BaseInputConnection.java revision 612cce92ad96eda1146c3abd2afa7aaa4d4f2b3f
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
5 * use this file except in compliance with the License. You may obtain a copy of
6 * the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations under
14 * the License.
15 */
16
17package android.view.inputmethod;
18
19import android.content.Context;
20import android.content.res.TypedArray;
21import android.os.Bundle;
22import android.os.Handler;
23import android.os.SystemClock;
24import android.text.Editable;
25import android.text.NoCopySpan;
26import android.text.Selection;
27import android.text.Spannable;
28import android.text.SpannableStringBuilder;
29import android.text.Spanned;
30import android.text.TextUtils;
31import android.text.method.MetaKeyKeyListener;
32import android.util.Log;
33import android.util.LogPrinter;
34import android.view.KeyCharacterMap;
35import android.view.KeyEvent;
36import android.view.View;
37import android.view.ViewRootImpl;
38
39class ComposingText implements NoCopySpan {
40}
41
42/**
43 * Base class for implementors of the InputConnection interface, taking care
44 * of most of the common behavior for providing a connection to an Editable.
45 * Implementors of this class will want to be sure to implement
46 * {@link #getEditable} to provide access to their own editable object, and
47 * to refer to the documentation in {@link InputConnection}.
48 */
49public class BaseInputConnection implements InputConnection {
50    private static final boolean DEBUG = false;
51    private static final String TAG = "BaseInputConnection";
52    static final Object COMPOSING = new ComposingText();
53
54    /** @hide */
55    protected final InputMethodManager mIMM;
56    final View mTargetView;
57    final boolean mDummyMode;
58
59    private Object[] mDefaultComposingSpans;
60
61    Editable mEditable;
62    KeyCharacterMap mKeyCharacterMap;
63
64    BaseInputConnection(InputMethodManager mgr, boolean fullEditor) {
65        mIMM = mgr;
66        mTargetView = null;
67        mDummyMode = !fullEditor;
68    }
69
70    public BaseInputConnection(View targetView, boolean fullEditor) {
71        mIMM = (InputMethodManager)targetView.getContext().getSystemService(
72                Context.INPUT_METHOD_SERVICE);
73        mTargetView = targetView;
74        mDummyMode = !fullEditor;
75    }
76
77    public static final void removeComposingSpans(Spannable text) {
78        text.removeSpan(COMPOSING);
79        Object[] sps = text.getSpans(0, text.length(), Object.class);
80        if (sps != null) {
81            for (int i=sps.length-1; i>=0; i--) {
82                Object o = sps[i];
83                if ((text.getSpanFlags(o)&Spanned.SPAN_COMPOSING) != 0) {
84                    text.removeSpan(o);
85                }
86            }
87        }
88    }
89
90    public static void setComposingSpans(Spannable text) {
91        setComposingSpans(text, 0, text.length());
92    }
93
94    /** @hide */
95    public static void setComposingSpans(Spannable text, int start, int end) {
96        final Object[] sps = text.getSpans(start, end, Object.class);
97        if (sps != null) {
98            for (int i=sps.length-1; i>=0; i--) {
99                final Object o = sps[i];
100                if (o == COMPOSING) {
101                    text.removeSpan(o);
102                    continue;
103                }
104
105                final int fl = text.getSpanFlags(o);
106                if ((fl&(Spanned.SPAN_COMPOSING|Spanned.SPAN_POINT_MARK_MASK))
107                        != (Spanned.SPAN_COMPOSING|Spanned.SPAN_EXCLUSIVE_EXCLUSIVE)) {
108                    text.setSpan(o, text.getSpanStart(o), text.getSpanEnd(o),
109                            (fl & ~Spanned.SPAN_POINT_MARK_MASK)
110                                    | Spanned.SPAN_COMPOSING
111                                    | Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
112                }
113            }
114        }
115
116        text.setSpan(COMPOSING, start, end,
117                Spanned.SPAN_EXCLUSIVE_EXCLUSIVE | Spanned.SPAN_COMPOSING);
118    }
119
120    public static int getComposingSpanStart(Spannable text) {
121        return text.getSpanStart(COMPOSING);
122    }
123
124    public static int getComposingSpanEnd(Spannable text) {
125        return text.getSpanEnd(COMPOSING);
126    }
127
128    /**
129     * Return the target of edit operations.  The default implementation
130     * returns its own fake editable that is just used for composing text;
131     * subclasses that are real text editors should override this and
132     * supply their own.
133     */
134    public Editable getEditable() {
135        if (mEditable == null) {
136            mEditable = Editable.Factory.getInstance().newEditable("");
137            Selection.setSelection(mEditable, 0);
138        }
139        return mEditable;
140    }
141
142    /**
143     * Default implementation does nothing.
144     */
145    public boolean beginBatchEdit() {
146        return false;
147    }
148
149    /**
150     * Default implementation does nothing.
151     */
152    public boolean endBatchEdit() {
153        return false;
154    }
155
156    /**
157     * Called when this InputConnection is no longer used by the InputMethodManager.
158     *
159     * @hide
160     */
161    protected void reportFinish() {
162        // Intentionaly empty
163    }
164
165    /**
166     * Default implementation uses
167     * {@link MetaKeyKeyListener#clearMetaKeyState(long, int)
168     * MetaKeyKeyListener.clearMetaKeyState(long, int)} to clear the state.
169     */
170    public boolean clearMetaKeyStates(int states) {
171        final Editable content = getEditable();
172        if (content == null) return false;
173        MetaKeyKeyListener.clearMetaKeyState(content, states);
174        return true;
175    }
176
177    /**
178     * Default implementation does nothing and returns false.
179     */
180    public boolean commitCompletion(CompletionInfo text) {
181        return false;
182    }
183
184    /**
185     * Default implementation does nothing and returns false.
186     */
187    public boolean commitCorrection(CorrectionInfo correctionInfo) {
188        return false;
189    }
190
191    /**
192     * Default implementation replaces any existing composing text with
193     * the given text.  In addition, only if dummy mode, a key event is
194     * sent for the new text and the current editable buffer cleared.
195     */
196    public boolean commitText(CharSequence text, int newCursorPosition) {
197        if (DEBUG) Log.v(TAG, "commitText " + text);
198        replaceText(text, newCursorPosition, false);
199        sendCurrentText();
200        return true;
201    }
202
203    /**
204     * The default implementation performs the deletion around the current selection position of the
205     * editable text.
206     *
207     * @param beforeLength The number of characters before the cursor to be deleted, in code unit.
208     *        If this is greater than the number of existing characters between the beginning of the
209     *        text and the cursor, then this method does not fail but deletes all the characters in
210     *        that range.
211     * @param afterLength The number of characters after the cursor to be deleted, in code unit.
212     *        If this is greater than the number of existing characters between the cursor and
213     *        the end of the text, then this method does not fail but deletes all the characters in
214     *        that range.
215     */
216    public boolean deleteSurroundingText(int beforeLength, int afterLength) {
217        if (DEBUG) Log.v(TAG, "deleteSurroundingText " + beforeLength
218                + " / " + afterLength);
219        final Editable content = getEditable();
220        if (content == null) return false;
221
222        beginBatchEdit();
223
224        int a = Selection.getSelectionStart(content);
225        int b = Selection.getSelectionEnd(content);
226
227        if (a > b) {
228            int tmp = a;
229            a = b;
230            b = tmp;
231        }
232
233        // Ignore the composing text.
234        int ca = getComposingSpanStart(content);
235        int cb = getComposingSpanEnd(content);
236        if (cb < ca) {
237            int tmp = ca;
238            ca = cb;
239            cb = tmp;
240        }
241        if (ca != -1 && cb != -1) {
242            if (ca < a) a = ca;
243            if (cb > b) b = cb;
244        }
245
246        int deleted = 0;
247
248        if (beforeLength > 0) {
249            int start = a - beforeLength;
250            if (start < 0) start = 0;
251            content.delete(start, a);
252            deleted = a - start;
253        }
254
255        if (afterLength > 0) {
256            b = b - deleted;
257
258            int end = b + afterLength;
259            if (end > content.length()) end = content.length();
260
261            content.delete(b, end);
262        }
263
264        endBatchEdit();
265
266        return true;
267    }
268
269    private static int INVALID_INDEX = -1;
270    private static int findIndexBackward(final CharSequence cs, final int from,
271            final int numCodePoints) {
272        int currentIndex = from;
273        boolean waitingHighSurrogate = false;
274        final int N = cs.length();
275        if (currentIndex < 0 || N < currentIndex) {
276            return INVALID_INDEX;  // The starting point is out of range.
277        }
278        if (numCodePoints < 0) {
279            return INVALID_INDEX;  // Basically this should not happen.
280        }
281        int remainingCodePoints = numCodePoints;
282        while (true) {
283            if (remainingCodePoints == 0) {
284                return currentIndex;  // Reached to the requested length in code points.
285            }
286
287            --currentIndex;
288            if (currentIndex < 0) {
289                if (waitingHighSurrogate) {
290                    return INVALID_INDEX;  // An invalid surrogate pair is found.
291                }
292                return 0;  // Reached to the beginning of the text w/o any invalid surrogate pair.
293            }
294            final char c = cs.charAt(currentIndex);
295            if (waitingHighSurrogate) {
296                if (!java.lang.Character.isHighSurrogate(c)) {
297                    return INVALID_INDEX;  // An invalid surrogate pair is found.
298                }
299                waitingHighSurrogate = false;
300                --remainingCodePoints;
301                continue;
302            }
303            if (!java.lang.Character.isSurrogate(c)) {
304                --remainingCodePoints;
305                continue;
306            }
307            if (java.lang.Character.isHighSurrogate(c)) {
308                return INVALID_INDEX;  // A invalid surrogate pair is found.
309            }
310            waitingHighSurrogate = true;
311        }
312    }
313
314    private static int findIndexForward(final CharSequence cs, final int from,
315            final int numCodePoints) {
316        int currentIndex = from;
317        boolean waitingLowSurrogate = false;
318        final int N = cs.length();
319        if (currentIndex < 0 || N < currentIndex) {
320            return INVALID_INDEX;  // The starting point is out of range.
321        }
322        if (numCodePoints < 0) {
323            return INVALID_INDEX;  // Basically this should not happen.
324        }
325        int remainingCodePoints = numCodePoints;
326
327        while (true) {
328            if (remainingCodePoints == 0) {
329                return currentIndex;  // Reached to the requested length in code points.
330            }
331
332            if (currentIndex >= N) {
333                if (waitingLowSurrogate) {
334                    return INVALID_INDEX;  // An invalid surrogate pair is found.
335                }
336                return N;  // Reached to the end of the text w/o any invalid surrogate pair.
337            }
338            final char c = cs.charAt(currentIndex);
339            if (waitingLowSurrogate) {
340                if (!java.lang.Character.isLowSurrogate(c)) {
341                    return INVALID_INDEX;  // An invalid surrogate pair is found.
342                }
343                --remainingCodePoints;
344                waitingLowSurrogate = false;
345                ++currentIndex;
346                continue;
347            }
348            if (!java.lang.Character.isSurrogate(c)) {
349                --remainingCodePoints;
350                ++currentIndex;
351                continue;
352            }
353            if (java.lang.Character.isLowSurrogate(c)) {
354                return INVALID_INDEX;  // A invalid surrogate pair is found.
355            }
356            waitingLowSurrogate = true;
357            ++currentIndex;
358        }
359    }
360
361    /**
362     * The default implementation performs the deletion around the current selection position of the
363     * editable text.
364     * @param beforeLength The number of characters before the cursor to be deleted, in code points.
365     *        If this is greater than the number of existing characters between the beginning of the
366     *        text and the cursor, then this method does not fail but deletes all the characters in
367     *        that range.
368     * @param afterLength The number of characters after the cursor to be deleted, in code points.
369     *        If this is greater than the number of existing characters between the cursor and
370     *        the end of the text, then this method does not fail but deletes all the characters in
371     *        that range.
372     */
373    public boolean deleteSurroundingTextInCodePoints(int beforeLength, int afterLength) {
374        if (DEBUG) Log.v(TAG, "deleteSurroundingText " + beforeLength
375                + " / " + afterLength);
376        final Editable content = getEditable();
377        if (content == null) return false;
378
379        beginBatchEdit();
380
381        int a = Selection.getSelectionStart(content);
382        int b = Selection.getSelectionEnd(content);
383
384        if (a > b) {
385            int tmp = a;
386            a = b;
387            b = tmp;
388        }
389
390        // Ignore the composing text.
391        int ca = getComposingSpanStart(content);
392        int cb = getComposingSpanEnd(content);
393        if (cb < ca) {
394            int tmp = ca;
395            ca = cb;
396            cb = tmp;
397        }
398        if (ca != -1 && cb != -1) {
399            if (ca < a) a = ca;
400            if (cb > b) b = cb;
401        }
402
403        if (a >= 0 && b >= 0) {
404            final int start = findIndexBackward(content, a, Math.max(beforeLength, 0));
405            if (start != INVALID_INDEX) {
406                final int end = findIndexForward(content, b, Math.max(afterLength, 0));
407                if (end != INVALID_INDEX) {
408                    final int numDeleteBefore = a - start;
409                    if (numDeleteBefore > 0) {
410                        content.delete(start, a);
411                    }
412                    final int numDeleteAfter = end - b;
413                    if (numDeleteAfter > 0) {
414                        content.delete(b - numDeleteBefore, end - numDeleteBefore);
415                    }
416                }
417            }
418            // NOTE: You may think we should return false here if start and/or end is INVALID_INDEX,
419            // but the truth is that IInputConnectionWrapper running in the middle of IPC calls
420            // always returns true to the IME without waiting for the completion of this method as
421            // IInputConnectionWrapper#isAtive() returns true.  This is actually why some methods
422            // including this method look like asynchronous calls from the IME.
423        }
424
425        endBatchEdit();
426
427        return true;
428    }
429
430    /**
431     * The default implementation removes the composing state from the
432     * current editable text.  In addition, only if dummy mode, a key event is
433     * sent for the new text and the current editable buffer cleared.
434     */
435    public boolean finishComposingText() {
436        if (DEBUG) Log.v(TAG, "finishComposingText");
437        final Editable content = getEditable();
438        if (content != null) {
439            beginBatchEdit();
440            removeComposingSpans(content);
441            // Note: sendCurrentText does nothing unless mDummyMode is set
442            sendCurrentText();
443            endBatchEdit();
444        }
445        return true;
446    }
447
448    /**
449     * The default implementation uses TextUtils.getCapsMode to get the
450     * cursor caps mode for the current selection position in the editable
451     * text, unless in dummy mode in which case 0 is always returned.
452     */
453    public int getCursorCapsMode(int reqModes) {
454        if (mDummyMode) return 0;
455
456        final Editable content = getEditable();
457        if (content == null) return 0;
458
459        int a = Selection.getSelectionStart(content);
460        int b = Selection.getSelectionEnd(content);
461
462        if (a > b) {
463            int tmp = a;
464            a = b;
465            b = tmp;
466        }
467
468        return TextUtils.getCapsMode(content, a, reqModes);
469    }
470
471    /**
472     * The default implementation always returns null.
473     */
474    public ExtractedText getExtractedText(ExtractedTextRequest request, int flags) {
475        return null;
476    }
477
478    /**
479     * The default implementation returns the given amount of text from the
480     * current cursor position in the buffer.
481     */
482    public CharSequence getTextBeforeCursor(int length, int flags) {
483        final Editable content = getEditable();
484        if (content == null) return null;
485
486        int a = Selection.getSelectionStart(content);
487        int b = Selection.getSelectionEnd(content);
488
489        if (a > b) {
490            int tmp = a;
491            a = b;
492            b = tmp;
493        }
494
495        if (a <= 0) {
496            return "";
497        }
498
499        if (length > a) {
500            length = a;
501        }
502
503        if ((flags&GET_TEXT_WITH_STYLES) != 0) {
504            return content.subSequence(a - length, a);
505        }
506        return TextUtils.substring(content, a - length, a);
507    }
508
509    /**
510     * The default implementation returns the text currently selected, or null if none is
511     * selected.
512     */
513    public CharSequence getSelectedText(int flags) {
514        final Editable content = getEditable();
515        if (content == null) return null;
516
517        int a = Selection.getSelectionStart(content);
518        int b = Selection.getSelectionEnd(content);
519
520        if (a > b) {
521            int tmp = a;
522            a = b;
523            b = tmp;
524        }
525
526        if (a == b) return null;
527
528        if ((flags&GET_TEXT_WITH_STYLES) != 0) {
529            return content.subSequence(a, b);
530        }
531        return TextUtils.substring(content, a, b);
532    }
533
534    /**
535     * The default implementation returns the given amount of text from the
536     * current cursor position in the buffer.
537     */
538    public CharSequence getTextAfterCursor(int length, int flags) {
539        final Editable content = getEditable();
540        if (content == null) return null;
541
542        int a = Selection.getSelectionStart(content);
543        int b = Selection.getSelectionEnd(content);
544
545        if (a > b) {
546            int tmp = a;
547            a = b;
548            b = tmp;
549        }
550
551        // Guard against the case where the cursor has not been positioned yet.
552        if (b < 0) {
553            b = 0;
554        }
555
556        if (b + length > content.length()) {
557            length = content.length() - b;
558        }
559
560
561        if ((flags&GET_TEXT_WITH_STYLES) != 0) {
562            return content.subSequence(b, b + length);
563        }
564        return TextUtils.substring(content, b, b + length);
565    }
566
567    /**
568     * The default implementation turns this into the enter key.
569     */
570    public boolean performEditorAction(int actionCode) {
571        long eventTime = SystemClock.uptimeMillis();
572        sendKeyEvent(new KeyEvent(eventTime, eventTime,
573                KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_ENTER, 0, 0,
574                KeyCharacterMap.VIRTUAL_KEYBOARD, 0,
575                KeyEvent.FLAG_SOFT_KEYBOARD | KeyEvent.FLAG_KEEP_TOUCH_MODE
576                | KeyEvent.FLAG_EDITOR_ACTION));
577        sendKeyEvent(new KeyEvent(SystemClock.uptimeMillis(), eventTime,
578                KeyEvent.ACTION_UP, KeyEvent.KEYCODE_ENTER, 0, 0,
579                KeyCharacterMap.VIRTUAL_KEYBOARD, 0,
580                KeyEvent.FLAG_SOFT_KEYBOARD | KeyEvent.FLAG_KEEP_TOUCH_MODE
581                | KeyEvent.FLAG_EDITOR_ACTION));
582        return true;
583    }
584
585    /**
586     * The default implementation does nothing.
587     */
588    public boolean performContextMenuAction(int id) {
589        return false;
590    }
591
592    /**
593     * The default implementation does nothing.
594     */
595    public boolean performPrivateCommand(String action, Bundle data) {
596        return false;
597    }
598
599    /**
600     * The default implementation does nothing.
601     */
602    public boolean requestCursorUpdates(int cursorUpdateMode) {
603        return false;
604    }
605
606    public Handler getHandler() {
607        return null;
608    }
609
610    /**
611     * The default implementation places the given text into the editable,
612     * replacing any existing composing text.  The new text is marked as
613     * in a composing state with the composing style.
614     */
615    public boolean setComposingText(CharSequence text, int newCursorPosition) {
616        if (DEBUG) Log.v(TAG, "setComposingText " + text);
617        replaceText(text, newCursorPosition, true);
618        return true;
619    }
620
621    public boolean setComposingRegion(int start, int end) {
622        final Editable content = getEditable();
623        if (content != null) {
624            beginBatchEdit();
625            removeComposingSpans(content);
626            int a = start;
627            int b = end;
628            if (a > b) {
629                int tmp = a;
630                a = b;
631                b = tmp;
632            }
633            // Clip the end points to be within the content bounds.
634            final int length = content.length();
635            if (a < 0) a = 0;
636            if (b < 0) b = 0;
637            if (a > length) a = length;
638            if (b > length) b = length;
639
640            ensureDefaultComposingSpans();
641            if (mDefaultComposingSpans != null) {
642                for (int i = 0; i < mDefaultComposingSpans.length; ++i) {
643                    content.setSpan(mDefaultComposingSpans[i], a, b,
644                            Spanned.SPAN_EXCLUSIVE_EXCLUSIVE | Spanned.SPAN_COMPOSING);
645                }
646            }
647
648            content.setSpan(COMPOSING, a, b,
649                    Spanned.SPAN_EXCLUSIVE_EXCLUSIVE | Spanned.SPAN_COMPOSING);
650
651            // Note: sendCurrentText does nothing unless mDummyMode is set
652            sendCurrentText();
653            endBatchEdit();
654        }
655        return true;
656    }
657
658    /**
659     * The default implementation changes the selection position in the
660     * current editable text.
661     */
662    public boolean setSelection(int start, int end) {
663        if (DEBUG) Log.v(TAG, "setSelection " + start + ", " + end);
664        final Editable content = getEditable();
665        if (content == null) return false;
666        int len = content.length();
667        if (start > len || end > len || start < 0 || end < 0) {
668            // If the given selection is out of bounds, just ignore it.
669            // Most likely the text was changed out from under the IME,
670            // and the IME is going to have to update all of its state
671            // anyway.
672            return true;
673        }
674        if (start == end && MetaKeyKeyListener.getMetaState(content,
675                MetaKeyKeyListener.META_SELECTING) != 0) {
676            // If we are in selection mode, then we want to extend the
677            // selection instead of replacing it.
678            Selection.extendSelection(content, start);
679        } else {
680            Selection.setSelection(content, start, end);
681        }
682        return true;
683    }
684
685    /**
686     * Provides standard implementation for sending a key event to the window
687     * attached to the input connection's view.
688     */
689    public boolean sendKeyEvent(KeyEvent event) {
690        mIMM.dispatchKeyEventFromInputMethod(mTargetView, event);
691        return false;
692    }
693
694    /**
695     * Updates InputMethodManager with the current fullscreen mode.
696     */
697    public boolean reportFullscreenMode(boolean enabled) {
698        return true;
699    }
700
701    private void sendCurrentText() {
702        if (!mDummyMode) {
703            return;
704        }
705
706        Editable content = getEditable();
707        if (content != null) {
708            final int N = content.length();
709            if (N == 0) {
710                return;
711            }
712            if (N == 1) {
713                // If it's 1 character, we have a chance of being
714                // able to generate normal key events...
715                if (mKeyCharacterMap == null) {
716                    mKeyCharacterMap = KeyCharacterMap.load(KeyCharacterMap.VIRTUAL_KEYBOARD);
717                }
718                char[] chars = new char[1];
719                content.getChars(0, 1, chars, 0);
720                KeyEvent[] events = mKeyCharacterMap.getEvents(chars);
721                if (events != null) {
722                    for (int i=0; i<events.length; i++) {
723                        if (DEBUG) Log.v(TAG, "Sending: " + events[i]);
724                        sendKeyEvent(events[i]);
725                    }
726                    content.clear();
727                    return;
728                }
729            }
730
731            // Otherwise, revert to the special key event containing
732            // the actual characters.
733            KeyEvent event = new KeyEvent(SystemClock.uptimeMillis(),
734                    content.toString(), KeyCharacterMap.VIRTUAL_KEYBOARD, 0);
735            sendKeyEvent(event);
736            content.clear();
737        }
738    }
739
740    private void ensureDefaultComposingSpans() {
741        if (mDefaultComposingSpans == null) {
742            Context context;
743            if (mTargetView != null) {
744                context = mTargetView.getContext();
745            } else if (mIMM.mServedView != null) {
746                context = mIMM.mServedView.getContext();
747            } else {
748                context = null;
749            }
750            if (context != null) {
751                TypedArray ta = context.getTheme()
752                        .obtainStyledAttributes(new int[] {
753                                com.android.internal.R.attr.candidatesTextStyleSpans
754                        });
755                CharSequence style = ta.getText(0);
756                ta.recycle();
757                if (style != null && style instanceof Spanned) {
758                    mDefaultComposingSpans = ((Spanned)style).getSpans(
759                            0, style.length(), Object.class);
760                }
761            }
762        }
763    }
764
765    private void replaceText(CharSequence text, int newCursorPosition,
766            boolean composing) {
767        final Editable content = getEditable();
768        if (content == null) {
769            return;
770        }
771
772        beginBatchEdit();
773
774        // delete composing text set previously.
775        int a = getComposingSpanStart(content);
776        int b = getComposingSpanEnd(content);
777
778        if (DEBUG) Log.v(TAG, "Composing span: " + a + " to " + b);
779
780        if (b < a) {
781            int tmp = a;
782            a = b;
783            b = tmp;
784        }
785
786        if (a != -1 && b != -1) {
787            removeComposingSpans(content);
788        } else {
789            a = Selection.getSelectionStart(content);
790            b = Selection.getSelectionEnd(content);
791            if (a < 0) a = 0;
792            if (b < 0) b = 0;
793            if (b < a) {
794                int tmp = a;
795                a = b;
796                b = tmp;
797            }
798        }
799
800        if (composing) {
801            Spannable sp = null;
802            if (!(text instanceof Spannable)) {
803                sp = new SpannableStringBuilder(text);
804                text = sp;
805                ensureDefaultComposingSpans();
806                if (mDefaultComposingSpans != null) {
807                    for (int i = 0; i < mDefaultComposingSpans.length; ++i) {
808                        sp.setSpan(mDefaultComposingSpans[i], 0, sp.length(),
809                                Spanned.SPAN_EXCLUSIVE_EXCLUSIVE | Spanned.SPAN_COMPOSING);
810                    }
811                }
812            } else {
813                sp = (Spannable)text;
814            }
815            setComposingSpans(sp);
816        }
817
818        if (DEBUG) Log.v(TAG, "Replacing from " + a + " to " + b + " with \""
819                + text + "\", composing=" + composing
820                + ", type=" + text.getClass().getCanonicalName());
821
822        if (DEBUG) {
823            LogPrinter lp = new LogPrinter(Log.VERBOSE, TAG);
824            lp.println("Current text:");
825            TextUtils.dumpSpans(content, lp, "  ");
826            lp.println("Composing text:");
827            TextUtils.dumpSpans(text, lp, "  ");
828        }
829
830        // Position the cursor appropriately, so that after replacing the
831        // desired range of text it will be located in the correct spot.
832        // This allows us to deal with filters performing edits on the text
833        // we are providing here.
834        if (newCursorPosition > 0) {
835            newCursorPosition += b - 1;
836        } else {
837            newCursorPosition += a;
838        }
839        if (newCursorPosition < 0) newCursorPosition = 0;
840        if (newCursorPosition > content.length())
841            newCursorPosition = content.length();
842        Selection.setSelection(content, newCursorPosition);
843
844        content.replace(a, b, text);
845
846        if (DEBUG) {
847            LogPrinter lp = new LogPrinter(Log.VERBOSE, TAG);
848            lp.println("Final text:");
849            TextUtils.dumpSpans(content, lp, "  ");
850        }
851
852        endBatchEdit();
853    }
854}
855