Bug 625652 - make sure accessible tree is correct when rendered text is changed, r=davidb, sr=roc, a=roc

accessible/src/base/NotificationController.cpp

@@ -56,6 +56,8 @@ NotificationController::NotificationController(nsDocAccessible* aDocument,
   mObservingState(eNotObservingRefresh), mDocument(aDocument),
   mPresShell(aPresShell), mTreeConstructedState(eTreeConstructionPending)
 {
+  mTextHash.Init();
+
   // Schedule initial accessible tree construction.
   ScheduleProcessing();
 }
@@ -113,6 +115,7 @@ NotificationController::Shutdown()
   mDocument = nsnull;
   mPresShell = nsnull;
 
+  mTextHash.Clear();
   mContentInsertions.Clear();
   mNotifications.Clear();
   mEvents.Clear();
@@ -208,6 +211,11 @@ NotificationController::WillRefresh(mozilla::TimeStamp aTime)
     if (!mDocument->IsBoundToParent())
       return;
 
+#ifdef DEBUG_NOTIFICATIONS
+    printf("\ninitial tree created, document: %p, document node: %p\n",
+           mDocument.get(), mDocument->GetDocumentNode());
+#endif
+
     mTreeConstructedState = eTreeConstructed;
     mDocument->CacheChildrenInSubtree(mDocument);
 
@@ -235,6 +243,10 @@ NotificationController::WillRefresh(mozilla::TimeStamp aTime)
       return;
   }
 
+  // Process rendered text change notifications.
+  mTextHash.EnumerateEntries(TextEnumerator, mDocument);
+  mTextHash.Clear();
+
   // Bind hanging child documents.
   PRUint32 childDocCount = mHangingChildDocuments.Length();
   for (PRUint32 idx = 0; idx < childDocCount; idx++) {
@@ -561,6 +573,89 @@ NotificationController::CreateTextChangeEventFor(AccMutationEvent* aEvent)
                            aEvent->mIsFromUserInput ? eFromUserInput : eNoUserInput);
 }
 
+PLDHashOperator
+NotificationController::TextEnumerator(nsPtrHashKey<nsIContent>* aEntry,
+                                       void* aUserArg)
+{
+  nsDocAccessible* document = static_cast<nsDocAccessible*>(aUserArg);
+  nsIContent* textNode = aEntry->GetKey();
+  nsAccessible* textAcc = document->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->GetNodeParent();
+  if (!containerNode) {
+    NS_ASSERTION(!textAcc,
+                 "Text node was removed but accessible is kept alive!");
+    return PL_DHASH_NEXT;
+  }
+
+  nsIFrame* textFrame = textNode->GetPrimaryFrame();
+  if (!textFrame) {
+    NS_ASSERTION(!textAcc,
+                 "Text node isn't rendered but accessible is kept alive!");
+    return PL_DHASH_NEXT;
+  }
+
+  nsIContent* containerElm = containerNode->IsElement() ?
+    containerNode->AsElement() : nsnull;
+
+  nsAutoString renderedText;
+  textFrame->GetRenderedText(&renderedText);
+
+  // Remove text accessible if rendered text is empty.
+  if (textAcc) {
+    if (renderedText.IsEmpty()) {
+#ifdef DEBUG_NOTIFICATIONS
+      PRUint32 index = containerNode->IndexOf(textNode);
+
+      nsCAutoString tag;
+      nsCAutoString id;
+      if (containerElm) {
+        containerElm->Tag()->ToUTF8String(tag);
+        nsIAtom* atomid = containerElm->GetID();
+        if (atomid)
+          atomid->ToUTF8String(id);
+      }
+
+      printf("\npending text node removal: container: %s@id='%s', index in container: %d\n\n",
+             tag.get(), id.get(), index);
+#endif
+
+      document->ContentRemoved(containerElm, textNode);
+    }
+
+    return PL_DHASH_NEXT;
+  }
+
+  // Append an accessible if rendered text is not empty.
+  if (!renderedText.IsEmpty()) {
+#ifdef DEBUG_NOTIFICATIONS
+      PRUint32 index = containerNode->IndexOf(textNode);
+
+      nsCAutoString tag;
+      nsCAutoString id;
+      if (containerElm) {
+        containerElm->Tag()->ToUTF8String(tag);
+        nsIAtom* atomid = containerElm->GetID();
+        if (atomid)
+          atomid->ToUTF8String(id);
+      }
+
+      printf("\npending text node insertion: container: %s@id='%s', index in container: %d\n\n",
+             tag.get(), id.get(), index);
+#endif
+
+    nsAccessible* container = document->GetAccessibleOrContainer(containerNode);
+    nsTArray<nsCOMPtr<nsIContent> > insertedContents;
+    insertedContents.AppendElement(textNode);
+    document->ProcessContentInserted(container, &insertedContents);
+  }
+
+  return PL_DHASH_NEXT;
+}
+
+
 ////////////////////////////////////////////////////////////////////////////////
 // NotificationController: content inserted notification
 
@@ -616,7 +711,7 @@ NotificationController::ContentInsertion::Process()
       catomid->ToUTF8String(cid);
   }
 
-  printf("\npending content insertion process: %s@id='%s', container: %s@id='%s', inserted content amount: %d\n\n",
+  printf("\npending content insertion: %s@id='%s', container: %s@id='%s', inserted content amount: %d\n\n",
          tag.get(), id.get(), ctag.get(), cid.get(), mInsertedContent.Length());
 #endif
 

accessible/src/base/NotificationController.h

@@ -149,6 +149,16 @@ public:
    */
   void ScheduleChildDocBinding(nsDocAccessible* aDocument);
 
+  /**
+   * Schedule the accessible tree update because of rendered text changes.
+   */
+  inline void ScheduleTextUpdate(nsIContent* aTextNode)
+  {
+    // Ignore the notification if initial tree construction hasn't been done yet.
+    if (mTreeConstructedState != eTreeConstructionPending)
+      mTextHash.PutEntry(aTextNode);
+  }
+
   /**
    * Pend accessible tree update for content insertion.
    */
@@ -323,6 +333,17 @@ private:
    */
   nsTArray<nsRefPtr<ContentInsertion> > mContentInsertions;
 
+  /**
+   * A pending accessible tree update notifications for rendered text changes.
+   */
+  nsTHashtable<nsPtrHashKey<nsIContent> > mTextHash;
+
+  /**
+   * Update the accessible tree for pending rendered text change notifications.
+   */
+  static PLDHashOperator TextEnumerator(nsPtrHashKey<nsIContent>* aEntry,
+                                        void* aUserArg);
+
   /**
    * Other notifications like DOM events. Don't make this an nsAutoTArray; we
    * use SwapElements() on it.

accessible/src/base/nsAccessibilityService.cpp

@@ -528,6 +528,15 @@ nsAccessibilityService::ContentRemoved(nsIPresShell* aPresShell,
     docAccessible->ContentRemoved(aContainer, aChild);
 }
 
+void
+nsAccessibilityService::UpdateText(nsIPresShell* aPresShell,
+                                   nsIContent* aContent)
+{
+  nsDocAccessible* document = GetDocAccessible(aPresShell->GetDocument());
+  if (document)
+    document->UpdateText(aContent);
+}
+
 void
 nsAccessibilityService::PresShellDestroyed(nsIPresShell *aPresShell)
 {

accessible/src/base/nsAccessibilityService.h

@@ -118,6 +118,8 @@ public:
   virtual void ContentRemoved(nsIPresShell* aPresShell, nsIContent* aContainer,
                               nsIContent* aChild);
 
+  virtual void UpdateText(nsIPresShell* aPresShell, nsIContent* aContent);
+
   virtual void NotifyOfAnchorJumpTo(nsIContent *aTarget);
 
   virtual void PresShellDestroyed(nsIPresShell* aPresShell);

accessible/src/base/nsDocAccessible.h

@@ -309,6 +309,17 @@ public:
    */
   void ContentRemoved(nsIContent* aContainerNode, nsIContent* aChildNode);
 
+  /**
+   * Updates accessible tree when rendered text is changed.
+   */
+  inline void UpdateText(nsIContent* aTextNode)
+  {
+    NS_ASSERTION(mNotificationController, "The document was shut down!");
+
+    if (mNotificationController)
+      mNotificationController->ScheduleTextUpdate(aTextNode);
+  }
+
   /**
    * Recreate an accessible, results in hide/show events pair.
    */

accessible/tests/mochitest/events.js

@@ -907,7 +907,7 @@ function invokerChecker(aEventType, aTargetOrFunc, aTargetFuncArg)
   function invokerChecker_targetDescrGetter()
   {
     if (typeof this.mTarget == "function")
-      return this.mTarget.toSource() + this.mTargetFuncArg;
+      return this.mTarget.name + ", arg: " + this.mTargetFuncArg;
 
     return prettyName(this.mTarget);
   }

accessible/tests/mochitest/tree/test_txtctrl.html

@@ -32,7 +32,7 @@
 
       testAccessibleTree("txc1", accTree);
 
-      // input@type="text"
+      // input@type="text", value
       accTree = {
         role: ROLE_ENTRY,
         children: [
@@ -45,6 +45,14 @@
 
       testAccessibleTree("txc2", accTree);
 
+      // input@type="text", no value
+      accTree =
+        { ENTRY: [
+          { TEXT_LEAF: [ ] }
+        ] };
+
+      testAccessibleTree("txc3", accTree);
+
       // textarea
       accTree = {
         role: ROLE_ENTRY,
@@ -58,7 +66,7 @@
         ]
       };
 
-      testAccessibleTree("txc3", accTree);
+      testAccessibleTree("txc4", accTree);
 
       // input@type="password"
       accTree = {
@@ -71,7 +79,7 @@
         ]
       };
 
-      testAccessibleTree("txc4", accTree);
+      testAccessibleTree("txc5", accTree);
 
       SimpleTest.finish();
     }
@@ -92,6 +100,11 @@
      title="Create child accessibles for text controls from native anonymous content">
     Mozilla Bug 542824
   </a>
+  <a target="_blank"
+     href="https://bugzilla.mozilla.org/show_bug.cgi?id=625652"
+     title="Make sure accessible tree is correct when rendered text is changed">
+    Mozilla Bug 625652
+  </a>
 
   <p id="display"></p>
   <div id="content" style="display: none"></div>
@@ -102,11 +115,12 @@
     1hellohello
   </div>
   <input id="txc2" value="hello">
-  <textarea id="txc3">
+  <input id="txc3">
+  <textarea id="txc4">
     hello1
     hello2
   </textarea>
-  <input id="txc4" type="password" value="hello">
+  <input id="txc5" type="password" value="hello">
 
 </body>
 </html>

accessible/tests/mochitest/treeupdate/Makefile.in

@@ -54,6 +54,7 @@ _TEST_FILES =\
 		test_select.html \
 		test_textleaf.html \
 		test_visibility.html \
+		test_whitespace.html \
 		$(NULL)
 
 libs:: $(_TEST_FILES)

accessible/tests/mochitest/treeupdate/test_whitespace.html

@@ -0,0 +1,188 @@
+<!DOCTYPE html>
+<html>
+
+<head>
+  <title>Whitespace text accessible creation/desctruction</title>
+
+  <link rel="stylesheet" type="text/css"
+        href="chrome://mochikit/content/tests/SimpleTest/test.css" />
+
+  <script type="application/javascript"
+          src="chrome://mochikit/content/MochiKit/packed.js"></script>
+  <script type="application/javascript"
+          src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+
+  <script type="application/javascript"
+          src="../common.js"></script>
+  <script type="application/javascript"
+          src="../role.js"></script>
+  <script type="application/javascript"
+          src="../events.js"></script>
+
+  <script type="application/javascript">
+
+    ////////////////////////////////////////////////////////////////////////////
+    // Invokers
+
+    /**
+     * Middle image accessible removal results in text accessible removal.
+     *
+     * Before:
+     *   DOM: whitespace img1 whitespace img2 whitespace img3 whitespace,
+     *   a11y: img1 whitespace img2 whitespace img3
+     * After:
+     *   DOM: whitespace img1 whitespace whitespace img3 whitespace,
+     *   a11y: img1 whitespace img3
+     */
+    function removeImg()
+    {
+      this.containerNode = getNode("container1");
+      this.imgNode = getNode("img1");
+      this.img = getAccessible(this.imgNode);
+      this.text = this.img.nextSibling;
+
+      this.eventSeq = [
+        new invokerChecker(EVENT_HIDE, this.img),
+        new invokerChecker(EVENT_HIDE, this.text),
+        new invokerChecker(EVENT_REORDER, this.containerNode)
+      ];
+
+      this.finalCheck = function textLeafUpdate_finalCheck()
+      {
+        var tree =
+          { SECTION: [
+            { GRAPHIC: [] },
+            { TEXT_LEAF: [] },
+            { GRAPHIC: [] }
+          ] };
+
+        testAccessibleTree(this.containerNode, tree);
+      }
+
+      this.invoke = function setOnClickAttr_invoke()
+      {
+        var tree =
+          { SECTION: [
+            { GRAPHIC: [] },
+            { TEXT_LEAF: [] },
+            { GRAPHIC: [] },
+            { TEXT_LEAF: [] },
+            { GRAPHIC: [] }
+          ] };
+
+        testAccessibleTree(this.containerNode, tree);
+
+        this.containerNode.removeChild(this.imgNode);
+      }
+
+      this.getID = function setOnClickAttr_getID()
+      {
+        return "remove middle img";
+      }
+    }
+
+    /**
+     * Append image making the whitespace visible and thus accessible.
+     * Note: images and whitespaces are on different leves of accessible trees,
+     * so that image container accessible update doesn't update the tree
+     * of whitespace container.
+     *
+     * Before:
+     *   DOM: whitespace emptylink whitespace linkwithimg whitespace
+     *   a11y: emptylink linkwithimg
+     * After:
+     *   DOM: whitespace linkwithimg whitespace linkwithimg whitespace
+     *   a11y: linkwithimg whitespace linkwithimg
+     */
+    function insertImg()
+    {
+      this.containerNode = getNode("container2");
+      this.topNode = this.containerNode.parentNode;
+      this.textNode = this.containerNode.nextSibling;
+      this.imgNode = document.createElement("img");
+      this.imgNode.setAttribute("src", "../moz.png");
+
+      this.eventSeq = [
+        new invokerChecker(EVENT_SHOW, getAccessible, this.imgNode),
+        new invokerChecker(EVENT_SHOW, getAccessible, this.textNode),
+        new invokerChecker(EVENT_REORDER, this.topNode)
+      ];
+
+      this.invoke = function insertImg_invoke()
+      {
+        var tree =
+          { SECTION: [
+            { LINK: [] },
+            { LINK: [
+              { GRAPHIC: [] }
+            ] }
+          ] };
+
+        testAccessibleTree(this.topNode, tree);
+
+        this.containerNode.appendChild(this.imgNode);
+      }
+
+      this.finalCheck = function insertImg_finalCheck()
+      {
+        var tree =
+          { SECTION: [
+            { LINK: [
+              { GRAPHIC: [ ] }
+            ] },
+            { TEXT_LEAF: [ ] },
+            { LINK: [
+              { GRAPHIC: [ ] }
+            ] }
+          ] };
+
+        testAccessibleTree(this.topNode, tree);
+      }
+
+      this.getID = function appendImg_getID()
+      {
+        return "insert img into internal container";
+      }
+    }
+
+    ////////////////////////////////////////////////////////////////////////////
+    // Test
+
+    //gA11yEventDumpID = "eventdump"; // debug stuff
+    //gA11yEventDumpToConsole = true;
+
+    var gQueue = null;
+
+    function doTest()
+    {
+      gQueue = new eventQueue();
+
+      gQueue.push(new removeImg());
+      gQueue.push(new insertImg());
+
+      gQueue.invoke(); // SimpleTest.finish() will be called in the end
+    }
+
+    SimpleTest.waitForExplicitFinish();
+    addA11yLoadEvent(doTest);
+  </script>
+</head>
+<body>
+
+  <a target="_blank"
+     title="Make sure accessible tree is correct when rendered text is changed"
+     href="https://bugzilla.mozilla.org/show_bug.cgi?id=625652">
+    Mozilla Bug 625652
+  </a>
+
+  <p id="display"></p>
+  <div id="content" style="display: none"></div>
+  <pre id="test">
+  </pre>
+
+  <div id="container1">  <img src="../moz.png">  <img id="img1" src="../moz.png">  <img src="../moz.png">  </div>
+  <div> <a id="container2"></a> <a><img src="../moz.png"></a> </div>
+
+  <div id="eventdump"></div>
+</body>
+</html>

layout/generic/nsTextFrameThebes.cpp

@@ -6908,6 +6908,14 @@ nsTextFrame::ReflowText(nsLineLayout& aLineLayout, nscoord aAvailableWidth,
          aMetrics.width, aMetrics.height, aMetrics.ascent,
          aStatus);
 #endif
+
+#ifdef ACCESSIBILITY
+  // Schedule the update of accessible tree when rendered text might be changed.
+  nsAccessibilityService* accService = nsIPresShell::AccService();
+  if (accService) {
+    accService->UpdateText(presContext->PresShell(), mContent);
+  }
+#endif
 }
 
 /* virtual */ PRBool