C++ Accessible类代码示例

void
TextRange::EmbeddedChildren(nsTArray<Accessible*>* aChildren) const
{
  if (mStartContainer == mEndContainer) {
    int32_t startIdx = mStartContainer->GetChildIndexAtOffset(mStartOffset);
    int32_t endIdx = mStartContainer->GetChildIndexAtOffset(mEndOffset);
    for (int32_t idx = startIdx; idx <= endIdx; idx++) {
      Accessible* child = mStartContainer->GetChildAt(idx);
      if (nsAccUtils::IsEmbeddedObject(child))
        aChildren->AppendElement(child);
    }
    return;
  }

  Accessible* p1 = mStartContainer->GetChildAtOffset(mStartOffset);
  Accessible* p2 = mEndContainer->GetChildAtOffset(mEndOffset);

  uint32_t pos1 = 0, pos2 = 0;
  AutoTArray<Accessible*, 30> parents1, parents2;
  Accessible* container =
    CommonParent(p1, p2, &parents1, &pos1, &parents2, &pos2);

  // Traverse the tree up to the container and collect embedded objects.
  for (uint32_t idx = 0; idx < pos1 - 1; idx++) {
    Accessible* parent = parents1[idx + 1];
    Accessible* child = parents1[idx];
    uint32_t childCount = parent->ChildCount();
    for (uint32_t childIdx = child->IndexInParent(); childIdx < childCount; childIdx++) {
      Accessible* next = parent->GetChildAt(childIdx);
      if (nsAccUtils::IsEmbeddedObject(next))
        aChildren->AppendElement(next);
    }
  }

  // Traverse through direct children in the container.
  int32_t endIdx = parents2[pos2 - 1]->IndexInParent();
  int32_t childIdx = parents1[pos1 - 1]->IndexInParent() + 1;
  for (; childIdx < endIdx; childIdx++) {
    Accessible* next = container->GetChildAt(childIdx);
    if (nsAccUtils::IsEmbeddedObject(next))
      aChildren->AppendElement(next);
  }

  // Traverse down from the container to end point.
  for (int32_t idx = pos2 - 2; idx > 0; idx--) {
    Accessible* parent = parents2[idx];
    Accessible* child = parents2[idx - 1];
    int32_t endIdx = child->IndexInParent();
    for (int32_t childIdx = 0; childIdx < endIdx; childIdx++) {
      Accessible* next = parent->GetChildAt(childIdx);
      if (nsAccUtils::IsEmbeddedObject(next))
        aChildren->AppendElement(next);
    }
  }
}

HyperTextAccessible*
nsAccessiblePivot::SearchForText(Accessible* aAccessible, bool aBackward)
{
  Accessible* root = GetActiveRoot();
  Accessible* accessible = aAccessible;
  while (true) {
    Accessible* child = nullptr;

    while ((child = (aBackward ? accessible->LastChild() :
                                 accessible->FirstChild()))) {
      accessible = child;
      if (child->IsHyperText())
        return child->AsHyperText();
    }

    Accessible* sibling = nullptr;
    Accessible* temp = accessible;
    do {
      if (temp == root)
        break;

      if (temp != aAccessible && temp->IsHyperText())
        return temp->AsHyperText();

      sibling = aBackward ? temp->PrevSibling() : temp->NextSibling();

      if (sibling)
        break;
    } while ((temp = temp->Parent()));

    if (!sibling)
      break;

    accessible = sibling;
    if (accessible->IsHyperText())
      return accessible->AsHyperText();
  }

  return nullptr;
}

nsresult
ARIAGridCellAccessible::GetAttributesInternal(nsIPersistentProperties* aAttributes)
{
  if (IsDefunct())
    return NS_ERROR_FAILURE;
  
  nsresult rv = HyperTextAccessibleWrap::GetAttributesInternal(aAttributes);
  NS_ENSURE_SUCCESS(rv, rv);

  // Expose "table-cell-index" attribute.

  Accessible* thisRow = Parent();
  if (!thisRow || thisRow->Role() != roles::ROW)
    return NS_OK;

  int32_t colIdx = 0, colCount = 0;
  uint32_t childCount = thisRow->ChildCount();
  for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) {
    Accessible* child = thisRow->GetChildAt(childIdx);
    if (child == this)
      colIdx = colCount;

    roles::Role role = child->Role();
    if (role == roles::GRID_CELL || role == roles::ROWHEADER ||
        role == roles::COLUMNHEADER)
      colCount++;
  }

  Accessible* table = thisRow->Parent();
  if (!table)
    return NS_OK;

  roles::Role tableRole = table->Role();
  if (tableRole != roles::TABLE && tableRole != roles::TREE_TABLE)
    return NS_OK;

  int32_t rowIdx = 0;
  childCount = table->ChildCount();
  for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) {
    Accessible* child = table->GetChildAt(childIdx);
    if (child == thisRow)
      break;

    if (child->Role() == roles::ROW)
      rowIdx++;
  }

  int32_t idx = rowIdx * colCount + colIdx;

  nsAutoString stringIdx;
  stringIdx.AppendInt(idx);
  nsAccUtils::SetAccAttr(aAttributes, nsGkAtoms::tableCellIndex,
                         stringIdx);

  return NS_OK;
}

void
EventQueue::ProcessEventQueue()
{
    // Process only currently queued events.
    nsTArray<nsRefPtr<AccEvent> > events;
    events.SwapElements(mEvents);

    uint32_t eventCount = events.Length();
#ifdef A11Y_LOG
    if (eventCount > 0 && logging::IsEnabled(logging::eEvents)) {
        logging::MsgBegin("EVENTS", "events processing");
        logging::Address("document", mDocument);
        logging::MsgEnd();
    }
#endif

    for (uint32_t idx = 0; idx < eventCount; idx++) {
        AccEvent* event = events[idx];
        if (event->mEventRule != AccEvent::eDoNotEmit) {
            Accessible* target = event->GetAccessible();
            if (!target || target->IsDefunct())
                continue;

            // Dispatch the focus event if target is still focused.
            if (event->mEventType == nsIAccessibleEvent::EVENT_FOCUS) {
                FocusMgr()->ProcessFocusEvent(event);
                continue;
            }

            // Dispatch caret moved and text selection change events.
            if (event->mEventType == nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED) {
                AccCaretMoveEvent* caretMoveEvent = downcast_accEvent(event);
                HyperTextAccessible* hyperText = target->AsHyperText();
                if (hyperText &&
                        NS_SUCCEEDED(hyperText->GetCaretOffset(&caretMoveEvent->mCaretOffset))) {

                    nsEventShell::FireEvent(caretMoveEvent);

                    // There's a selection so fire selection change as well.
                    int32_t selectionCount;
                    hyperText->GetSelectionCount(&selectionCount);
                    if (selectionCount)
                        nsEventShell::FireEvent(nsIAccessibleEvent::EVENT_TEXT_SELECTION_CHANGED,
                                                hyperText);
                }
                continue;
            }

            // Fire selected state change events in support to selection events.
            if (event->mEventType == nsIAccessibleEvent::EVENT_SELECTION_ADD) {
                nsEventShell::FireEvent(event->mAccessible, states::SELECTED,
                                        true, event->mIsFromUserInput);

            } else if (event->mEventType == nsIAccessibleEvent::EVENT_SELECTION_REMOVE) {
                nsEventShell::FireEvent(event->mAccessible, states::SELECTED,
                                        false, event->mIsFromUserInput);

            } else if (event->mEventType == nsIAccessibleEvent::EVENT_SELECTION) {
                AccSelChangeEvent* selChangeEvent = downcast_accEvent(event);
                nsEventShell::FireEvent(event->mAccessible, states::SELECTED,
                                        (selChangeEvent->mSelChangeType == AccSelChangeEvent::eSelectionAdd),
                                        event->mIsFromUserInput);

                if (selChangeEvent->mPackedEvent) {
                    nsEventShell::FireEvent(selChangeEvent->mPackedEvent->mAccessible,
                                            states::SELECTED,
                                            (selChangeEvent->mPackedEvent->mSelChangeType == AccSelChangeEvent::eSelectionAdd),
                                            selChangeEvent->mPackedEvent->mIsFromUserInput);
                }
            }

            nsEventShell::FireEvent(event);

            // Fire text change events.
            AccMutationEvent* mutationEvent = downcast_accEvent(event);
            if (mutationEvent) {
                if (mutationEvent->mTextChangeEvent)
                    nsEventShell::FireEvent(mutationEvent->mTextChangeEvent);
            }
        }

        if (event->mEventType == nsIAccessibleEvent::EVENT_HIDE)
            mDocument->ShutdownChildrenInSubtree(event->mAccessible);

        if (!mDocument)
            return;
    }
}

void
NotificationController::WillRefresh(mozilla::TimeStamp aTime)
{
  Telemetry::AutoTimer<Telemetry::A11Y_UPDATE_TIME> updateTimer;

  // If the document accessible that notification collector was created for is
  // now shut down, don't process notifications anymore.
  NS_ASSERTION(mDocument,
               "The document was shut down while refresh observer is attached!");
  if (!mDocument)
    return;

  // Any generic notifications should be queued if we're processing content
  // insertions or generic notifications.
  mObservingState = eRefreshProcessingForUpdate;

  // Initial accessible tree construction.
  if (!mDocument->HasLoadState(DocAccessible::eTreeConstructed)) {
    // If document is not bound to parent at this point then the document is not
    // ready yet (process notifications later).
    if (!mDocument->IsBoundToParent()) {
      mObservingState = eRefreshObserving;
      return;
    }

#ifdef A11Y_LOG
    if (logging::IsEnabled(logging::eTree)) {
      logging::MsgBegin("TREE", "initial tree created");
      logging::Address("document", mDocument);
      logging::MsgEnd();
    }
#endif

    mDocument->DoInitialUpdate();

    NS_ASSERTION(mContentInsertions.Length() == 0,
                 "Pending content insertions while initial accessible tree isn't created!");
  }

  // Process content inserted notifications to update the tree. Process other
  // notifications like DOM events and then flush event queue. If any new
  // notifications are queued during this processing then they will be processed
  // on next refresh. If notification processing queues up new events then they
  // are processed in this refresh. If events processing queues up new events
  // then new events are processed on next refresh.
  // Note: notification processing or event handling may shut down the owning
  // document accessible.

  // Process only currently queued content inserted notifications.
  nsTArray<nsRefPtr<ContentInsertion> > contentInsertions;
  contentInsertions.SwapElements(mContentInsertions);

  uint32_t insertionCount = contentInsertions.Length();
  for (uint32_t idx = 0; idx < insertionCount; idx++) {
    contentInsertions[idx]->Process();
    if (!mDocument)
      return;
  }

  // Process rendered text change notifications.
  mTextHash.EnumerateEntries(TextEnumerator, mDocument);
  mTextHash.Clear();

  // Bind hanging child documents.
  uint32_t hangingDocCnt = mHangingChildDocuments.Length();
  for (uint32_t idx = 0; idx < hangingDocCnt; idx++) {
    DocAccessible* childDoc = mHangingChildDocuments[idx];
    if (childDoc->IsDefunct())
      continue;

    nsIContent* ownerContent = mDocument->DocumentNode()->
      FindContentForSubDocument(childDoc->DocumentNode());
    if (ownerContent) {
      Accessible* outerDocAcc = mDocument->GetAccessible(ownerContent);
      if (outerDocAcc && outerDocAcc->AppendChild(childDoc)) {
        if (mDocument->AppendChildDocument(childDoc))
          continue;

        outerDocAcc->RemoveChild(childDoc);
      }

      // Failed to bind the child document, destroy it.
      childDoc->Shutdown();
    }
  }
  mHangingChildDocuments.Clear();

  // If the document is ready and all its subdocuments are completely loaded
  // then process the document load.
  if (mDocument->HasLoadState(DocAccessible::eReady) &&
      !mDocument->HasLoadState(DocAccessible::eCompletelyLoaded) &&
      hangingDocCnt == 0) {
    uint32_t childDocCnt = mDocument->ChildDocumentCount(), childDocIdx = 0;
    for (; childDocIdx < childDocCnt; childDocIdx++) {
      DocAccessible* childDoc = mDocument->GetChildDocumentAt(childDocIdx);
      if (!childDoc->HasLoadState(DocAccessible::eCompletelyLoaded))
        break;
    }

    if (childDocIdx == childDocCnt) {
//.........这里部分代码省略.........

TableAccessible*
ARIAGridCellAccessible::Table() const
{
    Accessible* table = nsAccUtils::TableFor(Row());
    return table ? table->AsTable() : nullptr;
}

// RootAccessible protected
void
RootAccessible::ProcessDOMEvent(nsIDOMEvent* aDOMEvent)
{
  nsCOMPtr<nsIDOMNSEvent> DOMNSEvent(do_QueryInterface(aDOMEvent));
  nsCOMPtr<nsIDOMEventTarget> DOMEventTarget;
  DOMNSEvent->GetOriginalTarget(getter_AddRefs(DOMEventTarget));
  nsCOMPtr<nsINode> origTargetNode(do_QueryInterface(DOMEventTarget));

  nsAutoString eventType;
  aDOMEvent->GetType(eventType);

  if (eventType.EqualsLiteral("popuphiding")) {
    HandlePopupHidingEvent(origTargetNode);
    return;
  }

  DocAccessible* targetDocument = GetAccService()->
    GetDocAccessible(origTargetNode->OwnerDoc());
  NS_ASSERTION(targetDocument, "No document while accessible is in document?!");

  Accessible* accessible = 
    targetDocument->GetAccessibleOrContainer(origTargetNode);
  if (!accessible)
    return;

  nsINode* targetNode = accessible->GetNode();

#ifdef MOZ_XUL
  XULTreeAccessible* treeAcc = accessible->AsXULTree();
  if (treeAcc) {
    if (eventType.EqualsLiteral("TreeRowCountChanged")) {
      HandleTreeRowCountChangedEvent(aDOMEvent, treeAcc);
      return;
    }

    if (eventType.EqualsLiteral("TreeInvalidated")) {
      HandleTreeInvalidatedEvent(aDOMEvent, treeAcc);
      return;
    }
  }
#endif

  if (eventType.EqualsLiteral("RadioStateChange")) {
    PRUint64 state = accessible->State();

    // radiogroup in prefWindow is exposed as a list,
    // and panebutton is exposed as XULListitem in A11y.
    // XULListitemAccessible::GetStateInternal uses STATE_SELECTED in this case,
    // so we need to check states::SELECTED also.
    bool isEnabled = (state & (states::CHECKED | states::SELECTED)) != 0;

    nsRefPtr<AccEvent> accEvent =
      new AccStateChangeEvent(accessible, states::CHECKED, isEnabled);
    nsEventShell::FireEvent(accEvent);

    if (isEnabled) {
      FocusMgr()->ActiveItemChanged(accessible);
      A11YDEBUG_FOCUS_ACTIVEITEMCHANGE_CAUSE("RadioStateChange", accessible)
    }

    return;
  }

void
EventQueue::ProcessEventQueue()
{
  // Process only currently queued events.
  nsTArray<RefPtr<AccEvent> > events;
  events.SwapElements(mEvents);

  uint32_t eventCount = events.Length();
#ifdef A11Y_LOG
  if (eventCount > 0 && logging::IsEnabled(logging::eEvents)) {
    logging::MsgBegin("EVENTS", "events processing");
    logging::Address("document", mDocument);
    logging::MsgEnd();
  }
#endif

  for (uint32_t idx = 0; idx < eventCount; idx++) {
    AccEvent* event = events[idx];
    if (event->mEventRule != AccEvent::eDoNotEmit) {
      Accessible* target = event->GetAccessible();
      if (!target || target->IsDefunct())
        continue;

      // Dispatch the focus event if target is still focused.
      if (event->mEventType == nsIAccessibleEvent::EVENT_FOCUS) {
        FocusMgr()->ProcessFocusEvent(event);
        continue;
      }

      // Dispatch caret moved and text selection change events.
      if (event->mEventType == nsIAccessibleEvent::EVENT_TEXT_SELECTION_CHANGED) {
        SelectionMgr()->ProcessTextSelChangeEvent(event);
        continue;
      }

      // Fire selected state change events in support to selection events.
      if (event->mEventType == nsIAccessibleEvent::EVENT_SELECTION_ADD) {
        nsEventShell::FireEvent(event->mAccessible, states::SELECTED,
                                true, event->mIsFromUserInput);

      } else if (event->mEventType == nsIAccessibleEvent::EVENT_SELECTION_REMOVE) {
        nsEventShell::FireEvent(event->mAccessible, states::SELECTED,
                                false, event->mIsFromUserInput);

      } else if (event->mEventType == nsIAccessibleEvent::EVENT_SELECTION) {
        AccSelChangeEvent* selChangeEvent = downcast_accEvent(event);
        nsEventShell::FireEvent(event->mAccessible, states::SELECTED,
                                (selChangeEvent->mSelChangeType == AccSelChangeEvent::eSelectionAdd),
                                event->mIsFromUserInput);

        if (selChangeEvent->mPackedEvent) {
          nsEventShell::FireEvent(selChangeEvent->mPackedEvent->mAccessible,
                                  states::SELECTED,
                                  (selChangeEvent->mPackedEvent->mSelChangeType == AccSelChangeEvent::eSelectionAdd),
                                  selChangeEvent->mPackedEvent->mIsFromUserInput);
        }
      }

      nsEventShell::FireEvent(event);
    }

    if (!mDocument)
      return;
  }
}

void
NotificationController::WillRefresh(mozilla::TimeStamp aTime)
{
  Telemetry::AutoTimer<Telemetry::A11Y_UPDATE_TIME> updateTimer;

  // If the document accessible that notification collector was created for is
  // now shut down, don't process notifications anymore.
  NS_ASSERTION(mDocument,
               "The document was shut down while refresh observer is attached!");
  if (!mDocument)
    return;

  if (mObservingState == eRefreshProcessing ||
      mObservingState == eRefreshProcessingForUpdate)
    return;

  // Any generic notifications should be queued if we're processing content
  // insertions or generic notifications.
  mObservingState = eRefreshProcessingForUpdate;

  // Initial accessible tree construction.
  if (!mDocument->HasLoadState(DocAccessible::eTreeConstructed)) {
    // If document is not bound to parent at this point then the document is not
    // ready yet (process notifications later).
    if (!mDocument->IsBoundToParent()) {
      mObservingState = eRefreshObserving;
      return;
    }

#ifdef A11Y_LOG
    if (logging::IsEnabled(logging::eTree)) {
      logging::MsgBegin("TREE", "initial tree created");
      logging::Address("document", mDocument);
      logging::MsgEnd();
    }
#endif

    mDocument->DoInitialUpdate();

    NS_ASSERTION(mContentInsertions.Length() == 0,
                 "Pending content insertions while initial accessible tree isn't created!");
  }

  // Initialize scroll support if needed.
  if (!(mDocument->mDocFlags & DocAccessible::eScrollInitialized))
    mDocument->AddScrollListener();

  // Process content inserted notifications to update the tree. Process other
  // notifications like DOM events and then flush event queue. If any new
  // notifications are queued during this processing then they will be processed
  // on next refresh. If notification processing queues up new events then they
  // are processed in this refresh. If events processing queues up new events
  // then new events are processed on next refresh.
  // Note: notification processing or event handling may shut down the owning
  // document accessible.

  // Process only currently queued content inserted notifications.
  nsTArray<RefPtr<ContentInsertion> > contentInsertions;
  contentInsertions.SwapElements(mContentInsertions);

  uint32_t insertionCount = contentInsertions.Length();
  for (uint32_t idx = 0; idx < insertionCount; idx++) {
    contentInsertions[idx]->Process();
    if (!mDocument)
      return;
  }

  // Process rendered text change notifications.
  for (auto iter = mTextHash.Iter(); !iter.Done(); iter.Next()) {
    nsCOMPtrHashKey<nsIContent>* entry = iter.Get();
    nsIContent* textNode = entry->GetKey();
    Accessible* textAcc = mDocument->GetAccessible(textNode);

    // If the text node is not in tree or doesn't have frame then this case should
    // have been handled already by content removal notifications.
    nsINode* containerNode = textNode->GetParentNode();
    if (!containerNode) {
      NS_ASSERTION(!textAcc,
                   "Text node was removed but accessible is kept alive!");
      continue;
    }

    nsIFrame* textFrame = textNode->GetPrimaryFrame();
    if (!textFrame) {
      NS_ASSERTION(!textAcc,
                   "Text node isn't rendered but accessible is kept alive!");
      continue;
    }

    nsIContent* containerElm = containerNode->IsElement() ?
      containerNode->AsElement() : nullptr;

    nsAutoString text;
    textFrame->GetRenderedText(&text);

    // Remove text accessible if rendered text is empty.
    if (textAcc) {
      if (text.IsEmpty()) {
  #ifdef A11Y_LOG
        if (logging::IsEnabled(logging::eTree | logging::eText)) {
//.........这里部分代码省略.........

EventTree*
EventTree::FindOrInsert(Accessible* aContainer)
{
  if (!mFirst) {
    mFirst.reset(new EventTree(aContainer, true));
    return mFirst.get();
  }

  EventTree* prevNode = nullptr;
  EventTree* node = mFirst.get();
  do {
    MOZ_ASSERT(!node->mContainer->IsApplication(),
               "No event for application accessible is expected here");
    MOZ_ASSERT(!node->mContainer->IsDefunct(), "An event target has to be alive");

    // Case of same target.
    if (node->mContainer == aContainer) {
      return node;
    }

    // Check if the given container is contained by a current node
    Accessible* top = mContainer ? mContainer : aContainer->Document();
    Accessible* parent = aContainer;
    while (parent) {
      // Reached a top, no match for a current event.
      if (parent == top) {
        break;
      }

      // We got a match.
      if (parent->Parent() == node->mContainer) {
        return node->FindOrInsert(aContainer);
      }

      parent = parent->Parent();
      MOZ_ASSERT(parent, "Wrong tree");
    }

    // If the given container contains a current node
    // then
    //   if show or hide of the given node contains a grand parent of the current node
    //   then ignore the current node and its show and hide events
    //   otherwise ignore the current node, but not its show and hide events
    Accessible* curParent = node->mContainer;
    while (curParent && !curParent->IsDoc()) {
      if (curParent->Parent() != aContainer) {
        curParent = curParent->Parent();
        continue;
      }

      // Insert the tail node into the hierarchy between the current node and
      // its parent.
      node->mFireReorder = false;
      UniquePtr<EventTree>& nodeOwnerRef = prevNode ? prevNode->mNext : mFirst;
      UniquePtr<EventTree> newNode(new EventTree(aContainer, mDependentEvents.IsEmpty()));
      newNode->mFirst = Move(nodeOwnerRef);
      nodeOwnerRef = Move(newNode);
      nodeOwnerRef->mNext = Move(node->mNext);

      // Check if a next node is contained by the given node too, and move them
      // under the given node if so.
      prevNode = nodeOwnerRef.get();
      node = nodeOwnerRef->mNext.get();
      UniquePtr<EventTree>* nodeRef = &nodeOwnerRef->mNext;
      EventTree* insNode = nodeOwnerRef->mFirst.get();
      while (node) {
        Accessible* curParent = node->mContainer;
        while (curParent && !curParent->IsDoc()) {
          if (curParent->Parent() != aContainer) {
            curParent = curParent->Parent();
            continue;
          }

          MOZ_ASSERT(!insNode->mNext);

          node->mFireReorder = false;
          insNode->mNext = Move(*nodeRef);
          insNode = insNode->mNext.get();

          prevNode->mNext = Move(node->mNext);
          node = prevNode;
          break;
        }

        prevNode = node;
        nodeRef = &node->mNext;
        node = node->mNext.get();
      }

      return nodeOwnerRef.get();
    }

    prevNode = node;
  } while ((node = node->mNext.get()));

  MOZ_ASSERT(prevNode, "Nowhere to insert");
  MOZ_ASSERT(!prevNode->mNext, "Taken by another node");

  // If 'this' node contains the given container accessible, then
  //   do not emit a reorder event for the container
//.........这里部分代码省略.........

void
FocusManager::ProcessFocusEvent(AccEvent* aEvent)
{
  NS_PRECONDITION(aEvent->GetEventType() == nsIAccessibleEvent::EVENT_FOCUS,
                  "Focus event is expected!");

  // Emit focus event if event target is the active item. Otherwise then check
  // if it's still focused and then update active item and emit focus event.
  Accessible* target = aEvent->GetAccessible();
  if (target != mActiveItem) {

    // Check if still focused. Otherwise we can end up with storing the active
    // item for control that isn't focused anymore.
    DocAccessible* document = aEvent->GetDocAccessible();
    nsINode* focusedNode = FocusedDOMNode();
    if (!focusedNode)
      return;

    Accessible* DOMFocus =
      document->GetAccessibleEvenIfNotInMapOrContainer(focusedNode);
    if (target != DOMFocus)
      return;

    Accessible* activeItem = target->CurrentItem();
    if (activeItem) {
      mActiveItem = activeItem;
      target = activeItem;
    }
  }

  // Fire menu start/end events for ARIA menus.
  if (target->IsARIARole(nsGkAtoms::menuitem)) {
    // The focus was moved into menu.
    Accessible* ARIAMenubar = nullptr;
    for (Accessible* parent = target->Parent(); parent; parent = parent->Parent()) {
      if (parent->IsARIARole(nsGkAtoms::menubar)) {
        ARIAMenubar = parent;
        break;
      }

      // Go up in the parent chain of the menu hierarchy.
      if (!parent->IsARIARole(nsGkAtoms::menuitem) &&
          !parent->IsARIARole(nsGkAtoms::menu)) {
        break;
      }
    }

    if (ARIAMenubar != mActiveARIAMenubar) {
      // Leaving ARIA menu. Fire menu_end event on current menubar.
      if (mActiveARIAMenubar) {
        RefPtr<AccEvent> menuEndEvent =
          new AccEvent(nsIAccessibleEvent::EVENT_MENU_END, mActiveARIAMenubar,
                       aEvent->FromUserInput());
        nsEventShell::FireEvent(menuEndEvent);
      }

      mActiveARIAMenubar = ARIAMenubar;

      // Entering ARIA menu. Fire menu_start event.
      if (mActiveARIAMenubar) {
        RefPtr<AccEvent> menuStartEvent =
          new AccEvent(nsIAccessibleEvent::EVENT_MENU_START,
                       mActiveARIAMenubar, aEvent->FromUserInput());
        nsEventShell::FireEvent(menuStartEvent);
      }
    }
  } else if (mActiveARIAMenubar) {
    // Focus left a menu. Fire menu_end event.
    RefPtr<AccEvent> menuEndEvent =
      new AccEvent(nsIAccessibleEvent::EVENT_MENU_END, mActiveARIAMenubar,
                   aEvent->FromUserInput());
    nsEventShell::FireEvent(menuEndEvent);

    mActiveARIAMenubar = nullptr;
  }

#ifdef A11Y_LOG
  if (logging::IsEnabled(logging::eFocus))
    logging::FocusNotificationTarget("fire focus event", "Target", target);
#endif

  // Reset cached caret value. The cache will be updated upon processing the
  // next caret move event. This ensures that we will return the correct caret
  // offset before the caret move event is handled.
  SelectionMgr()->ResetCaretOffset();

  RefPtr<AccEvent> focusEvent =
    new AccEvent(nsIAccessibleEvent::EVENT_FOCUS, target, aEvent->FromUserInput());
  nsEventShell::FireEvent(focusEvent);

  // Fire scrolling_start event when the document receives the focus if it has
  // an anchor jump. If an accessible within the document receive the focus
  // then null out the anchor jump because it no longer applies.
  DocAccessible* targetDocument = target->Document();
  Accessible* anchorJump = targetDocument->AnchorJump();
  if (anchorJump) {
    if (target == targetDocument) {
      // XXX: bug 625699, note in some cases the node could go away before we
      // we receive focus event, for example if the node is removed from DOM.
      nsEventShell::FireEvent(nsIAccessibleEvent::EVENT_SCROLLING_START,
//.........这里部分代码省略.........

bool
TableAccessible::IsProbablyLayoutTable()
{
  // Implement a heuristic to determine if table is most likely used for layout.

  // XXX do we want to look for rowspan or colspan, especialy that span all but
  // a couple cells  at the beginning or end of a row/col, and especially when
  // they occur at the edge of a table?

  // XXX For now debugging descriptions are always on via SHOW_LAYOUT_HEURISTIC
  // This will allow release trunk builds to be used by testers to refine
  // the algorithm. Integrate it into Logging.
  // Change to |#define SHOW_LAYOUT_HEURISTIC DEBUG| before final release
#ifdef SHOW_LAYOUT_HEURISTIC
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) \
  { \
    mLayoutHeuristic = isLayout ? \
      NS_LITERAL_STRING("layout table: " heuristic) : \
      NS_LITERAL_STRING("data table: " heuristic); \
    return isLayout; \
  }
#else
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) { return isLayout; }
#endif

  Accessible* thisacc = AsAccessible();

  // Need to see all elements while document is being edited.
  if (thisacc->Document()->State() & states::EDITABLE) {
    RETURN_LAYOUT_ANSWER(false, "In editable document");
  }

  // Check to see if an ARIA role overrides the role from native markup,
  // but for which we still expose table semantics (treegrid, for example).
  if (thisacc->HasARIARole()) {
    RETURN_LAYOUT_ANSWER(false, "Has role attribute");
  }

  dom::Element* el = thisacc->Elm();
  if (el->IsMathMLElement(nsGkAtoms::mtable_)) {
    RETURN_LAYOUT_ANSWER(false, "MathML matrix");
  }

  MOZ_ASSERT(el->IsHTMLElement(nsGkAtoms::table),
             "Table should not be built by CSS display:table style");

  // Check if datatable attribute has "0" value.
  if (el->AttrValueIs(kNameSpaceID_None, nsGkAtoms::datatable,
                      NS_LITERAL_STRING("0"), eCaseMatters)) {
    RETURN_LAYOUT_ANSWER(true, "Has datatable = 0 attribute, it's for layout");
  }

  // Check for legitimate data table attributes.
  nsAutoString summary;
  if (el->GetAttr(kNameSpaceID_None, nsGkAtoms::summary, summary) &&
      !summary.IsEmpty()) {
    RETURN_LAYOUT_ANSWER(false, "Has summary -- legitimate table structures");
  }

  // Check for legitimate data table elements.
  Accessible* caption = thisacc->FirstChild();
  if (caption && caption->IsHTMLCaption() && caption->HasChildren()) {
    RETURN_LAYOUT_ANSWER(false, "Not empty caption -- legitimate table structures");
  }

  for (nsIContent* childElm = el->GetFirstChild(); childElm;
       childElm = childElm->GetNextSibling()) {
    if (!childElm->IsHTMLElement())
      continue;

    if (childElm->IsAnyOfHTMLElements(nsGkAtoms::col,
                                      nsGkAtoms::colgroup,
                                      nsGkAtoms::tfoot,
                                      nsGkAtoms::thead)) {
      RETURN_LAYOUT_ANSWER(false,
                           "Has col, colgroup, tfoot or thead -- legitimate table structures");
    }

    if (childElm->IsHTMLElement(nsGkAtoms::tbody)) {
      for (nsIContent* rowElm = childElm->GetFirstChild(); rowElm;
           rowElm = rowElm->GetNextSibling()) {
        if (rowElm->IsHTMLElement(nsGkAtoms::tr)) {
          for (nsIContent* cellElm = rowElm->GetFirstChild(); cellElm;
               cellElm = cellElm->GetNextSibling()) {
            if (cellElm->IsHTMLElement()) {

              if (cellElm->NodeInfo()->Equals(nsGkAtoms::th)) {
                RETURN_LAYOUT_ANSWER(false,
                                     "Has th -- legitimate table structures");
              }

              if (cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::headers) ||
                  cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::scope) ||
                  cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::abbr)) {
                RETURN_LAYOUT_ANSWER(false,
                                     "Has headers, scope, or abbr attribute -- legitimate table structures");
              }

              Accessible* cell = thisacc->Document()->GetAccessible(cellElm);
              if (cell && cell->ChildCount() == 1 &&
//.........这里部分代码省略.........

Accessible*
HTMLTableAccessible::Caption()
{
  Accessible* child = mChildren.SafeElementAt(0, nullptr);
  return child && child->Role() == roles::CAPTION ? child : nullptr;
}

uint32_t AccGroupInfo::TotalItemCount(Accessible* aContainer,
                                      bool* aIsHierarchical) {
  uint32_t itemCount = 0;
  switch (aContainer->Role()) {
    case roles::TABLE:
      if (nsCoreUtils::GetUIntAttr(aContainer->GetContent(),
                                   nsGkAtoms::aria_rowcount,
                                   (int32_t*)&itemCount)) {
        break;
      }

      if (TableAccessible* tableAcc = aContainer->AsTable()) {
        return tableAcc->RowCount();
      }

      break;
    case roles::ROW:
      if (Accessible* table = nsAccUtils::TableFor(aContainer)) {
        if (nsCoreUtils::GetUIntAttr(table->GetContent(),
                                     nsGkAtoms::aria_colcount,
                                     (int32_t*)&itemCount)) {
          break;
        }

        if (TableAccessible* tableAcc = table->AsTable()) {
          return tableAcc->ColCount();
        }
      }

      break;
    case roles::OUTLINE:
    case roles::LIST:
    case roles::MENUBAR:
    case roles::MENUPOPUP:
    case roles::COMBOBOX:
    case roles::GROUPING:
    case roles::TREE_TABLE:
    case roles::COMBOBOX_LIST:
    case roles::LISTBOX:
    case roles::DEFINITION_LIST:
    case roles::EDITCOMBOBOX:
    case roles::RADIO_GROUP:
    case roles::PAGETABLIST: {
      Accessible* childItem = AccGroupInfo::FirstItemOf(aContainer);
      if (!childItem) {
        childItem = aContainer->FirstChild();
        if (childItem && childItem->IsTextLeaf()) {
          // First child can be a text leaf, check its sibling for an item.
          childItem = childItem->NextSibling();
        }
      }

      if (childItem) {
        GroupPos groupPos = childItem->GroupPosition();
        itemCount = groupPos.setSize;
        if (groupPos.level && aIsHierarchical) {
          *aIsHierarchical = true;
        }
      }
      break;
    }
    default:
      break;
  }

  return itemCount;
}

bool
HTMLTableAccessible::IsProbablyLayoutTable()
{
  // Implement a heuristic to determine if table is most likely used for layout
  // XXX do we want to look for rowspan or colspan, especialy that span all but a couple cells
  // at the beginning or end of a row/col, and especially when they occur at the edge of a table?
  // XXX expose this info via object attributes to AT-SPI

  // XXX For now debugging descriptions are always on via SHOW_LAYOUT_HEURISTIC
  // This will allow release trunk builds to be used by testers to refine the algorithm
  // Change to |#define SHOW_LAYOUT_HEURISTIC DEBUG| before final release
#ifdef SHOW_LAYOUT_HEURISTIC
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) \
  { \
    mLayoutHeuristic = isLayout ? \
      NS_LITERAL_STRING("layout table: " heuristic) : \
      NS_LITERAL_STRING("data table: " heuristic); \
    return isLayout; \
  }
#else
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) { return isLayout; }
#endif

  DocAccessible* docAccessible = Document();
  if (docAccessible) {
    uint64_t docState = docAccessible->State();
    if (docState & states::EDITABLE) {  // Need to see all elements while document is being edited
      RETURN_LAYOUT_ANSWER(false, "In editable document");
    }
  }

  // Check to see if an ARIA role overrides the role from native markup,
  // but for which we still expose table semantics (treegrid, for example).
  if (Role() != roles::TABLE)
    RETURN_LAYOUT_ANSWER(false, "Has role attribute");

  if (mContent->HasAttr(kNameSpaceID_None, nsGkAtoms::role)) {
    // Role attribute is present, but overridden roles have already been dealt with.
    // Only landmarks and other roles that don't override the role from native
    // markup are left to deal with here.
    RETURN_LAYOUT_ANSWER(false, "Has role attribute, weak role, and role is table");
  }

  if (mContent->Tag() != nsGkAtoms::table)
    RETURN_LAYOUT_ANSWER(true, "table built by CSS display:table style");

  // Check if datatable attribute has "0" value.
  if (mContent->AttrValueIs(kNameSpaceID_None, nsGkAtoms::datatable,
                            NS_LITERAL_STRING("0"), eCaseMatters)) {
    RETURN_LAYOUT_ANSWER(true, "Has datatable = 0 attribute, it's for layout");
  }

  // Check for legitimate data table attributes.
  nsAutoString summary;
  if (mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::summary, summary) &&
      !summary.IsEmpty())
    RETURN_LAYOUT_ANSWER(false, "Has summary -- legitimate table structures");

  // Check for legitimate data table elements.
  Accessible* caption = FirstChild();
  if (caption && caption->Role() == roles::CAPTION && caption->HasChildren()) 
    RETURN_LAYOUT_ANSWER(false, "Not empty caption -- legitimate table structures");

  for (nsIContent* childElm = mContent->GetFirstChild(); childElm;
       childElm = childElm->GetNextSibling()) {
    if (!childElm->IsHTML())
      continue;

    if (childElm->Tag() == nsGkAtoms::col ||
        childElm->Tag() == nsGkAtoms::colgroup ||
        childElm->Tag() == nsGkAtoms::tfoot ||
        childElm->Tag() == nsGkAtoms::thead) {
      RETURN_LAYOUT_ANSWER(false,
                           "Has col, colgroup, tfoot or thead -- legitimate table structures");
    }

    if (childElm->Tag() == nsGkAtoms::tbody) {
      for (nsIContent* rowElm = childElm->GetFirstChild(); rowElm;
           rowElm = rowElm->GetNextSibling()) {
        if (rowElm->IsHTML() && rowElm->Tag() == nsGkAtoms::tr) {
          for (nsIContent* cellElm = rowElm->GetFirstChild(); cellElm;
               cellElm = cellElm->GetNextSibling()) {
            if (cellElm->IsHTML()) {

              if (cellElm->NodeInfo()->Equals(nsGkAtoms::th)) {
                RETURN_LAYOUT_ANSWER(false,
                                     "Has th -- legitimate table structures");
              }

              if (cellElm->HasAttr(kNameSpaceID_None, nsGkAtoms::headers) ||
                  cellElm->HasAttr(kNameSpaceID_None, nsGkAtoms::scope) ||
                  cellElm->HasAttr(kNameSpaceID_None, nsGkAtoms::abbr)) {
                RETURN_LAYOUT_ANSWER(false,
                                     "Has headers, scope, or abbr attribute -- legitimate table structures");
              }

              Accessible* cell = mDoc->GetAccessible(cellElm);
              if (cell && cell->ChildCount() == 1 &&
                  cell->FirstChild()->IsAbbreviation()) {
                RETURN_LAYOUT_ANSWER(false,
//.........这里部分代码省略.........