Bug 381888. Caret tracking broken with Windows screen readers [Cairo-related]. When a11y active, follow Gecko caret around with invisible system caret. r=surkov

accessible/public/Makefile.in

@@ -59,7 +59,6 @@ XPIDLSRCS = \
       nsIAccessibleRole.idl \
       nsIAccessibleStates.idl \
       nsPIAccessible.idl \
-      nsIAccessibleCaret.idl \
       nsIAccessibleDocument.idl \
       nsPIAccessibleDocument.idl \
       nsIAccessibleProvider.idl \

accessible/public/nsIAccessibleCaret.idl

@@ -1,77 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
- *
- * ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- * http://www.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is the Mozilla browser.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1999
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either of the GNU General Public License Version 2 or later (the "GPL"),
- * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
-
-#include "nsISupports.idl"
-#include "nsIDOMNode.idl"
-
-[scriptable, uuid(ef372cc1-0fd4-4e71-ac32-64028e680f17)]
-interface nsIAccessibleCaret : nsISupports
-{
-  /**
-   * Listen to selection events on the focused control.
-   * Only one control's selection events are listened to at a time, per top-level window.
-   * This will remove the previous control's selection listener.
-   * It will fail if aFocusedNode is a document node -- document selection must be listened
-   * to via addDocSelectionListener().
-   * @param aFocusedNode   The node for the focused control
-   */
-  void setControlSelectionListener(in nsIDOMNode aFocusedNode);
-
-  /**
-   * Stop listening to selection events for any control.
-   * This does not have to be called explicitly in Shutdown() procedures,
-   * because the implementation of nsIAccessibleCaret will guarantee that.
-   */
-  void clearControlSelectionListener();
-
-  /**
-   * Start listening to selection events for a given document
-   * More than one document's selection events can be listened to
-   * at the same time, by a given nsIAccessibleCaret.
-   * @param aDocument   Document to listen to selection events for.
-   */
-  void addDocSelectionListener(in nsIDOMDocument aDocument);
-
-  /**
-   * Stop listening to selection events for a given document
-   * If the document goes away, this method needs to be called for 
-   * that document by the owner of the nsIAccessibleCaret 
-   * @param aDocument   Document to listen to selection events for.
-   */
-  void removeDocSelectionListener(in nsIDOMDocument aDocument);
-};

accessible/public/nsIAccessibleDocument.idl

@@ -58,7 +58,7 @@ interface nsIDOMWindow;
  *
  * @status UNDER_REVIEW
  */
-[scriptable, uuid(60f8b190-63c4-4919-ac92-a7a8212fc813)]
+[scriptable, uuid(ae5792a3-77ad-40d6-8450-d28d19b66889)]
 interface nsIAccessibleDocument : nsISupports
 {
   /**
@@ -91,11 +91,6 @@ interface nsIAccessibleDocument : nsISupports
    */
   readonly attribute nsIDOMWindow window;
 
-  /*
-   * The accessible for the caret belonging to this window.
-   */
-  readonly attribute nsIAccessible caretAccessible;
-
   /**
    * The namespace for each ID that is handed back.
    */

accessible/src/base/nsAccessNode.cpp

@@ -354,9 +354,9 @@ already_AddRefed<nsRootAccessible> nsAccessNode::GetRootAccessible()
 
   // nsRootAccessible has a special QI
   // that let us get that concrete type directly.
-  nsRootAccessible* foo;
+  nsRootAccessible* rootAccessible;
-  accDoc->QueryInterface(NS_GET_IID(nsRootAccessible), (void**)&foo); // addrefs
+  accDoc->QueryInterface(NS_GET_IID(nsRootAccessible), (void**)&rootAccessible); // addrefs
-  return foo;
+  return rootAccessible;
 }
 
 nsIFrame* nsAccessNode::GetFrame()

accessible/src/base/nsCaretAccessible.cpp

@@ -53,46 +53,47 @@
 #include "nsIViewManager.h"
 #include "nsIWidget.h"
 
-NS_IMPL_ISUPPORTS_INHERITED2(nsCaretAccessible, nsLeafAccessible, nsIAccessibleCaret, nsISelectionListener)
+NS_IMPL_ISUPPORTS1(nsCaretAccessible, nsISelectionListener)
   
-nsCaretAccessible::nsCaretAccessible(nsIDOMNode* aDocumentNode, nsIWeakReference* aShell, nsRootAccessible *aRootAccessible):
+nsCaretAccessible::nsCaretAccessible( nsRootAccessible *aRootAccessible):
-nsLeafAccessible(aDocumentNode, aShell), mCurrentControl(nsnull), mLastNodeWithCaret(nsnull),
 mLastCaretOffset(-1), mRootAccessible(aRootAccessible)
 {
 }
 
-NS_IMETHODIMP nsCaretAccessible::Shutdown()
+nsCaretAccessible::~nsCaretAccessible()
+{
+}
+
+void nsCaretAccessible::Shutdown()
 {
   // The caret accessible isn't shut down until the nsRootAccessible owning it is shut down
   // Each nsDocAccessible, including the nsRootAccessible, is responsible for clearing the
-  // doc selection listeners they registeed in this nsCaretAccessible
+  // doc selection listeners they registered in this nsCaretAccessible
-  ClearControlSelectionListener(); // Clear the selection listener for the currently focused control
-  mLastNodeWithCaret = nsnull;
-  mLastUsedSelection = nsnull;
 
-  return nsLeafAccessible::Shutdown();
+  ClearControlSelectionListener(); // Clear the selection listener for the currently focused control
+  mLastTextAccessible = nsnull;
+  mLastUsedSelection = nsnull;
 }
 
-NS_IMETHODIMP nsCaretAccessible::ClearControlSelectionListener()
+nsresult nsCaretAccessible::ClearControlSelectionListener()
 {
   nsCOMPtr<nsISelectionPrivate> selPrivate(do_QueryReferent(mCurrentControlSelection));
-  if (selPrivate) {
+  NS_ENSURE_TRUE(selPrivate, NS_ERROR_FAILURE);
-    mCurrentControlSelection = nsnull;
+
-    mCurrentControl = nsnull;
+  mCurrentControlSelection = nsnull;
-    return selPrivate->RemoveSelectionListener(this);
+  mCurrentControl = nsnull;
-  }
+  return selPrivate->RemoveSelectionListener(this);
-  return NS_OK;
 }
 
-NS_IMETHODIMP nsCaretAccessible::SetControlSelectionListener(nsIDOMNode *aCurrentNode)
+nsresult nsCaretAccessible::SetControlSelectionListener(nsIDOMNode *aCurrentNode)
 {
   mCurrentControl = aCurrentNode;
-  mLastNodeWithCaret = nsnull;
+  mLastTextAccessible = nsnull;
 
   // When focus moves such that the caret is part of a new frame selection
   // this removes the old selection listener and attaches a new one for the current focus
   nsCOMPtr<nsIPresShell> presShell = 
-    nsRootAccessible::GetPresShellFor(aCurrentNode);
+    mRootAccessible->GetPresShellFor(aCurrentNode);
   if (!presShell)
     return NS_ERROR_FAILURE;
 
@@ -127,7 +128,7 @@ NS_IMETHODIMP nsCaretAccessible::SetControlSelectionListener(nsIDOMNode *aCurren
   return selPrivate->AddSelectionListener(this);
 }
 
-NS_IMETHODIMP nsCaretAccessible::AddDocSelectionListener(nsIDOMDocument *aDoc)
+nsresult nsCaretAccessible::AddDocSelectionListener(nsIDOMDocument *aDoc)
 {
   nsCOMPtr<nsIDocument> doc = do_QueryInterface(aDoc);
   NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
@@ -142,7 +143,7 @@ NS_IMETHODIMP nsCaretAccessible::AddDocSelectionListener(nsIDOMDocument *aDoc)
   return selPrivate->AddSelectionListener(this);
 }
 
-NS_IMETHODIMP nsCaretAccessible::RemoveDocSelectionListener(nsIDOMDocument *aDoc)
+nsresult nsCaretAccessible::RemoveDocSelectionListener(nsIDOMDocument *aDoc)
 {
   nsCOMPtr<nsIDocument> doc = do_QueryInterface(aDoc);
   NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
@@ -168,13 +169,13 @@ NS_IMETHODIMP nsCaretAccessible::NotifySelectionChanged(nsIDOMDocument *aDoc, ns
 
   // Get first nnsIAccessibleText in parent chain and fire caret-move, selection-change event for it
   nsCOMPtr<nsIAccessible> accessible;
-  nsIAccessibilityService *accService = GetAccService();
+  nsIAccessibilityService *accService = mRootAccessible->GetAccService();
   NS_ENSURE_TRUE(accService, NS_ERROR_FAILURE);
   // Get accessible from selection's focus node or its parent
   nsCOMPtr<nsIDOMNode> focusNode;
   aSel->GetFocusNode(getter_AddRefs(focusNode));
   if (!focusNode) {
-    mLastNodeWithCaret = nsnull;
+    mLastTextAccessible = nsnull;
     return NS_OK; // No selection
   }
   nsCOMPtr<nsIDOMNode> nodeWithCaret = focusNode;
@@ -203,9 +204,10 @@ NS_IMETHODIMP nsCaretAccessible::NotifySelectionChanged(nsIDOMDocument *aDoc, ns
   NS_ENSURE_TRUE(textAcc, NS_ERROR_FAILURE);
 
   PRInt32 caretOffset;
-  textAcc->GetCaretOffset(&caretOffset);
+  nsresult rv = textAcc->GetCaretOffset(&caretOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
 
-  if (nodeWithCaret == mLastNodeWithCaret && caretOffset == mLastCaretOffset) {
+  if (textAcc == mLastTextAccessible && caretOffset == mLastCaretOffset) {
     PRInt32 selectionCount;
     textAcc->GetSelectionCount(&selectionCount);   // Don't swallow similar events when selecting text
     if (!selectionCount) {
@@ -213,122 +215,76 @@ NS_IMETHODIMP nsCaretAccessible::NotifySelectionChanged(nsIDOMDocument *aDoc, ns
     }
   }
   mLastCaretOffset = caretOffset;
-  mLastNodeWithCaret = nodeWithCaret;
+  mLastTextAccessible = textAcc;
 
   return mRootAccessible->FireDelayedToolkitEvent(nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED,
                                                   focusNode, nsnull, PR_FALSE);
 }
 
-already_AddRefed<nsICaret>
+nsRect
-nsCaretAccessible::GetLastCaret(nsRect *aRect, PRBool *aIsVisible)
+nsCaretAccessible::GetCaretRect(nsIWidget **aOutWidget)
 {
-  *aIsVisible = PR_FALSE;
+  nsRect caretRect;
-  if (!mLastNodeWithCaret) {
+  NS_ENSURE_TRUE(aOutWidget, caretRect);
-    return nsnull;
+  *aOutWidget = nsnull;
+
+  if (!mLastTextAccessible) {
+    return caretRect;    // Return empty rect
   }
 
-  nsCOMPtr<nsIPresShell> presShell = GetPresShellFor(mLastNodeWithCaret);
+  nsCOMPtr<nsIAccessNode> lastAccessNode(do_QueryInterface(mLastTextAccessible));
-  NS_ENSURE_TRUE(presShell, nsnull);
+  NS_ENSURE_TRUE(lastAccessNode, caretRect);
+
+  nsCOMPtr<nsIDOMNode> lastNodeWithCaret;
+  lastAccessNode->GetDOMNode(getter_AddRefs(lastNodeWithCaret));
+  NS_ENSURE_TRUE(lastNodeWithCaret, caretRect);
+
+  nsCOMPtr<nsIPresShell> presShell = mRootAccessible->GetPresShellFor(lastNodeWithCaret);
+  NS_ENSURE_TRUE(presShell, caretRect);
 
   nsICaret *caret;
   presShell->GetCaret(&caret);
-  NS_ENSURE_TRUE(caret, nsnull);
+  NS_ENSURE_TRUE(caret, caretRect);
 
-  nsRect caretRect;
   PRBool isCollapsed;
+  nsIView *view;
   nsCOMPtr<nsISelection> caretSelection(do_QueryReferent(mLastUsedSelection));
-  caret->GetCaretCoordinates(nsICaret::eTopLevelWindowCoordinates, caretSelection,
+  caret->GetCaretCoordinates(nsICaret::eRenderingViewCoordinates, caretSelection,
-                             aRect, &isCollapsed, nsnull);
+                             &caretRect, &isCollapsed, &view);
-  if (!aRect->IsEmpty()) {
+  if (!view || caretRect.IsEmpty()) {
-    caret->GetCaretVisible(aIsVisible);
+    return nsRect(); // Return empty rect
   }
-  return caret;
-}
 
-/** Return the caret's bounds */
-NS_IMETHODIMP nsCaretAccessible::GetBounds(PRInt32 *aX, PRInt32 *aY, PRInt32 *aWidth, PRInt32 *aHeight)
-{
-  *aX = *aY = *aWidth = *aHeight = 0;
-  nsRect caretRect;
   PRBool isVisible;
-  nsCOMPtr<nsICaret> caret = GetLastCaret(&caretRect, &isVisible);
+  caret->GetCaretVisible(&isVisible);
-  if (!caret || caretRect.IsEmpty()) {
+  if (!isVisible) {
-    return NS_ERROR_FAILURE;
+    return nsRect();  // Return empty rect
   }
-
+  nsPoint offsetFromWidget;
-  nsCOMPtr<nsIPresShell> presShell = GetPresShellFor(mLastNodeWithCaret);
+  *aOutWidget = view->GetNearestWidget(&offsetFromWidget);
-  NS_ENSURE_TRUE(presShell, NS_ERROR_FAILURE);
+  NS_ENSURE_TRUE(*aOutWidget, nsRect());
 
   nsPresContext *presContext = presShell->GetPresContext();
-  NS_ENSURE_TRUE(presContext, NS_ERROR_FAILURE);
+  NS_ENSURE_TRUE(presContext, nsRect());
 
-  nsIViewManager* viewManager = presShell->GetViewManager();
+  caretRect.x = presContext->AppUnitsToDevPixels(caretRect.x + offsetFromWidget.x);
-  NS_ENSURE_TRUE(viewManager, NS_ERROR_FAILURE);
+  caretRect.y = presContext->AppUnitsToDevPixels(caretRect.y + offsetFromWidget.y);
-
+  caretRect.width = presContext->AppUnitsToDevPixels(caretRect.width);
-  nsIView *view = nsnull;
-  viewManager->GetRootView(view);
-  NS_ENSURE_TRUE(view, NS_ERROR_FAILURE);
-
-  nsIWidget* widget = view->GetWidget();
-  NS_ENSURE_TRUE(widget, NS_ERROR_FAILURE);
-
-  caretRect.x      = presContext->AppUnitsToDevPixels(caretRect.x);
-  caretRect.y      = presContext->AppUnitsToDevPixels(caretRect.y);
-  caretRect.width  = presContext->AppUnitsToDevPixels(caretRect.width);
   caretRect.height = presContext->AppUnitsToDevPixels(caretRect.height);
 
-  nsRect caretScreenRect;
+  (*aOutWidget)->WidgetToScreen(caretRect, caretRect);
-  widget->WidgetToScreen(caretRect, caretScreenRect);
 
-  *aX = caretScreenRect.x;
+  // Correct for character size, so that caret always matches the size of the character
-  *aY = caretScreenRect.y;
+  // This is important for font size transitions, and is necessary because the Gecko caret uses the
-  *aWidth = caretScreenRect.width;
+  // previous character's size as the user moves forward in the text by character.
-  *aHeight = caretScreenRect.height;
+  PRInt32 charX, charY, charWidth, charHeight;
-
+  if (NS_SUCCEEDED(mLastTextAccessible->GetCharacterExtents(mLastCaretOffset, &charX, &charY,
-  return NS_OK;
+                                                            &charWidth, &charHeight,
-}
+                                                            nsIAccessibleCoordinateType::COORDTYPE_SCREEN_RELATIVE))) {
-
+    caretRect.height -= charY - caretRect.y;
-NS_IMETHODIMP nsCaretAccessible::GetRole(PRUint32 *_retval)
+    caretRect.y = charY;
-{
-  *_retval = nsIAccessibleRole::ROLE_CARET;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsCaretAccessible::GetState(PRUint32 *aState, PRUint32 *aExtraState)
-{
-  *aState = 0;
-  if (aExtraState)
-    *aExtraState = 0;
-
-  NS_ENSURE_TRUE(mLastNodeWithCaret, NS_ERROR_FAILURE);
-
-  nsCOMPtr<nsIPresShell> presShell = GetPresShellFor(mLastNodeWithCaret);
-  NS_ENSURE_TRUE(presShell, NS_ERROR_FAILURE);
-
-  nsRect caretRect;
-  PRBool isVisible;
-  GetLastCaret(&caretRect, &isVisible);
-  if (!isVisible) {
-    *aState = nsIAccessibleStates::STATE_INVISIBLE;
   }
-  return NS_OK;
+
-}
+  return caretRect;
-
-NS_IMETHODIMP nsCaretAccessible::GetParent(nsIAccessible **aParent)
-{   
-  NS_ADDREF(*aParent = mRootAccessible);
-  return NS_OK;
-}
-NS_IMETHODIMP nsCaretAccessible::GetPreviousSibling(nsIAccessible **_retval)
-{ 
-  *_retval = nsnull;
-  return NS_OK;
-}
-
-NS_IMETHODIMP nsCaretAccessible::GetNextSibling(nsIAccessible **_retval)
-{
-  *_retval = nsnull;
-  return NS_OK;
 }
 

accessible/src/base/nsCaretAccessible.h

@@ -38,14 +38,15 @@
 #ifndef __nsCaretAccessible_h__
 #define __nsCaretAccessible_h__
 
-#include "nsBaseWidgetAccessible.h"
 #include "nsIWeakReference.h"
+#include "nsIAccessibleText.h"
+#include "nsICaret.h"
 #include "nsIDOMNode.h"
-#include "nsIAccessibleCaret.h"
 #include "nsISelectionListener.h"
 #include "nsRect.h"
 
 class nsRootAccessible;
+class nsIView;
 
 /*
  * This special accessibility class is for the caret, which is really the currently focused selection.
@@ -54,10 +55,11 @@ class nsRootAccessible;
  *
  * The important selections are the one owned by each document, and the one in the currently focused control.
  *
- * The caret accesible does not exist within the normal accessible tree; it lives in a different world.
+ * The caret accessible is no longer an accessible object in its own right.
- * In MSAA, it is retrieved with via the WM_GETOBJECT message with lParam = OBJID_CARET, 
+ * On Windows it is used to move an invisible system caret that shadows the Mozilla caret. Windows will
+ * also automatically map this to the MSAA caret accessible object (via OBJID_CARET).
  * (as opposed to the root accessible tree for a window which is retrieved with OBJID_CLIENT)
- * In ATK, the caret accessible is never exposed as an accessible object, but is used to fire
+ * For ATK and Iaccessible2, the caret accessible is used to fire
  * caret move and selection change events.
  *
  * The caret accessible is owned by the nsRootAccessible for the top level window that it's in.
@@ -68,36 +70,52 @@ class nsRootAccessible;
  * selection listener when the doc goes away via removeDocSelectionListener().
  */
 
-class nsCaretAccessible : public nsLeafAccessible, public nsIAccessibleCaret, public nsISelectionListener
+class nsCaretAccessible : public nsISelectionListener
 {
 public:
-  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_ISUPPORTS
 
-  nsCaretAccessible(nsIDOMNode* aDocumentNode, nsIWeakReference* aShell, nsRootAccessible *aRootAccessible);
+  nsCaretAccessible(nsRootAccessible *aRootAccessible);
-
+  virtual ~nsCaretAccessible();
-  /* ----- nsIAccessible ----- */
+  void Shutdown();
-  NS_IMETHOD GetParent(nsIAccessible **_retval);
-  NS_IMETHOD GetRole(PRUint32 *_retval);
-  NS_IMETHOD GetState(PRUint32 *aState, PRUint32 *aExtraState);
-  NS_IMETHOD GetBounds(PRInt32 *x, PRInt32 *y, PRInt32 *width, PRInt32 *height);
-  NS_IMETHOD GetNextSibling(nsIAccessible **_retval);
-  NS_IMETHOD GetPreviousSibling(nsIAccessible **_retval);
-
-  /* ----- nsIAccessibleCaret ------ */
-  NS_DECL_NSIACCESSIBLECARET
 
   /* ----- nsISelectionListener ---- */
   NS_DECL_NSISELECTIONLISTENER
 
-  /* ----- nsIAccessNode ----- */
+  /**
-  NS_IMETHOD Init()
+   * Listen to selection events on the focused control.
-  {
+   * Only one control's selection events are listened to at a time, per top-level window.
-#ifdef DEBUG_A11Y
+   * This will remove the previous control's selection listener.
-    mIsInitialized = PR_TRUE;
+   * It will fail if aFocusedNode is a document node -- document selection must be listened
-#endif
+   * to via AddDocSelectionListener().
-    return NS_OK;
+   * @param aFocusedNode   The node for the focused control
-  }
+   */
-  NS_IMETHOD Shutdown();
+  nsresult SetControlSelectionListener(nsIDOMNode *aCurrentNode);
+
+  /**
+   * Stop listening to selection events for any control.
+   * This does not have to be called explicitly in Shutdown() procedures,
+   * because the nsCaretAccessible implementation guarantees that.
+   */
+  nsresult ClearControlSelectionListener();
+
+  /**
+   * Start listening to selection events for a given document
+   * More than one document's selection events can be listened to
+   * at the same time, by a given nsCaretAccessible
+   * @param aDocument   Document to listen to selection events for.
+   */
+  nsresult AddDocSelectionListener(nsIDOMDocument *aDoc);
+
+  /**
+   * Stop listening to selection events for a given document
+   * If the document goes away, this method needs to be called for 
+   * that document by the owner of the caret
+   * @param aDocument   Document to listen to selection events for.
+   */
+  nsresult RemoveDocSelectionListener(nsIDOMDocument *aDoc);
+
+  nsRect GetCaretRect(nsIWidget **aOutWidget);
 
 private:
   // The currently focused control -- never a document.
@@ -111,9 +129,8 @@ private:
   // If it was on a control, then mLastUsedSelection == mCurrentControlSelection
   // Otherwise, it's for a document where the selection changed
   nsCOMPtr<nsIWeakReference> mLastUsedSelection; // Weak ref to nsISelection
-  nsCOMPtr<nsIDOMNode> mLastNodeWithCaret;
+  nsCOMPtr<nsIAccessibleText> mLastTextAccessible;
   PRInt32 mLastCaretOffset;
-  already_AddRefed<nsICaret> GetLastCaret(nsRect *aRect, PRBool *aIsVisible);
 
   nsRootAccessible *mRootAccessible;
 };

accessible/src/base/nsDocAccessible.cpp

@@ -168,10 +168,10 @@ NS_IMETHODIMP nsDocAccessible::GetRole(PRUint32 *aRole)
   if (docShellTreeItem) {
     nsCOMPtr<nsIDocShellTreeItem> sameTypeRoot;
     docShellTreeItem->GetSameTypeRootTreeItem(getter_AddRefs(sameTypeRoot));
+    PRInt32 itemType;
+    docShellTreeItem->GetItemType(&itemType);
     if (sameTypeRoot == docShellTreeItem) {
       // Root of content or chrome tree
-      PRInt32 itemType;
-      docShellTreeItem->GetItemType(&itemType);
       if (itemType == nsIDocShellTreeItem::typeChrome) {
         *aRole = nsIAccessibleRole::ROLE_CHROME_WINDOW;
       }
@@ -188,6 +188,9 @@ NS_IMETHODIMP nsDocAccessible::GetRole(PRUint32 *aRole)
 #endif
       }
     }
+    else if (itemType == nsIDocShellTreeItem::typeContent) {
+      *aRole = nsIAccessibleRole::ROLE_DOCUMENT;
+    }
   }
 
   return NS_OK;
@@ -349,13 +352,6 @@ NS_IMETHODIMP nsDocAccessible::GetNameSpaceURIForID(PRInt16 aNameSpaceID, nsAStr
   return NS_ERROR_FAILURE;
 }
 
-NS_IMETHODIMP nsDocAccessible::GetCaretAccessible(nsIAccessible **aCaretAccessible)
-{
-  // We only have a caret accessible on the root document
-  *aCaretAccessible = nsnull;
-  return NS_OK;
-}
-
 NS_IMETHODIMP nsDocAccessible::GetWindowHandle(void **aWindow)
 {
   *aWindow = mWnd;
@@ -666,13 +662,13 @@ nsresult nsDocAccessible::AddEventListeners()
   nsCOMPtr<nsIDocShellTreeItem> rootTreeItem;
   docShellTreeItem->GetRootTreeItem(getter_AddRefs(rootTreeItem));
   if (rootTreeItem) {
-    nsCOMPtr<nsIAccessibleDocument> rootAccDoc = GetDocAccessibleFor(rootTreeItem, PR_TRUE);
+    GetDocAccessibleFor(rootTreeItem, PR_TRUE); // Ensure root accessible is created;
-    nsCOMPtr<nsIAccessible> caretAccessible;
+    nsRefPtr<nsRootAccessible> rootAccessible = GetRootAccessible();
-    rootAccDoc->GetCaretAccessible(getter_AddRefs(caretAccessible));
+    NS_ENSURE_TRUE(rootAccessible, NS_ERROR_FAILURE);
-    nsCOMPtr<nsIAccessibleCaret> caretAccessibleIface(do_QueryInterface(caretAccessible));
+    nsRefPtr<nsCaretAccessible> caretAccessible = rootAccessible->GetCaretAccessible();
-    if (caretAccessibleIface) {
+    if (caretAccessible) {
       nsCOMPtr<nsIDOMDocument> domDoc = do_QueryInterface(mDocument);
-      caretAccessibleIface->AddDocSelectionListener(domDoc);
+      caretAccessible->AddDocSelectionListener(domDoc);
     }
   }
 
@@ -697,12 +693,10 @@ nsresult nsDocAccessible::RemoveEventListeners()
 
   nsRefPtr<nsRootAccessible> rootAccessible(GetRootAccessible());
   if (rootAccessible) {
-    nsCOMPtr<nsIAccessible> caretAccessible;
+    nsRefPtr<nsCaretAccessible> caretAccessible = rootAccessible->GetCaretAccessible();
-    rootAccessible->GetCaretAccessible(getter_AddRefs(caretAccessible));
+    if (caretAccessible) {
-    nsCOMPtr<nsIAccessibleCaret> caretAccessibleIface(do_QueryInterface(caretAccessible));
-    if (caretAccessibleIface) {
       nsCOMPtr<nsIDOMDocument> domDoc = do_QueryInterface(mDocument);
-      caretAccessibleIface->RemoveDocSelectionListener(domDoc);
+      caretAccessible->RemoveDocSelectionListener(domDoc);
     }
   }
 

accessible/src/base/nsRootAccessible.cpp

@@ -38,9 +38,7 @@
 // NOTE: alphabetically ordered
 #include "nsAccessibilityService.h"
 #include "nsAccessibleEventData.h"
-#include "nsCaretAccessible.h"
 #include "nsHTMLSelectAccessible.h"
-#include "nsIAccessibleCaret.h"
 #include "nsIBaseWindow.h"
 #include "nsICaret.h"
 #include "nsIDocShell.h"
@@ -321,11 +319,7 @@ nsresult nsRootAccessible::AddEventListeners()
   }
 
   if (!mCaretAccessible) {
-    mCaretAccessible = new nsCaretAccessible(mDOMNode, mWeakShell, this);
+    mCaretAccessible = new nsCaretAccessible(this);
-    nsCOMPtr<nsPIAccessNode> accessNode(do_QueryInterface(mCaretAccessible));
-    if (accessNode && NS_FAILED(accessNode->Init())) {
-      mCaretAccessible = nsnull;
-    }
   }
 
   // Fire accessible focus event for pre-existing focus, but wait until all internal
@@ -356,23 +350,21 @@ nsresult nsRootAccessible::RemoveEventListeners()
     target->RemoveEventListener(NS_LITERAL_STRING("pagehide"), this, PR_TRUE);
   }
 
-  nsCOMPtr<nsPIAccessNode> caretAccessNode(do_QueryInterface(mCaretAccessible));
+  if (mCaretAccessible) {
-  if (caretAccessNode) {
+    mCaretAccessible->Shutdown();
-    caretAccessNode->Shutdown();
     mCaretAccessible = nsnull;
   }
 
   return nsDocAccessible::RemoveEventListeners();
 }
 
-NS_IMETHODIMP nsRootAccessible::GetCaretAccessible(nsIAccessible **aCaretAccessible)
+already_AddRefed<nsCaretAccessible>
+nsRootAccessible::GetCaretAccessible()
 {
-  *aCaretAccessible = nsnull;
   if (mCaretAccessible) {
-    CallQueryInterface(mCaretAccessible, aCaretAccessible);
+    NS_ADDREF(NS_STATIC_CAST(nsISupports*, mCaretAccessible));
   }
-
+  return mCaretAccessible;
-  return NS_OK;
 }
 
 void nsRootAccessible::TryFireEarlyLoadEvent(nsIDOMNode *aDocNode)

accessible/src/base/nsRootAccessible.h

@@ -41,11 +41,11 @@
 #include "nsDocAccessibleWrap.h"
 #include "nsHashtable.h"
 #include "nsIAccessibleDocument.h"
+#include "nsCaretAccessible.h"
 #include "nsIDocument.h"
 #include "nsIDOMFocusListener.h"
 #include "nsIDOMFormListener.h"
 #include "nsIDOMXULListener.h"
-#include "nsIAccessibleCaret.h"
 #include "nsITimer.h"
 
 #define NS_ROOTACCESSIBLE_IMPL_CID                      \
@@ -81,9 +81,6 @@ class nsRootAccessible : public nsDocAccessibleWrap,
     // ----- nsIDOMEventListener --------------------------
     NS_IMETHOD HandleEvent(nsIDOMEvent* aEvent);
 
-    // nsIAccessibleDocument
-    NS_IMETHOD GetCaretAccessible(nsIAccessible **aAccessibleCaret);
-
     // nsIAccessNode
     NS_IMETHOD Init();
     NS_IMETHOD Shutdown();
@@ -106,6 +103,8 @@ class nsRootAccessible : public nsDocAccessibleWrap,
                                     nsIDOMEvent *aFocusEvent,
                                     PRBool aForceEvent = PR_FALSE);
 
+    already_AddRefed<nsCaretAccessible> GetCaretAccessible();
+
   private:
     nsCOMPtr<nsITimer> mFireFocusTimer;
     static void FireFocusCallback(nsITimer *aTimer, void *aClosure);
@@ -124,7 +123,7 @@ class nsRootAccessible : public nsDocAccessibleWrap,
 #endif
     already_AddRefed<nsIDocShellTreeItem>
            GetContentDocShell(nsIDocShellTreeItem *aStart);
-    nsCOMPtr<nsIAccessibleCaret> mCaretAccessible;
+    nsRefPtr<nsCaretAccessible> mCaretAccessible;
     PRPackedBool mIsInDHTMLMenu;
 };
 

accessible/src/html/nsHyperTextAccessible.cpp

@@ -879,7 +879,8 @@ NS_IMETHODIMP nsHyperTextAccessible::GetRangeExtents(PRInt32 aStartOffset, PRInt
 {
   nsIntRect boundsRect;
   nsIFrame *endFrameUnused;
-  if (!GetPosAndText(aStartOffset, aEndOffset, nsnull, &endFrameUnused, &boundsRect)) {
+  if (!GetPosAndText(aStartOffset, aEndOffset, nsnull, &endFrameUnused, &boundsRect) ||
+      boundsRect.IsEmpty()) {
     return NS_ERROR_FAILURE;
   }
 

accessible/src/msaa/nsAccessNodeWrap.cpp

@@ -531,6 +531,7 @@ void nsAccessNodeWrap::InitAccessibility()
 void nsAccessNodeWrap::ShutdownAccessibility()
 {
   NS_IF_RELEASE(gTextEvent);
+  ::DestroyCaret();
 
   if (!gIsAccessibilityActive) {
     return;

accessible/src/msaa/nsAccessibleWrap.cpp

@@ -1511,15 +1511,9 @@ nsAccessibleWrap::FireAccessibleEvent(nsIAccessibleEvent *aEvent)
   nsCOMPtr<nsIAccessNode> accessNode(do_QueryInterface(accessible));
   NS_ENSURE_STATE(accessNode);
 
-  if (eventType == nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED) {
+  if (eventType == nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED ||
-    // Fire additional old-style MSAA caret events as well as the IA2 event
+      eventType == nsIAccessibleEvent::EVENT_FOCUS) {
-    nsRefPtr<nsRootAccessible> rootAccessible = GetRootAccessible();
+    UpdateSystemCaret();
-    if (rootAccessible) {
-      nsCOMPtr<nsIAccessible> caretAccessible;
-      void* handle = nsnull;
-      rootAccessible->GetWindowHandle(&handle);
-      NotifyWinEvent(EVENT_OBJECT_LOCATIONCHANGE, (HWND)handle, OBJID_CARET, CHILDID_SELF);
-    }
   }
  
   PRInt32 childID = GetChildIDFor(accessible); // get the id for the accessible
@@ -1664,3 +1658,38 @@ void nsAccessibleWrap::GetXPAccessibleFor(const VARIANT& aVarChild, nsIAccessibl
   NS_IF_ADDREF(*aXPAccessible);
 }
 
+void nsAccessibleWrap::UpdateSystemCaret()
+{
+  // Move the system caret so that Windows Tablet Edition and tradional ATs with 
+  // off-screen model can follow the caret
+  ::DestroyCaret();
+
+  nsRefPtr<nsRootAccessible> rootAccessible = GetRootAccessible();
+  if (!rootAccessible) {
+    return;
+  }
+
+  nsRefPtr<nsCaretAccessible> caretAccessible = rootAccessible->GetCaretAccessible();
+  if (!caretAccessible) {
+    return;
+  }
+
+  nsIWidget *widget;
+  nsRect caretRect = caretAccessible->GetCaretRect(&widget);        
+  HWND caretWnd; 
+  if (caretRect.IsEmpty() || !(caretWnd = (HWND)widget->GetNativeData(NS_NATIVE_WINDOW))) {
+    return;
+  }
+
+  // Create invisible bitmap for caret, otherwise its appearance interferes
+  // with Gecko caret
+  HBITMAP caretBitMap = CreateBitmap(1, caretRect.height, 1, 1, NULL);
+  if (::CreateCaret(caretWnd, caretBitMap, 1, caretRect.height)) {  // Also destroys the last caret
+    ::ShowCaret(caretWnd);
+    RECT windowRect;
+    ::GetWindowRect(caretWnd, &windowRect);
+    ::SetCaretPos(caretRect.x - windowRect.left, caretRect.y - windowRect.top);
+    ::DeleteObject(caretBitMap);
+  }
+}
+

accessible/src/msaa/nsAccessibleWrap.h

@@ -296,6 +296,15 @@ class nsAccessibleWrap : public nsAccessible,
   // Helper methods
   static PRInt32 GetChildIDFor(nsIAccessible* aAccessible);
 
+  /**
+   * System caret support: update the Windows caret position. 
+   * The system caret works more universally than the MSAA caret
+   * For example, Window-Eyes, JAWS, ZoomText and Windows Tablet Edition use it
+   * We will use an invisible system caret.
+   * Gecko is still responsible for drawing its own caret
+   */
+  void UpdateSystemCaret();
+
   virtual void GetXPAccessibleFor(const VARIANT& aVarChild, nsIAccessible **aXPAccessible);
   NS_IMETHOD GetNativeInterface(void **aOutAccessible);
 

widget/src/windows/nsWindow.cpp

@@ -5223,30 +5223,19 @@ PRBool nsWindow::ProcessMessage(UINT msg, WPARAM wParam, LPARAM lParam, LRESULT
 #ifdef ACCESSIBILITY
     case WM_GETOBJECT:
     {
-      LRESULT lAcc = 0;
+      *aRetValue = 0;
-      IAccessible *msaaAccessible = NULL;
       if (lParam == OBJID_CLIENT) { // oleacc.dll will be loaded dynamically
         nsCOMPtr<nsIAccessible> rootAccessible = GetRootAccessible(); // Held by a11y cache
         if (rootAccessible) {
+          IAccessible *msaaAccessible = NULL;
           rootAccessible->GetNativeInterface((void**)&msaaAccessible); // does an addref
-        }
+          if (msaaAccessible) {
-      }
+            *aRetValue = LresultFromObject(IID_IAccessible, wParam, msaaAccessible); // does an addref
-      else if (lParam == OBJID_CARET) {  // each root accessible owns a caret accessible
+            msaaAccessible->Release(); // release extra addref
-        nsCOMPtr<nsIAccessible> rootAccessible = GetRootAccessible();  // Held by a11y cache
+            result = PR_TRUE;  // We handled the WM_GETOBJECT message
-        nsCOMPtr<nsIAccessibleDocument> accDoc(do_QueryInterface(rootAccessible));
-        if (accDoc) {
-          nsCOMPtr<nsIAccessible> accessibleCaret;
-          accDoc->GetCaretAccessible(getter_AddRefs(accessibleCaret));
-          if (accessibleCaret) {
-            accessibleCaret->GetNativeInterface((void**)&msaaAccessible);
           }
         }
       }
-      if (msaaAccessible) {
-        lAcc = LresultFromObject(IID_IAccessible, wParam, msaaAccessible); // does an addref
-        msaaAccessible->Release(); // release extra addref
-      }
-      return (*aRetValue = lAcc) != 0;
     }
 #endif