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1"""
2An auto-completion window for IDLE, used by the autocomplete extension
3"""
4import platform
5
6from tkinter import *
7from tkinter.ttk import Scrollbar
8
9from idlelib.autocomplete import FILES, ATTRS
10from idlelib.multicall import MC_SHIFT
11
12HIDE_VIRTUAL_EVENT_NAME = "<<autocompletewindow-hide>>"
13HIDE_FOCUS_OUT_SEQUENCE = "<FocusOut>"
14HIDE_SEQUENCES = (HIDE_FOCUS_OUT_SEQUENCE, "<ButtonPress>")
15KEYPRESS_VIRTUAL_EVENT_NAME = "<<autocompletewindow-keypress>>"
16# We need to bind event beyond <Key> so that the function will be called
17# before the default specific IDLE function
18KEYPRESS_SEQUENCES = ("<Key>", "<Key-BackSpace>", "<Key-Return>", "<Key-Tab>",
19                      "<Key-Up>", "<Key-Down>", "<Key-Home>", "<Key-End>",
20                      "<Key-Prior>", "<Key-Next>", "<Key-Escape>")
21KEYRELEASE_VIRTUAL_EVENT_NAME = "<<autocompletewindow-keyrelease>>"
22KEYRELEASE_SEQUENCE = "<KeyRelease>"
23LISTUPDATE_SEQUENCE = "<B1-ButtonRelease>"
24WINCONFIG_SEQUENCE = "<Configure>"
25DOUBLECLICK_SEQUENCE = "<B1-Double-ButtonRelease>"
26
27class AutoCompleteWindow:
28
29    def __init__(self, widget, tags):
30        # The widget (Text) on which we place the AutoCompleteWindow
31        self.widget = widget
32        # Tags to mark inserted text with
33        self.tags = tags
34        # The widgets we create
35        self.autocompletewindow = self.listbox = self.scrollbar = None
36        # The default foreground and background of a selection. Saved because
37        # they are changed to the regular colors of list items when the
38        # completion start is not a prefix of the selected completion
39        self.origselforeground = self.origselbackground = None
40        # The list of completions
41        self.completions = None
42        # A list with more completions, or None
43        self.morecompletions = None
44        # The completion mode, either autocomplete.ATTRS or .FILES.
45        self.mode = None
46        # The current completion start, on the text box (a string)
47        self.start = None
48        # The index of the start of the completion
49        self.startindex = None
50        # The last typed start, used so that when the selection changes,
51        # the new start will be as close as possible to the last typed one.
52        self.lasttypedstart = None
53        # Do we have an indication that the user wants the completion window
54        # (for example, he clicked the list)
55        self.userwantswindow = None
56        # event ids
57        self.hideid = self.keypressid = self.listupdateid = \
58            self.winconfigid = self.keyreleaseid = self.doubleclickid = None
59        # Flag set if last keypress was a tab
60        self.lastkey_was_tab = False
61        # Flag set to avoid recursive <Configure> callback invocations.
62        self.is_configuring = False
63
64    def _change_start(self, newstart):
65        min_len = min(len(self.start), len(newstart))
66        i = 0
67        while i < min_len and self.start[i] == newstart[i]:
68            i += 1
69        if i < len(self.start):
70            self.widget.delete("%s+%dc" % (self.startindex, i),
71                               "%s+%dc" % (self.startindex, len(self.start)))
72        if i < len(newstart):
73            self.widget.insert("%s+%dc" % (self.startindex, i),
74                               newstart[i:],
75                               self.tags)
76        self.start = newstart
77
78    def _binary_search(self, s):
79        """Find the first index in self.completions where completions[i] is
80        greater or equal to s, or the last index if there is no such.
81        """
82        i = 0; j = len(self.completions)
83        while j > i:
84            m = (i + j) // 2
85            if self.completions[m] >= s:
86                j = m
87            else:
88                i = m + 1
89        return min(i, len(self.completions)-1)
90
91    def _complete_string(self, s):
92        """Assuming that s is the prefix of a string in self.completions,
93        return the longest string which is a prefix of all the strings which
94        s is a prefix of them. If s is not a prefix of a string, return s.
95        """
96        first = self._binary_search(s)
97        if self.completions[first][:len(s)] != s:
98            # There is not even one completion which s is a prefix of.
99            return s
100        # Find the end of the range of completions where s is a prefix of.
101        i = first + 1
102        j = len(self.completions)
103        while j > i:
104            m = (i + j) // 2
105            if self.completions[m][:len(s)] != s:
106                j = m
107            else:
108                i = m + 1
109        last = i-1
110
111        if first == last: # only one possible completion
112            return self.completions[first]
113
114        # We should return the maximum prefix of first and last
115        first_comp = self.completions[first]
116        last_comp = self.completions[last]
117        min_len = min(len(first_comp), len(last_comp))
118        i = len(s)
119        while i < min_len and first_comp[i] == last_comp[i]:
120            i += 1
121        return first_comp[:i]
122
123    def _selection_changed(self):
124        """Call when the selection of the Listbox has changed.
125
126        Updates the Listbox display and calls _change_start.
127        """
128        cursel = int(self.listbox.curselection()[0])
129
130        self.listbox.see(cursel)
131
132        lts = self.lasttypedstart
133        selstart = self.completions[cursel]
134        if self._binary_search(lts) == cursel:
135            newstart = lts
136        else:
137            min_len = min(len(lts), len(selstart))
138            i = 0
139            while i < min_len and lts[i] == selstart[i]:
140                i += 1
141            newstart = selstart[:i]
142        self._change_start(newstart)
143
144        if self.completions[cursel][:len(self.start)] == self.start:
145            # start is a prefix of the selected completion
146            self.listbox.configure(selectbackground=self.origselbackground,
147                                   selectforeground=self.origselforeground)
148        else:
149            self.listbox.configure(selectbackground=self.listbox.cget("bg"),
150                                   selectforeground=self.listbox.cget("fg"))
151            # If there are more completions, show them, and call me again.
152            if self.morecompletions:
153                self.completions = self.morecompletions
154                self.morecompletions = None
155                self.listbox.delete(0, END)
156                for item in self.completions:
157                    self.listbox.insert(END, item)
158                self.listbox.select_set(self._binary_search(self.start))
159                self._selection_changed()
160
161    def show_window(self, comp_lists, index, complete, mode, userWantsWin):
162        """Show the autocomplete list, bind events.
163
164        If complete is True, complete the text, and if there is exactly
165        one matching completion, don't open a list.
166        """
167        # Handle the start we already have
168        self.completions, self.morecompletions = comp_lists
169        self.mode = mode
170        self.startindex = self.widget.index(index)
171        self.start = self.widget.get(self.startindex, "insert")
172        if complete:
173            completed = self._complete_string(self.start)
174            start = self.start
175            self._change_start(completed)
176            i = self._binary_search(completed)
177            if self.completions[i] == completed and \
178               (i == len(self.completions)-1 or
179                self.completions[i+1][:len(completed)] != completed):
180                # There is exactly one matching completion
181                return completed == start
182        self.userwantswindow = userWantsWin
183        self.lasttypedstart = self.start
184
185        # Put widgets in place
186        self.autocompletewindow = acw = Toplevel(self.widget)
187        # Put it in a position so that it is not seen.
188        acw.wm_geometry("+10000+10000")
189        # Make it float
190        acw.wm_overrideredirect(1)
191        try:
192            # This command is only needed and available on Tk >= 8.4.0 for OSX
193            # Without it, call tips intrude on the typing process by grabbing
194            # the focus.
195            acw.tk.call("::tk::unsupported::MacWindowStyle", "style", acw._w,
196                        "help", "noActivates")
197        except TclError:
198            pass
199        self.scrollbar = scrollbar = Scrollbar(acw, orient=VERTICAL)
200        self.listbox = listbox = Listbox(acw, yscrollcommand=scrollbar.set,
201                                         exportselection=False)
202        for item in self.completions:
203            listbox.insert(END, item)
204        self.origselforeground = listbox.cget("selectforeground")
205        self.origselbackground = listbox.cget("selectbackground")
206        scrollbar.config(command=listbox.yview)
207        scrollbar.pack(side=RIGHT, fill=Y)
208        listbox.pack(side=LEFT, fill=BOTH, expand=True)
209        #acw.update_idletasks() # Need for tk8.6.8 on macOS: #40128.
210        acw.lift()  # work around bug in Tk 8.5.18+ (issue #24570)
211
212        # Initialize the listbox selection
213        self.listbox.select_set(self._binary_search(self.start))
214        self._selection_changed()
215
216        # bind events
217        self.hideaid = acw.bind(HIDE_VIRTUAL_EVENT_NAME, self.hide_event)
218        self.hidewid = self.widget.bind(HIDE_VIRTUAL_EVENT_NAME, self.hide_event)
219        acw.event_add(HIDE_VIRTUAL_EVENT_NAME, HIDE_FOCUS_OUT_SEQUENCE)
220        for seq in HIDE_SEQUENCES:
221            self.widget.event_add(HIDE_VIRTUAL_EVENT_NAME, seq)
222
223        self.keypressid = self.widget.bind(KEYPRESS_VIRTUAL_EVENT_NAME,
224                                           self.keypress_event)
225        for seq in KEYPRESS_SEQUENCES:
226            self.widget.event_add(KEYPRESS_VIRTUAL_EVENT_NAME, seq)
227        self.keyreleaseid = self.widget.bind(KEYRELEASE_VIRTUAL_EVENT_NAME,
228                                             self.keyrelease_event)
229        self.widget.event_add(KEYRELEASE_VIRTUAL_EVENT_NAME,KEYRELEASE_SEQUENCE)
230        self.listupdateid = listbox.bind(LISTUPDATE_SEQUENCE,
231                                         self.listselect_event)
232        self.is_configuring = False
233        self.winconfigid = acw.bind(WINCONFIG_SEQUENCE, self.winconfig_event)
234        self.doubleclickid = listbox.bind(DOUBLECLICK_SEQUENCE,
235                                          self.doubleclick_event)
236        return None
237
238    def winconfig_event(self, event):
239        if self.is_configuring:
240            # Avoid running on recursive <Configure> callback invocations.
241            return
242
243        self.is_configuring = True
244        if not self.is_active():
245            return
246
247        # Since the <Configure> event may occur after the completion window is gone,
248        # catch potential TclError exceptions when accessing acw.  See: bpo-41611.
249        try:
250            # Position the completion list window
251            text = self.widget
252            text.see(self.startindex)
253            x, y, cx, cy = text.bbox(self.startindex)
254            acw = self.autocompletewindow
255            if platform.system().startswith('Windows'):
256                # On Windows an update() call is needed for the completion
257                # list window to be created, so that we can fetch its width
258                # and height.  However, this is not needed on other platforms
259                # (tested on Ubuntu and macOS) but at one point began
260                # causing freezes on macOS.  See issues 37849 and 41611.
261                acw.update()
262            acw_width, acw_height = acw.winfo_width(), acw.winfo_height()
263            text_width, text_height = text.winfo_width(), text.winfo_height()
264            new_x = text.winfo_rootx() + min(x, max(0, text_width - acw_width))
265            new_y = text.winfo_rooty() + y
266            if (text_height - (y + cy) >= acw_height # enough height below
267                or y < acw_height): # not enough height above
268                # place acw below current line
269                new_y += cy
270            else:
271                # place acw above current line
272                new_y -= acw_height
273            acw.wm_geometry("+%d+%d" % (new_x, new_y))
274            acw.update_idletasks()
275        except TclError:
276            pass
277
278        if platform.system().startswith('Windows'):
279            # See issue 15786.  When on Windows platform, Tk will misbehave
280            # to call winconfig_event multiple times, we need to prevent this,
281            # otherwise mouse button double click will not be able to used.
282            try:
283                acw.unbind(WINCONFIG_SEQUENCE, self.winconfigid)
284            except TclError:
285                pass
286            self.winconfigid = None
287
288        self.is_configuring = False
289
290    def _hide_event_check(self):
291        if not self.autocompletewindow:
292            return
293
294        try:
295            if not self.autocompletewindow.focus_get():
296                self.hide_window()
297        except KeyError:
298            # See issue 734176, when user click on menu, acw.focus_get()
299            # will get KeyError.
300            self.hide_window()
301
302    def hide_event(self, event):
303        # Hide autocomplete list if it exists and does not have focus or
304        # mouse click on widget / text area.
305        if self.is_active():
306            if event.type == EventType.FocusOut:
307                # On Windows platform, it will need to delay the check for
308                # acw.focus_get() when click on acw, otherwise it will return
309                # None and close the window
310                self.widget.after(1, self._hide_event_check)
311            elif event.type == EventType.ButtonPress:
312                # ButtonPress event only bind to self.widget
313                self.hide_window()
314
315    def listselect_event(self, event):
316        if self.is_active():
317            self.userwantswindow = True
318            cursel = int(self.listbox.curselection()[0])
319            self._change_start(self.completions[cursel])
320
321    def doubleclick_event(self, event):
322        # Put the selected completion in the text, and close the list
323        cursel = int(self.listbox.curselection()[0])
324        self._change_start(self.completions[cursel])
325        self.hide_window()
326
327    def keypress_event(self, event):
328        if not self.is_active():
329            return None
330        keysym = event.keysym
331        if hasattr(event, "mc_state"):
332            state = event.mc_state
333        else:
334            state = 0
335        if keysym != "Tab":
336            self.lastkey_was_tab = False
337        if (len(keysym) == 1 or keysym in ("underscore", "BackSpace")
338            or (self.mode == FILES and keysym in
339                ("period", "minus"))) \
340           and not (state & ~MC_SHIFT):
341            # Normal editing of text
342            if len(keysym) == 1:
343                self._change_start(self.start + keysym)
344            elif keysym == "underscore":
345                self._change_start(self.start + '_')
346            elif keysym == "period":
347                self._change_start(self.start + '.')
348            elif keysym == "minus":
349                self._change_start(self.start + '-')
350            else:
351                # keysym == "BackSpace"
352                if len(self.start) == 0:
353                    self.hide_window()
354                    return None
355                self._change_start(self.start[:-1])
356            self.lasttypedstart = self.start
357            self.listbox.select_clear(0, int(self.listbox.curselection()[0]))
358            self.listbox.select_set(self._binary_search(self.start))
359            self._selection_changed()
360            return "break"
361
362        elif keysym == "Return":
363            self.complete()
364            self.hide_window()
365            return 'break'
366
367        elif (self.mode == ATTRS and keysym in
368              ("period", "space", "parenleft", "parenright", "bracketleft",
369               "bracketright")) or \
370             (self.mode == FILES and keysym in
371              ("slash", "backslash", "quotedbl", "apostrophe")) \
372             and not (state & ~MC_SHIFT):
373            # If start is a prefix of the selection, but is not '' when
374            # completing file names, put the whole
375            # selected completion. Anyway, close the list.
376            cursel = int(self.listbox.curselection()[0])
377            if self.completions[cursel][:len(self.start)] == self.start \
378               and (self.mode == ATTRS or self.start):
379                self._change_start(self.completions[cursel])
380            self.hide_window()
381            return None
382
383        elif keysym in ("Home", "End", "Prior", "Next", "Up", "Down") and \
384             not state:
385            # Move the selection in the listbox
386            self.userwantswindow = True
387            cursel = int(self.listbox.curselection()[0])
388            if keysym == "Home":
389                newsel = 0
390            elif keysym == "End":
391                newsel = len(self.completions)-1
392            elif keysym in ("Prior", "Next"):
393                jump = self.listbox.nearest(self.listbox.winfo_height()) - \
394                       self.listbox.nearest(0)
395                if keysym == "Prior":
396                    newsel = max(0, cursel-jump)
397                else:
398                    assert keysym == "Next"
399                    newsel = min(len(self.completions)-1, cursel+jump)
400            elif keysym == "Up":
401                newsel = max(0, cursel-1)
402            else:
403                assert keysym == "Down"
404                newsel = min(len(self.completions)-1, cursel+1)
405            self.listbox.select_clear(cursel)
406            self.listbox.select_set(newsel)
407            self._selection_changed()
408            self._change_start(self.completions[newsel])
409            return "break"
410
411        elif (keysym == "Tab" and not state):
412            if self.lastkey_was_tab:
413                # two tabs in a row; insert current selection and close acw
414                cursel = int(self.listbox.curselection()[0])
415                self._change_start(self.completions[cursel])
416                self.hide_window()
417                return "break"
418            else:
419                # first tab; let AutoComplete handle the completion
420                self.userwantswindow = True
421                self.lastkey_was_tab = True
422                return None
423
424        elif any(s in keysym for s in ("Shift", "Control", "Alt",
425                                       "Meta", "Command", "Option")):
426            # A modifier key, so ignore
427            return None
428
429        elif event.char and event.char >= ' ':
430            # Regular character with a non-length-1 keycode
431            self._change_start(self.start + event.char)
432            self.lasttypedstart = self.start
433            self.listbox.select_clear(0, int(self.listbox.curselection()[0]))
434            self.listbox.select_set(self._binary_search(self.start))
435            self._selection_changed()
436            return "break"
437
438        else:
439            # Unknown event, close the window and let it through.
440            self.hide_window()
441            return None
442
443    def keyrelease_event(self, event):
444        if not self.is_active():
445            return
446        if self.widget.index("insert") != \
447           self.widget.index("%s+%dc" % (self.startindex, len(self.start))):
448            # If we didn't catch an event which moved the insert, close window
449            self.hide_window()
450
451    def is_active(self):
452        return self.autocompletewindow is not None
453
454    def complete(self):
455        self._change_start(self._complete_string(self.start))
456        # The selection doesn't change.
457
458    def hide_window(self):
459        if not self.is_active():
460            return
461
462        # unbind events
463        self.autocompletewindow.event_delete(HIDE_VIRTUAL_EVENT_NAME,
464                                             HIDE_FOCUS_OUT_SEQUENCE)
465        for seq in HIDE_SEQUENCES:
466            self.widget.event_delete(HIDE_VIRTUAL_EVENT_NAME, seq)
467
468        self.autocompletewindow.unbind(HIDE_VIRTUAL_EVENT_NAME, self.hideaid)
469        self.widget.unbind(HIDE_VIRTUAL_EVENT_NAME, self.hidewid)
470        self.hideaid = None
471        self.hidewid = None
472        for seq in KEYPRESS_SEQUENCES:
473            self.widget.event_delete(KEYPRESS_VIRTUAL_EVENT_NAME, seq)
474        self.widget.unbind(KEYPRESS_VIRTUAL_EVENT_NAME, self.keypressid)
475        self.keypressid = None
476        self.widget.event_delete(KEYRELEASE_VIRTUAL_EVENT_NAME,
477                                 KEYRELEASE_SEQUENCE)
478        self.widget.unbind(KEYRELEASE_VIRTUAL_EVENT_NAME, self.keyreleaseid)
479        self.keyreleaseid = None
480        self.listbox.unbind(LISTUPDATE_SEQUENCE, self.listupdateid)
481        self.listupdateid = None
482        if self.winconfigid:
483            self.autocompletewindow.unbind(WINCONFIG_SEQUENCE, self.winconfigid)
484            self.winconfigid = None
485
486        # Re-focusOn frame.text (See issue #15786)
487        self.widget.focus_set()
488
489        # destroy widgets
490        self.scrollbar.destroy()
491        self.scrollbar = None
492        self.listbox.destroy()
493        self.listbox = None
494        self.autocompletewindow.destroy()
495        self.autocompletewindow = None
496
497
498if __name__ == '__main__':
499    from unittest import main
500    main('idlelib.idle_test.test_autocomplete_w', verbosity=2, exit=False)
501
502# TODO: autocomplete/w htest here
503