summaryrefslogtreecommitdiffstats
path: root/dom/events/TextComposition.cpp
blob: bd7ebbc46836620d909e01e64c309f94f9f3525d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "ContentEventHandler.h"
#include "IMEContentObserver.h"
#include "IMEStateManager.h"
#include "nsContentUtils.h"
#include "nsIContent.h"
#include "nsIEditor.h"
#include "nsIPresShell.h"
#include "nsPresContext.h"
#include "mozilla/AutoRestore.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/IMEStateManager.h"
#include "mozilla/MiscEvents.h"
#include "mozilla/Preferences.h"
#include "mozilla/TextComposition.h"
#include "mozilla/TextEvents.h"
#include "mozilla/Unused.h"
#include "mozilla/dom/TabParent.h"

#ifdef XP_MACOSX
// Some defiens will be conflict with OSX SDK
#define TextRange _TextRange
#define TextRangeArray _TextRangeArray
#define Comment _Comment
#endif

#include "nsPluginInstanceOwner.h"

#ifdef XP_MACOSX
#undef TextRange
#undef TextRangeArray
#undef Comment
#endif

using namespace mozilla::widget;

namespace mozilla {

#define IDEOGRAPHIC_SPACE (NS_LITERAL_STRING(u"\x3000"))

/******************************************************************************
 * TextComposition
 ******************************************************************************/

bool TextComposition::sHandlingSelectionEvent = false;

TextComposition::TextComposition(nsPresContext* aPresContext,
                                 nsINode* aNode,
                                 TabParent* aTabParent,
                                 WidgetCompositionEvent* aCompositionEvent)
  : mPresContext(aPresContext)
  , mNode(aNode)
  , mTabParent(aTabParent)
  , mNativeContext(aCompositionEvent->mNativeIMEContext)
  , mCompositionStartOffset(0)
  , mTargetClauseOffsetInComposition(0)
  , mIsSynthesizedForTests(aCompositionEvent->mFlags.mIsSynthesizedForTests)
  , mIsComposing(false)
  , mIsEditorHandlingEvent(false)
  , mIsRequestingCommit(false)
  , mIsRequestingCancel(false)
  , mRequestedToCommitOrCancel(false)
  , mWasNativeCompositionEndEventDiscarded(false)
  , mAllowControlCharacters(
      Preferences::GetBool("dom.compositionevent.allow_control_characters",
                           false))
  , mWasCompositionStringEmpty(true)
{
  MOZ_ASSERT(aCompositionEvent->mNativeIMEContext.IsValid());
}

void
TextComposition::Destroy()
{
  mPresContext = nullptr;
  mNode = nullptr;
  mTabParent = nullptr;
  // TODO: If the editor is still alive and this is held by it, we should tell
  //       this being destroyed for cleaning up the stuff.
}

bool
TextComposition::IsValidStateForComposition(nsIWidget* aWidget) const
{
  return !Destroyed() && aWidget && !aWidget->Destroyed() &&
         mPresContext->GetPresShell() &&
         !mPresContext->GetPresShell()->IsDestroying();
}

bool
TextComposition::MaybeDispatchCompositionUpdate(
                   const WidgetCompositionEvent* aCompositionEvent)
{
  MOZ_RELEASE_ASSERT(!mTabParent);

  if (!IsValidStateForComposition(aCompositionEvent->mWidget)) {
    return false;
  }

  if (mLastData == aCompositionEvent->mData) {
    return true;
  }
  CloneAndDispatchAs(aCompositionEvent, eCompositionUpdate);
  return IsValidStateForComposition(aCompositionEvent->mWidget);
}

BaseEventFlags
TextComposition::CloneAndDispatchAs(
                   const WidgetCompositionEvent* aCompositionEvent,
                   EventMessage aMessage,
                   nsEventStatus* aStatus,
                   EventDispatchingCallback* aCallBack)
{
  MOZ_RELEASE_ASSERT(!mTabParent);

  MOZ_ASSERT(IsValidStateForComposition(aCompositionEvent->mWidget),
             "Should be called only when it's safe to dispatch an event");

  WidgetCompositionEvent compositionEvent(aCompositionEvent->IsTrusted(),
                                          aMessage, aCompositionEvent->mWidget);
  compositionEvent.mTime = aCompositionEvent->mTime;
  compositionEvent.mTimeStamp = aCompositionEvent->mTimeStamp;
  compositionEvent.mData = aCompositionEvent->mData;
  compositionEvent.mNativeIMEContext = aCompositionEvent->mNativeIMEContext;
  compositionEvent.mOriginalMessage = aCompositionEvent->mMessage;
  compositionEvent.mFlags.mIsSynthesizedForTests =
    aCompositionEvent->mFlags.mIsSynthesizedForTests;

  nsEventStatus dummyStatus = nsEventStatus_eConsumeNoDefault;
  nsEventStatus* status = aStatus ? aStatus : &dummyStatus;
  if (aMessage == eCompositionUpdate) {
    mLastData = compositionEvent.mData;
    mLastRanges = aCompositionEvent->mRanges;
  }

  DispatchEvent(&compositionEvent, status, aCallBack, aCompositionEvent);
  return compositionEvent.mFlags;
}

void
TextComposition::DispatchEvent(WidgetCompositionEvent* aDispatchEvent,
                               nsEventStatus* aStatus,
                               EventDispatchingCallback* aCallBack,
                               const WidgetCompositionEvent *aOriginalEvent)
{
  nsPluginInstanceOwner::GeneratePluginEvent(aOriginalEvent,
                                             aDispatchEvent);

  EventDispatcher::Dispatch(mNode, mPresContext,
                            aDispatchEvent, nullptr, aStatus, aCallBack);

  OnCompositionEventDispatched(aDispatchEvent);
}

void
TextComposition::OnCompositionEventDiscarded(
                   WidgetCompositionEvent* aCompositionEvent)
{
  // Note that this method is never called for synthesized events for emulating
  // commit or cancel composition.

  MOZ_ASSERT(aCompositionEvent->IsTrusted(),
             "Shouldn't be called with untrusted event");

  if (mTabParent) {
    // The composition event should be discarded in the child process too.
    Unused << mTabParent->SendCompositionEvent(*aCompositionEvent);
  }

  // XXX If composition events are discarded, should we dispatch them with
  //     runnable event?  However, even if we do so, it might make native IME
  //     confused due to async modification.  Especially when native IME is
  //     TSF.
  if (!aCompositionEvent->CausesDOMCompositionEndEvent()) {
    return;
  }

  mWasNativeCompositionEndEventDiscarded = true;
}

static inline bool
IsControlChar(uint32_t aCharCode)
{
  return aCharCode < ' ' || aCharCode == 0x7F;
}

static size_t
FindFirstControlCharacter(const nsAString& aStr)
{
  const char16_t* sourceBegin = aStr.BeginReading();
  const char16_t* sourceEnd = aStr.EndReading();

  for (const char16_t* source = sourceBegin; source < sourceEnd; ++source) {
    if (*source != '\t' && IsControlChar(*source)) {
      return source - sourceBegin;
    }
  }

  return -1;
}

static void
RemoveControlCharactersFrom(nsAString& aStr, TextRangeArray* aRanges)
{
  size_t firstControlCharOffset = FindFirstControlCharacter(aStr);
  if (firstControlCharOffset == (size_t)-1) {
    return;
  }

  nsAutoString copy(aStr);
  const char16_t* sourceBegin = copy.BeginReading();
  const char16_t* sourceEnd = copy.EndReading();

  char16_t* dest = aStr.BeginWriting();
  if (NS_WARN_IF(!dest)) {
    return;
  }

  char16_t* curDest = dest + firstControlCharOffset;
  size_t i = firstControlCharOffset;
  for (const char16_t* source = sourceBegin + firstControlCharOffset;
       source < sourceEnd; ++source) {
    if (*source == '\t' || !IsControlChar(*source)) {
      *curDest = *source;
      ++curDest;
      ++i;
    } else if (aRanges) {
      aRanges->RemoveCharacter(i);
    }
  }

  aStr.SetLength(curDest - dest);
}

void
TextComposition::DispatchCompositionEvent(
                   WidgetCompositionEvent* aCompositionEvent,
                   nsEventStatus* aStatus,
                   EventDispatchingCallback* aCallBack,
                   bool aIsSynthesized)
{
  mWasCompositionStringEmpty = mString.IsEmpty();

  // If the content is a container of TabParent, composition should be in the
  // remote process.
  if (mTabParent) {
    Unused << mTabParent->SendCompositionEvent(*aCompositionEvent);
    aCompositionEvent->StopPropagation();
    if (aCompositionEvent->CausesDOMTextEvent()) {
      mLastData = aCompositionEvent->mData;
      mLastRanges = aCompositionEvent->mRanges;
      // Although, the composition event hasn't been actually handled yet,
      // emulate an editor to be handling the composition event.
      EditorWillHandleCompositionChangeEvent(aCompositionEvent);
      EditorDidHandleCompositionChangeEvent();
    }
    return;
  }

  if (!mAllowControlCharacters) {
    RemoveControlCharactersFrom(aCompositionEvent->mData,
                                aCompositionEvent->mRanges);
  }
  if (aCompositionEvent->mMessage == eCompositionCommitAsIs) {
    NS_ASSERTION(!aCompositionEvent->mRanges,
                 "mRanges of eCompositionCommitAsIs should be null");
    aCompositionEvent->mRanges = nullptr;
    NS_ASSERTION(aCompositionEvent->mData.IsEmpty(),
                 "mData of eCompositionCommitAsIs should be empty string");
    bool removePlaceholderCharacter =
      Preferences::GetBool("intl.ime.remove_placeholder_character_at_commit",
                           false);
    if (removePlaceholderCharacter && mLastData == IDEOGRAPHIC_SPACE) {
      // If the last data is an ideographic space (FullWidth space), it might be
      // a placeholder character of some Chinese IME.  So, committing with
      // this data might not be expected by users.  Let's use empty string.
      aCompositionEvent->mData.Truncate();
    } else {
      aCompositionEvent->mData = mLastData;
    }
  } else if (aCompositionEvent->mMessage == eCompositionCommit) {
    NS_ASSERTION(!aCompositionEvent->mRanges,
                 "mRanges of eCompositionCommit should be null");
    aCompositionEvent->mRanges = nullptr;
  }

  if (!IsValidStateForComposition(aCompositionEvent->mWidget)) {
    *aStatus = nsEventStatus_eConsumeNoDefault;
    return;
  }

  // If this instance has requested to commit or cancel composition but
  // is not synthesizing commit event, that means that the IME commits or
  // cancels the composition asynchronously.  Typically, iBus behaves so.
  // Then, synthesized events which were dispatched immediately after
  // the request has already committed our editor's composition string and
  // told it to web apps.  Therefore, we should ignore the delayed events.
  if (mRequestedToCommitOrCancel && !aIsSynthesized) {
    *aStatus = nsEventStatus_eConsumeNoDefault;
    return;
  }

  // IME may commit composition with empty string for a commit request or
  // with non-empty string for a cancel request.  We should prevent such
  // unexpected result.  E.g., web apps may be confused if they implement
  // autocomplete which attempts to commit composition forcibly when the user
  // selects one of suggestions but composition string is cleared by IME.
  // Note that most Chinese IMEs don't expose actual composition string to us.
  // They typically tell us an IDEOGRAPHIC SPACE or empty string as composition
  // string.  Therefore, we should hack it only when:
  // 1. committing string is empty string at requesting commit but the last
  //    data isn't IDEOGRAPHIC SPACE.
  // 2. non-empty string is committed at requesting cancel.
  if (!aIsSynthesized && (mIsRequestingCommit || mIsRequestingCancel)) {
    nsString* committingData = nullptr;
    switch (aCompositionEvent->mMessage) {
      case eCompositionEnd:
      case eCompositionChange:
      case eCompositionCommitAsIs:
      case eCompositionCommit:
        committingData = &aCompositionEvent->mData;
        break;
      default:
        NS_WARNING("Unexpected event comes during committing or "
                   "canceling composition");
        break;
    }
    if (committingData) {
      if (mIsRequestingCommit && committingData->IsEmpty() &&
          mLastData != IDEOGRAPHIC_SPACE) {
        committingData->Assign(mLastData);
      } else if (mIsRequestingCancel && !committingData->IsEmpty()) {
        committingData->Truncate();
      }
    }
  }

  bool dispatchEvent = true;
  bool dispatchDOMTextEvent = aCompositionEvent->CausesDOMTextEvent();

  // When mIsComposing is false but the committing string is different from
  // the last data (E.g., previous eCompositionChange event made the
  // composition string empty or didn't have clause information), we don't
  // need to dispatch redundant DOM text event.
  if (dispatchDOMTextEvent &&
      aCompositionEvent->mMessage != eCompositionChange &&
      !mIsComposing && mLastData == aCompositionEvent->mData) {
    dispatchEvent = dispatchDOMTextEvent = false;
  }

  // widget may dispatch redundant eCompositionChange event
  // which modifies neither composition string, clauses nor caret
  // position.  In such case, we shouldn't dispatch DOM events.
  if (dispatchDOMTextEvent &&
      aCompositionEvent->mMessage == eCompositionChange &&
      mLastData == aCompositionEvent->mData &&
      mRanges && aCompositionEvent->mRanges &&
      mRanges->Equals(*aCompositionEvent->mRanges)) {
    dispatchEvent = dispatchDOMTextEvent = false;
  }

  if (dispatchDOMTextEvent) {
    if (!MaybeDispatchCompositionUpdate(aCompositionEvent)) {
      return;
    }
  }

  if (dispatchEvent) {
    // If the composition event should cause a DOM text event, we should
    // overwrite the event message as eCompositionChange because due to
    // the limitation of mapping between event messages and DOM event types,
    // we cannot map multiple event messages to a DOM event type.
    if (dispatchDOMTextEvent &&
        aCompositionEvent->mMessage != eCompositionChange) {
      aCompositionEvent->mFlags =
        CloneAndDispatchAs(aCompositionEvent, eCompositionChange,
                           aStatus, aCallBack);
    } else {
      DispatchEvent(aCompositionEvent, aStatus, aCallBack);
    }
  } else {
    *aStatus = nsEventStatus_eConsumeNoDefault;
  }

  if (!IsValidStateForComposition(aCompositionEvent->mWidget)) {
    return;
  }

  // Emulate editor behavior of compositionchange event (DOM text event) handler
  // if no editor handles composition events.
  if (dispatchDOMTextEvent && !HasEditor()) {
    EditorWillHandleCompositionChangeEvent(aCompositionEvent);
    EditorDidHandleCompositionChangeEvent();
  }

  if (aCompositionEvent->CausesDOMCompositionEndEvent()) {
    // Dispatch a compositionend event if it's necessary.
    if (aCompositionEvent->mMessage != eCompositionEnd) {
      CloneAndDispatchAs(aCompositionEvent, eCompositionEnd);
    }
    MOZ_ASSERT(!mIsComposing, "Why is the editor still composing?");
    MOZ_ASSERT(!HasEditor(), "Why does the editor still keep to hold this?");
  }

  MaybeNotifyIMEOfCompositionEventHandled(aCompositionEvent);
}

// static
void
TextComposition::HandleSelectionEvent(nsPresContext* aPresContext,
                                      TabParent* aTabParent,
                                      WidgetSelectionEvent* aSelectionEvent)
{
  // If the content is a container of TabParent, composition should be in the
  // remote process.
  if (aTabParent) {
    Unused << aTabParent->SendSelectionEvent(*aSelectionEvent);
    aSelectionEvent->StopPropagation();
    return;
  }

  ContentEventHandler handler(aPresContext);
  AutoRestore<bool> saveHandlingSelectionEvent(sHandlingSelectionEvent);
  sHandlingSelectionEvent = true;
  // XXX During setting selection, a selection listener may change selection
  //     again.  In such case, sHandlingSelectionEvent doesn't indicate if
  //     the selection change is caused by a selection event.  However, it
  //     must be non-realistic scenario.
  handler.OnSelectionEvent(aSelectionEvent);
}

uint32_t
TextComposition::GetSelectionStartOffset()
{
  nsCOMPtr<nsIWidget> widget = mPresContext->GetRootWidget();
  WidgetQueryContentEvent selectedTextEvent(true, eQuerySelectedText, widget);
  // Due to a bug of widget, mRanges may not be nullptr even though composition
  // string is empty.  So, we need to check it here for avoiding to return
  // odd start offset.
  if (!mLastData.IsEmpty() && mRanges && mRanges->HasClauses()) {
    selectedTextEvent.InitForQuerySelectedText(
                        ToSelectionType(mRanges->GetFirstClause()->mRangeType));
  } else {
    NS_WARNING_ASSERTION(
      !mLastData.IsEmpty() || !mRanges || !mRanges->HasClauses(),
      "Shouldn't have empty clause info when composition string is empty");
    selectedTextEvent.InitForQuerySelectedText(SelectionType::eNormal);
  }

  // The editor which has this composition is observed by active
  // IMEContentObserver, we can use the cache of it.
  RefPtr<IMEContentObserver> contentObserver =
    IMEStateManager::GetActiveContentObserver();
  bool doQuerySelection = true;
  if (contentObserver) {
    if (contentObserver->IsManaging(this)) {
      doQuerySelection = false;
      contentObserver->HandleQueryContentEvent(&selectedTextEvent);
    }
    // If another editor already has focus, we cannot retrieve selection
    // in the editor which has this composition...
    else if (NS_WARN_IF(contentObserver->GetPresContext() == mPresContext)) {
      return 0;  // XXX Is this okay?
    }
  }

  // Otherwise, using slow path (i.e., compute every time with
  // ContentEventHandler)
  if (doQuerySelection) {
    ContentEventHandler handler(mPresContext);
    handler.HandleQueryContentEvent(&selectedTextEvent);
  }

  if (NS_WARN_IF(!selectedTextEvent.mSucceeded)) {
    return 0; // XXX Is this okay?
  }
  return selectedTextEvent.mReply.mOffset;
}

void
TextComposition::OnCompositionEventDispatched(
                   const WidgetCompositionEvent* aCompositionEvent)
{
  MOZ_RELEASE_ASSERT(!mTabParent);

  if (!IsValidStateForComposition(aCompositionEvent->mWidget)) {
    return;
  }

  // Every composition event may cause changing composition start offset,
  // especially when there is no composition string.  Therefore, we need to
  // update mCompositionStartOffset with the latest offset.

  MOZ_ASSERT(aCompositionEvent->mMessage != eCompositionStart ||
               mWasCompositionStringEmpty,
             "mWasCompositionStringEmpty should be true if the dispatched "
             "event is eCompositionStart");

  if (mWasCompositionStringEmpty &&
      !aCompositionEvent->CausesDOMCompositionEndEvent()) {
    // If there was no composition string, current selection start may be the
    // offset for inserting composition string.
    // Update composition start offset with current selection start.
    mCompositionStartOffset = GetSelectionStartOffset();
    mTargetClauseOffsetInComposition = 0;
  }

  if (aCompositionEvent->CausesDOMTextEvent()) {
    mTargetClauseOffsetInComposition = aCompositionEvent->TargetClauseOffset();
  }
}

void
TextComposition::OnStartOffsetUpdatedInChild(uint32_t aStartOffset)
{
  mCompositionStartOffset = aStartOffset;
}

void
TextComposition::MaybeNotifyIMEOfCompositionEventHandled(
                   const WidgetCompositionEvent* aCompositionEvent)
{
  if (aCompositionEvent->mMessage != eCompositionStart &&
      !aCompositionEvent->CausesDOMTextEvent()) {
    return;
  }

  RefPtr<IMEContentObserver> contentObserver =
    IMEStateManager::GetActiveContentObserver();
  // When IMEContentObserver is managing the editor which has this composition,
  // composition event handled notification should be sent after the observer
  // notifies all pending notifications.  Therefore, we should use it.
  // XXX If IMEContentObserver suddenly loses focus after here and notifying
  //     widget of pending notifications, we won't notify widget of composition
  //     event handled.  Although, this is a bug but it should be okay since
  //     destroying IMEContentObserver notifies IME of blur.  So, native IME
  //     handler can treat it as this notification too.
  if (contentObserver && contentObserver->IsManaging(this)) {
    contentObserver->MaybeNotifyCompositionEventHandled();
    return;
  }
  // Otherwise, e.g., this composition is in non-active window, we should
  // notify widget directly.
  NotifyIME(NOTIFY_IME_OF_COMPOSITION_EVENT_HANDLED);
}

void
TextComposition::DispatchCompositionEventRunnable(EventMessage aEventMessage,
                                                  const nsAString& aData,
                                                  bool aIsSynthesizingCommit)
{
  nsContentUtils::AddScriptRunner(
    new CompositionEventDispatcher(this, mNode, aEventMessage, aData,
                                   aIsSynthesizingCommit));
}

nsresult
TextComposition::RequestToCommit(nsIWidget* aWidget, bool aDiscard)
{
  // If this composition is already requested to be committed or canceled,
  // we don't need to request it again because even if the first request
  // failed, new request won't success, probably.  And we shouldn't synthesize
  // events for committing or canceling composition twice or more times.
  if (mRequestedToCommitOrCancel) {
    return NS_OK;
  }

  RefPtr<TextComposition> kungFuDeathGrip(this);
  const nsAutoString lastData(mLastData);

  {
    AutoRestore<bool> saveRequestingCancel(mIsRequestingCancel);
    AutoRestore<bool> saveRequestingCommit(mIsRequestingCommit);
    if (aDiscard) {
      mIsRequestingCancel = true;
      mIsRequestingCommit = false;
    } else {
      mIsRequestingCancel = false;
      mIsRequestingCommit = true;
    }
    // FYI: CompositionEvents caused by a call of NotifyIME() may be
    //      discarded by PresShell if it's not safe to dispatch the event.
    nsresult rv =
      aWidget->NotifyIME(IMENotification(aDiscard ?
                                           REQUEST_TO_CANCEL_COMPOSITION :
                                           REQUEST_TO_COMMIT_COMPOSITION));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }

  mRequestedToCommitOrCancel = true;

  // If the request is performed synchronously, this must be already destroyed.
  if (Destroyed()) {
    return NS_OK;
  }

  // Otherwise, synthesize the commit in content.
  nsAutoString data(aDiscard ? EmptyString() : lastData);
  if (data == mLastData) {
    DispatchCompositionEventRunnable(eCompositionCommitAsIs, EmptyString(),
                                     true);
  } else {
    DispatchCompositionEventRunnable(eCompositionCommit, data, true);
  }
  return NS_OK;
}

nsresult
TextComposition::NotifyIME(IMEMessage aMessage)
{
  NS_ENSURE_TRUE(mPresContext, NS_ERROR_NOT_AVAILABLE);
  return IMEStateManager::NotifyIME(aMessage, mPresContext);
}

void
TextComposition::EditorWillHandleCompositionChangeEvent(
                   const WidgetCompositionEvent* aCompositionChangeEvent)
{
  mIsComposing = aCompositionChangeEvent->IsComposing();
  mRanges = aCompositionChangeEvent->mRanges;
  mIsEditorHandlingEvent = true;

  MOZ_ASSERT(mLastData == aCompositionChangeEvent->mData,
    "The text of a compositionchange event must be same as previous data "
    "attribute value of the latest compositionupdate event");
}

void
TextComposition::OnEditorDestroyed()
{
  MOZ_RELEASE_ASSERT(!mTabParent);

  MOZ_ASSERT(!mIsEditorHandlingEvent,
             "The editor should have stopped listening events");
  nsCOMPtr<nsIWidget> widget = GetWidget();
  if (NS_WARN_IF(!widget)) {
    // XXX If this could happen, how do we notify IME of destroying the editor?
    return;
  }

  // Try to cancel the composition.
  RequestToCommit(widget, true);
}

void
TextComposition::EditorDidHandleCompositionChangeEvent()
{
  mString = mLastData;
  mIsEditorHandlingEvent = false;
}

void
TextComposition::StartHandlingComposition(nsIEditor* aEditor)
{
  MOZ_RELEASE_ASSERT(!mTabParent);

  MOZ_ASSERT(!HasEditor(), "There is a handling editor already");
  mEditorWeak = do_GetWeakReference(aEditor);
}

void
TextComposition::EndHandlingComposition(nsIEditor* aEditor)
{
  MOZ_RELEASE_ASSERT(!mTabParent);

#ifdef DEBUG
  nsCOMPtr<nsIEditor> editor = GetEditor();
  MOZ_ASSERT(editor == aEditor, "Another editor handled the composition?");
#endif // #ifdef DEBUG
  mEditorWeak = nullptr;
}

already_AddRefed<nsIEditor>
TextComposition::GetEditor() const
{
  nsCOMPtr<nsIEditor> editor = do_QueryReferent(mEditorWeak);
  return editor.forget();
}

bool
TextComposition::HasEditor() const
{
  nsCOMPtr<nsIEditor> editor = GetEditor();
  return !!editor;
}

/******************************************************************************
 * TextComposition::CompositionEventDispatcher
 ******************************************************************************/

TextComposition::CompositionEventDispatcher::CompositionEventDispatcher(
                                               TextComposition* aComposition,
                                               nsINode* aEventTarget,
                                               EventMessage aEventMessage,
                                               const nsAString& aData,
                                               bool aIsSynthesizedEvent)
  : mTextComposition(aComposition)
  , mEventTarget(aEventTarget)
  , mData(aData)
  , mEventMessage(aEventMessage)
  , mIsSynthesizedEvent(aIsSynthesizedEvent)
{
}

NS_IMETHODIMP
TextComposition::CompositionEventDispatcher::Run()
{
  // The widget can be different from the widget which has dispatched
  // composition events because GetWidget() returns a widget which is proper
  // for calling NotifyIME().  However, this must no be problem since both
  // widget should share native IME context.  Therefore, even if an event
  // handler uses the widget for requesting IME to commit or cancel, it works.
  nsCOMPtr<nsIWidget> widget(mTextComposition->GetWidget());
  if (!mTextComposition->IsValidStateForComposition(widget)) {
    return NS_OK; // cannot dispatch any events anymore
  }

  RefPtr<nsPresContext> presContext = mTextComposition->mPresContext;
  nsEventStatus status = nsEventStatus_eIgnore;
  switch (mEventMessage) {
    case eCompositionStart: {
      WidgetCompositionEvent compStart(true, eCompositionStart, widget);
      compStart.mNativeIMEContext = mTextComposition->mNativeContext;
      WidgetQueryContentEvent selectedText(true, eQuerySelectedText, widget);
      ContentEventHandler handler(presContext);
      handler.OnQuerySelectedText(&selectedText);
      NS_ASSERTION(selectedText.mSucceeded, "Failed to get selected text");
      compStart.mData = selectedText.mReply.mString;
      compStart.mFlags.mIsSynthesizedForTests =
        mTextComposition->IsSynthesizedForTests();
      IMEStateManager::DispatchCompositionEvent(mEventTarget, presContext,
                                                &compStart, &status, nullptr,
                                                mIsSynthesizedEvent);
      break;
    }
    case eCompositionChange:
    case eCompositionCommitAsIs:
    case eCompositionCommit: {
      WidgetCompositionEvent compEvent(true, mEventMessage, widget);
      compEvent.mNativeIMEContext = mTextComposition->mNativeContext;
      if (mEventMessage != eCompositionCommitAsIs) {
        compEvent.mData = mData;
      }
      compEvent.mFlags.mIsSynthesizedForTests =
        mTextComposition->IsSynthesizedForTests();
      IMEStateManager::DispatchCompositionEvent(mEventTarget, presContext,
                                                &compEvent, &status, nullptr,
                                                mIsSynthesizedEvent);
      break;
    }
    default:
      MOZ_CRASH("Unsupported event");
  }
  return NS_OK;
}

/******************************************************************************
 * TextCompositionArray
 ******************************************************************************/

TextCompositionArray::index_type
TextCompositionArray::IndexOf(const NativeIMEContext& aNativeIMEContext)
{
  if (!aNativeIMEContext.IsValid()) {
    return NoIndex;
  }
  for (index_type i = Length(); i > 0; --i) {
    if (ElementAt(i - 1)->GetNativeIMEContext() == aNativeIMEContext) {
      return i - 1;
    }
  }
  return NoIndex;
}

TextCompositionArray::index_type
TextCompositionArray::IndexOf(nsIWidget* aWidget)
{
  return IndexOf(aWidget->GetNativeIMEContext());
}

TextCompositionArray::index_type
TextCompositionArray::IndexOf(nsPresContext* aPresContext)
{
  for (index_type i = Length(); i > 0; --i) {
    if (ElementAt(i - 1)->GetPresContext() == aPresContext) {
      return i - 1;
    }
  }
  return NoIndex;
}

TextCompositionArray::index_type
TextCompositionArray::IndexOf(nsPresContext* aPresContext,
                              nsINode* aNode)
{
  index_type index = IndexOf(aPresContext);
  if (index == NoIndex) {
    return NoIndex;
  }
  nsINode* node = ElementAt(index)->GetEventTargetNode();
  return node == aNode ? index : NoIndex;
}

TextComposition*
TextCompositionArray::GetCompositionFor(nsIWidget* aWidget)
{
  index_type i = IndexOf(aWidget);
  if (i == NoIndex) {
    return nullptr;
  }
  return ElementAt(i);
}

TextComposition*
TextCompositionArray::GetCompositionFor(
                        const WidgetCompositionEvent* aCompositionEvent)
{
  index_type i = IndexOf(aCompositionEvent->mNativeIMEContext);
  if (i == NoIndex) {
    return nullptr;
  }
  return ElementAt(i);
}

TextComposition*
TextCompositionArray::GetCompositionFor(nsPresContext* aPresContext)
{
  index_type i = IndexOf(aPresContext);
  if (i == NoIndex) {
    return nullptr;
  }
  return ElementAt(i);
}

TextComposition*
TextCompositionArray::GetCompositionFor(nsPresContext* aPresContext,
                                           nsINode* aNode)
{
  index_type i = IndexOf(aPresContext, aNode);
  if (i == NoIndex) {
    return nullptr;
  }
  return ElementAt(i);
}

TextComposition*
TextCompositionArray::GetCompositionInContent(nsPresContext* aPresContext,
                                              nsIContent* aContent)
{
  // There should be only one composition per content object.
  for (index_type i = Length(); i > 0; --i) {
    nsINode* node = ElementAt(i - 1)->GetEventTargetNode();
    if (node && nsContentUtils::ContentIsDescendantOf(node, aContent)) {
      return ElementAt(i - 1);
    }
  }
  return nullptr;
}

} // namespace mozilla