michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=2 sw=2 et tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "ContentEventHandler.h"
michael@0: #include "IMEContentObserver.h"
michael@0: #include "mozilla/AsyncEventDispatcher.h"
michael@0: #include "mozilla/EventStateManager.h"
michael@0: #include "mozilla/IMEStateManager.h"
michael@0: #include "mozilla/TextComposition.h"
michael@0: #include "mozilla/dom/Element.h"
michael@0: #include "nsAutoPtr.h"
michael@0: #include "nsContentUtils.h"
michael@0: #include "nsGkAtoms.h"
michael@0: #include "nsIAtom.h"
michael@0: #include "nsIContent.h"
michael@0: #include "nsIDocument.h"
michael@0: #include "nsIDOMDocument.h"
michael@0: #include "nsIDOMRange.h"
michael@0: #include "nsIFrame.h"
michael@0: #include "nsINode.h"
michael@0: #include "nsIPresShell.h"
michael@0: #include "nsISelectionController.h"
michael@0: #include "nsISelectionPrivate.h"
michael@0: #include "nsISupports.h"
michael@0: #include "nsIWidget.h"
michael@0: #include "nsPresContext.h"
michael@0: #include "nsThreadUtils.h"
michael@0: #include "nsWeakReference.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: using namespace widget;
michael@0: 
michael@0: NS_IMPL_CYCLE_COLLECTION(IMEContentObserver,
michael@0:                          mWidget, mSelection,
michael@0:                          mRootContent, mEditableNode, mDocShell)
michael@0: 
michael@0: NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(IMEContentObserver)
michael@0:  NS_INTERFACE_MAP_ENTRY(nsISelectionListener)
michael@0:  NS_INTERFACE_MAP_ENTRY(nsIMutationObserver)
michael@0:  NS_INTERFACE_MAP_ENTRY(nsIReflowObserver)
michael@0:  NS_INTERFACE_MAP_ENTRY(nsIScrollObserver)
michael@0:  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
michael@0:  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsISelectionListener)
michael@0: NS_INTERFACE_MAP_END
michael@0: 
michael@0: NS_IMPL_CYCLE_COLLECTING_ADDREF(IMEContentObserver)
michael@0: NS_IMPL_CYCLE_COLLECTING_RELEASE(IMEContentObserver)
michael@0: 
michael@0: IMEContentObserver::IMEContentObserver()
michael@0:   : mESM(nullptr)
michael@0: {
michael@0: }
michael@0: 
michael@0: void
michael@0: IMEContentObserver::Init(nsIWidget* aWidget,
michael@0:                          nsPresContext* aPresContext,
michael@0:                          nsIContent* aContent)
michael@0: {
michael@0:   mESM = aPresContext->EventStateManager();
michael@0:   mESM->OnStartToObserveContent(this);
michael@0: 
michael@0:   mWidget = aWidget;
michael@0:   mEditableNode = IMEStateManager::GetRootEditableNode(aPresContext, aContent);
michael@0:   if (!mEditableNode) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   nsIPresShell* presShell = aPresContext->PresShell();
michael@0: 
michael@0:   // get selection and root content
michael@0:   nsCOMPtr<nsISelectionController> selCon;
michael@0:   if (mEditableNode->IsNodeOfType(nsINode::eCONTENT)) {
michael@0:     nsIFrame* frame =
michael@0:       static_cast<nsIContent*>(mEditableNode.get())->GetPrimaryFrame();
michael@0:     NS_ENSURE_TRUE_VOID(frame);
michael@0: 
michael@0:     frame->GetSelectionController(aPresContext,
michael@0:                                   getter_AddRefs(selCon));
michael@0:   } else {
michael@0:     // mEditableNode is a document
michael@0:     selCon = do_QueryInterface(presShell);
michael@0:   }
michael@0:   NS_ENSURE_TRUE_VOID(selCon);
michael@0: 
michael@0:   selCon->GetSelection(nsISelectionController::SELECTION_NORMAL,
michael@0:                        getter_AddRefs(mSelection));
michael@0:   NS_ENSURE_TRUE_VOID(mSelection);
michael@0: 
michael@0:   nsCOMPtr<nsIDOMRange> selDomRange;
michael@0:   if (NS_SUCCEEDED(mSelection->GetRangeAt(0, getter_AddRefs(selDomRange)))) {
michael@0:     nsRange* selRange = static_cast<nsRange*>(selDomRange.get());
michael@0:     NS_ENSURE_TRUE_VOID(selRange && selRange->GetStartParent());
michael@0: 
michael@0:     mRootContent = selRange->GetStartParent()->
michael@0:                      GetSelectionRootContent(presShell);
michael@0:   } else {
michael@0:     mRootContent = mEditableNode->GetSelectionRootContent(presShell);
michael@0:   }
michael@0:   if (!mRootContent && mEditableNode->IsNodeOfType(nsINode::eDOCUMENT)) {
michael@0:     // The document node is editable, but there are no contents, this document
michael@0:     // is not editable.
michael@0:     return;
michael@0:   }
michael@0:   NS_ENSURE_TRUE_VOID(mRootContent);
michael@0: 
michael@0:   if (IMEStateManager::IsTestingIME()) {
michael@0:     nsIDocument* doc = aPresContext->Document();
michael@0:     (new AsyncEventDispatcher(doc, NS_LITERAL_STRING("MozIMEFocusIn"),
michael@0:                               false, false))->RunDOMEventWhenSafe();
michael@0:   }
michael@0: 
michael@0:   aWidget->NotifyIME(IMENotification(NOTIFY_IME_OF_FOCUS));
michael@0: 
michael@0:   // NOTIFY_IME_OF_FOCUS might cause recreating IMEContentObserver
michael@0:   // instance via IMEStateManager::UpdateIMEState().  So, this
michael@0:   // instance might already have been destroyed, check it.
michael@0:   if (!mRootContent) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   mDocShell = aPresContext->GetDocShell();
michael@0: 
michael@0:   ObserveEditableNode();
michael@0: }
michael@0: 
michael@0: void
michael@0: IMEContentObserver::ObserveEditableNode()
michael@0: {
michael@0:   MOZ_ASSERT(mSelection);
michael@0:   MOZ_ASSERT(mRootContent);
michael@0: 
michael@0:   mUpdatePreference = mWidget->GetIMEUpdatePreference();
michael@0:   if (mUpdatePreference.WantSelectionChange()) {
michael@0:     // add selection change listener
michael@0:     nsCOMPtr<nsISelectionPrivate> selPrivate(do_QueryInterface(mSelection));
michael@0:     NS_ENSURE_TRUE_VOID(selPrivate);
michael@0:     nsresult rv = selPrivate->AddSelectionListener(this);
michael@0:     NS_ENSURE_SUCCESS_VOID(rv);
michael@0:   }
michael@0: 
michael@0:   if (mUpdatePreference.WantTextChange()) {
michael@0:     // add text change observer
michael@0:     mRootContent->AddMutationObserver(this);
michael@0:   }
michael@0: 
michael@0:   if (mUpdatePreference.WantPositionChanged() && mDocShell) {
michael@0:     // Add scroll position listener and reflow observer to detect position and
michael@0:     // size changes
michael@0:     mDocShell->AddWeakScrollObserver(this);
michael@0:     mDocShell->AddWeakReflowObserver(this);
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: IMEContentObserver::Destroy()
michael@0: {
michael@0:   // If CreateTextStateManager failed, mRootContent will be null,
michael@0:   // and we should not call NotifyIME(IMENotification(NOTIFY_IME_OF_BLUR))
michael@0:   if (mRootContent) {
michael@0:     if (IMEStateManager::IsTestingIME() && mEditableNode) {
michael@0:       nsIDocument* doc = mEditableNode->OwnerDoc();
michael@0:       (new AsyncEventDispatcher(doc, NS_LITERAL_STRING("MozIMEFocusOut"),
michael@0:                                 false, false))->RunDOMEventWhenSafe();
michael@0:     }
michael@0:     mWidget->NotifyIME(IMENotification(NOTIFY_IME_OF_BLUR));
michael@0:   }
michael@0:   // Even if there are some pending notification, it'll never notify the widget.
michael@0:   mWidget = nullptr;
michael@0:   if (mUpdatePreference.WantSelectionChange() && mSelection) {
michael@0:     nsCOMPtr<nsISelectionPrivate> selPrivate(do_QueryInterface(mSelection));
michael@0:     if (selPrivate) {
michael@0:       selPrivate->RemoveSelectionListener(this);
michael@0:     }
michael@0:   }
michael@0:   mSelection = nullptr;
michael@0:   if (mUpdatePreference.WantTextChange() && mRootContent) {
michael@0:     mRootContent->RemoveMutationObserver(this);
michael@0:   }
michael@0:   if (mUpdatePreference.WantPositionChanged() && mDocShell) {
michael@0:     mDocShell->RemoveWeakScrollObserver(this);
michael@0:     mDocShell->RemoveWeakReflowObserver(this);
michael@0:   }
michael@0:   mRootContent = nullptr;
michael@0:   mEditableNode = nullptr;
michael@0:   mDocShell = nullptr;
michael@0:   mUpdatePreference.mWantUpdates = nsIMEUpdatePreference::NOTIFY_NOTHING;
michael@0: 
michael@0:   if (mESM) {
michael@0:     mESM->OnStopObservingContent(this);
michael@0:     mESM = nullptr;
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: IMEContentObserver::DisconnectFromEventStateManager()
michael@0: {
michael@0:   mESM = nullptr;
michael@0: }
michael@0: 
michael@0: bool
michael@0: IMEContentObserver::IsManaging(nsPresContext* aPresContext,
michael@0:                                nsIContent* aContent)
michael@0: {
michael@0:   if (!mSelection || !mRootContent || !mEditableNode) {
michael@0:     return false; // failed to initialize.
michael@0:   }
michael@0:   if (!mRootContent->IsInDoc()) {
michael@0:     return false; // the focused editor has already been reframed.
michael@0:   }
michael@0:   return mEditableNode == IMEStateManager::GetRootEditableNode(aPresContext,
michael@0:                                                                aContent);
michael@0: }
michael@0: 
michael@0: bool
michael@0: IMEContentObserver::IsEditorHandlingEventForComposition() const
michael@0: {
michael@0:   if (!mWidget) {
michael@0:     return false;
michael@0:   }
michael@0:   nsRefPtr<TextComposition> composition =
michael@0:     IMEStateManager::GetTextCompositionFor(mWidget);
michael@0:   if (!composition) {
michael@0:     return false;
michael@0:   }
michael@0:   return composition->IsEditorHandlingEvent();
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: IMEContentObserver::GetSelectionAndRoot(nsISelection** aSelection,
michael@0:                                         nsIContent** aRootContent) const
michael@0: {
michael@0:   if (!mEditableNode || !mSelection) {
michael@0:     return NS_ERROR_NOT_AVAILABLE;
michael@0:   }
michael@0: 
michael@0:   NS_ASSERTION(mSelection && mRootContent, "uninitialized content observer");
michael@0:   NS_ADDREF(*aSelection = mSelection);
michael@0:   NS_ADDREF(*aRootContent = mRootContent);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: // Helper class, used for selection change notification
michael@0: class SelectionChangeEvent : public nsRunnable
michael@0: {
michael@0: public:
michael@0:   SelectionChangeEvent(IMEContentObserver* aDispatcher,
michael@0:                        bool aCausedByComposition)
michael@0:     : mDispatcher(aDispatcher)
michael@0:     , mCausedByComposition(aCausedByComposition)
michael@0:   {
michael@0:     MOZ_ASSERT(mDispatcher);
michael@0:   }
michael@0: 
michael@0:   NS_IMETHOD Run()
michael@0:   {
michael@0:     if (mDispatcher->GetWidget()) {
michael@0:       IMENotification notification(NOTIFY_IME_OF_SELECTION_CHANGE);
michael@0:       notification.mSelectionChangeData.mCausedByComposition =
michael@0:          mCausedByComposition;
michael@0:       mDispatcher->GetWidget()->NotifyIME(notification);
michael@0:     }
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   nsRefPtr<IMEContentObserver> mDispatcher;
michael@0:   bool mCausedByComposition;
michael@0: };
michael@0: 
michael@0: nsresult
michael@0: IMEContentObserver::NotifySelectionChanged(nsIDOMDocument* aDOMDocument,
michael@0:                                            nsISelection* aSelection,
michael@0:                                            int16_t aReason)
michael@0: {
michael@0:   bool causedByComposition = IsEditorHandlingEventForComposition();
michael@0:   if (causedByComposition &&
michael@0:       !mUpdatePreference.WantChangesCausedByComposition()) {
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   int32_t count = 0;
michael@0:   nsresult rv = aSelection->GetRangeCount(&count);
michael@0:   NS_ENSURE_SUCCESS(rv, rv);
michael@0:   if (count > 0 && mWidget) {
michael@0:     nsContentUtils::AddScriptRunner(
michael@0:       new SelectionChangeEvent(this, causedByComposition));
michael@0:   }
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: // Helper class, used for position change notification
michael@0: class PositionChangeEvent MOZ_FINAL : public nsRunnable
michael@0: {
michael@0: public:
michael@0:   PositionChangeEvent(IMEContentObserver* aDispatcher)
michael@0:     : mDispatcher(aDispatcher)
michael@0:   {
michael@0:     MOZ_ASSERT(mDispatcher);
michael@0:   }
michael@0: 
michael@0:   NS_IMETHOD Run()
michael@0:   {
michael@0:     if (mDispatcher->GetWidget()) {
michael@0:       mDispatcher->GetWidget()->NotifyIME(
michael@0:         IMENotification(NOTIFY_IME_OF_POSITION_CHANGE));
michael@0:     }
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   nsRefPtr<IMEContentObserver> mDispatcher;
michael@0: };
michael@0: 
michael@0: void
michael@0: IMEContentObserver::ScrollPositionChanged()
michael@0: {
michael@0:   if (mWidget) {
michael@0:     nsContentUtils::AddScriptRunner(new PositionChangeEvent(this));
michael@0:   }
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: IMEContentObserver::Reflow(DOMHighResTimeStamp aStart,
michael@0:                            DOMHighResTimeStamp aEnd)
michael@0: {
michael@0:   if (mWidget) {
michael@0:     nsContentUtils::AddScriptRunner(new PositionChangeEvent(this));
michael@0:   }
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: IMEContentObserver::ReflowInterruptible(DOMHighResTimeStamp aStart,
michael@0:                                         DOMHighResTimeStamp aEnd)
michael@0: {
michael@0:   if (mWidget) {
michael@0:     nsContentUtils::AddScriptRunner(new PositionChangeEvent(this));
michael@0:   }
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: // Helper class, used for text change notification
michael@0: class TextChangeEvent : public nsRunnable
michael@0: {
michael@0: public:
michael@0:   TextChangeEvent(IMEContentObserver* aDispatcher,
michael@0:                   uint32_t aStart, uint32_t aOldEnd, uint32_t aNewEnd,
michael@0:                   bool aCausedByComposition)
michael@0:     : mDispatcher(aDispatcher)
michael@0:     , mStart(aStart)
michael@0:     , mOldEnd(aOldEnd)
michael@0:     , mNewEnd(aNewEnd)
michael@0:     , mCausedByComposition(aCausedByComposition)
michael@0:   {
michael@0:     MOZ_ASSERT(mDispatcher);
michael@0:   }
michael@0: 
michael@0:   NS_IMETHOD Run()
michael@0:   {
michael@0:     if (mDispatcher->GetWidget()) {
michael@0:       IMENotification notification(NOTIFY_IME_OF_TEXT_CHANGE);
michael@0:       notification.mTextChangeData.mStartOffset = mStart;
michael@0:       notification.mTextChangeData.mOldEndOffset = mOldEnd;
michael@0:       notification.mTextChangeData.mNewEndOffset = mNewEnd;
michael@0:       notification.mTextChangeData.mCausedByComposition = mCausedByComposition;
michael@0:       mDispatcher->GetWidget()->NotifyIME(notification);
michael@0:     }
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   nsRefPtr<IMEContentObserver> mDispatcher;
michael@0:   uint32_t mStart, mOldEnd, mNewEnd;
michael@0:   bool mCausedByComposition;
michael@0: };
michael@0: 
michael@0: void
michael@0: IMEContentObserver::CharacterDataChanged(nsIDocument* aDocument,
michael@0:                                          nsIContent* aContent,
michael@0:                                          CharacterDataChangeInfo* aInfo)
michael@0: {
michael@0:   NS_ASSERTION(aContent->IsNodeOfType(nsINode::eTEXT),
michael@0:                "character data changed for non-text node");
michael@0: 
michael@0:   bool causedByComposition = IsEditorHandlingEventForComposition();
michael@0:   if (causedByComposition &&
michael@0:       !mUpdatePreference.WantChangesCausedByComposition()) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   uint32_t offset = 0;
michael@0:   // get offsets of change and fire notification
michael@0:   nsresult rv =
michael@0:     ContentEventHandler::GetFlatTextOffsetOfRange(mRootContent, aContent,
michael@0:                                                   aInfo->mChangeStart,
michael@0:                                                   &offset,
michael@0:                                                   LINE_BREAK_TYPE_NATIVE);
michael@0:   NS_ENSURE_SUCCESS_VOID(rv);
michael@0: 
michael@0:   uint32_t oldEnd = offset + aInfo->mChangeEnd - aInfo->mChangeStart;
michael@0:   uint32_t newEnd = offset + aInfo->mReplaceLength;
michael@0: 
michael@0:   nsContentUtils::AddScriptRunner(
michael@0:     new TextChangeEvent(this, offset, oldEnd, newEnd, causedByComposition));
michael@0: }
michael@0: 
michael@0: void
michael@0: IMEContentObserver::NotifyContentAdded(nsINode* aContainer,
michael@0:                                        int32_t aStartIndex,
michael@0:                                        int32_t aEndIndex)
michael@0: {
michael@0:   bool causedByComposition = IsEditorHandlingEventForComposition();
michael@0:   if (causedByComposition &&
michael@0:       !mUpdatePreference.WantChangesCausedByComposition()) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   uint32_t offset = 0;
michael@0:   nsresult rv =
michael@0:     ContentEventHandler::GetFlatTextOffsetOfRange(mRootContent, aContainer,
michael@0:                                                   aStartIndex, &offset,
michael@0:                                                   LINE_BREAK_TYPE_NATIVE);
michael@0:   NS_ENSURE_SUCCESS_VOID(rv);
michael@0: 
michael@0:   // get offset at the end of the last added node
michael@0:   nsIContent* childAtStart = aContainer->GetChildAt(aStartIndex);
michael@0:   uint32_t addingLength = 0;
michael@0:   rv = ContentEventHandler::GetFlatTextOffsetOfRange(childAtStart, aContainer,
michael@0:                                                      aEndIndex, &addingLength,
michael@0:                                                      LINE_BREAK_TYPE_NATIVE);
michael@0:   NS_ENSURE_SUCCESS_VOID(rv);
michael@0: 
michael@0:   if (!addingLength) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   nsContentUtils::AddScriptRunner(
michael@0:     new TextChangeEvent(this, offset, offset, offset + addingLength,
michael@0:                         causedByComposition));
michael@0: }
michael@0: 
michael@0: void
michael@0: IMEContentObserver::ContentAppended(nsIDocument* aDocument,
michael@0:                                     nsIContent* aContainer,
michael@0:                                     nsIContent* aFirstNewContent,
michael@0:                                     int32_t aNewIndexInContainer)
michael@0: {
michael@0:   NotifyContentAdded(aContainer, aNewIndexInContainer,
michael@0:                      aContainer->GetChildCount());
michael@0: }
michael@0: 
michael@0: void
michael@0: IMEContentObserver::ContentInserted(nsIDocument* aDocument,
michael@0:                                     nsIContent* aContainer,
michael@0:                                     nsIContent* aChild,
michael@0:                                     int32_t aIndexInContainer)
michael@0: {
michael@0:   NotifyContentAdded(NODE_FROM(aContainer, aDocument),
michael@0:                      aIndexInContainer, aIndexInContainer + 1);
michael@0: }
michael@0: 
michael@0: void
michael@0: IMEContentObserver::ContentRemoved(nsIDocument* aDocument,
michael@0:                                    nsIContent* aContainer,
michael@0:                                    nsIContent* aChild,
michael@0:                                    int32_t aIndexInContainer,
michael@0:                                    nsIContent* aPreviousSibling)
michael@0: {
michael@0:   bool causedByComposition = IsEditorHandlingEventForComposition();
michael@0:   if (causedByComposition &&
michael@0:       !mUpdatePreference.WantChangesCausedByComposition()) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   uint32_t offset = 0;
michael@0:   nsresult rv =
michael@0:     ContentEventHandler::GetFlatTextOffsetOfRange(mRootContent,
michael@0:                                                   NODE_FROM(aContainer,
michael@0:                                                             aDocument),
michael@0:                                                   aIndexInContainer, &offset,
michael@0:                                                   LINE_BREAK_TYPE_NATIVE);
michael@0:   NS_ENSURE_SUCCESS_VOID(rv);
michael@0: 
michael@0:   // get offset at the end of the deleted node
michael@0:   int32_t nodeLength =
michael@0:     aChild->IsNodeOfType(nsINode::eTEXT) ?
michael@0:       static_cast<int32_t>(aChild->TextLength()) :
michael@0:       std::max(static_cast<int32_t>(aChild->GetChildCount()), 1);
michael@0:   MOZ_ASSERT(nodeLength >= 0, "The node length is out of range");
michael@0:   uint32_t textLength = 0;
michael@0:   rv = ContentEventHandler::GetFlatTextOffsetOfRange(aChild, aChild,
michael@0:                                                      nodeLength, &textLength,
michael@0:                                                      LINE_BREAK_TYPE_NATIVE);
michael@0:   NS_ENSURE_SUCCESS_VOID(rv);
michael@0: 
michael@0:   if (!textLength) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   nsContentUtils::AddScriptRunner(
michael@0:     new TextChangeEvent(this, offset, offset + textLength, offset,
michael@0:                         causedByComposition));
michael@0: }
michael@0: 
michael@0: static nsIContent*
michael@0: GetContentBR(dom::Element* aElement)
michael@0: {
michael@0:   if (!aElement->IsNodeOfType(nsINode::eCONTENT)) {
michael@0:     return nullptr;
michael@0:   }
michael@0:   nsIContent* content = static_cast<nsIContent*>(aElement);
michael@0:   return content->IsHTML(nsGkAtoms::br) ? content : nullptr;
michael@0: }
michael@0: 
michael@0: void
michael@0: IMEContentObserver::AttributeWillChange(nsIDocument* aDocument,
michael@0:                                         dom::Element* aElement,
michael@0:                                         int32_t aNameSpaceID,
michael@0:                                         nsIAtom* aAttribute,
michael@0:                                         int32_t aModType)
michael@0: {
michael@0:   nsIContent *content = GetContentBR(aElement);
michael@0:   mPreAttrChangeLength = content ?
michael@0:     ContentEventHandler::GetNativeTextLength(content) : 0;
michael@0: }
michael@0: 
michael@0: void
michael@0: IMEContentObserver::AttributeChanged(nsIDocument* aDocument,
michael@0:                                      dom::Element* aElement,
michael@0:                                      int32_t aNameSpaceID,
michael@0:                                      nsIAtom* aAttribute,
michael@0:                                      int32_t aModType)
michael@0: {
michael@0:   bool causedByComposition = IsEditorHandlingEventForComposition();
michael@0:   if (causedByComposition &&
michael@0:       !mUpdatePreference.WantChangesCausedByComposition()) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   nsIContent *content = GetContentBR(aElement);
michael@0:   if (!content) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   uint32_t postAttrChangeLength =
michael@0:     ContentEventHandler::GetNativeTextLength(content);
michael@0:   if (postAttrChangeLength == mPreAttrChangeLength) {
michael@0:     return;
michael@0:   }
michael@0:   uint32_t start;
michael@0:   nsresult rv =
michael@0:     ContentEventHandler::GetFlatTextOffsetOfRange(mRootContent, content,
michael@0:                                                   0, &start,
michael@0:                                                   LINE_BREAK_TYPE_NATIVE);
michael@0:   NS_ENSURE_SUCCESS_VOID(rv);
michael@0: 
michael@0:   nsContentUtils::AddScriptRunner(
michael@0:     new TextChangeEvent(this, start, start + mPreAttrChangeLength,
michael@0:                         start + postAttrChangeLength, causedByComposition));
michael@0: }
michael@0: 
michael@0: } // namespace mozilla