C++ GetAccService函数代码示例

nsAccessible*
nsXFormsSelectableAccessible::GetSelectedItem(PRUint32 aIndex)
{
  nsresult rv;
  nsCOMPtr<nsIDOMNode> DOMNode(do_QueryInterface(mContent));
  if (mIsSelect1Element) {
    if (aIndex != 0)
      return nsnull;

    nsCOMPtr<nsIDOMNode> itemDOMNode;
    rv = sXFormsService->GetSelectedItemForSelect1(DOMNode,
                                                   getter_AddRefs(itemDOMNode));
    if (NS_SUCCEEDED(rv) && itemDOMNode) {
      nsCOMPtr<nsINode> itemNode(do_QueryInterface(itemDOMNode));
      return GetAccService()->GetAccessibleInWeakShell(itemNode, mWeakShell);
    }
    return nsnull;
  }

  nsCOMPtr<nsIDOMNodeList> itemNodeList;
  rv = sXFormsService->GetSelectedItemsForSelect(DOMNode,
                                                 getter_AddRefs(itemNodeList));
  if (NS_FAILED(rv) || !itemNodeList)
    return nsnull;

  nsCOMPtr<nsIDOMNode> itemDOMNode;
  itemNodeList->Item(aIndex, getter_AddRefs(itemDOMNode));

  nsCOMPtr<nsINode> itemNode(do_QueryInterface(itemDOMNode));
  return GetAccService()->GetAccessibleInWeakShell(itemNode, mWeakShell);
}

already_AddRefed<nsIArray>
nsXFormsSelectableAccessible::SelectedItems()
{
  nsCOMPtr<nsIMutableArray> selectedItems =
    do_CreateInstance(NS_ARRAY_CONTRACTID);
  if (!selectedItems)
    return nsnull;

  nsresult rv;
  nsCOMPtr<nsIDOMNode> DOMNode(do_QueryInterface(mContent));

  if (mIsSelect1Element) {
    nsCOMPtr<nsIDOMNode> itemDOMNode;
    rv = sXFormsService->GetSelectedItemForSelect1(DOMNode,
                                                   getter_AddRefs(itemDOMNode));
    if (NS_FAILED(rv) || !itemDOMNode)
      return nsnull;

    nsCOMPtr<nsINode> itemNode(do_QueryInterface(itemDOMNode));
    nsIAccessible* item = GetAccService()->GetAccessibleInWeakShell(itemNode,
                                                                    mWeakShell);
    if (item)
      selectedItems->AppendElement(item, PR_FALSE);

    nsIMutableArray* items = nsnull;
    selectedItems.forget(&items);
    return items;
  }

  nsCOMPtr<nsIDOMNodeList> itemNodeList;
  rv = sXFormsService->GetSelectedItemsForSelect(DOMNode,
                                                 getter_AddRefs(itemNodeList));
  if (NS_FAILED(rv) || !itemNodeList)
    return nsnull;

  PRUint32 length = 0;
  itemNodeList->GetLength(&length);
  for (PRUint32 index = 0; index < length; index++) {
    nsCOMPtr<nsIDOMNode> itemDOMNode;
    itemNodeList->Item(index, getter_AddRefs(itemDOMNode));
    if (!itemDOMNode)
      return nsnull;

    nsCOMPtr<nsINode> itemNode(do_QueryInterface(itemDOMNode));
    nsIAccessible* item = GetAccService()->GetAccessibleInWeakShell(itemNode,
                                                                    mWeakShell);
    if (item)
      selectedItems->AppendElement(item, PR_FALSE);
  }

  nsIMutableArray* items = nsnull;
  selectedItems.forget(&items);
  return items;
}

already_AddRefed<nsIAccessibleText>
nsAccUtils::GetTextAccessibleFromSelection(nsISelection *aSelection,
                                           nsIDOMNode **aNode)
{
  // Get accessible from selection's focus DOM point (the DOM point where
  // selection is ended).

  nsCOMPtr<nsIDOMNode> focusNode;
  aSelection->GetFocusNode(getter_AddRefs(focusNode));
  if (!focusNode)
    return nsnull;

  PRInt32 focusOffset = 0;
  aSelection->GetFocusOffset(&focusOffset);

  nsCOMPtr<nsIDOMNode> resultNode =
    nsCoreUtils::GetDOMNodeFromDOMPoint(focusNode, focusOffset);

  // Get text accessible containing the result node.
  while (resultNode) {
    // Make sure to get the correct starting node for selection events inside
    // XBL content trees.
    nsCOMPtr<nsIDOMNode> relevantNode;
    GetAccService()->GetRelevantContentNodeFor(resultNode, 
                                               getter_AddRefs(relevantNode));
    if (relevantNode)
      resultNode.swap(relevantNode);

    nsCOMPtr<nsIContent> content = do_QueryInterface(resultNode);
    if (!content || !content->IsNodeOfType(nsINode::eTEXT)) {
      nsCOMPtr<nsIAccessible> accessible;
      GetAccService()->GetAccessibleFor(resultNode, getter_AddRefs(accessible));
      if (accessible) {
        nsIAccessibleText *textAcc = nsnull;
        CallQueryInterface(accessible, &textAcc);
        if (textAcc) {
          if (aNode)
            NS_ADDREF(*aNode = resultNode);

          return textAcc;
        }
      }
    }

    nsCOMPtr<nsIDOMNode> parentNode;
    resultNode->GetParentNode(getter_AddRefs(parentNode));
    resultNode.swap(parentNode);
  }

  NS_NOTREACHED("No nsIAccessibleText for selection change event!");

  return nsnull;
}

// Interface methods
NS_IMETHODIMP nsXULSelectableAccessible::GetSelectedChildren(nsIArray **aChildren)
{
  *aChildren = nsnull;
  if (!mSelectControl) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIMutableArray> selectedAccessibles =
    do_CreateInstance(NS_ARRAY_CONTRACTID);
  NS_ENSURE_STATE(selectedAccessibles);

  // For XUL multi-select control
  nsCOMPtr<nsIDOMXULMultiSelectControlElement> xulMultiSelect =
    do_QueryInterface(mSelectControl);
  nsCOMPtr<nsIAccessible> selectedAccessible;
  if (xulMultiSelect) {
    PRInt32 length = 0;
    xulMultiSelect->GetSelectedCount(&length);
    for (PRInt32 index = 0; index < length; index++) {
      nsCOMPtr<nsIDOMXULSelectControlItemElement> selectedItem;
      xulMultiSelect->GetSelectedItem(index, getter_AddRefs(selectedItem));
      nsCOMPtr<nsIDOMNode> selectedNode(do_QueryInterface(selectedItem));
      GetAccService()->GetAccessibleInWeakShell(selectedNode, mWeakShell,
                                            getter_AddRefs(selectedAccessible));
      if (selectedAccessible)
        selectedAccessibles->AppendElement(selectedAccessible, PR_FALSE);
    }
  }
  else {  // Single select?
    nsCOMPtr<nsIDOMXULSelectControlItemElement> selectedItem;
    mSelectControl->GetSelectedItem(getter_AddRefs(selectedItem));
    nsCOMPtr<nsIDOMNode> selectedNode(do_QueryInterface(selectedItem));
    if(selectedNode) {
      GetAccService()->GetAccessibleInWeakShell(selectedNode, mWeakShell,
                                            getter_AddRefs(selectedAccessible));
      if (selectedAccessible)
        selectedAccessibles->AppendElement(selectedAccessible, PR_FALSE);
    }
  }

  PRUint32 uLength = 0;
  selectedAccessibles->GetLength(&uLength);
  if (uLength != 0) { // length of nsIArray containing selected options
    NS_ADDREF(*aChildren = selectedAccessibles);
  }

  return NS_OK;
}

void
FocusManager::NotifyOfDOMBlur(nsISupports* aTarget)
{
#ifdef A11Y_LOG
  if (logging::IsEnabled(logging::eFocus))
    logging::FocusNotificationTarget("DOM blur", "Target", aTarget);
#endif

  mActiveItem = nullptr;

  // If DOM document stays focused then fire accessible focus event to process
  // the case when no element within this DOM document will be focused.
  nsCOMPtr<nsINode> targetNode(do_QueryInterface(aTarget));
  if (targetNode && targetNode->OwnerDoc() == FocusedDOMDocument()) {
    nsIDocument* DOMDoc = targetNode->OwnerDoc();
    DocAccessible* document =
      GetAccService()->GetDocAccessible(DOMDoc);
    if (document) {
      // Clear selection listener for previously focused element.
      if (targetNode->IsElement())
        SelectionMgr()->ClearControlSelectionListener();

      document->HandleNotification<FocusManager, nsINode>
        (this, &FocusManager::ProcessDOMFocus, DOMDoc);
    }
  }
}

mozilla::ipc::IPCResult
DocAccessibleParent::RecvSelectionEvent(const uint64_t& aID,
                                        const uint64_t& aWidgetID,
                                        const uint32_t& aType)
{
  if (mShutdown) {
    return IPC_OK();
  }

  ProxyAccessible* target = GetAccessible(aID);
  ProxyAccessible* widget = GetAccessible(aWidgetID);
  if (!target || !widget) {
    NS_ERROR("invalid id in selection event");
    return IPC_OK();
  }

  ProxySelectionEvent(target, widget, aType);
  if (!nsCoreUtils::AccEventObserversExist()) {
    return IPC_OK();
  }
  xpcAccessibleGeneric* xpcTarget = GetXPCAccessible(target);
  xpcAccessibleDocument* xpcDoc = GetAccService()->GetXPCDocument(this);
  RefPtr<xpcAccEvent> event = new xpcAccEvent(aType, xpcTarget, xpcDoc,
                                              nullptr, false);
  nsCoreUtils::DispatchAccEvent(Move(event));

  return IPC_OK();
}

NS_IMETHODIMP
nsXULListboxAccessible::GetCellAt(PRInt32 aRow, PRInt32 aColumn,
                                  nsIAccessible **aAccessibleCell)
{
  NS_ENSURE_ARG_POINTER(aAccessibleCell);
  *aAccessibleCell = nsnull;

  if (IsDefunct())
    return NS_OK;

  nsCOMPtr<nsIDOMXULSelectControlElement> control =
    do_QueryInterface(mContent);

  nsCOMPtr<nsIDOMXULSelectControlItemElement> item;
  control->GetItemAtIndex(aRow, getter_AddRefs(item));
  NS_ENSURE_TRUE(item, NS_ERROR_INVALID_ARG);

  nsCOMPtr<nsIContent> itemContent(do_QueryInterface(item));

  nsAccessible *row =
    GetAccService()->GetAccessibleInWeakShell(itemContent, mWeakShell);
  NS_ENSURE_STATE(row);

  nsresult rv = row->GetChildAt(aColumn, aAccessibleCell);
  NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);

  return NS_OK;
}

void
FocusManager::ProcessDOMFocus(nsINode* aTarget)
{
#ifdef A11Y_LOG
  if (logging::IsEnabled(logging::eFocus))
    logging::FocusNotificationTarget("process DOM focus", "Target", aTarget);
#endif

  DocAccessible* document =
    GetAccService()->GetDocAccessible(aTarget->OwnerDoc());
  if (!document)
    return;

  Accessible* target = document->GetAccessibleEvenIfNotInMapOrContainer(aTarget);
  if (target) {
    // Check if still focused. Otherwise we can end up with storing the active
    // item for control that isn't focused anymore.
    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;
    }

    DispatchFocusEvent(document, target);
  }
}

NS_IMETHODIMP
nsXULComboboxAccessible::GetDescription(nsAString& aDescription)
{
  aDescription.Truncate();

  if (IsDefunct())
    return NS_ERROR_FAILURE;

  // Use description of currently focused option
  nsCOMPtr<nsIDOMXULMenuListElement> menuListElm(do_QueryInterface(mDOMNode));
  if (!menuListElm)
    return NS_ERROR_FAILURE;

  nsCOMPtr<nsIDOMXULSelectControlItemElement> focusedOptionItem;
  menuListElm->GetSelectedItem(getter_AddRefs(focusedOptionItem));
  nsCOMPtr<nsIDOMNode> focusedOptionNode(do_QueryInterface(focusedOptionItem));
  if (focusedOptionNode) {
    nsCOMPtr<nsIAccessible> focusedOption;
    GetAccService()->GetAccessibleInWeakShell(focusedOptionNode, mWeakShell, 
                                              getter_AddRefs(focusedOption));
    NS_ENSURE_TRUE(focusedOption, NS_ERROR_FAILURE);

    return focusedOption->GetDescription(aDescription);
  }

  return NS_OK;
}

void
ProxyAccessible::Shutdown()
{
  MOZ_DIAGNOSTIC_ASSERT(!IsDoc());
  NS_ASSERTION(!mOuterDoc, "Why do we still have a child doc?");
  xpcAccessibleDocument* xpcDoc =
    GetAccService()->GetCachedXPCDocument(Document());
  if (xpcDoc) {
    xpcDoc->NotifyOfShutdown(this);
  }

  // XXX Ideally  this wouldn't be necessary, but it seems OuterDoc accessibles
  // can be destroyed before the doc they own.
  if (!mOuterDoc) {
    uint32_t childCount = mChildren.Length();
    for (uint32_t idx = 0; idx < childCount; idx++)
      mChildren[idx]->Shutdown();
  } else {
    if (mChildren.Length() != 1)
      MOZ_CRASH("outer doc doesn't own adoc!");

    mChildren[0]->AsDoc()->Unbind();
  }

  mChildren.Clear();
  ProxyDestroyed(this);
  mDoc->RemoveAccessible(this);
}

void
nsXFormsAccessible::CacheSelectChildren(nsIDOMNode *aContainerNode)
{
  nsCOMPtr<nsIDOMNode> container(aContainerNode);
  if (!container)
    container = do_QueryInterface(mContent);

  nsCOMPtr<nsIDOMNodeList> children;
  sXFormsService->GetSelectChildrenFor(container, getter_AddRefs(children));

  if (!children)
    return;

  nsCOMPtr<nsIPresShell> presShell(do_QueryReferent(mWeakShell));

  PRUint32 length = 0;
  children->GetLength(&length);

  for (PRUint32 index = 0; index < length; index++) {
    nsCOMPtr<nsIDOMNode> DOMChild;
    children->Item(index, getter_AddRefs(DOMChild));
    if (!DOMChild)
      continue;

    nsCOMPtr<nsIContent> child(do_QueryInterface(DOMChild));
    nsAccessible* accessible =
      GetAccService()->GetOrCreateAccessible(child, presShell, mWeakShell);
    if (!accessible)
      continue;

    AppendChild(accessible);
  }
}

nsAccessible *
AccEvent::GetAccessibleForNode() const
{
  if (!mNode)
    return nsnull;

  nsAccessible *accessible = GetAccService()->GetAccessible(mNode);

#ifdef MOZ_XUL
  // hack for xul tree table. We need a better way for firing delayed event
  // against xul tree table. see bug 386821.
  // There will be problem if some day we want to fire delayed event against
  // the xul tree itself or an unselected treeitem.
  nsCOMPtr<nsIContent> content(do_QueryInterface(mNode));
  if (content && content->NodeInfo()->Equals(nsAccessibilityAtoms::tree,
                                             kNameSpaceID_XUL)) {

    nsCOMPtr<nsIDOMXULMultiSelectControlElement> multiSelect =
      do_QueryInterface(mNode);

    if (multiSelect) {
      PRInt32 treeIndex = -1;
      multiSelect->GetCurrentIndex(&treeIndex);
      if (treeIndex >= 0) {
        nsRefPtr<nsXULTreeAccessible> treeAcc = do_QueryObject(accessible);
        if (treeAcc)
          return treeAcc->GetTreeItemAccessible(treeIndex);
      }
    }
  }
#endif

  return accessible;
}

void
nsHTMLSelectListAccessible::CacheOptSiblings(nsIContent *aParentContent)
{
  nsCOMPtr<nsIPresShell> presShell(do_QueryReferent(mWeakShell));
  PRUint32 numChildren = aParentContent->GetChildCount();
  for (PRUint32 count = 0; count < numChildren; count ++) {
    nsIContent *childContent = aParentContent->GetChildAt(count);
    if (!childContent->IsHTML()) {
      continue;
    }

    nsCOMPtr<nsIAtom> tag = childContent->Tag();
    if (tag == nsAccessibilityAtoms::option ||
        tag == nsAccessibilityAtoms::optgroup) {

      // Get an accessible for option or optgroup and cache it.
      nsRefPtr<nsAccessible> accessible =
        GetAccService()->GetOrCreateAccessible(childContent, presShell,
                                               mWeakShell);
      if (accessible)
        AppendChild(accessible);

      // Deep down into optgroup element.
      if (tag == nsAccessibilityAtoms::optgroup)
        CacheOptSiblings(childContent);
    }
  }
}

PRBool
nsHTMLSelectableAccessible::iterator::GetAccessibleIfSelected(PRInt32 aIndex,
                                                              nsPresContext *aContext, 
                                                              nsIAccessible **aAccessible)
{
  PRBool isSelected = PR_FALSE;

  *aAccessible = nsnull;

  if (mOption) {
    mOption->GetSelected(&isSelected);
    if (isSelected) {
      if (mSelCount == aIndex) {
        nsCOMPtr<nsIContent> optionContent(do_QueryInterface(mOption));
        nsAccessible *accessible =
          GetAccService()->GetAccessibleInWeakShell(optionContent, mWeakShell);
        NS_IF_ADDREF(*aAccessible = accessible);

        return PR_TRUE;
      }
      mSelCount++;
    }
  }

  return PR_FALSE;
}

PRBool
nsAccUtils::IsNodeRelevant(nsIDOMNode *aNode)
{
  nsCOMPtr<nsIDOMNode> relevantNode;
  GetAccService()->GetRelevantContentNodeFor(aNode, getter_AddRefs(relevantNode));
  return aNode == relevantNode;
}