Bug 1274381 - scope accessible elements search to inserted nodes, r=yzen, f=marcoz

accessible/base/TreeWalker.cpp

@@ -57,14 +57,29 @@ TreeWalker::~TreeWalker()
   MOZ_COUNT_DTOR(TreeWalker);
 }
 
+Accessible*
+TreeWalker::Scope(nsIContent* aAnchorNode)
+{
+  Reset();
+
+  mAnchorNode = aAnchorNode;
+
+  bool skipSubtree = false;
+  Accessible* acc = AccessibleFor(aAnchorNode, 0, &skipSubtree);
+  if (acc) {
+    mPhase = eAtEnd;
+    return acc;
+  }
+
+  return skipSubtree ? nullptr : Next();
+}
+
 bool
 TreeWalker::Seek(nsIContent* aChildNode)
 {
   MOZ_ASSERT(aChildNode, "Child cannot be null");
 
-  mPhase = eAtStart;
-  mStateStack.Clear();
-  mARIAOwnsIdx = 0;
+  Reset();
 
   nsIContent* childNode = nullptr;
   nsINode* parentNode = aChildNode;
@@ -110,7 +125,7 @@ TreeWalker::Seek(nsIContent* aChildNode)
 }
 
 Accessible*
-TreeWalker::Next(nsIContent* aStopNode)
+TreeWalker::Next()
 {
   if (mStateStack.IsEmpty()) {
     if (mPhase == eAtEnd) {
@@ -139,10 +154,6 @@ TreeWalker::Next(nsIContent* aStopNode)
 
   dom::AllChildrenIterator* top = &mStateStack[mStateStack.Length() - 1];
   while (top) {
-    if (aStopNode && top->Get() == aStopNode) {
-      return nullptr;
-    }
-
     while (nsIContent* childNode = top->GetNextChild()) {
       bool skipSubtree = false;
       Accessible* child = AccessibleFor(childNode, mFlags, &skipSubtree);
@@ -150,14 +161,10 @@ TreeWalker::Next(nsIContent* aStopNode)
         return child;
       }
 
-      // Walk down the subtree if allowed, otherwise check if we have reached
-      // a stop node.
+      // Walk down the subtree if allowed.
       if (!skipSubtree && childNode->IsElement()) {
         top = PushState(childNode, true);
       }
-      else if (childNode == aStopNode) {
-        return nullptr;
-      }
     }
     top = PopState();
   }
@@ -171,7 +178,7 @@ TreeWalker::Next(nsIContent* aStopNode)
       mPhase = eAtEnd;
       return nullptr;
     }
-    return Next(aStopNode);
+    return Next();
   }
 
   nsINode* contextNode = mContext->GetNode();
@@ -184,7 +191,7 @@ TreeWalker::Next(nsIContent* aStopNode)
     top = PushState(parent, true);
     if (top->Seek(mAnchorNode)) {
       mAnchorNode = parent;
-      return Next(aStopNode);
+      return Next();
     }
 
     // XXX We really should never get here, it means we're trying to find an
@@ -194,7 +201,7 @@ TreeWalker::Next(nsIContent* aStopNode)
     mAnchorNode = parent;
   }
 
-  return Next(aStopNode);
+  return Next();
 }
 
 Accessible*

accessible/base/TreeWalker.h

@@ -50,8 +50,23 @@ public:
   ~TreeWalker();
 
   /**
-   * Clears the tree walker state and resets it to the given child within
-   * the anchor.
+   * Resets the walker state, and sets the given node as an anchor. Returns a
+   * first accessible element within the node including the node itself.
+   */
+  Accessible* Scope(nsIContent* aAnchorNode);
+
+  /**
+   * Resets the walker state.
+   */
+  void Reset()
+  {
+    mPhase = eAtStart;
+    mStateStack.Clear();
+    mARIAOwnsIdx = 0;
+  }
+
+  /**
+   * Sets the walker state to the given child node if it's within the anchor.
    */
   bool Seek(nsIContent* aChildNode);
 
@@ -62,7 +77,7 @@ public:
    *       rejected during tree creation then the caller should be unbind it
    *       from the document.
    */
-  Accessible* Next(nsIContent* aStopNode = nullptr);
+  Accessible* Next();
   Accessible* Prev();
 
   Accessible* Context() const { return mContext; }

accessible/generic/DocAccessible.cpp

@@ -1663,7 +1663,7 @@ public:
   InsertIterator(Accessible* aContext,
                  const nsTArray<nsCOMPtr<nsIContent> >* aNodes) :
     mChild(nullptr), mChildBefore(nullptr), mWalker(aContext),
-    mStopNode(nullptr), mNodes(aNodes), mNodesIdx(0)
+    mNodes(aNodes), mNodesIdx(0)
   {
     MOZ_ASSERT(aContext, "No context");
     MOZ_ASSERT(aNodes, "No nodes to search for accessible elements");
@@ -1685,7 +1685,6 @@ private:
   Accessible* mChild;
   Accessible* mChildBefore;
   TreeWalker mWalker;
-  nsIContent* mStopNode;
 
   const nsTArray<nsCOMPtr<nsIContent> >* mNodes;
   uint32_t mNodesIdx;
@@ -1695,7 +1694,7 @@ bool
 InsertIterator::Next()
 {
   if (mNodesIdx > 0) {
-    Accessible* nextChild = mWalker.Next(mStopNode);
+    Accessible* nextChild = mWalker.Next();
     if (nextChild) {
       mChildBefore = mChild;
       mChild = nextChild;
@@ -1737,20 +1736,21 @@ InsertIterator::Next()
 
     // If inserted nodes are siblings then just move the walker next.
     if (prevNode && prevNode->GetNextSibling() == node) {
-      mStopNode = node;
-      Accessible* nextChild = mWalker.Next(mStopNode);
+      Accessible* nextChild = mWalker.Scope(node);
       if (nextChild) {
         mChildBefore = mChild;
         mChild = nextChild;
         return true;
       }
     }
-    else if (mWalker.Seek(node)) {
-      mStopNode = node;
-      mChildBefore = mWalker.Prev();
-      mChild = mWalker.Next(mStopNode);
-      if (mChild) {
-        return true;
+    else {
+      TreeWalker finder(container);
+      if (finder.Seek(node)) {
+        mChild = mWalker.Scope(node);
+        if (mChild) {
+          mChildBefore = finder.Prev();
+          return true;
+        }
       }
     }
   }