Bug 377783. Fix crash and clean up table a11y. r=evan.yan

accessible/public/nsIAccessibilityService.idl

@@ -45,7 +45,7 @@ interface nsIFrame;
 interface nsObjectFrame;
 interface nsIContent;
 
-[uuid(e4cdb7c5-d029-4bee-bff5-99455c6e0057)]
+[uuid(0e9e2f00-b6f1-440d-821f-6b09d264cdaf)]
 interface nsIAccessibilityService : nsIAccessibleRetrieval
 {
   nsIAccessible createOuterDocAccessible(in nsIDOMNode aNode);
@@ -74,6 +74,7 @@ interface nsIAccessibilityService : nsIAccessibleRetrieval
   nsIAccessible createHTMLTableHeadAccessible(in nsIDOMNode aDOMNode);
   nsIAccessible createHTMLTextAccessible(in nsISupports aFrame);
   nsIAccessible createHTMLTextFieldAccessible(in nsISupports aFrame);
+  nsIAccessible createHTMLCaptionAccessible(in nsISupports aFrame);
 
   nsIAccessible getAccessible(in nsIDOMNode aNode, in nsIPresShell aPresShell,                          
                               in nsIWeakReference aWeakShell, 

accessible/public/nsIAccessibleTable.idl

@@ -43,11 +43,11 @@
 
 interface nsIAccessible;
 
-[scriptable, uuid(a776fee4-c0b8-4872-9e1e-72017243383f)]
+[scriptable, uuid(dc13d184-a6df-45a1-92f0-5476fdaebc5a)]
 interface nsIAccessibleTable : nsISupports
 {
-           attribute nsIAccessible       caption;
-           attribute AString           summary;
+  readonly attribute nsIAccessible       caption;
+  readonly attribute AString             summary;
   readonly attribute long                columns;
   readonly attribute nsIAccessibleTable  columnHeader;
   readonly attribute long                rows;

accessible/src/atk/nsXULTreeAccessibleWrap.cpp

@@ -50,7 +50,6 @@ NS_IMPL_ISUPPORTS_INHERITED1(nsXULTreeAccessibleWrap, nsXULTreeAccessible, nsIAc
 nsXULTreeAccessibleWrap::nsXULTreeAccessibleWrap(nsIDOMNode *aDOMNode, nsIWeakReference *aShell):
 nsXULTreeAccessible(aDOMNode, aShell)
 {
-  mCaption = nsnull;
 }
 
 // tree's children count is row count * col count + treecols count
@@ -78,26 +77,13 @@ NS_IMETHODIMP nsXULTreeAccessibleWrap::GetChildCount(PRInt32 *aAccChildCount)
 
 NS_IMETHODIMP nsXULTreeAccessibleWrap::GetCaption(nsIAccessible **aCaption)
 {
-  *aCaption = mCaption;
-  NS_IF_ADDREF(*aCaption);
-  return NS_OK;
-}
-
-NS_IMETHODIMP nsXULTreeAccessibleWrap::SetCaption(nsIAccessible *aCaption)
-{
-  mCaption = aCaption;
+  *aCaption = nsnull;
   return NS_OK;
 }
 
 NS_IMETHODIMP nsXULTreeAccessibleWrap::GetSummary(nsAString &aSummary)
 {
-  aSummary = mSummary;
-  return NS_OK;
-}
-
-NS_IMETHODIMP nsXULTreeAccessibleWrap::SetSummary(const nsAString &aSummary)
-{
-  mSummary = aSummary;
+  aSummary.Truncate();
   return NS_OK;
 }
 
@@ -426,32 +412,17 @@ NS_IMPL_ISUPPORTS_INHERITED1(nsXULTreeColumnsAccessibleWrap, nsXULTreeColumnsAcc
 nsXULTreeColumnsAccessibleWrap::nsXULTreeColumnsAccessibleWrap(nsIDOMNode *aDOMNode, nsIWeakReference *aShell):
 nsXULTreeColumnsAccessible(aDOMNode, aShell)
 {
-  mCaption = nsnull;
 }
 
 NS_IMETHODIMP nsXULTreeColumnsAccessibleWrap::GetCaption(nsIAccessible **aCaption)
 {
-  *aCaption = mCaption;
-  NS_IF_ADDREF(*aCaption);
-
-  return NS_OK;
-}
-
-NS_IMETHODIMP nsXULTreeColumnsAccessibleWrap::SetCaption(nsIAccessible *aCaption)
-{
-  mCaption = aCaption;
+  *aCaption = nsnull;
   return NS_OK;
 }
 
 NS_IMETHODIMP nsXULTreeColumnsAccessibleWrap::GetSummary(nsAString &aSummary)
 {
-  aSummary = mSummary;
-  return NS_OK;
-}
-
-NS_IMETHODIMP nsXULTreeColumnsAccessibleWrap::SetSummary(const nsAString &aSummary)
-{
-  mSummary = aSummary;
+  aSummary.Truncate();
   return NS_OK;
 }
 

accessible/src/atk/nsXULTreeAccessibleWrap.h

@@ -57,10 +57,6 @@ public:
 
   NS_IMETHOD GetChildCount(PRInt32 *_retval);
   NS_IMETHOD ChangeSelection(PRInt32 aIndex, PRUint8 aMethod, PRBool *aSelState);
-    
-private:
-  nsCOMPtr<nsIAccessible> mCaption;
-  nsString mSummary;
 };
 
 class nsXULTreeColumnsAccessibleWrap : public nsXULTreeColumnsAccessible,
@@ -72,10 +68,6 @@ public:
 
   nsXULTreeColumnsAccessibleWrap(nsIDOMNode* aDOMNode, nsIWeakReference* aShell);
   virtual ~nsXULTreeColumnsAccessibleWrap() {}
-
-private:
-  nsCOMPtr<nsIAccessible> mCaption;
-  nsString mSummary;
 };
 
 #endif

accessible/src/base/nsAccessibilityAtomList.h

@@ -90,7 +90,6 @@ ACCESSIBILITY_ATOM(area, "area")
 ACCESSIBILITY_ATOM(blockquote, "blockquote")
 ACCESSIBILITY_ATOM(br, "br")
 ACCESSIBILITY_ATOM(body, "body")
-ACCESSIBILITY_ATOM(caption, "caption")
 ACCESSIBILITY_ATOM(choices, "choices") // XForms
 ACCESSIBILITY_ATOM(description, "description")    // XUL
 ACCESSIBILITY_ATOM(dd, "dd")

accessible/src/base/nsAccessibilityService.cpp

@@ -477,7 +477,6 @@ nsAccessibilityService::CreateHTMLAccessibleByMarkup(nsIFrame *aFrame,
   else if (tag == nsAccessibilityAtoms::abbr ||
            tag == nsAccessibilityAtoms::acronym ||
            tag == nsAccessibilityAtoms::blockquote ||
-           tag == nsAccessibilityAtoms::caption ||
            tag == nsAccessibilityAtoms::dd ||
            tag == nsAccessibilityAtoms::dl ||
            tag == nsAccessibilityAtoms::dt ||
@@ -882,6 +881,24 @@ nsAccessibilityService::CreateHTMLBRAccessible(nsISupports *aFrame, nsIAccessibl
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsAccessibilityService::CreateHTMLCaptionAccessible(nsISupports *aFrame, nsIAccessible **_retval)
+{
+  nsIFrame* frame;
+  nsCOMPtr<nsIDOMNode> node;
+  nsCOMPtr<nsIWeakReference> weakShell;
+  nsresult rv = GetInfo(aFrame, &frame, getter_AddRefs(weakShell), getter_AddRefs(node));
+  if (NS_FAILED(rv))
+    return rv;
+
+  *_retval = new nsHTMLCaptionAccessible(node, weakShell);
+  if (! *_retval) 
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  NS_ADDREF(*_retval);
+  return NS_OK;
+}
+
 NS_IMETHODIMP nsAccessibilityService::GetCachedAccessible(nsIDOMNode *aNode, 
                                                           nsIWeakReference *aWeakShell,
                                                           nsIAccessible **aAccessible)
@@ -1369,6 +1386,10 @@ NS_IMETHODIMP nsAccessibilityService::GetAccessible(nsIDOMNode *aNode,
     }
 
     if (tryFrame) {
+      if (frame->GetRect().IsEmpty()) {
+        *aIsHidden = PR_TRUE;
+        return NS_OK;
+      }
       frame->GetAccessible(getter_AddRefs(newAcc)); // Try using frame to do it
     }
   }

accessible/src/html/nsHTMLTableAccessible.cpp

@@ -49,7 +49,6 @@
 #include "nsIAccessibilityService.h"
 #include "nsIDOMCSSStyleDeclaration.h"
 #include "nsIDOMHTMLCollection.h"
-#include "nsIDOMHTMLTableCaptionElem.h"
 #include "nsIDOMHTMLTableCellElement.h"
 #include "nsIDOMHTMLTableElement.h"
 #include "nsIDOMHTMLTableRowElement.h"
@@ -92,7 +91,6 @@ NS_IMPL_ISUPPORTS_INHERITED1(nsHTMLTableAccessible, nsAccessible, nsIAccessibleT
 nsHTMLTableAccessible::nsHTMLTableAccessible(nsIDOMNode* aDomNode, nsIWeakReference* aShell):
 nsAccessibleWrap(aDomNode, aShell)
 { 
-  mHasCaption = PR_FALSE;
 }
 
 void nsHTMLTableAccessible::CacheChildren()
@@ -104,49 +102,35 @@ void nsHTMLTableAccessible::CacheChildren()
   }
   
   if (mAccChildCount == eChildCountUninitialized) {
-    PRInt32 childCount = 0;
-    nsCOMPtr<nsPIAccessible> privatePrevAccessible;
+    nsAccessible::CacheChildren();
     nsCOMPtr<nsIAccessible> captionAccessible;
-    GetCaption(getter_AddRefs(captionAccessible));
-    if (captionAccessible) {
-      mHasCaption = PR_TRUE;
-      SetFirstChild(captionAccessible);
-      ++ childCount;
-      privatePrevAccessible = do_QueryInterface(captionAccessible);
-      privatePrevAccessible->SetParent(this);
-    }
-    else {
-      mHasCaption = PR_FALSE;
-    }
-
-    PRBool allowsAnonChildren = PR_FALSE;
-    GetAllowsAnonChildAccessibles(&allowsAnonChildren);
-    nsAccessibleTreeWalker walker(mWeakShell, mDOMNode, allowsAnonChildren);
-    walker.mState.frame = GetFrame();
-
-    walker.GetFirstChild();
-    while (walker.mState.accessible) {
-      nsCOMPtr<nsIContent> content(do_QueryInterface(walker.mState.domNode));
-      NS_ASSERTION(content, "Creating accessible for node in HTMLTable with no content");
-      if (content && content->IsNodeOfType(nsINode::eHTML) &&
-          content->Tag() == nsAccessibilityAtoms::caption) {
-        // We have already dealt with caption, ignore this one
-        walker.GetNextSibling();
-        continue;
+    while (NextChild(captionAccessible)) {
+      if (Role(captionAccessible) == nsIAccessibleRole::ROLE_CAPTION) {
+        nsCOMPtr<nsIAccessible> captionParentAccessible;
+        captionAccessible->GetParent(getter_AddRefs(captionParentAccessible));
+        if (captionParentAccessible != this) {
+          NS_WARNING("Should not happen: parser ensures caption is the table's child, not the tbody's");
+          return;
+        }
+        nsCOMPtr<nsIAccessible> beforeCaptionAccessible;
+        captionAccessible->GetPreviousSibling(getter_AddRefs(beforeCaptionAccessible));
+        if (beforeCaptionAccessible) {
+          // Move caption accessible so that it's the first child
+          nsCOMPtr<nsIAccessible> afterCaptionAccessible;
+          captionAccessible->GetNextSibling(getter_AddRefs(afterCaptionAccessible));
+          nsCOMPtr<nsPIAccessible> privateAcc = do_QueryInterface(beforeCaptionAccessible);
+          privateAcc->SetNextSibling(afterCaptionAccessible);
+          GetFirstChild(getter_AddRefs(afterCaptionAccessible));
+          SetFirstChild(captionAccessible);
+          privateAcc = do_QueryInterface(captionAccessible);
+          privateAcc->SetNextSibling(afterCaptionAccessible);        
+        }
+        // Don't check for more captions, because nsAccessibilityService ensures
+        // we don't create accessibles for the other captions, since only the
+        // first is actually visible
+        break;
       }
-
-      ++ childCount;
-      if (privatePrevAccessible) {
-        privatePrevAccessible->SetNextSibling(walker.mState.accessible);
-      }
-      else {
-        SetFirstChild(walker.mState.accessible);
-      }
-      privatePrevAccessible = do_QueryInterface(walker.mState.accessible);
-      privatePrevAccessible->SetParent(this);
-      walker.GetNextSibling();
     }
-    mAccChildCount = childCount;
   }
 }
 
@@ -173,34 +157,14 @@ NS_IMETHODIMP nsHTMLTableAccessible::GetName(nsAString& aName)
 {
   aName.Truncate();  // Default name is blank
 
-  if (mRoleMapEntry) {
-    nsAccessible::GetName(aName);
-    if (!aName.IsEmpty()) {
-      return NS_OK;
-    }
-  }
-
-  nsCOMPtr<nsIDOMElement> element(do_QueryInterface(mDOMNode));
-  if (element) {
-    nsCOMPtr<nsIDOMNodeList> captions;
-    nsAutoString nameSpaceURI;
-    element->GetNamespaceURI(nameSpaceURI);
-    element->GetElementsByTagNameNS(nameSpaceURI, NS_LITERAL_STRING("caption"), 
-                                    getter_AddRefs(captions));
-    if (captions) {
-      nsCOMPtr<nsIDOMNode> captionNode;
-      captions->Item(0, getter_AddRefs(captionNode));
-      if (captionNode) {
-        nsCOMPtr<nsIContent> captionContent(do_QueryInterface(captionNode));
-        AppendFlatStringFromSubtree(captionContent, &aName);
-      }
-    }
-    if (aName.IsEmpty()) {
-      nsCOMPtr<nsIContent> content(do_QueryInterface(element));
-      NS_ASSERTION(content, "No content for DOM element");
+  nsAccessible::GetName(aName);
+  if (aName.IsEmpty()) {
+    nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
+    if (content) { 
       content->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::summary, aName);
     }
   }
+
   return NS_OK;
 }
 
@@ -226,65 +190,39 @@ nsHTMLTableAccessible::GetAttributesInternal(nsIPersistentProperties *aAttribute
 }
 
 NS_IMETHODIMP
-nsHTMLTableAccessible::GetCaption(nsIAccessible **aCaption)
+nsHTMLTableAccessible::GetAccessibleRelated(PRUint32 aRelationType,
+                                            nsIAccessible **aRelated)
 {
-  *aCaption = nsnull;
-  nsresult rv = NS_OK;
+  NS_ENSURE_ARG_POINTER(aRelated);
+  *aRelated = nsnull;
 
-  nsCOMPtr<nsIDOMHTMLTableElement> table(do_QueryInterface(mDOMNode));
-  NS_ENSURE_TRUE(table, NS_ERROR_FAILURE);
-
-  nsCOMPtr<nsIDOMHTMLTableCaptionElement> caption;
-  rv = table->GetCaption(getter_AddRefs(caption));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  nsCOMPtr<nsIDOMNode> captionNode(do_QueryInterface(caption));
-  if (!captionNode) {
-    return NS_OK;
+  if (!mDOMNode) {
+    return NS_ERROR_FAILURE;
   }
 
-  nsCOMPtr<nsIAccessibilityService> accService = GetAccService();
-  NS_ENSURE_TRUE(accService, NS_ERROR_FAILURE);
-
-  accService->GetCachedAccessible(captionNode, mWeakShell, aCaption);
-  if (*aCaption)
-    return NS_OK;
-
-  nsCOMPtr<nsIPresShell> presShell(GetPresShell());
-  nsCOMPtr<nsIContent> content(do_QueryInterface(captionNode));
-  NS_ENSURE_TRUE(presShell && content, NS_ERROR_FAILURE);
-  nsIFrame* frame = presShell->GetPrimaryFrameFor(content);
-  if (!frame) {
-    return NS_OK;
+  nsresult rv = nsAccessibleWrap::GetAccessibleRelated(aRelationType, aRelated);
+  if (NS_FAILED(rv) || *aRelated) {
+    // Either the node is shut down, or another relation mechanism has been used
+    return rv;
   }
-  accService->CreateHyperTextAccessible(frame, aCaption);
-  nsCOMPtr<nsPIAccessNode> accessNode(do_QueryInterface(*aCaption));
-  return accessNode ? accessNode->Init() : NS_ERROR_FAILURE;
+
+  if (aRelationType == nsIAccessibleRelation::RELATION_DESCRIBED_BY) {
+    return GetCaption(aRelated);
+  }
+
+  return NS_OK;
 }
 
+
 NS_IMETHODIMP
-nsHTMLTableAccessible::SetCaption(nsIAccessible *aCaption)
+nsHTMLTableAccessible::GetCaption(nsIAccessible **aCaption)
 {
-  nsresult rv = NS_OK;
-
-  nsCOMPtr<nsIDOMHTMLTableElement> table(do_QueryInterface(mDOMNode));
-  NS_ENSURE_TRUE(table, NS_ERROR_FAILURE);
-
-  nsCOMPtr<nsIAccessNode> accessNode(do_QueryInterface(aCaption));
-  NS_ASSERTION(accessNode, "Unable to QI to nsIAccessNode");
-  nsCOMPtr<nsIDOMNode> domNode;
-  rv = accessNode->GetDOMNode(getter_AddRefs(domNode));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  nsCOMPtr<nsIDOMNode> newDOMNode;
-  rv = domNode->CloneNode(PR_TRUE, getter_AddRefs(newDOMNode));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  nsCOMPtr<nsIDOMHTMLTableCaptionElement>
-    captionElement(do_QueryInterface(newDOMNode));
-  NS_ENSURE_TRUE(captionElement, NS_ERROR_FAILURE);
-
-  return table->SetCaption(captionElement);
+  nsCOMPtr<nsIAccessible> firstChild;
+  GetFirstChild(getter_AddRefs(firstChild));
+  if (firstChild && Role(firstChild) == nsIAccessibleRole::ROLE_CAPTION) {
+    NS_ADDREF(*aCaption = firstChild);
+  }
+  return NS_OK;
 }
 
 NS_IMETHODIMP
@@ -296,15 +234,6 @@ nsHTMLTableAccessible::GetSummary(nsAString &aSummary)
   return table->GetSummary(aSummary);
 }
 
-NS_IMETHODIMP
-nsHTMLTableAccessible::SetSummary(const nsAString &aSummary)
-{
-  nsCOMPtr<nsIDOMHTMLTableElement> table(do_QueryInterface(mDOMNode));
-  NS_ENSURE_TRUE(table, NS_ERROR_FAILURE);
-
-  return table->SetSummary(aSummary);
-}
-
 NS_IMETHODIMP
 nsHTMLTableAccessible::GetColumns(PRInt32 *aColumns)
 {
@@ -820,20 +749,39 @@ nsHTMLTableAccessible::GetCellAt(PRInt32        aRowIndex,
                                     isSelected);
 }
 
-#ifdef SHOW_LAYOUT_HEURISTIC
 NS_IMETHODIMP nsHTMLTableAccessible::GetDescription(nsAString& aDescription)
 {
   // Helpful for debugging layout vs. data tables
   aDescription.Truncate();
-  PRBool isProbablyForLayout;
-  IsProbablyForLayout(&isProbablyForLayout);
-  aDescription = mLayoutHeuristic;
+  nsAccessible::GetDescription(aDescription);
+  if (!aDescription.IsEmpty()) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIAccessible> captionAccessible;
+  GetCaption(getter_AddRefs(captionAccessible));
+  nsCOMPtr<nsIAccessNode> captionAccessNode = do_QueryInterface(captionAccessible);
+  if (captionAccessNode) {
+    nsCOMPtr<nsIDOMNode> captionNode;
+    captionAccessNode->GetDOMNode(getter_AddRefs(captionNode));
+    nsCOMPtr<nsIContent> captionContent = do_QueryInterface(captionNode);
+    if (captionContent) {
+      AppendFlatStringFromSubtree(captionContent, &aDescription);
+    }
+  }
+#ifdef SHOW_LAYOUT_HEURISTIC
+  if (aDescription.IsEmpty()) {
+    PRBool isProbablyForLayout;
+    IsProbablyForLayout(&isProbablyForLayout);
+    aDescription = mLayoutHeuristic;
+  }
 #ifdef DEBUG_A11Y
   printf("\nTABLE: %s\n", NS_ConvertUTF16toUTF8(mLayoutHeuristic).get());
 #endif
+#endif
+
   return NS_OK;
 }
-#endif
 
 PRBool nsHTMLTableAccessible::HasDescendant(char *aTagName, PRBool aAllowEmpty)
 {
@@ -1059,24 +1007,12 @@ nsHTMLTableHeadAccessible::GetCaption(nsIAccessible **aCaption)
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
-NS_IMETHODIMP
-nsHTMLTableHeadAccessible::SetCaption(nsIAccessible *aCaption)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 NS_IMETHODIMP
 nsHTMLTableHeadAccessible::GetSummary(nsAString &aSummary)
 {
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
-NS_IMETHODIMP
-nsHTMLTableHeadAccessible::SetSummary(const nsAString &aSummary)
-{
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 NS_IMETHODIMP
 nsHTMLTableHeadAccessible::GetColumnHeader(nsIAccessibleTable **aColumnHeader)
 {
@@ -1098,3 +1034,29 @@ nsHTMLTableHeadAccessible::GetRows(PRInt32 *aRows)
   return rows->GetLength((PRUint32 *)aRows);
 }
 
+NS_IMETHODIMP
+nsHTMLCaptionAccessible::GetAccessibleRelated(PRUint32 aRelationType,
+                                              nsIAccessible **aRelated)
+{
+  NS_ENSURE_ARG_POINTER(aRelated);
+  *aRelated = nsnull;
+
+  if (!mDOMNode) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsresult rv = nsHyperTextAccessible::GetAccessibleRelated(aRelationType, aRelated);
+  if (NS_FAILED(rv) || *aRelated) {
+    // Either the node is shut down, or another relation mechanism has been used
+    return rv;
+  }
+
+  if (aRelationType == nsIAccessibleRelation::RELATION_DESCRIPTION_FOR) {
+    return GetParent(aRelated);
+  }
+
+  return NS_OK;
+}
+
+
+

accessible/src/html/nsHTMLTableAccessible.h

@@ -71,9 +71,8 @@ public:
   NS_IMETHOD GetState(PRUint32 *aState, PRUint32 *aExtraState);
   NS_IMETHOD GetName(nsAString& aResult);
   virtual nsresult GetAttributesInternal(nsIPersistentProperties *aAttributes);
-#ifdef SHOW_LAYOUT_HEURISTIC
   NS_IMETHOD GetDescription(nsAString& aDescription);
-#endif
+  NS_IMETHOD GetAccessibleRelated(PRUint32 aRelationType, nsIAccessible **aRelated);
 
 protected:
 
@@ -106,7 +105,6 @@ protected:
                      PRInt32        aColIndex,
                      nsIDOMElement* &aCell);
   PRBool HasDescendant(char *aTagName, PRBool aAllowEmpty = PR_TRUE);
-  PRBool mHasCaption;
 #ifdef SHOW_LAYOUT_HEURISTIC
   nsAutoString mLayoutHeuristic;
 #endif
@@ -124,11 +122,21 @@ public:
 
   /* nsIAccessibleTable */
   NS_IMETHOD GetCaption(nsIAccessible **aCaption);
-  NS_IMETHOD SetCaption(nsIAccessible *aCaption);
   NS_IMETHOD GetSummary(nsAString &aSummary);
-  NS_IMETHOD SetSummary(const nsAString &aSummary);
   NS_IMETHOD GetColumnHeader(nsIAccessibleTable **aColumnHeader);
   NS_IMETHOD GetRows(PRInt32 *aRows);
 };
 
+class nsHTMLCaptionAccessible : public nsHyperTextAccessibleWrap
+{
+public:
+  nsHTMLCaptionAccessible(nsIDOMNode *aDomNode, nsIWeakReference *aShell) :
+    nsHyperTextAccessibleWrap(aDomNode, aShell) { }
+
+  // nsIAccessible
+  NS_IMETHOD GetRole(PRUint32 *aRole)
+    { *aRole = nsIAccessibleRole::ROLE_CAPTION; return NS_OK; }
+  NS_IMETHOD GetAccessibleRelated(PRUint32 aRelationType, nsIAccessible **aRelated);
+};
+
 #endif  

accessible/src/html/nsHyperTextAccessible.cpp

@@ -140,10 +140,7 @@ NS_IMETHODIMP nsHyperTextAccessible::GetRole(PRUint32 *aRole)
 
   nsIAtom *tag = content->Tag();
 
-  if (tag == nsAccessibilityAtoms::caption) {
-    *aRole = nsIAccessibleRole::ROLE_CAPTION;
-  }
-  else if (tag == nsAccessibilityAtoms::form) {
+  if (tag == nsAccessibilityAtoms::form) {
     *aRole = nsIAccessibleRole::ROLE_FORM;
   }
   else if (tag == nsAccessibilityAtoms::div ||

layout/tables/nsTableOuterFrame.cpp

@@ -137,6 +137,21 @@ nsTableCaptionFrame::GetParentStyleContextFrame(nsPresContext* aPresContext,
                                                   aIsChild);
 }
 
+#ifdef ACCESSIBILITY
+NS_IMETHODIMP nsTableCaptionFrame::GetAccessible(nsIAccessible** aAccessible)
+{
+  *aAccessible = nsnull;
+  if (!GetRect().IsEmpty()) {
+    nsCOMPtr<nsIAccessibilityService> accService = do_GetService("@mozilla.org/accessibilityService;1");
+    if (accService) {
+      return accService->CreateHTMLCaptionAccessible(NS_STATIC_CAST(nsIFrame*, this), aAccessible);
+    }
+  }
+
+  return NS_ERROR_FAILURE;
+}
+#endif
+
 #ifdef NS_DEBUG
 NS_IMETHODIMP
 nsTableCaptionFrame::GetFrameName(nsAString& aResult) const

layout/tables/nsTableOuterFrame.h

@@ -60,6 +60,10 @@ public:
   NS_IMETHOD GetParentStyleContextFrame(nsPresContext* aPresContext,
                                         nsIFrame**      aProviderFrame,
                                         PRBool*         aIsChild);
+#ifdef ACCESSIBILITY
+  NS_IMETHOD GetAccessible(nsIAccessible** aAccessible);
+#endif
+
 #ifdef NS_DEBUG
   NS_IMETHOD GetFrameName(nsAString& aResult) const;
 #endif