sp.marker) - extraLeft(marker);
5388      var toCmp = cmp(found.to, to) || extraRight(sp.marker) - extraRight(marker);
5389      if (fromCmp >= 0 && toCmp <= 0 || fromCmp <= 0 && toCmp >= 0) continue;
5390      if (fromCmp <= 0 && (cmp(found.to, from) || extraRight(sp.marker) - extraLeft(marker)) > 0 ||
5391          fromCmp >= 0 && (cmp(found.from, to) || extraLeft(sp.marker) - extraRight(marker)) < 0)
5392        return true;
5393    }
5394  }
5395
5396  // A visual line is a line as drawn on the screen. Folding, for
5397  // example, can cause multiple logical lines to appear on the same
5398  // visual line. This finds the start of the visual line that the
5399  // given line is part of (usually that is the line itself).
5400  function visualLine(line) {
5401    var merged;
5402    while (merged = collapsedSpanAtStart(line))
5403      line = merged.find(-1, true).line;
5404    return line;
5405  }
5406
5407  // Returns an array of logical lines that continue the visual line
5408  // started by the argument, or undefined if there are no such lines.
5409  function visualLineContinued(line) {
5410    var merged, lines;
5411    while (merged = collapsedSpanAtEnd(line)) {
5412      line = merged.find(1, true).line;
5413      (lines || (lines = [])).push(line);
5414    }
5415    return lines;
5416  }
5417
5418  // Get the line number of the start of the visual line that the
5419  // given line number is part of.
5420  function visualLineNo(doc, lineN) {
5421    var line = getLine(doc, lineN), vis = visualLine(line);
5422    if (line == vis) return lineN;
5423    return lineNo(vis);
5424  }
5425  // Get the line number of the start of the next visual line after
5426  // the given line.
5427  function visualLineEndNo(doc, lineN) {
5428    if (lineN > doc.lastLine()) return lineN;
5429    var line = getLine(doc, lineN), merged;
5430    if (!lineIsHidden(doc, line)) return lineN;
5431    while (merged = collapsedSpanAtEnd(line))
5432      line = merged.find(1, true).line;
5433    return lineNo(line) + 1;
5434  }
5435
5436  // Compute whether a line is hidden. Lines count as hidden when they
5437  // are part of a visual line that starts with another line, or when
5438  // they are entirely covered by collapsed, non-widget span.
5439  function lineIsHidden(doc, line) {
5440    var sps = sawCollapsedSpans && line.markedSpans;
5441    if (sps) for (var sp, i = 0; i < sps.length; ++i) {
5442      sp = sps[i];
5443      if (!sp.marker.collapsed) continue;
5444      if (sp.from == null) return true;
5445      if (sp.marker.widgetNode) continue;
5446      if (sp.from == 0 && sp.marker.inclusiveLeft && lineIsHiddenInner(doc, line, sp))
5447        return true;
5448    }
5449  }
5450  function lineIsHiddenInner(doc, line, span) {
5451    if (span.to == null) {
5452      var end = span.marker.find(1, true);
5453      return lineIsHiddenInner(doc, end.line, getMarkedSpanFor(end.line.markedSpans, span.marker));
5454    }
5455    if (span.marker.inclusiveRight && span.to == line.text.length)
5456      return true;
5457    for (var sp, i = 0; i < line.markedSpans.length; ++i) {
5458      sp = line.markedSpans[i];
5459      if (sp.marker.collapsed && !sp.marker.widgetNode && sp.from == span.to &&
5460          (sp.to == null || sp.to != span.from) &&
5461          (sp.marker.inclusiveLeft || span.marker.inclusiveRight) &&
5462          lineIsHiddenInner(doc, line, sp)) return true;
5463    }
5464  }
5465
5466  // LINE WIDGETS
5467
5468  // Line widgets are block elements displayed above or below a line.
5469
5470  var LineWidget = CodeMirror.LineWidget = function(cm, node, options) {
5471    if (options) for (var opt in options) if (options.hasOwnProperty(opt))
5472      this[opt] = options[opt];
5473    this.cm = cm;
5474    this.node = node;
5475  };
5476  eventMixin(LineWidget);
5477
5478  function adjustScrollWhenAboveVisible(cm, line, diff) {
5479    if (heightAtLine(line) < ((cm.curOp && cm.curOp.scrollTop) || cm.doc.scrollTop))
5480      addToScrollPos(cm, null, diff);
5481  }
5482
5483  LineWidget.prototype.clear = function() {
5484    var cm = this.cm, ws = this.line.widgets, line = this.line, no = lineNo(line);
5485    if (no == null || !ws) return;
5486    for (var i = 0; i < ws.length; ++i) if (ws[i] == this) ws.splice(i--, 1);
5487    if (!ws.length) line.widgets = null;
5488    var height = widgetHeight(this);
5489    runInOp(cm, function() {
5490      adjustScrollWhenAboveVisible(cm, line, -height);
5491      regLineChange(cm, no, "widget");
5492      updateLineHeight(line, Math.max(0, line.height - height));
5493    });
5494  };
5495  LineWidget.prototype.changed = function() {
5496    var oldH = this.height, cm = this.cm, line = this.line;
5497    this.height = null;
5498    var diff = widgetHeight(this) - oldH;
5499    if (!diff) return;
5500    runInOp(cm, function() {
5501      cm.curOp.forceUpdate = true;
5502      adjustScrollWhenAboveVisible(cm, line, diff);
5503      updateLineHeight(line, line.height + diff);
5504    });
5505  };
5506
5507  function widgetHeight(widget) {
5508    if (widget.height != null) return widget.height;
5509    if (!contains(document.body, widget.node))
5510      removeChildrenAndAdd(widget.cm.display.measure, elt("div", [widget.node], null, "position: relative"));
5511    return widget.height = widget.node.offsetHeight;
5512  }
5513
5514  function addLineWidget(cm, handle, node, options) {
5515    var widget = new LineWidget(cm, node, options);
5516    if (widget.noHScroll) cm.display.alignWidgets = true;
5517    changeLine(cm, handle, "widget", function(line) {
5518      var widgets = line.widgets || (line.widgets = []);
5519      if (widget.insertAt == null) widgets.push(widget);
5520      else widgets.splice(Math.min(widgets.length - 1, Math.max(0, widget.insertAt)), 0, widget);
5521      widget.line = line;
5522      if (!lineIsHidden(cm.doc, line)) {
5523        var aboveVisible = heightAtLine(line) < cm.doc.scrollTop;
5524        updateLineHeight(line, line.height + widgetHeight(widget));
5525        if (aboveVisible) addToScrollPos(cm, null, widget.height);
5526        cm.curOp.forceUpdate = true;
5527      }
5528      return true;
5529    });
5530    return widget;
5531  }
5532
5533  // LINE DATA STRUCTURE
5534
5535  // Line objects. These hold state related to a line, including
5536  // highlighting info (the styles array).
5537  var Line = CodeMirror.Line = function(text, markedSpans, estimateHeight) {
5538    this.text = text;
5539    attachMarkedSpans(this, markedSpans);
5540    this.height = estimateHeight ? estimateHeight(this) : 1;
5541  };
5542  eventMixin(Line);
5543  Line.prototype.lineNo = function() { return lineNo(this); };
5544
5545  // Change the content (text, markers) of a line. Automatically
5546  // invalidates cached information and tries to re-estimate the
5547  // line's height.
5548  function updateLine(line, text, markedSpans, estimateHeight) {
5549    line.text = text;
5550    if (line.stateAfter) line.stateAfter = null;
5551    if (line.styles) line.styles = null;
5552    if (line.order != null) line.order = null;
5553    detachMarkedSpans(line);
5554    attachMarkedSpans(line, markedSpans);
5555    var estHeight = estimateHeight ? estimateHeight(line) : 1;
5556    if (estHeight != line.height) updateLineHeight(line, estHeight);
5557  }
5558
5559  // Detach a line from the document tree and its markers.
5560  function cleanUpLine(line) {
5561    line.parent = null;
5562    detachMarkedSpans(line);
5563  }
5564
5565  function extractLineClasses(type, output) {
5566    if (type) for (;;) {
5567      var lineClass = type.match(/(?:^|\s+)line-(background-)?(\S+)/);
5568      if (!lineClass) break;
5569      type = type.slice(0, lineClass.index) + type.slice(lineClass.index + lineClass[0].length);
5570      var prop = lineClass[1] ? "bgClass" : "textClass";
5571      if (output[prop] == null)
5572        output[prop] = lineClass[2];
5573      else if (!(new RegExp("(?:^|\s)" + lineClass[2] + "(?:$|\s)")).test(output[prop]))
5574        output[prop] += " " + lineClass[2];
5575    }
5576    return type;
5577  }
5578
5579  function callBlankLine(mode, state) {
5580    if (mode.blankLine) return mode.blankLine(state);
5581    if (!mode.innerMode) return;
5582    var inner = CodeMirror.innerMode(mode, state);
5583    if (inner.mode.blankLine) return inner.mode.blankLine(inner.state);
5584  }
5585
5586  function readToken(mode, stream, state) {
5587    var style = mode.token(stream, state);
5588    if (stream.pos <= stream.start)
5589      throw new Error("Mode " + mode.name + " failed to advance stream.");
5590    return style;
5591  }
5592
5593  // Run the given mode's parser over a line, calling f for each token.
5594  function runMode(cm, text, mode, state, f, lineClasses, forceToEnd) {
5595    var flattenSpans = mode.flattenSpans;
5596    if (flattenSpans == null) flattenSpans = cm.options.flattenSpans;
5597    var curStart = 0, curStyle = null;
5598    var stream = new StringStream(text, cm.options.tabSize), style;
5599    if (text == "") extractLineClasses(callBlankLine(mode, state), lineClasses);
5600    while (!stream.eol()) {
5601      if (stream.pos > cm.options.maxHighlightLength) {
5602        flattenSpans = false;
5603        if (forceToEnd) processLine(cm, text, state, stream.pos);
5604        stream.pos = text.length;
5605        style = null;
5606      } else {
5607        style = extractLineClasses(readToken(mode, stream, state), lineClasses);
5608      }
5609      if (cm.options.addModeClass) {
5610        var mName = CodeMirror.innerMode(mode, state).mode.name;
5611        if (mName) style = "m-" + (style ? mName + " " + style : mName);
5612      }
5613      if (!flattenSpans || curStyle != style) {
5614        if (curStart < stream.start) f(stream.start, curStyle);
5615        curStart = stream.start; curStyle = style;
5616      }
5617      stream.start = stream.pos;
5618    }
5619    while (curStart < stream.pos) {
5620      // Webkit seems to refuse to render text nodes longer than 57444 characters
5621      var pos = Math.min(stream.pos, curStart + 50000);
5622      f(pos, curStyle);
5623      curStart = pos;
5624    }
5625  }
5626
5627  // Compute a style array (an array starting with a mode generation
5628  // -- for invalidation -- followed by pairs of end positions and
5629  // style strings), which is used to highlight the tokens on the
5630  // line.
5631  function highlightLine(cm, line, state, forceToEnd) {
5632    // A styles array always starts with a number identifying the
5633    // mode/overlays that it is based on (for easy invalidation).
5634    var st = [cm.state.modeGen], lineClasses = {};
5635    // Compute the base array of styles
5636    runMode(cm, line.text, cm.doc.mode, state, function(end, style) {
5637      st.push(end, style);
5638    }, lineClasses, forceToEnd);
5639
5640    // Run overlays, adjust style array.
5641    for (var o = 0; o < cm.state.overlays.length; ++o) {
5642      var overlay = cm.state.overlays[o], i = 1, at = 0;
5643      runMode(cm, line.text, overlay.mode, true, function(end, style) {
5644        var start = i;
5645        // Ensure there's a token end at the current position, and that i points at it
5646        while (at < end) {
5647          var i_end = st[i];
5648          if (i_end > end)
5649            st.splice(i, 1, end, st[i+1], i_end);
5650          i += 2;
5651          at = Math.min(end, i_end);
5652        }
5653        if (!style) return;
5654        if (overlay.opaque) {
5655          st.splice(start, i - start, end, "cm-overlay " + style);
5656          i = start + 2;
5657        } else {
5658          for (; start < i; start += 2) {
5659            var cur = st[start+1];
5660            st[start+1] = (cur ? cur + " " : "") + "cm-overlay " + style;
5661          }
5662        }
5663      }, lineClasses);
5664    }
5665
5666    return {styles: st, classes: lineClasses.bgClass || lineClasses.textClass ? lineClasses : null};
5667  }
5668
5669  function getLineStyles(cm, line) {
5670    if (!line.styles || line.styles[0] != cm.state.modeGen) {
5671      var result = highlightLine(cm, line, line.stateAfter = getStateBefore(cm, lineNo(line)));
5672      line.styles = result.styles;
5673      if (result.classes) line.styleClasses = result.classes;
5674      else if (line.styleClasses) line.styleClasses = null;
5675    }
5676    return line.styles;
5677  }
5678
5679  // Lightweight form of highlight -- proceed over this line and
5680  // update state, but don't save a style array. Used for lines that
5681  // aren't currently visible.
5682  function processLine(cm, text, state, startAt) {
5683    var mode = cm.doc.mode;
5684    var stream = new StringStream(text, cm.options.tabSize);
5685    stream.start = stream.pos = startAt || 0;
5686    if (text == "") callBlankLine(mode, state);
5687    while (!stream.eol() && stream.pos <= cm.options.maxHighlightLength) {
5688      readToken(mode, stream, state);
5689      stream.start = stream.pos;
5690    }
5691  }
5692
5693  // Convert a style as returned by a mode (either null, or a string
5694  // containing one or more styles) to a CSS style. This is cached,
5695  // and also looks for line-wide styles.
5696  var styleToClassCache = {}, styleToClassCacheWithMode = {};
5697  function interpretTokenStyle(style, options) {
5698    if (!style || /^\s*$/.test(style)) return null;
5699    var cache = options.addModeClass ? styleToClassCacheWithMode : styleToClassCache;
5700    return cache[style] ||
5701      (cache[style] = style.replace(/\S+/g, "cm-$&"));
5702  }
5703
5704  // Render the DOM representation of the text of a line. Also builds
5705  // up a 'line map', which points at the DOM nodes that represent
5706  // specific stretches of text, and is used by the measuring code.
5707  // The returned object contains the DOM node, this map, and
5708  // information about line-wide styles that were set by the mode.
5709  function buildLineContent(cm, lineView) {
5710    // The padding-right forces the element to have a 'border', which
5711    // is needed on Webkit to be able to get line-level bounding
5712    // rectangles for it (in measureChar).
5713    var content = elt("span", null, null, webkit ? "padding-right: .1px" : null);
5714    var builder = {pre: elt("pre", [content]), content: content, col: 0, pos: 0, cm: cm};
5715    lineView.measure = {};
5716
5717    // Iterate over the logical lines that make up this visual line.
5718    for (var i = 0; i <= (lineView.rest ? lineView.rest.length : 0); i++) {
5719      var line = i ? lineView.rest[i - 1] : lineView.line, order;
5720      builder.pos = 0;
5721      builder.addToken = buildToken;
5722      // Optionally wire in some hacks into the token-rendering
5723      // algorithm, to deal with browser quirks.
5724      if ((ie || webkit) && cm.getOption("lineWrapping"))
5725        builder.addToken = buildTokenSplitSpaces(builder.addToken);
5726      if (hasBadBidiRects(cm.display.measure) && (order = getOrder(line)))
5727        builder.addToken = buildTokenBadBidi(builder.addToken, order);
5728      builder.map = [];
5729      insertLineContent(line, builder, getLineStyles(cm, line));
5730      if (line.styleClasses) {
5731        if (line.styleClasses.bgClass)
5732          builder.bgClass = joinClasses(line.styleClasses.bgClass, builder.bgClass || "");
5733        if (line.styleClasses.textClass)
5734          builder.textClass = joinClasses(line.styleClasses.textClass, builder.textClass || "");
5735      }
5736
5737      // Ensure at least a single node is present, for measuring.
5738      if (builder.map.length == 0)
5739        builder.map.push(0, 0, builder.content.appendChild(zeroWidthElement(cm.display.measure)));
5740
5741      // Store the map and a cache object for the current logical line
5742      if (i == 0) {
5743        lineView.measure.map = builder.map;
5744        lineView.measure.cache = {};
5745      } else {
5746        (lineView.measure.maps || (lineView.measure.maps = [])).push(builder.map);
5747        (lineView.measure.caches || (lineView.measure.caches = [])).push({});
5748      }
5749    }
5750
5751    signal(cm, "renderLine", cm, lineView.line, builder.pre);
5752    return builder;
5753  }
5754
5755  function defaultSpecialCharPlaceholder(ch) {
5756    var token = elt("span", "\u2022", "cm-invalidchar");
5757    token.title = "\\u" + ch.charCodeAt(0).toString(16);
5758    return token;
5759  }
5760
5761  // Build up the DOM representation for a single token, and add it to
5762  // the line map. Takes care to render special characters separately.
5763  function buildToken(builder, text, style, startStyle, endStyle, title) {
5764    if (!text) return;
5765    var special = builder.cm.options.specialChars, mustWrap = false;
5766    if (!special.test(text)) {
5767      builder.col += text.length;
5768      var content = document.createTextNode(text);
5769      builder.map.push(builder.pos, builder.pos + text.length, content);
5770      if (ie_upto8) mustWrap = true;
5771      builder.pos += text.length;
5772    } else {
5773      var content = document.createDocumentFragment(), pos = 0;
5774      while (true) {
5775        special.lastIndex = pos;
5776        var m = special.exec(text);
5777        var skipped = m ? m.index - pos : text.length - pos;
5778        if (skipped) {
5779          var txt = document.createTextNode(text.slice(pos, pos + skipped));
5780          if (ie_upto8) content.appendChild(elt("span", [txt]));
5781          else content.appendChild(txt);
5782          builder.map.push(builder.pos, builder.pos + skipped, txt);
5783          builder.col += skipped;
5784          builder.pos += skipped;
5785        }
5786        if (!m) break;
5787        pos += skipped + 1;
5788        if (m[0] == "\t") {
5789          var tabSize = builder.cm.options.tabSize, tabWidth = tabSize - builder.col % tabSize;
5790          var txt = content.appendChild(elt("span", spaceStr(tabWidth), "cm-tab"));
5791          builder.col += tabWidth;
5792        } else {
5793          var txt = builder.cm.options.specialCharPlaceholder(m[0]);
5794          if (ie_upto8) content.appendChild(elt("span", [txt]));
5795          else content.appendChild(txt);
5796          builder.col += 1;
5797        }
5798        builder.map.push(builder.pos, builder.pos + 1, txt);
5799        builder.pos++;
5800      }
5801    }
5802    if (style || startStyle || endStyle || mustWrap) {
5803      var fullStyle = style || "";
5804      if (startStyle) fullStyle += startStyle;
5805      if (endStyle) fullStyle += endStyle;
5806      var token = elt("span", [content], fullStyle);
5807      if (title) token.title = title;
5808      return builder.content.appendChild(token);
5809    }
5810    builder.content.appendChild(content);
5811  }
5812
5813  function buildTokenSplitSpaces(inner) {
5814    function split(old) {
5815      var out = " ";
5816      for (var i = 0; i < old.length - 2; ++i) out += i % 2 ? " " : "\u00a0";
5817      out += " ";
5818      return out;
5819    }
5820    return function(builder, text, style, startStyle, endStyle, title) {
5821      inner(builder, text.replace(/ {3,}/g, split), style, startStyle, endStyle, title);
5822    };
5823  }
5824
5825  // Work around nonsense dimensions being reported for stretches of
5826  // right-to-left text.
5827  function buildTokenBadBidi(inner, order) {
5828    return function(builder, text, style, startStyle, endStyle, title) {
5829      style = style ? style + " cm-force-border" : "cm-force-border";
5830      var start = builder.pos, end = start + text.length;
5831      for (;;) {
5832        // Find the part that overlaps with the start of this text
5833        for (var i = 0; i < order.length; i++) {
5834          var part = order[i];
5835          if (part.to > start && part.from <= start) break;
5836        }
5837        if (part.to >= end) return inner(builder, text, style, startStyle, endStyle, title);
5838        inner(builder, text.slice(0, part.to - start), style, startStyle, null, title);
5839        startStyle = null;
5840        text = text.slice(part.to - start);
5841        start = part.to;
5842      }
5843    };
5844  }
5845
5846  function buildCollapsedSpan(builder, size, marker, ignoreWidget) {
5847    var widget = !ignoreWidget && marker.widgetNode;
5848    if (widget) {
5849      builder.map.push(builder.pos, builder.pos + size, widget);
5850      builder.content.appendChild(widget);
5851    }
5852    builder.pos += size;
5853  }
5854
5855  // Outputs a number of spans to make up a line, taking highlighting
5856  // and marked text into account.
5857  function insertLineContent(line, builder, styles) {
5858    var spans = line.markedSpans, allText = line.text, at = 0;
5859    if (!spans) {
5860      for (var i = 1; i < styles.length; i+=2)
5861        builder.addToken(builder, allText.slice(at, at = styles[i]), interpretTokenStyle(styles[i+1], builder.cm.options));
5862      return;
5863    }
5864
5865    var len = allText.length, pos = 0, i = 1, text = "", style;
5866    var nextChange = 0, spanStyle, spanEndStyle, spanStartStyle, title, collapsed;
5867    for (;;) {
5868      if (nextChange == pos) { // Update current marker set
5869        spanStyle = spanEndStyle = spanStartStyle = title = "";
5870        collapsed = null; nextChange = Infinity;
5871        var foundBookmarks = [];
5872        for (var j = 0; j < spans.length; ++j) {
5873          var sp = spans[j], m = sp.marker;
5874          if (sp.from <= pos && (sp.to == null || sp.to > pos)) {
5875            if (sp.to != null && nextChange > sp.to) { nextChange = sp.to; spanEndStyle = ""; }
5876            if (m.className) spanStyle += " " + m.className;
5877            if (m.startStyle && sp.from == pos) spanStartStyle += " " + m.startStyle;
5878            if (m.endStyle && sp.to == nextChange) spanEndStyle += " " + m.endStyle;
5879            if (m.title && !title) title = m.title;
5880            if (m.collapsed && (!collapsed || compareCollapsedMarkers(collapsed.marker, m) < 0))
5881              collapsed = sp;
5882          } else if (sp.from > pos && nextChange > sp.from) {
5883            nextChange = sp.from;
5884          }
5885          if (m.type == "bookmark" && sp.from == pos && m.widgetNode) foundBookmarks.push(m);
5886        }
5887        if (collapsed && (collapsed.from || 0) == pos) {
5888          buildCollapsedSpan(builder, (collapsed.to == null ? len + 1 : collapsed.to) - pos,
5889                             collapsed.marker, collapsed.from == null);
5890          if (collapsed.to == null) return;
5891        }
5892        if (!collapsed && foundBookmarks.length) for (var j = 0; j < foundBookmarks.length; ++j)
5893          buildCollapsedSpan(builder, 0, foundBookmarks[j]);
5894      }
5895      if (pos >= len) break;
5896
5897      var upto = Math.min(len, nextChange);
5898      while (true) {
5899        if (text) {
5900          var end = pos + text.length;
5901          if (!collapsed) {
5902            var tokenText = end > upto ? text.slice(0, upto - pos) : text;
5903            builder.addToken(builder, tokenText, style ? style + spanStyle : spanStyle,
5904                             spanStartStyle, pos + tokenText.length == nextChange ? spanEndStyle : "", title);
5905          }
5906          if (end >= upto) {text = text.slice(upto - pos); pos = upto; break;}
5907          pos = end;
5908          spanStartStyle = "";
5909        }
5910        text = allText.slice(at, at = styles[i++]);
5911        style = interpretTokenStyle(styles[i++], builder.cm.options);
5912      }
5913    }
5914  }
5915
5916  // DOCUMENT DATA STRUCTURE
5917
5918  // By default, updates that start and end at the beginning of a line
5919  // are treated specially, in order to make the association of line
5920  // widgets and marker elements with the text behave more intuitive.
5921  function isWholeLineUpdate(doc, change) {
5922    return change.from.ch == 0 && change.to.ch == 0 && lst(change.text) == "" &&
5923      (!doc.cm || doc.cm.options.wholeLineUpdateBefore);
5924  }
5925
5926  // Perform a change on the document data structure.
5927  function updateDoc(doc, change, markedSpans, estimateHeight) {
5928    function spansFor(n) {return markedSpans ? markedSpans[n] : null;}
5929    function update(line, text, spans) {
5930      updateLine(line, text, spans, estimateHeight);
5931      signalLater(line, "change", line, change);
5932    }
5933
5934    var from = change.from, to = change.to, text = change.text;
5935    var firstLine = getLine(doc, from.line), lastLine = getLine(doc, to.line);
5936    var lastText = lst(text), lastSpans = spansFor(text.length - 1), nlines = to.line - from.line;
5937
5938    // Adjust the line structure
5939    if (isWholeLineUpdate(doc, change)) {
5940      // This is a whole-line replace. Treated specially to make
5941      // sure line objects move the way they are supposed to.
5942      for (var i = 0, added = []; i < text.length - 1; ++i)
5943        added.push(new Line(text[i], spansFor(i), estimateHeight));
5944      update(lastLine, lastLine.text, lastSpans);
5945      if (nlines) doc.remove(from.line, nlines);
5946      if (added.length) doc.insert(from.line, added);
5947    } else if (firstLine == lastLine) {
5948      if (text.length == 1) {
5949        update(firstLine, firstLine.text.slice(0, from.ch) + lastText + firstLine.text.slice(to.ch), lastSpans);
5950      } else {
5951        for (var added = [], i = 1; i < text.length - 1; ++i)
5952          added.push(new Line(text[i], spansFor(i), estimateHeight));
5953        added.push(new Line(lastText + firstLine.text.slice(to.ch), lastSpans, estimateHeight));
5954        update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
5955        doc.insert(from.line + 1, added);
5956      }
5957    } else if (text.length == 1) {
5958      update(firstLine, firstLine.text.slice(0, from.ch) + text[0] + lastLine.text.slice(to.ch), spansFor(0));
5959      doc.remove(from.line + 1, nlines);
5960    } else {
5961      update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
5962      update(lastLine, lastText + lastLine.text.slice(to.ch), lastSpans);
5963      for (var i = 1, added = []; i < text.length - 1; ++i)
5964        added.push(new Line(text[i], spansFor(i), estimateHeight));
5965      if (nlines > 1) doc.remove(from.line + 1, nlines - 1);
5966      doc.insert(from.line + 1, added);
5967    }
5968
5969    signalLater(doc, "change", doc, change);
5970  }
5971
5972  // The document is represented as a BTree consisting of leaves, with
5973  // chunk of lines in them, and branches, with up to ten leaves or
5974  // other branch nodes below them. The top node is always a branch
5975  // node, and is the document object itself (meaning it has
5976  // additional methods and properties).
5977  //
5978  // All nodes have parent links. The tree is used both to go from
5979  // line numbers to line objects, and to go from objects to numbers.
5980  // It also indexes by height, and is used to convert between height
5981  // and line object, and to find the total height of the document.
5982  //
5983  // See also http://marijnhaverbeke.nl/blog/codemirror-line-tree.html
5984
5985  function LeafChunk(lines) {
5986    this.lines = lines;
5987    this.parent = null;
5988    for (var i = 0, height = 0; i < lines.length; ++i) {
5989      lines[i].parent = this;
5990      height += lines[i].height;
5991    }
5992    this.height = height;
5993  }
5994
5995  LeafChunk.prototype = {
5996    chunkSize: function() { return this.lines.length; },
5997    // Remove the n lines at offset 'at'.
5998    removeInner: function(at, n) {
5999      for (var i = at, e = at + n; i < e; ++i) {
6000        var line = this.lines[i];
6001        this.height -= line.height;
6002        cleanUpLine(line);
6003        signalLater(line, "delete");
6004      }
6005      this.lines.splice(at, n);
6006    },
6007    // Helper used to collapse a small branch into a single leaf.
6008    collapse: function(lines) {
6009      lines.push.apply(lines, this.lines);
6010    },
6011    // Insert the given array of lines at offset 'at', count them as
6012    // having the given height.
6013    insertInner: function(at, lines, height) {
6014      this.height += height;
6015      this.lines = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at));
6016      for (var i = 0; i < lines.length; ++i) lines[i].parent = this;
6017    },
6018    // Used to iterate over a part of the tree.
6019    iterN: function(at, n, op) {
6020      for (var e = at + n; at < e; ++at)
6021        if (op(this.lines[at])) return true;
6022    }
6023  };
6024
6025  function BranchChunk(children) {
6026    this.children = children;
6027    var size = 0, height = 0;
6028    for (var i = 0; i < children.length; ++i) {
6029      var ch = children[i];
6030      size += ch.chunkSize(); height += ch.height;
6031      ch.parent = this;
6032    }
6033    this.size = size;
6034    this.height = height;
6035    this.parent = null;
6036  }
6037
6038  BranchChunk.prototype = {
6039    chunkSize: function() { return this.size; },
6040    removeInner: function(at, n) {
6041      this.size -= n;
6042      for (var i = 0; i < this.children.length; ++i) {
6043        var child = this.children[i], sz = child.chunkSize();
6044        if (at < sz) {
6045          var rm = Math.min(n, sz - at), oldHeight = child.height;
6046          child.removeInner(at, rm);
6047          this.height -= oldHeight - child.height;
6048          if (sz == rm) { this.children.splice(i--, 1); child.parent = null; }
6049          if ((n -= rm) == 0) break;
6050          at = 0;
6051        } else at -= sz;
6052      }
6053      // If the result is smaller than 25 lines, ensure that it is a
6054      // single leaf node.
6055      if (this.size - n < 25 &&
6056          (this.children.length > 1 || !(this.children[0] instanceof LeafChunk))) {
6057        var lines = [];
6058        this.collapse(lines);
6059        this.children = [new LeafChunk(lines)];
6060        this.children[0].parent = this;
6061      }
6062    },
6063    collapse: function(lines) {
6064      for (var i = 0; i < this.children.length; ++i) this.children[i].collapse(lines);
6065    },
6066    insertInner: function(at, lines, height) {
6067      this.size += lines.length;
6068      this.height += height;
6069      for (var i = 0; i < this.children.length; ++i) {
6070        var child = this.children[i], sz = child.chunkSize();
6071        if (at <= sz) {
6072          child.insertInner(at, lines, height);
6073          if (child.lines && child.lines.length > 50) {
6074            while (child.lines.length > 50) {
6075              var spilled = child.lines.splice(child.lines.length - 25, 25);
6076              var newleaf = new LeafChunk(spilled);
6077              child.height -= newleaf.height;
6078              this.children.splice(i + 1, 0, newleaf);
6079              newleaf.parent = this;
6080            }
6081            this.maybeSpill();
6082          }
6083          break;
6084        }
6085        at -= sz;
6086      }
6087    },
6088    // When a node has grown, check whether it should be split.
6089    maybeSpill: function() {
6090      if (this.children.length <= 10) return;
6091      var me = this;
6092      do {
6093        var spilled = me.children.splice(me.children.length - 5, 5);
6094        var sibling = new BranchChunk(spilled);
6095        if (!me.parent) { // Become the parent node
6096          var copy = new BranchChunk(me.children);
6097          copy.parent = me;
6098          me.children = [copy, sibling];
6099          me = copy;
6100        } else {
6101          me.size -= sibling.size;
6102          me.height -= sibling.height;
6103          var myIndex = indexOf(me.parent.children, me);
6104          me.parent.children.splice(myIndex + 1, 0, sibling);
6105        }
6106        sibling.parent = me.parent;
6107      } while (me.children.length > 10);
6108      me.parent.maybeSpill();
6109    },
6110    iterN: function(at, n, op) {
6111      for (var i = 0; i < this.children.length; ++i) {
6112        var child = this.children[i], sz = child.chunkSize();
6113        if (at < sz) {
6114          var used = Math.min(n, sz - at);
6115          if (child.iterN(at, used, op)) return true;
6116          if ((n -= used) == 0) break;
6117          at = 0;
6118        } else at -= sz;
6119      }
6120    }
6121  };
6122
6123  var nextDocId = 0;
6124  var Doc = CodeMirror.Doc = function(text, mode, firstLine) {
6125    if (!(this instanceof Doc)) return new Doc(text, mode, firstLine);
6126    if (firstLine == null) firstLine = 0;
6127
6128    BranchChunk.call(this, [new LeafChunk([new Line("", null)])]);
6129    this.first = firstLine;
6130    this.scrollTop = this.scrollLeft = 0;
6131    this.cantEdit = false;
6132    this.cleanGeneration = 1;
6133    this.frontier = firstLine;
6134    var start = Pos(firstLine, 0);
6135    this.sel = simpleSelection(start);
6136    this.history = new History(null);
6137    this.id = ++nextDocId;
6138    this.modeOption = mode;
6139
6140    if (typeof text == "string") text = splitLines(text);
6141    updateDoc(this, {from: start, to: start, text: text});
6142    setSelection(this, simpleSelection(start), sel_dontScroll);
6143  };
6144
6145  Doc.prototype = createObj(BranchChunk.prototype, {
6146    constructor: Doc,
6147    // Iterate over the document. Supports two forms -- with only one
6148    // argument, it calls that for each line in the document. With
6149    // three, it iterates over the range given by the first two (with
6150    // the second being non-inclusive).
6151    iter: function(from, to, op) {
6152      if (op) this.iterN(from - this.first, to - from, op);
6153      else this.iterN(this.first, this.first + this.size, from);
6154    },
6155
6156    // Non-public interface for adding and removing lines.
6157    insert: function(at, lines) {
6158      var height = 0;
6159      for (var i = 0; i < lines.length; ++i) height += lines[i].height;
6160      this.insertInner(at - this.first, lines, height);
6161    },
6162    remove: function(at, n) { this.removeInner(at - this.first, n); },
6163
6164    // From here, the methods are part of the public interface. Most
6165    // are also available from CodeMirror (editor) instances.
6166
6167    getValue: function(lineSep) {
6168      var lines = getLines(this, this.first, this.first + this.size);
6169      if (lineSep === false) return lines;
6170      return lines.join(lineSep || "\n");
6171    },
6172    setValue: docMethodOp(function(code) {
6173      var top = Pos(this.first, 0), last = this.first + this.size - 1;
6174      makeChange(this, {from: top, to: Pos(last, getLine(this, last).text.length),
6175                        text: splitLines(code), origin: "setValue"}, true);
6176      setSelection(this, simpleSelection(top));
6177    }),
6178    replaceRange: function(code, from, to, origin) {
6179      from = clipPos(this, from);
6180      to = to ? clipPos(this, to) : from;
6181      replaceRange(this, code, from, to, origin);
6182    },
6183    getRange: function(from, to, lineSep) {
6184      var lines = getBetween(this, clipPos(this, from), clipPos(this, to));
6185      if (lineSep === false) return lines;
6186      return lines.join(lineSep || "\n");
6187    },
6188
6189    getLine: function(line) {var l = this.getLineHandle(line); return l && l.text;},
6190
6191    getLineHandle: function(line) {if (isLine(this, line)) return getLine(this, line);},
6192    getLineNumber: function(line) {return lineNo(line);},
6193
6194    getLineHandleVisualStart: function(line) {
6195      if (typeof line == "number") line = getLine(this, line);
6196      return visualLine(line);
6197    },
6198
6199    lineCount: function() {return this.size;},
6200    firstLine: function() {return this.first;},
6201    lastLine: function() {return this.first + this.size - 1;},
6202
6203    clipPos: function(pos) {return clipPos(this, pos);},
6204
6205    getCursor: function(start) {
6206      var range = this.sel.primary(), pos;
6207      if (start == null || start == "head") pos = range.head;
6208      else if (start == "anchor") pos = range.anchor;
6209      else if (start == "end" || start == "to" || start === false) pos = range.to();
6210      else pos = range.from();
6211      return pos;
6212    },
6213    listSelections: function() { return this.sel.ranges; },
6214    somethingSelected: function() {return this.sel.somethingSelected();},
6215
6216    setCursor: docMethodOp(function(line, ch, options) {
6217      setSimpleSelection(this, clipPos(this, typeof line == "number" ? Pos(line, ch || 0) : line), null, options);
6218    }),
6219    setSelection: docMethodOp(function(anchor, head, options) {
6220      setSimpleSelection(this, clipPos(this, anchor), clipPos(this, head || anchor), options);
6221    }),
6222    extendSelection: docMethodOp(function(head, other, options) {
6223      extendSelection(this, clipPos(this, head), other && clipPos(this, other), options);
6224    }),
6225    extendSelections: docMethodOp(function(heads, options) {
6226      extendSelections(this, clipPosArray(this, heads, options));
6227    }),
6228    extendSelectionsBy: docMethodOp(function(f, options) {
6229      extendSelections(this, map(this.sel.ranges, f), options);
6230    }),
6231    setSelections: docMethodOp(function(ranges, primary, options) {
6232      if (!ranges.length) return;
6233      for (var i = 0, out = []; i < ranges.length; i++)
6234        out[i] = new Range(clipPos(this, ranges[i].anchor),
6235                           clipPos(this, ranges[i].head));
6236      if (primary == null) primary = Math.min(ranges.length - 1, this.sel.primIndex);
6237      setSelection(this, normalizeSelection(out, primary), options);
6238    }),
6239    addSelection: docMethodOp(function(anchor, head, options) {
6240      var ranges = this.sel.ranges.slice(0);
6241      ranges.push(new Range(clipPos(this, anchor), clipPos(this, head || anchor)));
6242      setSelection(this, normalizeSelection(ranges, ranges.length - 1), options);
6243    }),
6244
6245    getSelection: function(lineSep) {
6246      var ranges = this.sel.ranges, lines;
6247      for (var i = 0; i < ranges.length; i++) {
6248        var sel = getBetween(this, ranges[i].from(), ranges[i].to());
6249        lines = lines ? lines.concat(sel) : sel;
6250      }
6251      if (lineSep === false) return lines;
6252      else return lines.join(lineSep || "\n");
6253    },
6254    getSelections: function(lineSep) {
6255      var parts = [], ranges = this.sel.ranges;
6256      for (var i = 0; i < ranges.length; i++) {
6257        var sel = getBetween(this, ranges[i].from(), ranges[i].to());
6258        if (lineSep !== false) sel = sel.join(lineSep || "\n");
6259        parts[i] = sel;
6260      }
6261      return parts;
6262    },
6263    replaceSelection: function(code, collapse, origin) {
6264      var dup = [];
6265      for (var i = 0; i < this.sel.ranges.length; i++)
6266        dup[i] = code;
6267      this.replaceSelections(dup, collapse, origin || "+input");
6268    },
6269    replaceSelections: docMethodOp(function(code, collapse, origin) {
6270      var changes = [], sel = this.sel;
6271      for (var i = 0; i < sel.ranges.length; i++) {
6272        var range = sel.ranges[i];
6273        changes[i] = {from: range.from(), to: range.to(), text: splitLines(code[i]), origin: origin};
6274      }
6275      var newSel = collapse && collapse != "end" && computeReplacedSel(this, changes, collapse);
6276      for (var i = changes.length - 1; i >= 0; i--)
6277        makeChange(this, changes[i]);
6278      if (newSel) setSelectionReplaceHistory(this, newSel);
6279      else if (this.cm) ensureCursorVisible(this.cm);
6280    }),
6281    undo: docMethodOp(function() {makeChangeFromHistory(this, "undo");}),
6282    redo: docMethodOp(function() {makeChangeFromHistory(this, "redo");}),
6283    undoSelection: docMethodOp(function() {makeChangeFromHistory(this, "undo", true);}),
6284    redoSelection: docMethodOp(function() {makeChangeFromHistory(this, "redo", true);}),
6285
6286    setExtending: function(val) {this.extend = val;},
6287    getExtending: function() {return this.extend;},
6288
6289    historySize: function() {
6290      var hist = this.history, done = 0, undone = 0;
6291      for (var i = 0; i < hist.done.length; i++) if (!hist.done[i].ranges) ++done;
6292      for (var i = 0; i < hist.undone.length; i++) if (!hist.undone[i].ranges) ++undone;
6293      return {undo: done, redo: undone};
6294    },
6295    clearHistory: function() {this.history = new History(this.history.maxGeneration);},
6296
6297    markClean: function() {
6298      this.cleanGeneration = this.changeGeneration(true);
6299    },
6300    changeGeneration: function(forceSplit) {
6301      if (forceSplit)
6302        this.history.lastOp = this.history.lastOrigin = null;
6303      return this.history.generation;
6304    },
6305    isClean: function (gen) {
6306      return this.history.generation == (gen || this.cleanGeneration);
6307    },
6308
6309    getHistory: function() {
6310      return {done: copyHistoryArray(this.history.done),
6311              undone: copyHistoryArray(this.history.undone)};
6312    },
6313    setHistory: function(histData) {
6314      var hist = this.history = new History(this.history.maxGeneration);
6315      hist.done = copyHistoryArray(histData.done.slice(0), null, true);
6316      hist.undone = copyHistoryArray(histData.undone.slice(0), null, true);
6317    },
6318
6319    markText: function(from, to, options) {
6320      return markText(this, clipPos(this, from), clipPos(this, to), options, "range");
6321    },
6322    setBookmark: function(pos, options) {
6323      var realOpts = {replacedWith: options && (options.nodeType == null ? options.widget : options),
6324                      insertLeft: options && options.insertLeft,
6325                      clearWhenEmpty: false, shared: options && options.shared};
6326      pos = clipPos(this, pos);
6327      return markText(this, pos, pos, realOpts, "bookmark");
6328    },
6329    findMarksAt: function(pos) {
6330      pos = clipPos(this, pos);
6331      var markers = [], spans = getLine(this, pos.line).markedSpans;
6332      if (spans) for (var i = 0; i < spans.length; ++i) {
6333        var span = spans[i];
6334        if ((span.from == null || span.from <= pos.ch) &&
6335            (span.to == null || span.to >= pos.ch))
6336          markers.push(span.marker.parent || span.marker);
6337      }
6338      return markers;
6339    },
6340    findMarks: function(from, to, filter) {
6341      from = clipPos(this, from); to = clipPos(this, to);
6342      var found = [], lineNo = from.line;
6343      this.iter(from.line, to.line + 1, function(line) {
6344        var spans = line.markedSpans;
6345        if (spans) for (var i = 0; i < spans.length; i++) {
6346          var span = spans[i];
6347          if (!(lineNo == from.line && from.ch > span.to ||
6348                span.from == null && lineNo != from.line||
6349                lineNo == to.line && span.from > to.ch) &&
6350              (!filter || filter(span.marker)))
6351            found.push(span.marker.parent || span.marker);
6352        }
6353        ++lineNo;
6354      });
6355      return found;
6356    },
6357    getAllMarks: function() {
6358      var markers = [];
6359      this.iter(function(line) {
6360        var sps = line.markedSpans;
6361        if (sps) for (var i = 0; i < sps.length; ++i)
6362          if (sps[i].from != null) markers.push(sps[i].marker);
6363      });
6364      return markers;
6365    },
6366
6367    posFromIndex: function(off) {
6368      var ch, lineNo = this.first;
6369      this.iter(function(line) {
6370        var sz = line.text.length + 1;
6371        if (sz > off) { ch = off; return true; }
6372        off -= sz;
6373        ++lineNo;
6374      });
6375      return clipPos(this, Pos(lineNo, ch));
6376    },
6377    indexFromPos: function (coords) {
6378      coords = clipPos(this, coords);
6379      var index = coords.ch;
6380      if (coords.line < this.first || coords.ch < 0) return 0;
6381      this.iter(this.first, coords.line, function (line) {
6382        index += line.text.length + 1;
6383      });
6384      return index;
6385    },
6386
6387    copy: function(copyHistory) {
6388      var doc = new Doc(getLines(this, this.first, this.first + this.size), this.modeOption, this.first);
6389      doc.scrollTop = this.scrollTop; doc.scrollLeft = this.scrollLeft;
6390      doc.sel = this.sel;
6391      doc.extend = false;
6392      if (copyHistory) {
6393        doc.history.undoDepth = this.history.undoDepth;
6394        doc.setHistory(this.getHistory());
6395      }
6396      return doc;
6397    },
6398
6399    linkedDoc: function(options) {
6400      if (!options) options = {};
6401      var from = this.first, to = this.first + this.size;
6402      if (options.from != null && options.from > from) from = options.from;
6403      if (options.to != null && options.to < to) to = options.to;
6404      var copy = new Doc(getLines(this, from, to), options.mode || this.modeOption, from);
6405      if (options.sharedHist) copy.history = this.history;
6406      (this.linked || (this.linked = [])).push({doc: copy, sharedHist: options.sharedHist});
6407      copy.linked = [{doc: this, isParent: true, sharedHist: options.sharedHist}];
6408      copySharedMarkers(copy, findSharedMarkers(this));
6409      return copy;
6410    },
6411    unlinkDoc: function(other) {
6412      if (other instanceof CodeMirror) other = other.doc;
6413      if (this.linked) for (var i = 0; i < this.linked.length; ++i) {
6414        var link = this.linked[i];
6415        if (link.doc != other) continue;
6416        this.linked.splice(i, 1);
6417        other.unlinkDoc(this);
6418        detachSharedMarkers(findSharedMarkers(this));
6419        break;
6420      }
6421      // If the histories were shared, split them again
6422      if (other.history == this.history) {
6423        var splitIds = [other.id];
6424        linkedDocs(other, function(doc) {splitIds.push(doc.id);}, true);
6425        other.history = new History(null);
6426        other.history.done = copyHistoryArray(this.history.done, splitIds);
6427        other.history.undone = copyHistoryArray(this.history.undone, splitIds);
6428      }
6429    },
6430    iterLinkedDocs: function(f) {linkedDocs(this, f);},
6431
6432    getMode: function() {return this.mode;},
6433    getEditor: function() {return this.cm;}
6434  });
6435
6436  // Public alias.
6437  Doc.prototype.eachLine = Doc.prototype.iter;
6438
6439  // Set up methods on CodeMirror's prototype to redirect to the editor's document.
6440  var dontDelegate = "iter insert remove copy getEditor".split(" ");
6441  for (var prop in Doc.prototype) if (Doc.prototype.hasOwnProperty(prop) && indexOf(dontDelegate, prop) < 0)
6442    CodeMirror.prototype[prop] = (function(method) {
6443      return function() {return method.apply(this.doc, arguments);};
6444    })(Doc.prototype[prop]);
6445
6446  eventMixin(Doc);
6447
6448  // Call f for all linked documents.
6449  function linkedDocs(doc, f, sharedHistOnly) {
6450    function propagate(doc, skip, sharedHist) {
6451      if (doc.linked) for (var i = 0; i < doc.linked.length; ++i) {
6452        var rel = doc.linked[i];
6453        if (rel.doc == skip) continue;
6454        var shared = sharedHist && rel.sharedHist;
6455        if (sharedHistOnly && !shared) continue;
6456        f(rel.doc, shared);
6457        propagate(rel.doc, doc, shared);
6458      }
6459    }
6460    propagate(doc, null, true);
6461  }
6462
6463  // Attach a document to an editor.
6464  function attachDoc(cm, doc) {
6465    if (doc.cm) throw new Error("This document is already in use.");
6466    cm.doc = doc;
6467    doc.cm = cm;
6468    estimateLineHeights(cm);
6469    loadMode(cm);
6470    if (!cm.options.lineWrapping) findMaxLine(cm);
6471    cm.options.mode = doc.modeOption;
6472    regChange(cm);
6473  }
6474
6475  // LINE UTILITIES
6476
6477  // Find the line object corresponding to the given line number.
6478  function getLine(doc, n) {
6479    n -= doc.first;
6480    if (n < 0 || n >= doc.size) throw new Error("There is no line " + (n + doc.first) + " in the document.");
6481    for (var chunk = doc; !chunk.lines;) {
6482      for (var i = 0;; ++i) {
6483        var child = chunk.children[i], sz = child.chunkSize();
6484        if (n < sz) { chunk = child; break; }
6485        n -= sz;
6486      }
6487    }
6488    return chunk.lines[n];
6489  }
6490
6491  // Get the part of a document between two positions, as an array of
6492  // strings.
6493  function getBetween(doc, start, end) {
6494    var out = [], n = start.line;
6495    doc.iter(start.line, end.line + 1, function(line) {
6496      var text = line.text;
6497      if (n == end.line) text = text.slice(0, end.ch);
6498      if (n == start.line) text = text.slice(start.ch);
6499      out.push(text);
6500      ++n;
6501    });
6502    return out;
6503  }
6504  // Get the lines between from and to, as array of strings.
6505  function getLines(doc, from, to) {
6506    var out = [];
6507    doc.iter(from, to, function(line) { out.push(line.text); });
6508    return out;
6509  }
6510
6511  // Update the height of a line, propagating the height change
6512  // upwards to parent nodes.
6513  function updateLineHeight(line, height) {
6514    var diff = height - line.height;
6515    if (diff) for (var n = line; n; n = n.parent) n.height += diff;
6516  }
6517
6518  // Given a line object, find its line number by walking up through
6519  // its parent links.
6520  function lineNo(line) {
6521    if (line.parent == null) return null;
6522    var cur = line.parent, no = indexOf(cur.lines, line);
6523    for (var chunk = cur.parent; chunk; cur = chunk, chunk = chunk.parent) {
6524      for (var i = 0;; ++i) {
6525        if (chunk.children[i] == cur) break;
6526        no += chunk.children[i].chunkSize();
6527      }
6528    }
6529    return no + cur.first;
6530  }
6531
6532  // Find the line at the given vertical position, using the height
6533  // information in the document tree.
6534  function lineAtHeight(chunk, h) {
6535    var n = chunk.first;
6536    outer: do {
6537      for (var i = 0; i < chunk.children.length; ++i) {
6538        var child = chunk.children[i], ch = child.height;
6539        if (h < ch) { chunk = child; continue outer; }
6540        h -= ch;
6541        n += child.chunkSize();
6542      }
6543      return n;
6544    } while (!chunk.lines);
6545    for (var i = 0; i < chunk.lines.length; ++i) {
6546      var line = chunk.lines[i], lh = line.height;
6547      if (h < lh) break;
6548      h -= lh;
6549    }
6550    return n + i;
6551  }
6552
6553
6554  // Find the height above the given line.
6555  function heightAtLine(lineObj) {
6556    lineObj = visualLine(lineObj);
6557
6558    var h = 0, chunk = lineObj.parent;
6559    for (var i = 0; i < chunk.lines.length; ++i) {
6560      var line = chunk.lines[i];
6561      if (line == lineObj) break;
6562      else h += line.height;
6563    }
6564    for (var p = chunk.parent; p; chunk = p, p = chunk.parent) {
6565      for (var i = 0; i < p.children.length; ++i) {
6566        var cur = p.children[i];
6567        if (cur == chunk) break;
6568        else h += cur.height;
6569      }
6570    }
6571    return h;
6572  }
6573
6574  // Get the bidi ordering for the given line (and cache it). Returns
6575  // false for lines that are fully left-to-right, and an array of
6576  // BidiSpan objects otherwise.
6577  function getOrder(line) {
6578    var order = line.order;
6579    if (order == null) order = line.order = bidiOrdering(line.text);
6580    return order;
6581  }
6582
6583  // HISTORY
6584
6585  function History(startGen) {
6586    // Arrays of change events and selections. Doing something adds an
6587    // event to done and clears undo. Undoing moves events from done
6588    // to undone, redoing moves them in the other direction.
6589    this.done = []; this.undone = [];
6590    this.undoDepth = Infinity;
6591    // Used to track when changes can be merged into a single undo
6592    // event
6593    this.lastModTime = this.lastSelTime = 0;
6594    this.lastOp = null;
6595    this.lastOrigin = this.lastSelOrigin = null;
6596    // Used by the isClean() method
6597    this.generation = this.maxGeneration = startGen || 1;
6598  }
6599
6600  // Create a history change event from an updateDoc-style change
6601  // object.
6602  function historyChangeFromChange(doc, change) {
6603    var histChange = {from: copyPos(change.from), to: changeEnd(change), text: getBetween(doc, change.from, change.to)};
6604    attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);
6605    linkedDocs(doc, function(doc) {attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);}, true);
6606    return histChange;
6607  }
6608
6609  // Pop all selection events off the end of a history array. Stop at
6610  // a change event.
6611  function clearSelectionEvents(array) {
6612    while (array.length) {
6613      var last = lst(array);
6614      if (last.ranges) array.pop();
6615      else break;
6616    }
6617  }
6618
6619  // Find the top change event in the history. Pop off selection
6620  // events that are in the way.
6621  function lastChangeEvent(hist, force) {
6622    if (force) {
6623      clearSelectionEvents(hist.done);
6624      return lst(hist.done);
6625    } else if (hist.done.length && !lst(hist.done).ranges) {
6626      return lst(hist.done);
6627    } else if (hist.done.length > 1 && !hist.done[hist.done.length - 2].ranges) {
6628      hist.done.pop();
6629      return lst(hist.done);
6630    }
6631  }
6632
6633  // Register a change in the history. Merges changes that are within
6634  // a single operation, ore are close together with an origin that
6635  // allows merging (starting with "+") into a single event.
6636  function addChangeToHistory(doc, change, selAfter, opId) {
6637    var hist = doc.history;
6638    hist.undone.length = 0;
6639    var time = +new Date, cur;
6640
6641    if ((hist.lastOp == opId ||
6642         hist.lastOrigin == change.origin && change.origin &&
6643         ((change.origin.charAt(0) == "+" && doc.cm && hist.lastModTime > time - doc.cm.options.historyEventDelay) ||
6644          change.origin.charAt(0) == "*")) &&
6645        (cur = lastChangeEvent(hist, hist.lastOp == opId))) {
6646      // Merge this change into the last event
6647      var last = lst(cur.changes);
6648      if (cmp(change.from, change.to) == 0 && cmp(change.from, last.to) == 0) {
6649        // Optimized case for simple insertion -- don't want to add
6650        // new changesets for every character typed
6651        last.to = changeEnd(change);
6652      } else {
6653        // Add new sub-event
6654        cur.changes.push(historyChangeFromChange(doc, change));
6655      }
6656    } else {
6657      // Can not be merged, start a new event.
6658      var before = lst(hist.done);
6659      if (!before || !before.ranges)
6660        pushSelectionToHistory(doc.sel, hist.done);
6661      cur = {changes: [historyChangeFromChange(doc, change)],
6662             generation: hist.generation};
6663      hist.done.push(cur);
6664      while (hist.done.length > hist.undoDepth) {
6665        hist.done.shift();
6666        if (!hist.done[0].ranges) hist.done.shift();
6667      }
6668    }
6669    hist.done.push(selAfter);
6670    hist.generation = ++hist.maxGeneration;
6671    hist.lastModTime = hist.lastSelTime = time;
6672    hist.lastOp = opId;
6673    hist.lastOrigin = hist.lastSelOrigin = change.origin;
6674
6675    if (!last) signal(doc, "historyAdded");
6676  }
6677
6678  function selectionEventCanBeMerged(doc, origin, prev, sel) {
6679    var ch = origin.charAt(0);
6680    return ch == "*" ||
6681      ch == "+" &&
6682      prev.ranges.length == sel.ranges.length &&
6683      prev.somethingSelected() == sel.somethingSelected() &&
6684      new Date - doc.history.lastSelTime <= (doc.cm ? doc.cm.options.historyEventDelay : 500);
6685  }
6686
6687  // Called whenever the selection changes, sets the new selection as
6688  // the pending selection in the history, and pushes the old pending
6689  // selection into the 'done' array when it was significantly
6690  // different (in number of selected ranges, emptiness, or time).
6691  function addSelectionToHistory(doc, sel, opId, options) {
6692    var hist = doc.history, origin = options && options.origin;
6693
6694    // A new event is started when the previous origin does not match
6695    // the current, or the origins don't allow matching. Origins
6696    // starting with * are always merged, those starting with + are
6697    // merged when similar and close together in time.
6698    if (opId == hist.lastOp ||
6699        (origin && hist.lastSelOrigin == origin &&
6700         (hist.lastModTime == hist.lastSelTime && hist.lastOrigin == origin ||
6701          selectionEventCanBeMerged(doc, origin, lst(hist.done), sel))))
6702      hist.done[hist.done.length - 1] = sel;
6703    else
6704      pushSelectionToHistory(sel, hist.done);
6705
6706    hist.lastSelTime = +new Date;
6707    hist.lastSelOrigin = origin;
6708    hist.lastOp = opId;
6709    if (options && options.clearRedo !== false)
6710      clearSelectionEvents(hist.undone);
6711  }
6712
6713  function pushSelectionToHistory(sel, dest) {
6714    var top = lst(dest);
6715    if (!(top && top.ranges && top.equals(sel)))
6716      dest.push(sel);
6717  }
6718
6719  // Used to store marked span information in the history.
6720  function attachLocalSpans(doc, change, from, to) {
6721    var existing = change["spans_" + doc.id], n = 0;
6722    doc.iter(Math.max(doc.first, from), Math.min(doc.first + doc.size, to), function(line) {
6723      if (line.markedSpans)
6724        (existing || (existing = change["spans_" + doc.id] = {}))[n] = line.markedSpans;
6725      ++n;
6726    });
6727  }
6728
6729  // When un/re-doing restores text containing marked spans, those
6730  // that have been explicitly cleared should not be restored.
6731  function removeClearedSpans(spans) {
6732    if (!spans) return null;
6733    for (var i = 0, out; i < spans.length; ++i) {
6734      if (spans[i].marker.explicitlyCleared) { if (!out) out = spans.slice(0, i); }
6735      else if (out) out.push(spans[i]);
6736    }
6737    return !out ? spans : out.length ? out : null;
6738  }
6739
6740  // Retrieve and filter the old marked spans stored in a change event.
6741  function getOldSpans(doc, change) {
6742    var found = change["spans_" + doc.id];
6743    if (!found) return null;
6744    for (var i = 0, nw = []; i < change.text.length; ++i)
6745      nw.push(removeClearedSpans(found[i]));
6746    return nw;
6747  }
6748
6749  // Used both to provide a JSON-safe object in .getHistory, and, when
6750  // detaching a document, to split the history in two
6751  function copyHistoryArray(events, newGroup, instantiateSel) {
6752    for (var i = 0, copy = []; i < events.length; ++i) {
6753      var event = events[i];
6754      if (event.ranges) {
6755        copy.push(instantiateSel ? Selection.prototype.deepCopy.call(event) : event);
6756        continue;
6757      }
6758      var changes = event.changes, newChanges = [];
6759      copy.push({changes: newChanges});
6760      for (var j = 0; j < changes.length; ++j) {
6761        var change = changes[j], m;
6762        newChanges.push({from: change.from, to: change.to, text: change.text});
6763        if (newGroup) for (var prop in change) if (m = prop.match(/^spans_(\d+)$/)) {
6764          if (indexOf(newGroup, Number(m[1])) > -1) {
6765            lst(newChanges)[prop] = change[prop];
6766            delete change[prop];
6767          }
6768        }
6769      }
6770    }
6771    return copy;
6772  }
6773
6774  // Rebasing/resetting history to deal with externally-sourced changes
6775
6776  function rebaseHistSelSingle(pos, from, to, diff) {
6777    if (to < pos.line) {
6778      pos.line += diff;
6779    } else if (from < pos.line) {
6780      pos.line = from;
6781      pos.ch = 0;
6782    }
6783  }
6784
6785  // Tries to rebase an array of history events given a change in the
6786  // document. If the change touches the same lines as the event, the
6787  // event, and everything 'behind' it, is discarded. If the change is
6788  // before the event, the event's positions are updated. Uses a
6789  // copy-on-write scheme for the positions, to avoid having to
6790  // reallocate them all on every rebase, but also avoid problems with
6791  // shared position objects being unsafely updated.
6792  function rebaseHistArray(array, from, to, diff) {
6793    for (var i = 0; i < array.length; ++i) {
6794      var sub = array[i], ok = true;
6795      if (sub.ranges) {
6796        if (!sub.copied) { sub = array[i] = sub.deepCopy(); sub.copied = true; }
6797        for (var j = 0; j < sub.ranges.length; j++) {
6798          rebaseHistSelSingle(sub.ranges[j].anchor, from, to, diff);
6799          rebaseHistSelSingle(sub.ranges[j].head, from, to, diff);
6800        }
6801        continue;
6802      }
6803      for (var j = 0; j < sub.changes.length; ++j) {
6804        var cur = sub.changes[j];
6805        if (to < cur.from.line) {
6806          cur.from = Pos(cur.from.line + diff, cur.from.ch);
6807          cur.to = Pos(cur.to.line + diff, cur.to.ch);
6808        } else if (from <= cur.to.line) {
6809          ok = false;
6810          break;
6811        }
6812      }
6813      if (!ok) {
6814        array.splice(0, i + 1);
6815        i = 0;
6816      }
6817    }
6818  }
6819
6820  function rebaseHist(hist, change) {
6821    var from = change.from.line, to = change.to.line, diff = change.text.length - (to - from) - 1;
6822    rebaseHistArray(hist.done, from, to, diff);
6823    rebaseHistArray(hist.undone, from, to, diff);
6824  }
6825
6826  // EVENT UTILITIES
6827
6828  // Due to the fact that we still support jurassic IE versions, some
6829  // compatibility wrappers are needed.
6830
6831  var e_preventDefault = CodeMirror.e_preventDefault = function(e) {
6832    if (e.preventDefault) e.preventDefault();
6833    else e.returnValue = false;
6834  };
6835  var e_stopPropagation = CodeMirror.e_stopPropagation = function(e) {
6836    if (e.stopPropagation) e.stopPropagation();
6837    else e.cancelBubble = true;
6838  };
6839  function e_defaultPrevented(e) {
6840    return e.defaultPrevented != null ? e.defaultPrevented : e.returnValue == false;
6841  }
6842  var e_stop = CodeMirror.e_stop = function(e) {e_preventDefault(e); e_stopPropagation(e);};
6843
6844  function e_target(e) {return e.target || e.srcElement;}
6845  function e_button(e) {
6846    var b = e.which;
6847    if (b == null) {
6848      if (e.button & 1) b = 1;
6849      else if (e.button & 2) b = 3;
6850      else if (e.button & 4) b = 2;
6851    }
6852    if (mac && e.ctrlKey && b == 1) b = 3;
6853    return b;
6854  }
6855
6856  // EVENT HANDLING
6857
6858  // Lightweight event framework. on/off also work on DOM nodes,
6859  // registering native DOM handlers.
6860
6861  var on = CodeMirror.on = function(emitter, type, f) {
6862    if (emitter.addEventListener)
6863      emitter.addEventListener(type, f, false);
6864    else if (emitter.attachEvent)
6865      emitter.attachEvent("on" + type, f);
6866    else {
6867      var map = emitter._handlers || (emitter._handlers = {});
6868      var arr = map[type] || (map[type] = []);
6869      arr.push(f);
6870    }
6871  };
6872
6873  var off = CodeMirror.off = function(emitter, type, f) {
6874    if (emitter.removeEventListener)
6875      emitter.removeEventListener(type, f, false);
6876    else if (emitter.detachEvent)
6877      emitter.detachEvent("on" + type, f);
6878    else {
6879      var arr = emitter._handlers && emitter._handlers[type];
6880      if (!arr) return;
6881      for (var i = 0; i < arr.length; ++i)
6882        if (arr[i] == f) { arr.splice(i, 1); break; }
6883    }
6884  };
6885
6886  var signal = CodeMirror.signal = function(emitter, type /*, values...*/) {
6887    var arr = emitter._handlers && emitter._handlers[type];
6888    if (!arr) return;
6889    var args = Array.prototype.slice.call(arguments, 2);
6890    for (var i = 0; i < arr.length; ++i) arr[i].apply(null, args);
6891  };
6892
6893  // Often, we want to signal events at a point where we are in the
6894  // middle of some work, but don't want the handler to start calling
6895  // other methods on the editor, which might be in an inconsistent
6896  // state or simply not expect any other events to happen.
6897  // signalLater looks whether there are any handlers, and schedules
6898  // them to be executed when the last operation ends, or, if no
6899  // operation is active, when a timeout fires.
6900  var delayedCallbacks, delayedCallbackDepth = 0;
6901  function signalLater(emitter, type /*, values...*/) {
6902    var arr = emitter._handlers && emitter._handlers[type];
6903    if (!arr) return;
6904    var args = Array.prototype.slice.call(arguments, 2);
6905    if (!delayedCallbacks) {
6906      ++delayedCallbackDepth;
6907      delayedCallbacks = [];
6908      setTimeout(fireDelayed, 0);
6909    }
6910    function bnd(f) {return function(){f.apply(null, args);};};
6911    for (var i = 0; i < arr.length; ++i)
6912      delayedCallbacks.push(bnd(arr[i]));
6913  }
6914
6915  function fireDelayed() {
6916    --delayedCallbackDepth;
6917    var delayed = delayedCallbacks;
6918    delayedCallbacks = null;
6919    for (var i = 0; i < delayed.length; ++i) delayed[i]();
6920  }
6921
6922  // The DOM events that CodeMirror handles can be overridden by
6923  // registering a (non-DOM) handler on the editor for the event name,
6924  // and preventDefault-ing the event in that handler.
6925  function signalDOMEvent(cm, e, override) {
6926    signal(cm, override || e.type, cm, e);
6927    return e_defaultPrevented(e) || e.codemirrorIgnore;
6928  }
6929
6930  function signalCursorActivity(cm) {
6931    var arr = cm._handlers && cm._handlers.cursorActivity;
6932    if (!arr) return;
6933    var set = cm.curOp.cursorActivityHandlers || (cm.curOp.cursorActivityHandlers = []);
6934    for (var i = 0; i < arr.length; ++i) if (indexOf(set, arr[i]) == -1)
6935      set.push(arr[i]);
6936  }
6937
6938  function hasHandler(emitter, type) {
6939    var arr = emitter._handlers && emitter._handlers[type];
6940    return arr && arr.length > 0;
6941  }
6942
6943  // Add on and off methods to a constructor's prototype, to make
6944  // registering events on such objects more convenient.
6945  function eventMixin(ctor) {
6946    ctor.prototype.on = function(type, f) {on(this, type, f);};
6947    ctor.prototype.off = function(type, f) {off(this, type, f);};
6948  }
6949
6950  // MISC UTILITIES
6951
6952  // Number of pixels added to scroller and sizer to hide scrollbar
6953  var scrollerCutOff = 30;
6954
6955  // Returned or thrown by various protocols to signal 'I'm not
6956  // handling this'.
6957  var Pass = CodeMirror.Pass = {toString: function(){return "CodeMirror.Pass";}};
6958
6959  // Reused option objects for setSelection & friends
6960  var sel_dontScroll = {scroll: false}, sel_mouse = {origin: "*mouse"}, sel_move = {origin: "+move"};
6961
6962  function Delayed() {this.id = null;}
6963  Delayed.prototype.set = function(ms, f) {
6964    clearTimeout(this.id);
6965    this.id = setTimeout(f, ms);
6966  };
6967
6968  // Counts the column offset in a string, taking tabs into account.
6969  // Used mostly to find indentation.
6970  var countColumn = CodeMirror.countColumn = function(string, end, tabSize, startIndex, startValue) {
6971    if (end == null) {
6972      end = string.search(/[^\s\u00a0]/);
6973      if (end == -1) end = string.length;
6974    }
6975    for (var i = startIndex || 0, n = startValue || 0;;) {
6976      var nextTab = string.indexOf("\t", i);
6977      if (nextTab < 0 || nextTab >= end)
6978        return n + (end - i);
6979      n += nextTab - i;
6980      n += tabSize - (n % tabSize);
6981      i = nextTab + 1;
6982    }
6983  };
6984
6985  // The inverse of countColumn -- find the offset that corresponds to
6986  // a particular column.
6987  function findColumn(string, goal, tabSize) {
6988    for (var pos = 0, col = 0;;) {
6989      var nextTab = string.indexOf("\t", pos);
6990      if (nextTab == -1) nextTab = string.length;
6991      var skipped = nextTab - pos;
6992      if (nextTab == string.length || col + skipped >= goal)
6993        return pos + Math.min(skipped, goal - col);
6994      col += nextTab - pos;
6995      col += tabSize - (col % tabSize);
6996      pos = nextTab + 1;
6997      if (col >= goal) return pos;
6998    }
6999  }
7000
7001  var spaceStrs = [""];
7002  function spaceStr(n) {
7003    while (spaceStrs.length <= n)
7004      spaceStrs.push(lst(spaceStrs) + " ");
7005    return spaceStrs[n];
7006  }
7007
7008  function lst(arr) { return arr[arr.length-1]; }
7009
7010  var selectInput = function(node) { node.select(); };
7011  if (ios) // Mobile Safari apparently has a bug where select() is broken.
7012    selectInput = function(node) { node.selectionStart = 0; node.selectionEnd = node.value.length; };
7013  else if (ie) // Suppress mysterious IE10 errors
7014    selectInput = function(node) { try { node.select(); } catch(_e) {} };
7015
7016  function indexOf(array, elt) {
7017    for (var i = 0; i < array.length; ++i)
7018      if (array[i] == elt) return i;
7019    return -1;
7020  }
7021  if ([].indexOf) indexOf = function(array, elt) { return array.indexOf(elt); };
7022  function map(array, f) {
7023    var out = [];
7024    for (var i = 0; i < array.length; i++) out[i] = f(array[i], i);
7025    return out;
7026  }
7027  if ([].map) map = function(array, f) { return array.map(f); };
7028
7029  function createObj(base, props) {
7030    var inst;
7031    if (Object.create) {
7032      inst = Object.create(base);
7033    } else {
7034      var ctor = function() {};
7035      ctor.prototype = base;
7036      inst = new ctor();
7037    }
7038    if (props) copyObj(props, inst);
7039    return inst;
7040  };
7041
7042  function copyObj(obj, target, overwrite) {
7043    if (!target) target = {};
7044    for (var prop in obj)
7045      if (obj.hasOwnProperty(prop) && (overwrite !== false || !target.hasOwnProperty(prop)))
7046        target[prop] = obj[prop];
7047    return target;
7048  }
7049
7050  function bind(f) {
7051    var args = Array.prototype.slice.call(arguments, 1);
7052    return function(){return f.apply(null, args);};
7053  }
7054
7055  var nonASCIISingleCaseWordChar = /[\u00df\u3040-\u309f\u30a0-\u30ff\u3400-\u4db5\u4e00-\u9fcc\uac00-\ud7af]/;
7056  var isWordChar = CodeMirror.isWordChar = function(ch) {
7057    return /\w/.test(ch) || ch > "\x80" &&
7058      (ch.toUpperCase() != ch.toLowerCase() || nonASCIISingleCaseWordChar.test(ch));
7059  };
7060
7061  function isEmpty(obj) {
7062    for (var n in obj) if (obj.hasOwnProperty(n) && obj[n]) return false;
7063    return true;
7064  }
7065
7066  // Extending unicode characters. A series of a non-extending char +
7067  // any number of extending chars is treated as a single unit as far
7068  // as editing and measuring is concerned. This is not fully correct,
7069  // since some scripts/fonts/browsers also treat other configurations
7070  // of code points as a group.
7071  var extendingChars = /[\u0300-\u036f\u0483-\u0489\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u064b-\u065e\u0670\u06d6-\u06dc\u06de-\u06e4\u06e7\u06e8\u06ea-\u06ed\u0711\u0730-\u074a\u07a6-\u07b0\u07eb-\u07f3\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0900-\u0902\u093c\u0941-\u0948\u094d\u0951-\u0955\u0962\u0963\u0981\u09bc\u09be\u09c1-\u09c4\u09cd\u09d7\u09e2\u09e3\u0a01\u0a02\u0a3c\u0a41\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a70\u0a71\u0a75\u0a81\u0a82\u0abc\u0ac1-\u0ac5\u0ac7\u0ac8\u0acd\u0ae2\u0ae3\u0b01\u0b3c\u0b3e\u0b3f\u0b41-\u0b44\u0b4d\u0b56\u0b57\u0b62\u0b63\u0b82\u0bbe\u0bc0\u0bcd\u0bd7\u0c3e-\u0c40\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62\u0c63\u0cbc\u0cbf\u0cc2\u0cc6\u0ccc\u0ccd\u0cd5\u0cd6\u0ce2\u0ce3\u0d3e\u0d41-\u0d44\u0d4d\u0d57\u0d62\u0d63\u0dca\u0dcf\u0dd2-\u0dd4\u0dd6\u0ddf\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0eb1\u0eb4-\u0eb9\u0ebb\u0ebc\u0ec8-\u0ecd\u0f18\u0f19\u0f35\u0f37\u0f39\u0f71-\u0f7e\u0f80-\u0f84\u0f86\u0f87\u0f90-\u0f97\u0f99-\u0fbc\u0fc6\u102d-\u1030\u1032-\u1037\u1039\u103a\u103d\u103e\u1058\u1059\u105e-\u1060\u1071-\u1074\u1082\u1085\u1086\u108d\u109d\u135f\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17b7-\u17bd\u17c6\u17c9-\u17d3\u17dd\u180b-\u180d\u18a9\u1920-\u1922\u1927\u1928\u1932\u1939-\u193b\u1a17\u1a18\u1a56\u1a58-\u1a5e\u1a60\u1a62\u1a65-\u1a6c\u1a73-\u1a7c\u1a7f\u1b00-\u1b03\u1b34\u1b36-\u1b3a\u1b3c\u1b42\u1b6b-\u1b73\u1b80\u1b81\u1ba2-\u1ba5\u1ba8\u1ba9\u1c2c-\u1c33\u1c36\u1c37\u1cd0-\u1cd2\u1cd4-\u1ce0\u1ce2-\u1ce8\u1ced\u1dc0-\u1de6\u1dfd-\u1dff\u200c\u200d\u20d0-\u20f0\u2cef-\u2cf1\u2de0-\u2dff\u302a-\u302f\u3099\u309a\ua66f-\ua672\ua67c\ua67d\ua6f0\ua6f1\ua802\ua806\ua80b\ua825\ua826\ua8c4\ua8e0-\ua8f1\ua926-\ua92d\ua947-\ua951\ua980-\ua982\ua9b3\ua9b6-\ua9b9\ua9bc\uaa29-\uaa2e\uaa31\uaa32\uaa35\uaa36\uaa43\uaa4c\uaab0\uaab2-\uaab4\uaab7\uaab8\uaabe\uaabf\uaac1\uabe5\uabe8\uabed\udc00-\udfff\ufb1e\ufe00-\ufe0f\ufe20-\ufe26\uff9e\uff9f]/;
7072  function isExtendingChar(ch) { return ch.charCodeAt(0) >= 768 && extendingChars.test(ch); }
7073
7074  // DOM UTILITIES
7075
7076  function elt(tag, content, className, style) {
7077    var e = document.createElement(tag);
7078    if (className) e.className = className;
7079    if (style) e.style.cssText = style;
7080    if (typeof content == "string") e.appendChild(document.createTextNode(content));
7081    else if (content) for (var i = 0; i < content.length; ++i) e.appendChild(content[i]);
7082    return e;
7083  }
7084
7085  var range;
7086  if (document.createRange) range = function(node, start, end) {
7087    var r = document.createRange();
7088    r.setEnd(node, end);
7089    r.setStart(node, start);
7090    return r;
7091  };
7092  else range = function(node, start, end) {
7093    var r = document.body.createTextRange();
7094    r.moveToElementText(node.parentNode);
7095    r.collapse(true);
7096    r.moveEnd("character", end);
7097    r.moveStart("character", start);
7098    return r;
7099  };
7100
7101  function removeChildren(e) {
7102    for (var count = e.childNodes.length; count > 0; --count)
7103      e.removeChild(e.firstChild);
7104    return e;
7105  }
7106
7107  function removeChildrenAndAdd(parent, e) {
7108    return removeChildren(parent).appendChild(e);
7109  }
7110
7111  function contains(parent, child) {
7112    if (parent.contains)
7113      return parent.contains(child);
7114    while (child = child.parentNode)
7115      if (child == parent) return true;
7116  }
7117
7118  function activeElt() { return document.activeElement; }
7119  // Older versions of IE throws unspecified error when touching
7120  // document.activeElement in some cases (during loading, in iframe)
7121  if (ie_upto10) activeElt = function() {
7122    try { return document.activeElement; }
7123    catch(e) { return document.body; }
7124  };
7125
7126  function classTest(cls) { return new RegExp("\\b" + cls + "\\b\\s*"); }
7127  function rmClass(node, cls) {
7128    var test = classTest(cls);
7129    if (test.test(node.className)) node.className = node.className.replace(test, "");
7130  }
7131  function addClass(node, cls) {
7132    if (!classTest(cls).test(node.className)) node.className += " " + cls;
7133  }
7134  function joinClasses(a, b) {
7135    var as = a.split(" ");
7136    for (var i = 0; i < as.length; i++)
7137      if (as[i] && !classTest(as[i]).test(b)) b += " " + as[i];
7138    return b;
7139  }
7140
7141  // FEATURE DETECTION
7142
7143  // Detect drag-and-drop
7144  var dragAndDrop = function() {
7145    // There is *some* kind of drag-and-drop support in IE6-8, but I
7146    // couldn't get it to work yet.
7147    if (ie_upto8) return false;
7148    var div = elt('div');
7149    return "draggable" in div || "dragDrop" in div;
7150  }();
7151
7152  var knownScrollbarWidth;
7153  function scrollbarWidth(measure) {
7154    if (knownScrollbarWidth != null) return knownScrollbarWidth;
7155    var test = elt("div", null, null, "width: 50px; height: 50px; overflow-x: scroll");
7156    removeChildrenAndAdd(measure, test);
7157    if (test.offsetWidth)
7158      knownScrollbarWidth = test.offsetHeight - test.clientHeight;
7159    return knownScrollbarWidth || 0;
7160  }
7161
7162  var zwspSupported;
7163  function zeroWidthElement(measure) {
7164    if (zwspSupported == null) {
7165      var test = elt("span", "\u200b");
7166      removeChildrenAndAdd(measure, elt("span", [test, document.createTextNode("x")]));
7167      if (measure.firstChild.offsetHeight != 0)
7168        zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !ie_upto7;
7169    }
7170    if (zwspSupported) return elt("span", "\u200b");
7171    else return elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px");
7172  }
7173
7174  // Feature-detect IE's crummy client rect reporting for bidi text
7175  var badBidiRects;
7176  function hasBadBidiRects(measure) {
7177    if (badBidiRects != null) return badBidiRects;
7178    var txt = removeChildrenAndAdd(measure, document.createTextNode("A\u062eA"));
7179    var r0 = range(txt, 0, 1).getBoundingClientRect();
7180    if (r0.left == r0.right) return false;
7181    var r1 = range(txt, 1, 2).getBoundingClientRect();
7182    return badBidiRects = (r1.right - r0.right < 3);
7183  }
7184
7185  // See if "".split is the broken IE version, if so, provide an
7186  // alternative way to split lines.
7187  var splitLines = CodeMirror.splitLines = "\n\nb".split(/\n/).length != 3 ? function(string) {
7188    var pos = 0, result = [], l = string.length;
7189    while (pos <= l) {
7190      var nl = string.indexOf("\n", pos);
7191      if (nl == -1) nl = string.length;
7192      var line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl);
7193      var rt = line.indexOf("\r");
7194      if (rt != -1) {
7195        result.push(line.slice(0, rt));
7196        pos += rt + 1;
7197      } else {
7198        result.push(line);
7199        pos = nl + 1;
7200      }
7201    }
7202    return result;
7203  } : function(string){return string.split(/\r\n?|\n/);};
7204
7205  var hasSelection = window.getSelection ? function(te) {
7206    try { return te.selectionStart != te.selectionEnd; }
7207    catch(e) { return false; }
7208  } : function(te) {
7209    try {var range = te.ownerDocument.selection.createRange();}
7210    catch(e) {}
7211    if (!range || range.parentElement() != te) return false;
7212    return range.compareEndPoints("StartToEnd", range) != 0;
7213  };
7214
7215  var hasCopyEvent = (function() {
7216    var e = elt("div");
7217    if ("oncopy" in e) return true;
7218    e.setAttribute("oncopy", "return;");
7219    return typeof e.oncopy == "function";
7220  })();
7221
7222  // KEY NAMES
7223
7224  var keyNames = {3: "Enter", 8: "Backspace", 9: "Tab", 13: "Enter", 16: "Shift", 17: "Ctrl", 18: "Alt",
7225                  19: "Pause", 20: "CapsLock", 27: "Esc", 32: "Space", 33: "PageUp", 34: "PageDown", 35: "End",
7226                  36: "Home", 37: "Left", 38: "Up", 39: "Right", 40: "Down", 44: "PrintScrn", 45: "Insert",
7227                  46: "Delete", 59: ";", 61: "=", 91: "Mod", 92: "Mod", 93: "Mod", 107: "=", 109: "-", 127: "Delete",
7228                  173: "-", 186: ";", 187: "=", 188: ",", 189: "-", 190: ".", 191: "/", 192: "`", 219: "[", 220: "\\",
7229                  221: "]", 222: "'", 63232: "Up", 63233: "Down", 63234: "Left", 63235: "Right", 63272: "Delete",
7230                  63273: "Home", 63275: "End", 63276: "PageUp", 63277: "PageDown", 63302: "Insert"};
7231  CodeMirror.keyNames = keyNames;
7232  (function() {
7233    // Number keys
7234    for (var i = 0; i < 10; i++) keyNames[i + 48] = keyNames[i + 96] = String(i);
7235    // Alphabetic keys
7236    for (var i = 65; i <= 90; i++) keyNames[i] = String.fromCharCode(i);
7237    // Function keys
7238    for (var i = 1; i <= 12; i++) keyNames[i + 111] = keyNames[i + 63235] = "F" + i;
7239  })();
7240
7241  // BIDI HELPERS
7242
7243  function iterateBidiSections(order, from, to, f) {
7244    if (!order) return f(from, to, "ltr");
7245    var found = false;
7246    for (var i = 0; i < order.length; ++i) {
7247      var part = order[i];
7248      if (part.from < to && part.to > from || from == to && part.to == from) {
7249        f(Math.max(part.from, from), Math.min(part.to, to), part.level == 1 ? "rtl" : "ltr");
7250        found = true;
7251      }
7252    }
7253    if (!found) f(from, to, "ltr");
7254  }
7255
7256  function bidiLeft(part) { return part.level % 2 ? part.to : part.from; }
7257  function bidiRight(part) { return part.level % 2 ? part.from : part.to; }
7258
7259  function lineLeft(line) { var order = getOrder(line); return order ? bidiLeft(order[0]) : 0; }
7260  function lineRight(line) {
7261    var order = getOrder(line);
7262    if (!order) return line.text.length;
7263    return bidiRight(lst(order));
7264  }
7265
7266  function lineStart(cm, lineN) {
7267    var line = getLine(cm.doc, lineN);
7268    var visual = visualLine(line);
7269    if (visual != line) lineN = lineNo(visual);
7270    var order = getOrder(visual);
7271    var ch = !order ? 0 : order[0].level % 2 ? lineRight(visual) : lineLeft(visual);
7272    return Pos(lineN, ch);
7273  }
7274  function lineEnd(cm, lineN) {
7275    var merged, line = getLine(cm.doc, lineN);
7276    while (merged = collapsedSpanAtEnd(line)) {
7277      line = merged.find(1, true).line;
7278      lineN = null;
7279    }
7280    var order = getOrder(line);
7281    var ch = !order ? line.text.length : order[0].level % 2 ? lineLeft(line) : lineRight(line);
7282    return Pos(lineN == null ? lineNo(line) : lineN, ch);
7283  }
7284
7285  function compareBidiLevel(order, a, b) {
7286    var linedir = order[0].level;
7287    if (a == linedir) return true;
7288    if (b == linedir) return false;
7289    return a < b;
7290  }
7291  var bidiOther;
7292  function getBidiPartAt(order, pos) {
7293    bidiOther = null;
7294    for (var i = 0, found; i < order.length; ++i) {
7295      var cur = order[i];
7296      if (cur.from < pos && cur.to > pos) return i;
7297      if ((cur.from == pos || cur.to == pos)) {
7298        if (found == null) {
7299          found = i;
7300        } else if (compareBidiLevel(order, cur.level, order[found].level)) {
7301          if (cur.from != cur.to) bidiOther = found;
7302          return i;
7303        } else {
7304          if (cur.from != cur.to) bidiOther = i;
7305          return found;
7306        }
7307      }
7308    }
7309    return found;
7310  }
7311
7312  function moveInLine(line, pos, dir, byUnit) {
7313    if (!byUnit) return pos + dir;
7314    do pos += dir;
7315    while (pos > 0 && isExtendingChar(line.text.charAt(pos)));
7316    return pos;
7317  }
7318
7319  // This is needed in order to move 'visually' through bi-directional
7320  // text -- i.e., pressing left should make the cursor go left, even
7321  // when in RTL text. The tricky part is the 'jumps', where RTL and
7322  // LTR text touch each other. This often requires the cursor offset
7323  // to move more than one unit, in order to visually move one unit.
7324  function moveVisually(line, start, dir, byUnit) {
7325    var bidi = getOrder(line);
7326    if (!bidi) return moveLogically(line, start, dir, byUnit);
7327    var pos = getBidiPartAt(bidi, start), part = bidi[pos];
7328    var target = moveInLine(line, start, part.level % 2 ? -dir : dir, byUnit);
7329
7330    for (;;) {
7331      if (target > part.from && target < part.to) return target;
7332      if (target == part.from || target == part.to) {
7333        if (getBidiPartAt(bidi, target) == pos) return target;
7334        part = bidi[pos += dir];
7335        return (dir > 0) == part.level % 2 ? part.to : part.from;
7336      } else {
7337        part = bidi[pos += dir];
7338        if (!part) return null;
7339        if ((dir > 0) == part.level % 2)
7340          target = moveInLine(line, part.to, -1, byUnit);
7341        else
7342          target = moveInLine(line, part.from, 1, byUnit);
7343      }
7344    }
7345  }
7346
7347  function moveLogically(line, start, dir, byUnit) {
7348    var target = start + dir;
7349    if (byUnit) while (target > 0 && isExtendingChar(line.text.charAt(target))) target += dir;
7350    return target < 0 || target > line.text.length ? null : target;
7351  }
7352
7353  // Bidirectional ordering algorithm
7354  // See http://unicode.org/reports/tr9/tr9-13.html for the algorithm
7355  // that this (partially) implements.
7356
7357  // One-char codes used for character types:
7358  // L (L):   Left-to-Right
7359  // R (R):   Right-to-Left
7360  // r (AL):  Right-to-Left Arabic
7361  // 1 (EN):  European Number
7362  // + (ES):  European Number Separator
7363  // % (ET):  European Number Terminator
7364  // n (AN):  Arabic Number
7365  // , (CS):  Common Number Separator
7366  // m (NSM): Non-Spacing Mark
7367  // b (BN):  Boundary Neutral
7368  // s (B):   Paragraph Separator
7369  // t (S):   Segment Separator
7370  // w (WS):  Whitespace
7371  // N (ON):  Other Neutrals
7372
7373  // Returns null if characters are ordered as they appear
7374  // (left-to-right), or an array of sections ({from, to, level}
7375  // objects) in the order in which they occur visually.
7376  var bidiOrdering = (function() {
7377    // Character types for codepoints 0 to 0xff
7378    var lowTypes = "bbbbbbbbbtstwsbbbbbbbbbbbbbbssstwNN%%%NNNNNN,N,N1111111111NNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNbbbbbbsbbbbbbbbbbbbbbbbbbbbbbbbbb,N%%%%NNNNLNNNNN%%11NLNNN1LNNNNNLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLN";
7379    // Character types for codepoints 0x600 to 0x6ff
7380    var arabicTypes = "rrrrrrrrrrrr,rNNmmmmmmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmrrrrrrrnnnnnnnnnn%nnrrrmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmmmmmmNmmmm";
7381    function charType(code) {
7382      if (code <= 0xf7) return lowTypes.charAt(code);
7383      else if (0x590 <= code && code <= 0x5f4) return "R";
7384      else if (0x600 <= code && code <= 0x6ed) return arabicTypes.charAt(code - 0x600);
7385      else if (0x6ee <= code && code <= 0x8ac) return "r";
7386      else if (0x2000 <= code && code <= 0x200b) return "w";
7387      else if (code == 0x200c) return "b";
7388      else return "L";
7389    }
7390
7391    var bidiRE = /[\u0590-\u05f4\u0600-\u06ff\u0700-\u08ac]/;
7392    var isNeutral = /[stwN]/, isStrong = /[LRr]/, countsAsLeft = /[Lb1n]/, countsAsNum = /[1n]/;
7393    // Browsers seem to always treat the boundaries of block elements as being L.
7394    var outerType = "L";
7395
7396    function BidiSpan(level, from, to) {
7397      this.level = level;
7398      this.from = from; this.to = to;
7399    }
7400
7401    return function(str) {
7402      if (!bidiRE.test(str)) return false;
7403      var len = str.length, types = [];
7404      for (var i = 0, type; i < len; ++i)
7405        types.push(type = charType(str.charCodeAt(i)));
7406
7407      // W1. Examine each non-spacing mark (NSM) in the level run, and
7408      // change the type of the NSM to the type of the previous
7409      // character. If the NSM is at the start of the level run, it will
7410      // get the type of sor.
7411      for (var i = 0, prev = outerType; i < len; ++i) {
7412        var type = types[i];
7413        if (type == "m") types[i] = prev;
7414        else prev = type;
7415      }
7416
7417      // W2. Search backwards from each instance of a European number
7418      // until the first strong type (R, L, AL, or sor) is found. If an
7419      // AL is found, change the type of the European number to Arabic
7420      // number.
7421      // W3. Change all ALs to R.
7422      for (var i = 0, cur = outerType; i < len; ++i) {
7423        var type = types[i];
7424        if (type == "1" && cur == "r") types[i] = "n";
7425        else if (isStrong.test(type)) { cur = type; if (type == "r") types[i] = "R"; }
7426      }
7427
7428      // W4. A single European separator between two European numbers
7429      // changes to a European number. A single common separator between
7430      // two numbers of the same type changes to that type.
7431      for (var i = 1, prev = types[0]; i < len - 1; ++i) {
7432        var type = types[i];
7433        if (type == "+" && prev == "1" && types[i+1] == "1") types[i] = "1";
7434        else if (type == "," && prev == types[i+1] &&
7435                 (prev == "1" || prev == "n")) types[i] = prev;
7436        prev = type;
7437      }
7438
7439      // W5. A sequence of European terminators adjacent to European
7440      // numbers changes to all European numbers.
7441      // W6. Otherwise, separators and terminators change to Other
7442      // Neutral.
7443      for (var i = 0; i < len; ++i) {
7444        var type = types[i];
7445        if (type == ",") types[i] = "N";
7446        else if (type == "%") {
7447          for (var end = i + 1; end < len && types[end] == "%"; ++end) {}
7448          var replace = (i && types[i-1] == "!") || (end < len && types[end] == "1") ? "1" : "N";
7449          for (var j = i; j < end; ++j) types[j] = replace;
7450          i = end - 1;
7451        }
7452      }
7453
7454      // W7. Search backwards from each instance of a European number
7455      // until the first strong type (R, L, or sor) is found. If an L is
7456      // found, then change the type of the European number to L.
7457      for (var i = 0, cur = outerType; i < len; ++i) {
7458        var type = types[i];
7459        if (cur == "L" && type == "1") types[i] = "L";
7460        else if (isStrong.test(type)) cur = type;
7461      }
7462
7463      // N1. A sequence of neutrals takes the direction of the
7464      // surrounding strong text if the text on both sides has the same
7465      // direction. European and Arabic numbers act as if they were R in
7466      // terms of their influence on neutrals. Start-of-level-run (sor)
7467      // and end-of-level-run (eor) are used at level run boundaries.
7468      // N2. Any remaining neutrals take the embedding direction.
7469      for (var i = 0; i < len; ++i) {
7470        if (isNeutral.test(types[i])) {
7471          for (var end = i + 1; end < len && isNeutral.test(types[end]); ++end) {}
7472          var before = (i ? types[i-1] : outerType) == "L";
7473          var after = (end < len ? types[end] : outerType) == "L";
7474          var replace = before || after ? "L" : "R";
7475          for (var j = i; j < end; ++j) types[j] = replace;
7476          i = end - 1;
7477        }
7478      }
7479
7480      // Here we depart from the documented algorithm, in order to avoid
7481      // building up an actual levels array. Since there are only three
7482      // levels (0, 1, 2) in an implementation that doesn't take
7483      // explicit embedding into account, we can build up the order on
7484      // the fly, without following the level-based algorithm.
7485      var order = [], m;
7486      for (var i = 0; i < len;) {
7487        if (countsAsLeft.test(types[i])) {
7488          var start = i;
7489          for (++i; i < len && countsAsLeft.test(types[i]); ++i) {}
7490          order.push(new BidiSpan(0, start, i));
7491        } else {
7492          var pos = i, at = order.length;
7493          for (++i; i < len && types[i] != "L"; ++i) {}
7494          for (var j = pos; j < i;) {
7495            if (countsAsNum.test(types[j])) {
7496              if (pos < j) order.splice(at, 0, new BidiSpan(1, pos, j));
7497              var nstart = j;
7498              for (++j; j < i && countsAsNum.test(types[j]); ++j) {}
7499              order.splice(at, 0, new BidiSpan(2, nstart, j));
7500              pos = j;
7501            } else ++j;
7502          }
7503          if (pos < i) order.splice(at, 0, new BidiSpan(1, pos, i));
7504        }
7505      }
7506      if (order[0].level == 1 && (m = str.match(/^\s+/))) {
7507        order[0].from = m[0].length;
7508        order.unshift(new BidiSpan(0, 0, m[0].length));
7509      }
7510      if (lst(order).level == 1 && (m = str.match(/\s+$/))) {
7511        lst(order).to -= m[0].length;
7512        order.push(new BidiSpan(0, len - m[0].length, len));
7513      }
7514      if (order[0].level != lst(order).level)
7515        order.push(new BidiSpan(order[0].level, len, len));
7516
7517      return order;
7518    };
7519  })();
7520
7521  // THE END
7522
7523  CodeMirror.version = "4.1.0";
7524
7525  return CodeMirror;
7526});
7527