Bug 371593. Expose nsIAccessNode::scrollTo(). Patch by Alexander Surkov. r=aaronlev

accessible/public/nsIAccessNode.idl

@@ -55,7 +55,7 @@ interface nsIAccessibleDocument;
  *
  * @status UNDER_REVIEW
  */
-[scriptable, uuid(46820F9B-3088-4046-AB0F-56FDACDC7A82)]
+[scriptable, uuid(0bd7ccde-486d-483c-a6df-79869cb6647d)]
 interface nsIAccessNode : nsISupports
 {
   /**
@@ -115,6 +115,14 @@ interface nsIAccessNode : nsISupports
    */
   readonly attribute DOMString innerHTML;
 
+  /**
+   * Makes an object visible on screen.
+   *
+   * @param topLeft - if false then it will scroll the shortest distance it
+   *                  needs to put the element on-screen.
+   */
+  void scrollTo(in boolean aTopLeft);
+
   /**
    * The OS window handle for the window this node
    * is being displayed in.

accessible/src/base/nsAccessNode.cpp

@@ -352,6 +352,22 @@ nsAccessNode::GetInnerHTML(nsAString& aInnerHTML)
   return domNSElement->GetInnerHTML(aInnerHTML);
 }
 
+NS_IMETHODIMP
+nsAccessNode::ScrollTo(PRBool aTopLeft)
+{
+  NS_ENSURE_TRUE(mDOMNode, NS_ERROR_FAILURE);
+
+  nsCOMPtr<nsIPresShell> shell(GetPresShell());
+  NS_ENSURE_TRUE(shell, NS_ERROR_FAILURE);
+
+  nsIFrame *frame = GetFrame();
+  NS_ENSURE_TRUE(frame, NS_ERROR_FAILURE);
+
+  PRInt32 percent = aTopLeft ? NS_PRESSHELL_SCROLL_TOP :
+    NS_PRESSHELL_SCROLL_ANYWHERE;
+  return shell->ScrollFrameIntoView(frame, percent, percent);
+}
+
 nsresult
 nsAccessNode::MakeAccessNode(nsIDOMNode *aNode, nsIAccessNode **aAccessNode)
 {

accessible/src/msaa/nsAccessNodeWrap.cpp

@@ -314,19 +314,9 @@ STDMETHODIMP nsAccessNodeWrap::get_computedStyleForProperties(
 
 STDMETHODIMP nsAccessNodeWrap::scrollTo(/* [in] */ boolean aScrollTopLeft)
 {
-  nsCOMPtr<nsIPresShell> shell(GetPresShell());
-  if (!mDOMNode || !shell) {
-    return E_FAIL;
-  }
-
-  nsIFrame *frame = GetFrame();
-
-  if (frame) {
-    PRInt32 percent = NS_PRESSHELL_SCROLL_ANYWHERE;
-    if (aScrollTopLeft)
-      percent = 0;
-    return shell->ScrollFrameIntoView(frame, percent, percent);
-  }
+  nsresult rv = ScrollTo(aScrollTopLeft);
+  if (NS_SUCCEEDED(rv))
+    return S_OK;
 
   return E_FAIL;
 }