From 4bb31ec532bac06b6b84b24c246795ee4782f3ee Mon Sep 17 00:00:00 2001
From: Alexander Surkov <surkov.alexander@gmail.com>
Date: Fri, 28 Dec 2012 17:15:02 +0900
Subject: [PATCH] Bug 814836 - <xul:deck> element messes up screen readers,
 r=tbsaunde, sr=roc

---
 accessible/public/nsIAccessibleProvider.idl   |   4 +-
 accessible/src/base/AccTypes.h                |   2 +-
 .../src/base/nsAccessibilityService.cpp       | 112 +++++++++++-------
 accessible/src/base/nsAccessibilityService.h  |  14 +--
 accessible/src/generic/Accessible.cpp         |   1 +
 accessible/src/generic/Accessible.h           |   2 +-
 accessible/src/mac/AccessibleWrap.mm          |   4 +-
 accessible/src/xul/XULTabAccessible.cpp       |   4 +-
 accessible/src/xul/XULTabAccessible.h         |   6 +-
 .../mochitest/states/test_visibility.xul      |   1 -
 .../tests/mochitest/treeupdate/Makefile.in    |   1 +
 .../tests/mochitest/treeupdate/test_deck.xul  | 109 +++++++++++++++++
 layout/xul/base/src/nsDeckFrame.cpp           |  12 ++
 toolkit/content/widgets/tabbox.xml            |   2 +-
 14 files changed, 211 insertions(+), 63 deletions(-)
 create mode 100644 accessible/tests/mochitest/treeupdate/test_deck.xul

diff --git a/accessible/public/nsIAccessibleProvider.idl b/accessible/public/nsIAccessibleProvider.idl
index a854fba8b0d..d95054f4b93 100644
--- a/accessible/public/nsIAccessibleProvider.idl
+++ b/accessible/public/nsIAccessibleProvider.idl
@@ -62,8 +62,8 @@ interface nsIAccessibleProvider : nsISupports
   const long XULTab = 0x00001017;
   /** Used for XUL tabs element, a container for tab elements */
   const long XULTabs = 0x00001018;
-  /** Used for XUL deck frame */
-  const long XULDeck = 0x00001019;
+  /** Used for XUL tabpanels element */
+  const long XULTabpanels = 0x00001019;
 
   const long XULText             = 0x0000101A;
   const long XULTextBox          = 0x0000101B;
diff --git a/accessible/src/base/AccTypes.h b/accessible/src/base/AccTypes.h
index e707a350ee7..2f5886fbe44 100644
--- a/accessible/src/base/AccTypes.h
+++ b/accessible/src/base/AccTypes.h
@@ -52,7 +52,7 @@ enum AccType {
   eMenuPopupType,
   eProgressType,
   eRootType,
-  eXULDeckType,
+  eXULTabpanelsType,
   eXULTreeType,
 
   eLastAccType = eXULTreeType
diff --git a/accessible/src/base/nsAccessibilityService.cpp b/accessible/src/base/nsAccessibilityService.cpp
index 44cea801c71..42cf653f54d 100644
--- a/accessible/src/base/nsAccessibilityService.cpp
+++ b/accessible/src/base/nsAccessibilityService.cpp
@@ -60,6 +60,7 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/Services.h"
 #include "mozilla/Util.h"
+#include "nsDeckFrame.h"
 
 #ifdef MOZ_XUL
 #include "XULAlertAccessible.h"
@@ -254,6 +255,47 @@ nsAccessibilityService::CreatePluginAccessible(nsObjectFrame* aFrame,
   return nullptr;
 }
 
+void
+nsAccessibilityService::DeckPanelSwitched(nsIPresShell* aPresShell,
+                                          nsIContent* aDeckNode,
+                                          nsIFrame* aPrevBoxFrame,
+                                          nsIFrame* aCurrentBoxFrame)
+{
+  // Ignore tabpanels elements (a deck having an accessible) since their
+  // children are accessible not depending on selected tab.
+  DocAccessible* document = GetDocAccessible(aPresShell);
+  if (!document || document->HasAccessible(aDeckNode))
+    return;
+
+  if (aPrevBoxFrame) {
+    nsIContent* panelNode = aPrevBoxFrame->GetContent();
+#ifdef A11Y_LOG
+    if (logging::IsEnabled(logging::eTree)) {
+      logging::MsgBegin("TREE", "deck panel unselected");
+      logging::Node("container", panelNode);
+      logging::Node("content", aDeckNode);
+      logging::MsgEnd();
+    }
+#endif
+
+    document->ContentRemoved(aDeckNode, panelNode);
+  }
+
+  if (aCurrentBoxFrame) {
+    nsIContent* panelNode = aCurrentBoxFrame->GetContent();
+#ifdef A11Y_LOG
+    if (logging::IsEnabled(logging::eTree)) {
+      logging::MsgBegin("TREE", "deck panel selected");
+      logging::Node("container", panelNode);
+      logging::Node("content", aDeckNode);
+      logging::MsgEnd();
+    }
+#endif
+
+    document->ContentInserted(aDeckNode, panelNode, panelNode->GetNextSibling());
+  }
+}
+
 void
 nsAccessibilityService::ContentRangeInserted(nsIPresShell* aPresShell,
                                              nsIContent* aContainer,
@@ -843,28 +885,43 @@ nsAccessibilityService::GetOrCreateAccessible(nsINode* aNode,
     }
   }
 
-  if (!newAcc) {
+  // Accessible XBL types and deck stuff are used in XUL only currently.
+  if (!newAcc && content->IsXUL()) {
+    // No accessible for not selected deck panel and its children.
+    if (!aContext->IsXULTabpanels()) {
+      nsDeckFrame* deckFrame = do_QueryFrame(frame->GetParent());
+      if (deckFrame && deckFrame->GetSelectedBox() != frame) {
+        if (aIsSubtreeHidden)
+          *aIsSubtreeHidden = true;
+
+        return nullptr;
+      }
+    }
+
     // Elements may implement nsIAccessibleProvider via XBL. This allows them to
     // say what kind of accessible to create.
     newAcc = CreateAccessibleByType(content, document);
+
+    // Any XUL box can be used as tabpanel, make sure we create a proper
+    // accessible for it.
+    if (!newAcc && aContext->IsXULTabpanels() &&
+        content->GetParent() == aContext->GetContent()) {
+      nsIAtom* frameType = frame->GetType();
+      if (frameType == nsGkAtoms::boxFrame ||
+          frameType == nsGkAtoms::scrollFrame) {
+        newAcc = new XULTabpanelAccessible(content, document);
+      }
+    }
   }
 
   if (!newAcc) {
-    // xul:deck does not have XBL and nsIFrame::CreateAccessible() is only called 
-    // on HTML elements
-    nsIAtom* tag = content->Tag();
-    if ((tag == nsGkAtoms::deck) || (tag == nsGkAtoms::tabpanels)) {
-      newAcc = new XULDeckAccessible(content, document);
-    } else if (content->IsSVG(nsGkAtoms::svg)) {
+    if (content->IsSVG(nsGkAtoms::svg)) {
       newAcc = new EnumRoleAccessible(content, document, roles::DIAGRAM);
     } else if (content->IsMathML(nsGkAtoms::math)) {
       newAcc = new EnumRoleAccessible(content, document, roles::EQUATION);
     }
   }
 
-  if (!newAcc)
-    newAcc = CreateAccessibleForDeckChild(frame, content, document);
-
   // If no accessible, see if we need to create a generic accessible because
   // of some property that makes this object interesting
   // We don't do this for <body>, <html>, <window>, <dialog> etc. which
@@ -1011,8 +1068,8 @@ nsAccessibilityService::CreateAccessibleByType(nsIContent* aContent,
       accessible = new XULComboboxAccessible(aContent, aDoc);
       break;
 
-    case nsIAccessibleProvider::XULDeck:
-      accessible = new XULDeckAccessible(aContent, aDoc);
+    case nsIAccessibleProvider::XULTabpanels:
+      accessible = new XULTabpanelsAccessible(aContent, aDoc);
       break;
 
     case nsIAccessibleProvider::XULDropmarker:
@@ -1480,37 +1537,6 @@ NS_GetAccessibilityService(nsIAccessibilityService** aResult)
 ////////////////////////////////////////////////////////////////////////////////
 // nsAccessibilityService private (DON'T put methods here)
 
-already_AddRefed<Accessible>
-nsAccessibilityService::CreateAccessibleForDeckChild(nsIFrame* aFrame,
-                                                     nsIContent* aContent,
-                                                     DocAccessible* aDoc)
-{
-  if (aFrame->GetType() == nsGkAtoms::boxFrame ||
-      aFrame->GetType() == nsGkAtoms::scrollFrame) {
-
-    nsIFrame* parentFrame = aFrame->GetParent();
-    if (parentFrame && parentFrame->GetType() == nsGkAtoms::deckFrame) {
-      // If deck frame is for xul:tabpanels element then the given node has
-      // tabpanel accessible.
-      nsIContent* parentContent = parentFrame->GetContent();
-#ifdef MOZ_XUL
-      if (parentContent->NodeInfo()->Equals(nsGkAtoms::tabpanels,
-                                            kNameSpaceID_XUL)) {
-        Accessible* accessible = new XULTabpanelAccessible(aContent, aDoc);
-        NS_ADDREF(accessible);
-        return accessible;
-      }
-#endif
-      Accessible* accessible = new EnumRoleAccessible(aContent, aDoc,
-                                                      roles::PROPERTYPAGE);
-      NS_ADDREF(accessible);
-      return accessible;
-    }
-  }
-
-  return nullptr;
-}
-
 #ifdef MOZ_XUL
 already_AddRefed<Accessible>
 nsAccessibilityService::CreateAccessibleForXULTree(nsIContent* aContent,
diff --git a/accessible/src/base/nsAccessibilityService.h b/accessible/src/base/nsAccessibilityService.h
index d30bca016c1..dbdf66f53d1 100644
--- a/accessible/src/base/nsAccessibilityService.h
+++ b/accessible/src/base/nsAccessibilityService.h
@@ -64,6 +64,13 @@ public:
   virtual Accessible* AddNativeRootAccessible(void* aAtkAccessible);
   virtual void RemoveNativeRootAccessible(Accessible* aRootAccessible);
 
+  /**
+   * Notification used to update the accessible tree when deck panel is
+   * switched.
+   */
+  void DeckPanelSwitched(nsIPresShell* aPresShell, nsIContent* aDeckNode,
+                         nsIFrame* aPrevBoxFrame, nsIFrame* aCurrentBoxFrame);
+
   /**
    * Notification used to update the accessible tree when new content is
    * inserted.
@@ -173,13 +180,6 @@ private:
     CreateAccessibleByFrameType(nsIFrame* aFrame, nsIContent* aContent,
                                 Accessible* aContext);
 
-  /**
-   * Create accessible if parent is a deck frame.
-   */
-  already_AddRefed<Accessible>
-    CreateAccessibleForDeckChild(nsIFrame* aFrame, nsIContent* aContent,
-                                 DocAccessible* aDoc);
-
 #ifdef MOZ_XUL
   /**
    * Create accessible for XUL tree element.
diff --git a/accessible/src/generic/Accessible.cpp b/accessible/src/generic/Accessible.cpp
index f8aedc4197f..f0090458bca 100644
--- a/accessible/src/generic/Accessible.cpp
+++ b/accessible/src/generic/Accessible.cpp
@@ -612,6 +612,7 @@ Accessible::VisibilityState()
           deckFrame->GetContent()->Tag() == nsGkAtoms::tabpanels)
         return states::OFFSCREEN;
 
+      NS_NOTREACHED("Children of not selected deck panel are not accessible.");
       return states::INVISIBLE;
     }
 
diff --git a/accessible/src/generic/Accessible.h b/accessible/src/generic/Accessible.h
index 9eb2e62ab4f..007b345bb6e 100644
--- a/accessible/src/generic/Accessible.h
+++ b/accessible/src/generic/Accessible.h
@@ -520,7 +520,7 @@ public:
   bool IsTextLeaf() const { return mType == eTextLeafType; }
   TextLeafAccessible* AsTextLeaf();
 
-  bool IsXULDeck() const { return mType == eXULDeckType; }
+  bool IsXULTabpanels() const { return mType == eXULTabpanelsType; }
 
   bool IsXULTree() const { return mType == eXULTreeType; }
   XULTreeAccessible* AsXULTree();
diff --git a/accessible/src/mac/AccessibleWrap.mm b/accessible/src/mac/AccessibleWrap.mm
index b02c8d7bac8..87b53380ae8 100644
--- a/accessible/src/mac/AccessibleWrap.mm
+++ b/accessible/src/mac/AccessibleWrap.mm
@@ -60,9 +60,9 @@ AccessibleWrap::GetNativeType ()
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NIL;
 
-  if (IsXULDeck())
+  if (IsXULTabpanels())
     return [mozPaneAccessible class];
-  
+
   roles::Role role = Role();
   switch (role) {
     case roles::PUSHBUTTON:
diff --git a/accessible/src/xul/XULTabAccessible.cpp b/accessible/src/xul/XULTabAccessible.cpp
index e46a447ed8a..7f15827de3f 100644
--- a/accessible/src/xul/XULTabAccessible.cpp
+++ b/accessible/src/xul/XULTabAccessible.cpp
@@ -163,11 +163,11 @@ XULTabsAccessible::NativeName(nsString& aName)
 
 
 ////////////////////////////////////////////////////////////////////////////////
-// XULDeckAccessible
+// XULTabpanelsAccessible
 ////////////////////////////////////////////////////////////////////////////////
 
 role
-XULDeckAccessible::NativeRole()
+XULTabpanelsAccessible::NativeRole()
 {
   return roles::PANE;
 }
diff --git a/accessible/src/xul/XULTabAccessible.h b/accessible/src/xul/XULTabAccessible.h
index 260035bf797..b8fe6ecee09 100644
--- a/accessible/src/xul/XULTabAccessible.h
+++ b/accessible/src/xul/XULTabAccessible.h
@@ -62,12 +62,12 @@ protected:
 /**
  * A container of tab panels, xul:tabpanels element.
  */
-class XULDeckAccessible : public AccessibleWrap
+class XULTabpanelsAccessible : public AccessibleWrap
 {
 public:
-  XULDeckAccessible(nsIContent* aContent, DocAccessible* aDoc) :
+  XULTabpanelsAccessible(nsIContent* aContent, DocAccessible* aDoc) :
     AccessibleWrap(aContent, aDoc)
-    { mType = eXULDeckType; }
+    { mType = eXULTabpanelsType; }
 
   // Accessible
   virtual a11y::role NativeRole();
diff --git a/accessible/tests/mochitest/states/test_visibility.xul b/accessible/tests/mochitest/states/test_visibility.xul
index 5978ddb9b7f..3f999113172 100644
--- a/accessible/tests/mochitest/states/test_visibility.xul
+++ b/accessible/tests/mochitest/states/test_visibility.xul
@@ -20,7 +20,6 @@
   <![CDATA[
     function doTest()
     {
-      testStates("deck_pane1", STATE_INVISIBLE, 0, STATE_OFFSCREEN);
       testStates("deck_pane2", 0, 0, STATE_INVISIBLE | STATE_OFFSCREEN);
       testStates("tabs_pane1", 0, 0, STATE_INVISIBLE | STATE_OFFSCREEN);
       testStates("tabs_pane2", STATE_OFFSCREEN, 0, STATE_INVISIBLE);
diff --git a/accessible/tests/mochitest/treeupdate/Makefile.in b/accessible/tests/mochitest/treeupdate/Makefile.in
index 849c699eeac..804208b1925 100644
--- a/accessible/tests/mochitest/treeupdate/Makefile.in
+++ b/accessible/tests/mochitest/treeupdate/Makefile.in
@@ -17,6 +17,7 @@ MOCHITEST_A11Y_FILES =\
 		test_colorpicker.xul \
 		test_cssoverflow.html \
 		test_contextmenu.xul \
+		test_deck.xul \
 		test_doc.html \
 		test_gencontent.html \
 		test_hidden.html \
diff --git a/accessible/tests/mochitest/treeupdate/test_deck.xul b/accessible/tests/mochitest/treeupdate/test_deck.xul
new file mode 100644
index 00000000000..13561abab6f
--- /dev/null
+++ b/accessible/tests/mochitest/treeupdate/test_deck.xul
@@ -0,0 +1,109 @@
+<?xml version="1.0"?>
+<?xml-stylesheet href="chrome://global/skin" type="text/css"?>
+<?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css"
+                 type="text/css"?>
+
+<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
+        title="Tree update on XUL deck panel switching">
+
+  <script type="application/javascript"
+          src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js" />
+
+  <script type="application/javascript"
+          src="../common.js" />
+  <script type="application/javascript"
+          src="../role.js" />
+  <script type="application/javascript"
+          src="../states.js" />
+  <script type="application/javascript"
+          src="../events.js" />
+
+  <script type="application/javascript">
+  <![CDATA[
+    function switchDeckPanel(aContainerID, aDeckID)
+    {
+      this.panelIndex = 0;
+
+      this.container = getAccessible(aContainerID);
+      this.deckNode = getNode(aDeckID);
+      this.prevPanel = getAccessible(this.deckNode.selectedPanel);
+      this.panelNode = this.deckNode.childNodes[this.panelIndex];
+
+      this.eventSeq = [
+        new invokerChecker(EVENT_HIDE, this.prevPanel),
+        new invokerChecker(EVENT_SHOW, this.panelNode),
+        new invokerChecker(EVENT_REORDER, this.container)
+      ];
+
+      this.invoke = function switchDeckPanel_invoke()
+      {
+        var tree =
+          { GROUPING: [ // role="group"
+            { GROUPING: [ // groupbox, a selected panel #2
+              { PUSHBUTTON: [ ] } // button
+            ] }
+          ] };
+        testAccessibleTree(this.container, tree);
+
+        this.deckNode.selectedIndex = this.panelIndex;
+      }
+
+      this.finalCheck = function switchDeckPanel_finalCheck()
+      {
+        var tree =
+          { GROUPING: [ // role="group"
+            { LABEL: [ // description, a selected panel #1
+              { TEXT_LEAF: []  } // text leaf, a description value
+            ] }
+          ] };
+        testAccessibleTree(this.container, tree);
+      }
+
+      this.getID = function switchDeckPanel_getID()
+      {
+        return "switch deck panel";
+      }
+    }
+
+    var gQueue = null;
+    function doTest()
+    {
+      gQueue = new eventQueue();
+      gQueue.push(new switchDeckPanel("container", "deck"));
+      gQueue.invoke(); // will call SimpleTest.finish();
+    }
+
+    SimpleTest.waitForExplicitFinish();
+    addA11yLoadEvent(doTest);
+  ]]>
+  </script>
+
+  <hbox flex="1" style="overflow: auto;">
+    <body xmlns="http://www.w3.org/1999/xhtml">
+     <a target="_blank"
+         href="https://bugzilla.mozilla.org/show_bug.cgi?id=814836"
+         title=" xul:deck element messes up screen reader">
+        Mozilla Bug 814836
+     </a>
+
+      <p id="display"></p>
+      <div id="content" style="display: none">
+      </div>
+      <pre id="test">
+      </pre>
+    </body>
+
+    <vbox flex="1" id="container" role="group">
+
+      <deck id="deck" selectedIndex="1">
+        <description>This is the first page</description>
+        <groupbox>
+          <button label="This is the second page"/>
+        </groupbox>
+      </deck>
+
+    </vbox>
+  </hbox>
+
+</window>
+
diff --git a/layout/xul/base/src/nsDeckFrame.cpp b/layout/xul/base/src/nsDeckFrame.cpp
index 27ae0896a68..50f4611bf7f 100644
--- a/layout/xul/base/src/nsDeckFrame.cpp
+++ b/layout/xul/base/src/nsDeckFrame.cpp
@@ -26,6 +26,10 @@
 #include "nsDisplayList.h"
 #include "nsContainerFrame.h"
 
+#ifdef ACCESSIBILITY
+#include "nsAccessibilityService.h"
+#endif
+
 nsIFrame*
 NS_NewDeckFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 {
@@ -105,6 +109,14 @@ nsDeckFrame::IndexChanged()
     HideBox(currentBox);
 
   mIndex = index;
+
+#ifdef ACCESSIBILITY
+  nsAccessibilityService* accService = GetAccService();
+  if (accService) {
+    accService->DeckPanelSwitched(PresContext()->GetPresShell(), mContent,
+                                  currentBox, GetSelectedBox());
+  }
+#endif
 }
 
 int32_t
diff --git a/toolkit/content/widgets/tabbox.xml b/toolkit/content/widgets/tabbox.xml
index 35388c0a5f9..83703223072 100644
--- a/toolkit/content/widgets/tabbox.xml
+++ b/toolkit/content/widgets/tabbox.xml
@@ -601,7 +601,7 @@
       <property name="accessibleType" readonly="true">
         <getter>
           <![CDATA[
-            return Components.interfaces.nsIAccessibleProvider.XULDeck;
+            return Components.interfaces.nsIAccessibleProvider.XULTabpanels;
           ]]>
         </getter>
       </property>