widget/TextEventDispatcher.cpp
author Noemi Erli <nerli@mozilla.com>
Tue, 26 Feb 2019 03:43:12 +0200
changeset 461110 3c030119c0dcf447dd1afe7165b2d6846a0bc7f0
parent 459845 7eae0724c0aa291d7439cb64dc851e0026cdebe2
child 467860 3b94c20ba87374c8df1af15e903c38b0945975a0
permissions -rw-r--r--
Backed out 10 changesets (bug 1505871) for wrench bustages CLOSED TREE Backed out changeset 045ab0ec3613 (bug 1505871) Backed out changeset 6486435a048d (bug 1505871) Backed out changeset 9be871042749 (bug 1505871) Backed out changeset 0007feaf988d (bug 1505871) Backed out changeset 3cb8fb01e77e (bug 1505871) Backed out changeset 2fff213d97e3 (bug 1505871) Backed out changeset 1ad20d485eca (bug 1505871) Backed out changeset 0fd8742fa662 (bug 1505871) Backed out changeset 1899600a7985 (bug 1505871) Backed out changeset f9578d20e54e (bug 1505871)

/* -*- Mode: C++; tab-width: 2; 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 "mozilla/Preferences.h"
#include "mozilla/TextEvents.h"
#include "mozilla/TextEventDispatcher.h"
#include "nsIDocShell.h"
#include "nsIFrame.h"
#include "nsIPresShell.h"
#include "nsIWidget.h"
#include "nsPIDOMWindow.h"
#include "nsView.h"
#include "PuppetWidget.h"

namespace mozilla {
namespace widget {

/******************************************************************************
 * TextEventDispatcher
 *****************************************************************************/

bool TextEventDispatcher::sDispatchKeyEventsDuringComposition = false;
bool TextEventDispatcher::sDispatchKeyPressEventsOnlySystemGroupInContent =
    false;

TextEventDispatcher::TextEventDispatcher(nsIWidget* aWidget)
    : mWidget(aWidget),
      mDispatchingEvent(0),
      mInputTransactionType(eNoInputTransaction),
      mIsComposing(false),
      mIsHandlingComposition(false),
      mHasFocus(false) {
  MOZ_RELEASE_ASSERT(mWidget, "aWidget must not be nullptr");

  static bool sInitialized = false;
  if (!sInitialized) {
    Preferences::AddBoolVarCache(
        &sDispatchKeyEventsDuringComposition,
        "dom.keyboardevent.dispatch_during_composition", true);
    Preferences::AddBoolVarCache(
        &sDispatchKeyPressEventsOnlySystemGroupInContent,
        "dom.keyboardevent.keypress."
        "dispatch_non_printable_keys_only_system_group_in_content",
        true);
    sInitialized = true;
  }

  ClearNotificationRequests();
}

nsresult TextEventDispatcher::BeginInputTransaction(
    TextEventDispatcherListener* aListener) {
  return BeginInputTransactionInternal(aListener,
                                       eSameProcessSyncInputTransaction);
}

nsresult TextEventDispatcher::BeginTestInputTransaction(
    TextEventDispatcherListener* aListener, bool aIsAPZAware) {
  return BeginInputTransactionInternal(
      aListener, aIsAPZAware ? eAsyncTestInputTransaction
                             : eSameProcessSyncTestInputTransaction);
}

nsresult TextEventDispatcher::BeginNativeInputTransaction() {
  if (NS_WARN_IF(!mWidget)) {
    return NS_ERROR_FAILURE;
  }
  RefPtr<TextEventDispatcherListener> listener =
      mWidget->GetNativeTextEventDispatcherListener();
  if (NS_WARN_IF(!listener)) {
    return NS_ERROR_FAILURE;
  }
  return BeginInputTransactionInternal(listener, eNativeInputTransaction);
}

nsresult TextEventDispatcher::BeginInputTransactionInternal(
    TextEventDispatcherListener* aListener, InputTransactionType aType) {
  if (NS_WARN_IF(!aListener)) {
    return NS_ERROR_INVALID_ARG;
  }
  nsCOMPtr<TextEventDispatcherListener> listener = do_QueryReferent(mListener);
  if (listener) {
    if (listener == aListener && mInputTransactionType == aType) {
      UpdateNotificationRequests();
      return NS_OK;
    }
    // If this has composition or is dispatching an event, any other listener
    // can steal ownership.  Especially, if the latter case is allowed,
    // nobody cannot begin input transaction with this if a modal dialog is
    // opened during dispatching an event.
    if (IsComposing() || IsDispatchingEvent()) {
      return NS_ERROR_ALREADY_INITIALIZED;
    }
  }
  mListener = do_GetWeakReference(aListener);
  mInputTransactionType = aType;
  if (listener && listener != aListener) {
    listener->OnRemovedFrom(this);
  }
  UpdateNotificationRequests();
  return NS_OK;
}

nsresult TextEventDispatcher::BeginInputTransactionFor(
    const WidgetGUIEvent* aEvent, PuppetWidget* aPuppetWidget) {
  MOZ_ASSERT(XRE_IsContentProcess());
  MOZ_ASSERT(!IsDispatchingEvent());

  switch (aEvent->mMessage) {
    case eKeyDown:
    case eKeyPress:
    case eKeyUp:
      MOZ_ASSERT(aEvent->mClass == eKeyboardEventClass);
      break;
    case eCompositionStart:
    case eCompositionChange:
    case eCompositionCommit:
    case eCompositionCommitAsIs:
      MOZ_ASSERT(aEvent->mClass == eCompositionEventClass);
      break;
    default:
      return NS_ERROR_INVALID_ARG;
  }

  if (aEvent->mFlags.mIsSynthesizedForTests) {
    // If the event is for an automated test and this instance dispatched
    // an event to the parent process, we can assume that this is already
    // initialized properly.
    if (mInputTransactionType == eAsyncTestInputTransaction) {
      return NS_OK;
    }
    // Even if the event coming from the parent process is synthesized for
    // tests, this process should treat it as "sync" test here because
    // it won't be go back to the parent process.
    nsresult rv = BeginInputTransactionInternal(
        static_cast<TextEventDispatcherListener*>(aPuppetWidget),
        eSameProcessSyncTestInputTransaction);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  } else {
    nsresult rv = BeginNativeInputTransaction();
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }

  // Emulate modifying members which indicate the state of composition.
  // If we need to manage more states and/or more complexly, we should create
  // internal methods which are called by both here and each event dispatcher
  // method of this class.
  switch (aEvent->mMessage) {
    case eKeyDown:
    case eKeyPress:
    case eKeyUp:
      return NS_OK;
    case eCompositionStart:
      MOZ_ASSERT(!mIsComposing);
      mIsComposing = mIsHandlingComposition = true;
      return NS_OK;
    case eCompositionChange:
      MOZ_ASSERT(mIsComposing);
      MOZ_ASSERT(mIsHandlingComposition);
      mIsComposing = mIsHandlingComposition = true;
      return NS_OK;
    case eCompositionCommit:
    case eCompositionCommitAsIs:
      MOZ_ASSERT(mIsComposing);
      MOZ_ASSERT(mIsHandlingComposition);
      mIsComposing = false;
      mIsHandlingComposition = true;
      return NS_OK;
    default:
      MOZ_ASSERT_UNREACHABLE("You forgot to handle the event");
      return NS_ERROR_UNEXPECTED;
  }
}
void TextEventDispatcher::EndInputTransaction(
    TextEventDispatcherListener* aListener) {
  if (NS_WARN_IF(IsComposing()) || NS_WARN_IF(IsDispatchingEvent())) {
    return;
  }

  mInputTransactionType = eNoInputTransaction;

  nsCOMPtr<TextEventDispatcherListener> listener = do_QueryReferent(mListener);
  if (NS_WARN_IF(!listener)) {
    return;
  }

  if (NS_WARN_IF(listener != aListener)) {
    return;
  }

  mListener = nullptr;
  listener->OnRemovedFrom(this);
  UpdateNotificationRequests();
}

void TextEventDispatcher::OnDestroyWidget() {
  mWidget = nullptr;
  mHasFocus = false;
  ClearNotificationRequests();
  mPendingComposition.Clear();
  nsCOMPtr<TextEventDispatcherListener> listener = do_QueryReferent(mListener);
  mListener = nullptr;
  mInputTransactionType = eNoInputTransaction;
  if (listener) {
    listener->OnRemovedFrom(this);
  }
}

nsresult TextEventDispatcher::GetState() const {
  nsCOMPtr<TextEventDispatcherListener> listener = do_QueryReferent(mListener);
  if (!listener) {
    return NS_ERROR_NOT_INITIALIZED;
  }
  if (!mWidget || mWidget->Destroyed()) {
    return NS_ERROR_NOT_AVAILABLE;
  }
  return NS_OK;
}

void TextEventDispatcher::InitEvent(WidgetGUIEvent& aEvent) const {
  aEvent.mTime = PR_IntervalNow();
  aEvent.mRefPoint = LayoutDeviceIntPoint(0, 0);
  aEvent.mFlags.mIsSynthesizedForTests = IsForTests();
  if (aEvent.mClass != eCompositionEventClass) {
    return;
  }
  void* pseudoIMEContext = GetPseudoIMEContext();
  if (pseudoIMEContext) {
    aEvent.AsCompositionEvent()->mNativeIMEContext.InitWithRawNativeIMEContext(
        pseudoIMEContext);
  }
#ifdef DEBUG
  else {
    MOZ_ASSERT(!XRE_IsContentProcess(),
               "Why did the content process start native event transaction?");
    MOZ_ASSERT(aEvent.AsCompositionEvent()->mNativeIMEContext.IsValid(),
               "Native IME context shouldn't be invalid");
  }
#endif  // #ifdef DEBUG
}

nsresult TextEventDispatcher::DispatchEvent(nsIWidget* aWidget,
                                            WidgetGUIEvent& aEvent,
                                            nsEventStatus& aStatus) {
  MOZ_ASSERT(!aEvent.AsInputEvent(), "Use DispatchInputEvent()");

  RefPtr<TextEventDispatcher> kungFuDeathGrip(this);
  nsCOMPtr<nsIWidget> widget(aWidget);
  mDispatchingEvent++;
  nsresult rv = widget->DispatchEvent(&aEvent, aStatus);
  mDispatchingEvent--;
  return rv;
}

nsresult TextEventDispatcher::DispatchInputEvent(nsIWidget* aWidget,
                                                 WidgetInputEvent& aEvent,
                                                 nsEventStatus& aStatus) {
  RefPtr<TextEventDispatcher> kungFuDeathGrip(this);
  nsCOMPtr<nsIWidget> widget(aWidget);
  mDispatchingEvent++;

  // If the event is dispatched via nsIWidget::DispatchInputEvent(), it
  // sends the event to the parent process first since APZ needs to handle it
  // first.  However, some callers (e.g., keyboard apps on B2G and tests
  // expecting synchronous dispatch) don't want this to do that.
  nsresult rv = NS_OK;
  if (ShouldSendInputEventToAPZ()) {
    aStatus = widget->DispatchInputEvent(&aEvent);
  } else {
    rv = widget->DispatchEvent(&aEvent, aStatus);
  }

  mDispatchingEvent--;
  return rv;
}

nsresult TextEventDispatcher::StartComposition(
    nsEventStatus& aStatus, const WidgetEventTime* aEventTime) {
  aStatus = nsEventStatus_eIgnore;

  nsresult rv = GetState();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (NS_WARN_IF(mIsComposing)) {
    return NS_ERROR_FAILURE;
  }

  // When you change some members from here, you may need same change in
  // BeginInputTransactionFor().
  mIsComposing = mIsHandlingComposition = true;
  WidgetCompositionEvent compositionStartEvent(true, eCompositionStart,
                                               mWidget);
  InitEvent(compositionStartEvent);
  if (aEventTime) {
    compositionStartEvent.AssignEventTime(*aEventTime);
  }
  rv = DispatchEvent(mWidget, compositionStartEvent, aStatus);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

nsresult TextEventDispatcher::StartCompositionAutomaticallyIfNecessary(
    nsEventStatus& aStatus, const WidgetEventTime* aEventTime) {
  if (IsComposing()) {
    return NS_OK;
  }

  nsresult rv = StartComposition(aStatus, aEventTime);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  // If started composition has already been committed, we shouldn't dispatch
  // the compositionchange event.
  if (!IsComposing()) {
    aStatus = nsEventStatus_eConsumeNoDefault;
    return NS_OK;
  }

  // Note that the widget might be destroyed during a call of
  // StartComposition().  In such case, we shouldn't keep dispatching next
  // event.
  rv = GetState();
  if (NS_FAILED(rv)) {
    MOZ_ASSERT(rv != NS_ERROR_NOT_INITIALIZED,
               "aDispatcher must still be initialized in this case");
    aStatus = nsEventStatus_eConsumeNoDefault;
    return NS_OK;  // Don't throw exception in this case
  }

  aStatus = nsEventStatus_eIgnore;
  return NS_OK;
}

nsresult TextEventDispatcher::CommitComposition(
    nsEventStatus& aStatus, const nsAString* aCommitString,
    const WidgetEventTime* aEventTime) {
  aStatus = nsEventStatus_eIgnore;

  nsresult rv = GetState();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  // When there is no composition, caller shouldn't try to commit composition
  // with non-existing composition string nor commit composition with empty
  // string.
  if (NS_WARN_IF(!IsComposing() &&
                 (!aCommitString || aCommitString->IsEmpty()))) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIWidget> widget(mWidget);
  rv = StartCompositionAutomaticallyIfNecessary(aStatus, aEventTime);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  if (aStatus == nsEventStatus_eConsumeNoDefault) {
    return NS_OK;
  }

  // When you change some members from here, you may need same change in
  // BeginInputTransactionFor().

  // End current composition and make this free for other IMEs.
  mIsComposing = false;

  EventMessage message =
      aCommitString ? eCompositionCommit : eCompositionCommitAsIs;
  WidgetCompositionEvent compositionCommitEvent(true, message, widget);
  InitEvent(compositionCommitEvent);
  if (aEventTime) {
    compositionCommitEvent.AssignEventTime(*aEventTime);
  }
  if (message == eCompositionCommit) {
    compositionCommitEvent.mData = *aCommitString;
    // If aCommitString comes from TextInputProcessor, it may be void, but
    // editor requires non-void string even when it's empty.
    compositionCommitEvent.mData.SetIsVoid(false);
    // Don't send CRLF nor CR, replace it with LF here.
    compositionCommitEvent.mData.ReplaceSubstring(NS_LITERAL_STRING("\r\n"),
                                                  NS_LITERAL_STRING("\n"));
    compositionCommitEvent.mData.ReplaceSubstring(NS_LITERAL_STRING("\r"),
                                                  NS_LITERAL_STRING("\n"));
  }
  rv = DispatchEvent(widget, compositionCommitEvent, aStatus);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

nsresult TextEventDispatcher::NotifyIME(
    const IMENotification& aIMENotification) {
  nsresult rv = NS_ERROR_NOT_IMPLEMENTED;

  switch (aIMENotification.mMessage) {
    case NOTIFY_IME_OF_BLUR:
      mHasFocus = false;
      ClearNotificationRequests();
      break;
    case NOTIFY_IME_OF_COMPOSITION_EVENT_HANDLED:
      // If content handles composition events when native IME doesn't have
      // composition, that means that we completely finished handling
      // composition(s).  Note that when focused content is in a remote
      // process, this is sent when all dispatched composition events
      // have been handled in the remote process.
      if (!IsComposing()) {
        mIsHandlingComposition = false;
      }
      break;
    default:
      break;
  }

  // First, send the notification to current input transaction's listener.
  nsCOMPtr<TextEventDispatcherListener> listener = do_QueryReferent(mListener);
  if (listener) {
    rv = listener->NotifyIME(this, aIMENotification);
  }

  if (!mWidget) {
    return rv;
  }

  // If current input transaction isn't for native event handler, we should
  // send the notification to the native text event dispatcher listener
  // since native event handler may need to do something from
  // TextEventDispatcherListener::NotifyIME() even before there is no
  // input transaction yet.  For example, native IME handler may need to
  // create new context at receiving NOTIFY_IME_OF_FOCUS.  In this case,
  // mListener may not be initialized since input transaction should be
  // initialized immediately before dispatching every WidgetKeyboardEvent
  // and WidgetCompositionEvent (dispatching events always occurs after
  // focus move).
  nsCOMPtr<TextEventDispatcherListener> nativeListener =
      mWidget->GetNativeTextEventDispatcherListener();
  if (listener != nativeListener && nativeListener) {
    switch (aIMENotification.mMessage) {
      case REQUEST_TO_COMMIT_COMPOSITION:
      case REQUEST_TO_CANCEL_COMPOSITION:
        // It's not necessary to notify native IME of requests.
        break;
      default: {
        // Even if current input transaction's listener returns NS_OK or
        // something, we need to notify native IME of notifications because
        // when user typing after TIP does something, the changed information
        // is necessary for them.
        nsresult rv2 = nativeListener->NotifyIME(this, aIMENotification);
        // But return the result from current listener except when the
        // notification isn't handled.
        if (rv == NS_ERROR_NOT_IMPLEMENTED) {
          rv = rv2;
        }
        break;
      }
    }
  }

  if (aIMENotification.mMessage == NOTIFY_IME_OF_FOCUS) {
    mHasFocus = true;
    UpdateNotificationRequests();
  }

  return rv;
}

void TextEventDispatcher::ClearNotificationRequests() {
  mIMENotificationRequests = IMENotificationRequests();
}

void TextEventDispatcher::UpdateNotificationRequests() {
  ClearNotificationRequests();

  // If it doesn't has focus, no notifications are available.
  if (!mHasFocus || !mWidget) {
    return;
  }

  // If there is a listener, its requests are necessary.
  nsCOMPtr<TextEventDispatcherListener> listener = do_QueryReferent(mListener);
  if (listener) {
    mIMENotificationRequests = listener->GetIMENotificationRequests();
  }

  // Even if this is in non-native input transaction, native IME needs
  // requests.  So, add native IME requests too.
  if (!IsInNativeInputTransaction()) {
    nsCOMPtr<TextEventDispatcherListener> nativeListener =
        mWidget->GetNativeTextEventDispatcherListener();
    if (nativeListener) {
      mIMENotificationRequests |= nativeListener->GetIMENotificationRequests();
    }
  }
}

bool TextEventDispatcher::DispatchKeyboardEvent(
    EventMessage aMessage, const WidgetKeyboardEvent& aKeyboardEvent,
    nsEventStatus& aStatus, void* aData) {
  return DispatchKeyboardEventInternal(aMessage, aKeyboardEvent, aStatus,
                                       aData);
}

bool TextEventDispatcher::DispatchKeyboardEventInternal(
    EventMessage aMessage, const WidgetKeyboardEvent& aKeyboardEvent,
    nsEventStatus& aStatus, void* aData, uint32_t aIndexOfKeypress,
    bool aNeedsCallback) {
  // Note that this method is also used for dispatching key events on a plugin
  // because key events on a plugin should be dispatched same as normal key
  // events.  Then, only some handlers which need to intercept key events
  // before the focused plugin (e.g., reserved shortcut key handlers) can
  // consume the events.
  MOZ_ASSERT(WidgetKeyboardEvent::IsKeyDownOrKeyDownOnPlugin(aMessage) ||
                 WidgetKeyboardEvent::IsKeyUpOrKeyUpOnPlugin(aMessage) ||
                 aMessage == eKeyPress,
             "Invalid aMessage value");
  nsresult rv = GetState();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return false;
  }

  // If the key shouldn't cause keypress events, don't this patch them.
  if (aMessage == eKeyPress && !aKeyboardEvent.ShouldCauseKeypressEvents()) {
    return false;
  }

  // Basically, key events shouldn't be dispatched during composition.
  // Note that plugin process has different IME context.  Therefore, we don't
  // need to check our composition state when the key event is fired on a
  // plugin.
  if (IsComposing() && !WidgetKeyboardEvent::IsKeyEventOnPlugin(aMessage)) {
    // However, if we need to behave like other browsers, we need the keydown
    // and keyup events.  Note that this behavior is also allowed by D3E spec.
    // FYI: keypress events must not be fired during composition.
    if (!sDispatchKeyEventsDuringComposition || aMessage == eKeyPress) {
      return false;
    }
    // XXX If there was mOnlyContentDispatch for this case, it might be useful
    //     because our chrome doesn't assume that key events are fired during
    //     composition.
  }

  WidgetKeyboardEvent keyEvent(true, aMessage, mWidget);
  InitEvent(keyEvent);
  keyEvent.AssignKeyEventData(aKeyboardEvent, false);
  // Command arrays are not duplicated by AssignKeyEventData() due to
  // both performance and footprint reasons.  So, when TextInputProcessor
  // emulates real text input, the arrays may be initialized all commands
  // already.  If so, we need to duplicate the arrays here.
  if (keyEvent.mIsSynthesizedByTIP) {
    keyEvent.AssignCommands(aKeyboardEvent);
  }

  if (aStatus == nsEventStatus_eConsumeNoDefault) {
    // If the key event should be dispatched as consumed event, marking it here.
    // This is useful to prevent double action.  This is intended to the system
    // has already consumed the event but we need to dispatch the event for
    // compatibility with older version and other browsers.  So, we should not
    // stop cross process forwarding of them.
    keyEvent.PreventDefaultBeforeDispatch(CrossProcessForwarding::eAllow);
  }

  // Corrects each member for the specific key event type.
  if (keyEvent.mKeyNameIndex != KEY_NAME_INDEX_USE_STRING) {
    MOZ_ASSERT(!aIndexOfKeypress,
               "aIndexOfKeypress must be 0 for non-printable key");
    // If the keyboard event isn't caused by printable key, its charCode should
    // be 0.
    keyEvent.SetCharCode(0);
  } else {
    if (WidgetKeyboardEvent::IsKeyDownOrKeyDownOnPlugin(aMessage) ||
        WidgetKeyboardEvent::IsKeyUpOrKeyUpOnPlugin(aMessage)) {
      MOZ_RELEASE_ASSERT(
          !aIndexOfKeypress,
          "aIndexOfKeypress must be 0 for either eKeyDown or eKeyUp");
    } else {
      MOZ_RELEASE_ASSERT(
          !aIndexOfKeypress || aIndexOfKeypress < keyEvent.mKeyValue.Length(),
          "aIndexOfKeypress must be 0 - mKeyValue.Length() - 1");
    }
    wchar_t ch =
        keyEvent.mKeyValue.IsEmpty() ? 0 : keyEvent.mKeyValue[aIndexOfKeypress];
    keyEvent.SetCharCode(static_cast<uint32_t>(ch));
    if (aMessage == eKeyPress) {
      // keyCode of eKeyPress events of printable keys should be always 0.
      keyEvent.mKeyCode = 0;
      // eKeyPress events are dispatched for every character.
      // So, each key value of eKeyPress events should be a character.
      if (ch) {
        keyEvent.mKeyValue.Assign(ch);
      } else {
        keyEvent.mKeyValue.Truncate();
      }
    }
  }
  if (WidgetKeyboardEvent::IsKeyUpOrKeyUpOnPlugin(aMessage)) {
    // mIsRepeat of keyup event must be false.
    keyEvent.mIsRepeat = false;
  }
  // mIsComposing should be initialized later.
  keyEvent.mIsComposing = false;
  if (mInputTransactionType == eNativeInputTransaction) {
    // Copy mNativeKeyEvent here because for safety for other users of
    // AssignKeyEventData(), it doesn't copy this.
    keyEvent.mNativeKeyEvent = aKeyboardEvent.mNativeKeyEvent;
  } else {
    // If it's not a keyboard event for native key event, we should ensure that
    // mNativeKeyEvent and mPluginEvent are null/empty.
    keyEvent.mNativeKeyEvent = nullptr;
    keyEvent.mPluginEvent.Clear();
  }
  // TODO: Manage mUniqueId here.

  // Request the alternative char codes for the key event.
  // eKeyDown also needs alternative char codes because nsXBLWindowKeyHandler
  // needs to check if a following keypress event is reserved by chrome for
  // stopping propagation of its preceding keydown event.
  keyEvent.mAlternativeCharCodes.Clear();
  if ((WidgetKeyboardEvent::IsKeyDownOrKeyDownOnPlugin(aMessage) ||
       aMessage == eKeyPress) &&
      (aNeedsCallback || keyEvent.IsControl() || keyEvent.IsAlt() ||
       keyEvent.IsMeta() || keyEvent.IsOS())) {
    nsCOMPtr<TextEventDispatcherListener> listener =
        do_QueryReferent(mListener);
    if (listener) {
      DebugOnly<WidgetKeyboardEvent> original(keyEvent);
      listener->WillDispatchKeyboardEvent(this, keyEvent, aIndexOfKeypress,
                                          aData);
      MOZ_ASSERT(keyEvent.mMessage ==
                 static_cast<WidgetKeyboardEvent&>(original).mMessage);
      MOZ_ASSERT(keyEvent.mKeyCode ==
                 static_cast<WidgetKeyboardEvent&>(original).mKeyCode);
      MOZ_ASSERT(keyEvent.mLocation ==
                 static_cast<WidgetKeyboardEvent&>(original).mLocation);
      MOZ_ASSERT(keyEvent.mIsRepeat ==
                 static_cast<WidgetKeyboardEvent&>(original).mIsRepeat);
      MOZ_ASSERT(keyEvent.mIsComposing ==
                 static_cast<WidgetKeyboardEvent&>(original).mIsComposing);
      MOZ_ASSERT(keyEvent.mKeyNameIndex ==
                 static_cast<WidgetKeyboardEvent&>(original).mKeyNameIndex);
      MOZ_ASSERT(keyEvent.mCodeNameIndex ==
                 static_cast<WidgetKeyboardEvent&>(original).mCodeNameIndex);
      MOZ_ASSERT(keyEvent.mKeyValue ==
                 static_cast<WidgetKeyboardEvent&>(original).mKeyValue);
      MOZ_ASSERT(keyEvent.mCodeValue ==
                 static_cast<WidgetKeyboardEvent&>(original).mCodeValue);
    }
  }

  if (sDispatchKeyPressEventsOnlySystemGroupInContent &&
      keyEvent.mMessage == eKeyPress &&
      !keyEvent.ShouldKeyPressEventBeFiredOnContent()) {
    // Note that even if we set it to true, this may be overwritten by
    // PresShell::DispatchEventToDOM().
    keyEvent.mFlags.mOnlySystemGroupDispatchInContent = true;
  }

  DispatchInputEvent(mWidget, keyEvent, aStatus);
  return true;
}

bool TextEventDispatcher::MaybeDispatchKeypressEvents(
    const WidgetKeyboardEvent& aKeyboardEvent, nsEventStatus& aStatus,
    void* aData, bool aNeedsCallback) {
  // If the key event was consumed, keypress event shouldn't be fired.
  if (aStatus == nsEventStatus_eConsumeNoDefault) {
    return false;
  }

  // If the key shouldn't cause keypress events, don't fire them.
  if (!aKeyboardEvent.ShouldCauseKeypressEvents()) {
    return false;
  }

  // If the key isn't a printable key or just inputting one character or
  // no character, we should dispatch only one keypress.  Otherwise, i.e.,
  // if the key is a printable key and inputs multiple characters, keypress
  // event should be dispatched the count of inputting characters times.
  size_t keypressCount =
      aKeyboardEvent.mKeyNameIndex != KEY_NAME_INDEX_USE_STRING
          ? 1
          : std::max(static_cast<nsAString::size_type>(1),
                     aKeyboardEvent.mKeyValue.Length());
  bool isDispatched = false;
  bool consumed = false;
  for (size_t i = 0; i < keypressCount; i++) {
    aStatus = nsEventStatus_eIgnore;
    if (!DispatchKeyboardEventInternal(eKeyPress, aKeyboardEvent, aStatus,
                                       aData, i, aNeedsCallback)) {
      // The widget must have been gone.
      break;
    }
    isDispatched = true;
    if (!consumed) {
      consumed = (aStatus == nsEventStatus_eConsumeNoDefault);
    }
  }

  // If one of the keypress event was consumed, return ConsumeNoDefault.
  if (consumed) {
    aStatus = nsEventStatus_eConsumeNoDefault;
  }

  return isDispatched;
}

/******************************************************************************
 * TextEventDispatcher::PendingComposition
 *****************************************************************************/

TextEventDispatcher::PendingComposition::PendingComposition() { Clear(); }

void TextEventDispatcher::PendingComposition::Clear() {
  mString.Truncate();
  mClauses = nullptr;
  mCaret.mRangeType = TextRangeType::eUninitialized;
  mReplacedNativeLineBreakers = false;
}

void TextEventDispatcher::PendingComposition::EnsureClauseArray() {
  if (mClauses) {
    return;
  }
  mClauses = new TextRangeArray();
}

nsresult TextEventDispatcher::PendingComposition::SetString(
    const nsAString& aString) {
  MOZ_ASSERT(!mReplacedNativeLineBreakers);
  mString = aString;
  return NS_OK;
}

nsresult TextEventDispatcher::PendingComposition::AppendClause(
    uint32_t aLength, TextRangeType aTextRangeType) {
  MOZ_ASSERT(!mReplacedNativeLineBreakers);

  if (NS_WARN_IF(!aLength)) {
    return NS_ERROR_INVALID_ARG;
  }

  switch (aTextRangeType) {
    case TextRangeType::eRawClause:
    case TextRangeType::eSelectedRawClause:
    case TextRangeType::eConvertedClause:
    case TextRangeType::eSelectedClause: {
      EnsureClauseArray();
      TextRange textRange;
      textRange.mStartOffset =
          mClauses->IsEmpty() ? 0 : mClauses->LastElement().mEndOffset;
      textRange.mEndOffset = textRange.mStartOffset + aLength;
      textRange.mRangeType = aTextRangeType;
      mClauses->AppendElement(textRange);
      return NS_OK;
    }
    default:
      return NS_ERROR_INVALID_ARG;
  }
}

nsresult TextEventDispatcher::PendingComposition::SetCaret(uint32_t aOffset,
                                                           uint32_t aLength) {
  MOZ_ASSERT(!mReplacedNativeLineBreakers);

  mCaret.mStartOffset = aOffset;
  mCaret.mEndOffset = mCaret.mStartOffset + aLength;
  mCaret.mRangeType = TextRangeType::eCaret;
  return NS_OK;
}

nsresult TextEventDispatcher::PendingComposition::Set(
    const nsAString& aString, const TextRangeArray* aRanges) {
  Clear();

  nsresult rv = SetString(aString);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (!aRanges || aRanges->IsEmpty()) {
    // Create dummy range if mString isn't empty.
    if (!mString.IsEmpty()) {
      rv = AppendClause(mString.Length(), TextRangeType::eRawClause);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
      ReplaceNativeLineBreakers();
    }
    return NS_OK;
  }

  // Adjust offsets in the ranges for XP linefeed character (only \n).
  for (uint32_t i = 0; i < aRanges->Length(); ++i) {
    TextRange range = aRanges->ElementAt(i);
    if (range.mRangeType == TextRangeType::eCaret) {
      mCaret = range;
    } else {
      EnsureClauseArray();
      mClauses->AppendElement(range);
    }
  }
  ReplaceNativeLineBreakers();
  return NS_OK;
}

void TextEventDispatcher::PendingComposition::ReplaceNativeLineBreakers() {
  mReplacedNativeLineBreakers = true;

  // If the composition string is empty, we don't need to do anything.
  if (mString.IsEmpty()) {
    return;
  }

  nsAutoString nativeString(mString);
  // Don't expose CRLF nor CR to web contents, instead, use LF.
  mString.ReplaceSubstring(NS_LITERAL_STRING("\r\n"), NS_LITERAL_STRING("\n"));
  mString.ReplaceSubstring(NS_LITERAL_STRING("\r"), NS_LITERAL_STRING("\n"));

  // If the length isn't changed, we don't need to adjust any offset and length
  // of mClauses nor mCaret.
  if (nativeString.Length() == mString.Length()) {
    return;
  }

  if (mClauses) {
    for (TextRange& clause : *mClauses) {
      AdjustRange(clause, nativeString);
    }
  }
  if (mCaret.mRangeType == TextRangeType::eCaret) {
    AdjustRange(mCaret, nativeString);
  }
}

// static
void TextEventDispatcher::PendingComposition::AdjustRange(
    TextRange& aRange, const nsAString& aNativeString) {
  TextRange nativeRange = aRange;
  // XXX Following code wastes runtime cost because this causes computing
  //     mStartOffset for each clause from the start of composition string.
  //     If we'd make TextRange have only its length, we don't need to do
  //     this.  However, this must not be so serious problem because
  //     composition string is usually short and separated as a few clauses.
  if (nativeRange.mStartOffset > 0) {
    nsAutoString preText(Substring(aNativeString, 0, nativeRange.mStartOffset));
    preText.ReplaceSubstring(NS_LITERAL_STRING("\r\n"),
                             NS_LITERAL_STRING("\n"));
    aRange.mStartOffset = preText.Length();
  }
  if (nativeRange.Length() == 0) {
    aRange.mEndOffset = aRange.mStartOffset;
  } else {
    nsAutoString clause(Substring(aNativeString, nativeRange.mStartOffset,
                                  nativeRange.Length()));
    clause.ReplaceSubstring(NS_LITERAL_STRING("\r\n"), NS_LITERAL_STRING("\n"));
    aRange.mEndOffset = aRange.mStartOffset + clause.Length();
  }
}

nsresult TextEventDispatcher::PendingComposition::Flush(
    TextEventDispatcher* aDispatcher, nsEventStatus& aStatus,
    const WidgetEventTime* aEventTime) {
  aStatus = nsEventStatus_eIgnore;

  nsresult rv = aDispatcher->GetState();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (mClauses && !mClauses->IsEmpty() &&
      mClauses->LastElement().mEndOffset != mString.Length()) {
    NS_WARNING(
        "Sum of length of the all clauses must be same as the string "
        "length");
    Clear();
    return NS_ERROR_ILLEGAL_VALUE;
  }
  if (mCaret.mRangeType == TextRangeType::eCaret) {
    if (mCaret.mEndOffset > mString.Length()) {
      NS_WARNING("Caret position is out of the composition string");
      Clear();
      return NS_ERROR_ILLEGAL_VALUE;
    }
    EnsureClauseArray();
    mClauses->AppendElement(mCaret);
  }

  // If the composition string is set without Set(), we need to replace native
  // line breakers in the composition string with XP line breaker.
  if (!mReplacedNativeLineBreakers) {
    ReplaceNativeLineBreakers();
  }

  RefPtr<TextEventDispatcher> kungFuDeathGrip(aDispatcher);
  nsCOMPtr<nsIWidget> widget(aDispatcher->mWidget);
  WidgetCompositionEvent compChangeEvent(true, eCompositionChange, widget);
  aDispatcher->InitEvent(compChangeEvent);
  if (aEventTime) {
    compChangeEvent.AssignEventTime(*aEventTime);
  }
  compChangeEvent.mData = mString;
  // If mString comes from TextInputProcessor, it may be void, but editor
  // requires non-void string even when it's empty.
  compChangeEvent.mData.SetIsVoid(false);
  if (mClauses) {
    MOZ_ASSERT(!mClauses->IsEmpty(),
               "mClauses must be non-empty array when it's not nullptr");
    compChangeEvent.mRanges = mClauses;
  }

  // While this method dispatches a composition event, some other event handler
  // cause more clauses to be added.  So, we should clear pending composition
  // before dispatching the event.
  Clear();

  rv = aDispatcher->StartCompositionAutomaticallyIfNecessary(aStatus,
                                                             aEventTime);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  if (aStatus == nsEventStatus_eConsumeNoDefault) {
    return NS_OK;
  }
  rv = aDispatcher->DispatchEvent(widget, compChangeEvent, aStatus);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

}  // namespace widget
}  // namespace mozilla