1"""
2An auto-completion window for IDLE, used by the AutoComplete extension
3"""
4from Tkinter import *
5from idlelib.MultiCall import MC_SHIFT
6from idlelib.AutoComplete import COMPLETE_FILES, COMPLETE_ATTRIBUTES
7
8HIDE_VIRTUAL_EVENT_NAME = "<<autocompletewindow-hide>>"
9HIDE_SEQUENCES = ("<FocusOut>", "<ButtonPress>")
10KEYPRESS_VIRTUAL_EVENT_NAME = "<<autocompletewindow-keypress>>"
11# We need to bind event beyond <Key> so that the function will be called
12# before the default specific IDLE function
13KEYPRESS_SEQUENCES = ("<Key>", "<Key-BackSpace>", "<Key-Return>", "<Key-Tab>",
14                      "<Key-Up>", "<Key-Down>", "<Key-Home>", "<Key-End>",
15                      "<Key-Prior>", "<Key-Next>")
16KEYRELEASE_VIRTUAL_EVENT_NAME = "<<autocompletewindow-keyrelease>>"
17KEYRELEASE_SEQUENCE = "<KeyRelease>"
18LISTUPDATE_SEQUENCE = "<B1-ButtonRelease>"
19WINCONFIG_SEQUENCE = "<Configure>"
20DOUBLECLICK_SEQUENCE = "<B1-Double-ButtonRelease>"
21
22class AutoCompleteWindow:
23
24    def __init__(self, widget):
25        # The widget (Text) on which we place the AutoCompleteWindow
26        self.widget = widget
27        # The widgets we create
28        self.autocompletewindow = self.listbox = self.scrollbar = None
29        # The default foreground and background of a selection. Saved because
30        # they are changed to the regular colors of list items when the
31        # completion start is not a prefix of the selected completion
32        self.origselforeground = self.origselbackground = None
33        # The list of completions
34        self.completions = None
35        # A list with more completions, or None
36        self.morecompletions = None
37        # The completion mode. Either AutoComplete.COMPLETE_ATTRIBUTES or
38        # AutoComplete.COMPLETE_FILES
39        self.mode = None
40        # The current completion start, on the text box (a string)
41        self.start = None
42        # The index of the start of the completion
43        self.startindex = None
44        # The last typed start, used so that when the selection changes,
45        # the new start will be as close as possible to the last typed one.
46        self.lasttypedstart = None
47        # Do we have an indication that the user wants the completion window
48        # (for example, he clicked the list)
49        self.userwantswindow = None
50        # event ids
51        self.hideid = self.keypressid = self.listupdateid = self.winconfigid \
52        = self.keyreleaseid = self.doubleclickid                         = None
53        # Flag set if last keypress was a tab
54        self.lastkey_was_tab = False
55
56    def _change_start(self, newstart):
57        min_len = min(len(self.start), len(newstart))
58        i = 0
59        while i < min_len and self.start[i] == newstart[i]:
60            i += 1
61        if i < len(self.start):
62            self.widget.delete("%s+%dc" % (self.startindex, i),
63                               "%s+%dc" % (self.startindex, len(self.start)))
64        if i < len(newstart):
65            self.widget.insert("%s+%dc" % (self.startindex, i),
66                               newstart[i:])
67        self.start = newstart
68
69    def _binary_search(self, s):
70        """Find the first index in self.completions where completions[i] is
71        greater or equal to s, or the last index if there is no such
72        one."""
73        i = 0; j = len(self.completions)
74        while j > i:
75            m = (i + j) // 2
76            if self.completions[m] >= s:
77                j = m
78            else:
79                i = m + 1
80        return min(i, len(self.completions)-1)
81
82    def _complete_string(self, s):
83        """Assuming that s is the prefix of a string in self.completions,
84        return the longest string which is a prefix of all the strings which
85        s is a prefix of them. If s is not a prefix of a string, return s."""
86        first = self._binary_search(s)
87        if self.completions[first][:len(s)] != s:
88            # There is not even one completion which s is a prefix of.
89            return s
90        # Find the end of the range of completions where s is a prefix of.
91        i = first + 1
92        j = len(self.completions)
93        while j > i:
94            m = (i + j) // 2
95            if self.completions[m][:len(s)] != s:
96                j = m
97            else:
98                i = m + 1
99        last = i-1
100
101        if first == last: # only one possible completion
102            return self.completions[first]
103
104        # We should return the maximum prefix of first and last
105        first_comp = self.completions[first]
106        last_comp = self.completions[last]
107        min_len = min(len(first_comp), len(last_comp))
108        i = len(s)
109        while i < min_len and first_comp[i] == last_comp[i]:
110            i += 1
111        return first_comp[:i]
112
113    def _selection_changed(self):
114        """Should be called when the selection of the Listbox has changed.
115        Updates the Listbox display and calls _change_start."""
116        cursel = int(self.listbox.curselection()[0])
117
118        self.listbox.see(cursel)
119
120        lts = self.lasttypedstart
121        selstart = self.completions[cursel]
122        if self._binary_search(lts) == cursel:
123            newstart = lts
124        else:
125            min_len = min(len(lts), len(selstart))
126            i = 0
127            while i < min_len and lts[i] == selstart[i]:
128                i += 1
129            newstart = selstart[:i]
130        self._change_start(newstart)
131
132        if self.completions[cursel][:len(self.start)] == self.start:
133            # start is a prefix of the selected completion
134            self.listbox.configure(selectbackground=self.origselbackground,
135                                   selectforeground=self.origselforeground)
136        else:
137            self.listbox.configure(selectbackground=self.listbox.cget("bg"),
138                                   selectforeground=self.listbox.cget("fg"))
139            # If there are more completions, show them, and call me again.
140            if self.morecompletions:
141                self.completions = self.morecompletions
142                self.morecompletions = None
143                self.listbox.delete(0, END)
144                for item in self.completions:
145                    self.listbox.insert(END, item)
146                self.listbox.select_set(self._binary_search(self.start))
147                self._selection_changed()
148
149    def show_window(self, comp_lists, index, complete, mode, userWantsWin):
150        """Show the autocomplete list, bind events.
151        If complete is True, complete the text, and if there is exactly one
152        matching completion, don't open a list."""
153        # Handle the start we already have
154        self.completions, self.morecompletions = comp_lists
155        self.mode = mode
156        self.startindex = self.widget.index(index)
157        self.start = self.widget.get(self.startindex, "insert")
158        if complete:
159            completed = self._complete_string(self.start)
160            self._change_start(completed)
161            i = self._binary_search(completed)
162            if self.completions[i] == completed and \
163               (i == len(self.completions)-1 or
164                self.completions[i+1][:len(completed)] != completed):
165                # There is exactly one matching completion
166                return
167        self.userwantswindow = userWantsWin
168        self.lasttypedstart = self.start
169
170        # Put widgets in place
171        self.autocompletewindow = acw = Toplevel(self.widget)
172        # Put it in a position so that it is not seen.
173        acw.wm_geometry("+10000+10000")
174        # Make it float
175        acw.wm_overrideredirect(1)
176        try:
177            # This command is only needed and available on Tk >= 8.4.0 for OSX
178            # Without it, call tips intrude on the typing process by grabbing
179            # the focus.
180            acw.tk.call("::tk::unsupported::MacWindowStyle", "style", acw._w,
181                        "help", "noActivates")
182        except TclError:
183            pass
184        self.scrollbar = scrollbar = Scrollbar(acw, orient=VERTICAL)
185        self.listbox = listbox = Listbox(acw, yscrollcommand=scrollbar.set,
186                                         exportselection=False, bg="white")
187        for item in self.completions:
188            listbox.insert(END, item)
189        self.origselforeground = listbox.cget("selectforeground")
190        self.origselbackground = listbox.cget("selectbackground")
191        scrollbar.config(command=listbox.yview)
192        scrollbar.pack(side=RIGHT, fill=Y)
193        listbox.pack(side=LEFT, fill=BOTH, expand=True)
194
195        # Initialize the listbox selection
196        self.listbox.select_set(self._binary_search(self.start))
197        self._selection_changed()
198
199        # bind events
200        self.hideid = self.widget.bind(HIDE_VIRTUAL_EVENT_NAME,
201                                       self.hide_event)
202        for seq in HIDE_SEQUENCES:
203            self.widget.event_add(HIDE_VIRTUAL_EVENT_NAME, seq)
204        self.keypressid = self.widget.bind(KEYPRESS_VIRTUAL_EVENT_NAME,
205                                           self.keypress_event)
206        for seq in KEYPRESS_SEQUENCES:
207            self.widget.event_add(KEYPRESS_VIRTUAL_EVENT_NAME, seq)
208        self.keyreleaseid = self.widget.bind(KEYRELEASE_VIRTUAL_EVENT_NAME,
209                                             self.keyrelease_event)
210        self.widget.event_add(KEYRELEASE_VIRTUAL_EVENT_NAME,KEYRELEASE_SEQUENCE)
211        self.listupdateid = listbox.bind(LISTUPDATE_SEQUENCE,
212                                         self.listselect_event)
213        self.winconfigid = acw.bind(WINCONFIG_SEQUENCE, self.winconfig_event)
214        self.doubleclickid = listbox.bind(DOUBLECLICK_SEQUENCE,
215                                          self.doubleclick_event)
216
217    def winconfig_event(self, event):
218        if not self.is_active():
219            return
220        # Position the completion list window
221        text = self.widget
222        text.see(self.startindex)
223        x, y, cx, cy = text.bbox(self.startindex)
224        acw = self.autocompletewindow
225        acw_width, acw_height = acw.winfo_width(), acw.winfo_height()
226        text_width, text_height = text.winfo_width(), text.winfo_height()
227        new_x = text.winfo_rootx() + min(x, max(0, text_width - acw_width))
228        new_y = text.winfo_rooty() + y
229        if (text_height - (y + cy) >= acw_height # enough height below
230            or y < acw_height): # not enough height above
231            # place acw below current line
232            new_y += cy
233        else:
234            # place acw above current line
235            new_y -= acw_height
236        acw.wm_geometry("+%d+%d" % (new_x, new_y))
237
238    def hide_event(self, event):
239        if not self.is_active():
240            return
241        self.hide_window()
242
243    def listselect_event(self, event):
244        if not self.is_active():
245            return
246        self.userwantswindow = True
247        cursel = int(self.listbox.curselection()[0])
248        self._change_start(self.completions[cursel])
249
250    def doubleclick_event(self, event):
251        # Put the selected completion in the text, and close the list
252        cursel = int(self.listbox.curselection()[0])
253        self._change_start(self.completions[cursel])
254        self.hide_window()
255
256    def keypress_event(self, event):
257        if not self.is_active():
258            return
259        keysym = event.keysym
260        if hasattr(event, "mc_state"):
261            state = event.mc_state
262        else:
263            state = 0
264        if keysym != "Tab":
265            self.lastkey_was_tab = False
266        if (len(keysym) == 1 or keysym in ("underscore", "BackSpace")
267            or (self.mode == COMPLETE_FILES and keysym in
268                ("period", "minus"))) \
269           and not (state & ~MC_SHIFT):
270            # Normal editing of text
271            if len(keysym) == 1:
272                self._change_start(self.start + keysym)
273            elif keysym == "underscore":
274                self._change_start(self.start + '_')
275            elif keysym == "period":
276                self._change_start(self.start + '.')
277            elif keysym == "minus":
278                self._change_start(self.start + '-')
279            else:
280                # keysym == "BackSpace"
281                if len(self.start) == 0:
282                    self.hide_window()
283                    return
284                self._change_start(self.start[:-1])
285            self.lasttypedstart = self.start
286            self.listbox.select_clear(0, int(self.listbox.curselection()[0]))
287            self.listbox.select_set(self._binary_search(self.start))
288            self._selection_changed()
289            return "break"
290
291        elif keysym == "Return":
292            self.hide_window()
293            return
294
295        elif (self.mode == COMPLETE_ATTRIBUTES and keysym in
296              ("period", "space", "parenleft", "parenright", "bracketleft",
297               "bracketright")) or \
298             (self.mode == COMPLETE_FILES and keysym in
299              ("slash", "backslash", "quotedbl", "apostrophe")) \
300             and not (state & ~MC_SHIFT):
301            # If start is a prefix of the selection, but is not '' when
302            # completing file names, put the whole
303            # selected completion. Anyway, close the list.
304            cursel = int(self.listbox.curselection()[0])
305            if self.completions[cursel][:len(self.start)] == self.start \
306               and (self.mode == COMPLETE_ATTRIBUTES or self.start):
307                self._change_start(self.completions[cursel])
308            self.hide_window()
309            return
310
311        elif keysym in ("Home", "End", "Prior", "Next", "Up", "Down") and \
312             not state:
313            # Move the selection in the listbox
314            self.userwantswindow = True
315            cursel = int(self.listbox.curselection()[0])
316            if keysym == "Home":
317                newsel = 0
318            elif keysym == "End":
319                newsel = len(self.completions)-1
320            elif keysym in ("Prior", "Next"):
321                jump = self.listbox.nearest(self.listbox.winfo_height()) - \
322                       self.listbox.nearest(0)
323                if keysym == "Prior":
324                    newsel = max(0, cursel-jump)
325                else:
326                    assert keysym == "Next"
327                    newsel = min(len(self.completions)-1, cursel+jump)
328            elif keysym == "Up":
329                newsel = max(0, cursel-1)
330            else:
331                assert keysym == "Down"
332                newsel = min(len(self.completions)-1, cursel+1)
333            self.listbox.select_clear(cursel)
334            self.listbox.select_set(newsel)
335            self._selection_changed()
336            self._change_start(self.completions[newsel])
337            return "break"
338
339        elif (keysym == "Tab" and not state):
340            if self.lastkey_was_tab:
341                # two tabs in a row; insert current selection and close acw
342                cursel = int(self.listbox.curselection()[0])
343                self._change_start(self.completions[cursel])
344                self.hide_window()
345                return "break"
346            else:
347                # first tab; let AutoComplete handle the completion
348                self.userwantswindow = True
349                self.lastkey_was_tab = True
350                return
351
352        elif any(s in keysym for s in ("Shift", "Control", "Alt",
353                                       "Meta", "Command", "Option")):
354            # A modifier key, so ignore
355            return
356
357        else:
358            # Unknown event, close the window and let it through.
359            self.hide_window()
360            return
361
362    def keyrelease_event(self, event):
363        if not self.is_active():
364            return
365        if self.widget.index("insert") != \
366           self.widget.index("%s+%dc" % (self.startindex, len(self.start))):
367            # If we didn't catch an event which moved the insert, close window
368            self.hide_window()
369
370    def is_active(self):
371        return self.autocompletewindow is not None
372
373    def complete(self):
374        self._change_start(self._complete_string(self.start))
375        # The selection doesn't change.
376
377    def hide_window(self):
378        if not self.is_active():
379            return
380
381        # unbind events
382        for seq in HIDE_SEQUENCES:
383            self.widget.event_delete(HIDE_VIRTUAL_EVENT_NAME, seq)
384        self.widget.unbind(HIDE_VIRTUAL_EVENT_NAME, self.hideid)
385        self.hideid = None
386        for seq in KEYPRESS_SEQUENCES:
387            self.widget.event_delete(KEYPRESS_VIRTUAL_EVENT_NAME, seq)
388        self.widget.unbind(KEYPRESS_VIRTUAL_EVENT_NAME, self.keypressid)
389        self.keypressid = None
390        self.widget.event_delete(KEYRELEASE_VIRTUAL_EVENT_NAME,
391                                 KEYRELEASE_SEQUENCE)
392        self.widget.unbind(KEYRELEASE_VIRTUAL_EVENT_NAME, self.keyreleaseid)
393        self.keyreleaseid = None
394        self.listbox.unbind(LISTUPDATE_SEQUENCE, self.listupdateid)
395        self.listupdateid = None
396        self.autocompletewindow.unbind(WINCONFIG_SEQUENCE, self.winconfigid)
397        self.winconfigid = None
398
399        # destroy widgets
400        self.scrollbar.destroy()
401        self.scrollbar = None
402        self.listbox.destroy()
403        self.listbox = None
404        self.autocompletewindow.destroy()
405        self.autocompletewindow = None
406