Bug 194977. Support <label> elements as ROLE_STATICTEXT like IE does, fix use of label name for controls when no form element. r=kyle, sr=henry

accessible/public/nsIAccessibilityService.idl

@@ -49,7 +49,9 @@ interface nsIAccessibilityService : nsISupports
   nsIAccessible createHTMLCheckboxAccessibleXBL(in nsIDOMNode aNode);
   nsIAccessible createHTMLComboboxAccessible(in nsIDOMNode aNode, in nsISupports aPresShell);
   nsIAccessible createHTMLGroupboxAccessible(in nsISupports aFrame);
+  nsIAccessible createHTMLHRAccessible(in nsISupports aFrame);
   nsIAccessible createHTMLImageAccessible(in nsISupports aFrame);
+  nsIAccessible createHTMLLabelAccessible(in nsISupports aFrame);
   nsIAccessible createHTMLListboxAccessible(in nsIDOMNode aNode, in nsISupports aPresShell);
   nsIAccessible createHTMLNativeWindowAccessible(in nsIDOMNode aDOMNode, in nsIWeakReference aShell, in PRInt32 aHWnd);
   nsIAccessible createHTMLPluginAccessible(in nsIDOMNode aDOMNode, in nsIWeakReference aShell);
@@ -62,7 +64,6 @@ interface nsIAccessibilityService : nsISupports
   nsIAccessible createHTMLTableHeadAccessible(in nsIDOMNode aDOMNode);
   nsIAccessible createHTMLTextAccessible(in nsISupports aFrame);
   nsIAccessible createHTMLTextFieldAccessible(in nsISupports aFrame);
-  nsIAccessible createHTMLHRAccessible(in nsISupports aFrame);
 
   nsIAccessible createXULButtonAccessible(in nsIDOMNode aNode);
   nsIAccessible createXULCheckboxAccessible(in nsIDOMNode aNode);

accessible/src/base/nsAccessibilityService.cpp

@@ -839,6 +839,24 @@ nsAccessibilityService::CreateHTMLTextFieldAccessible(nsISupports *aFrame, nsIAc
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsAccessibilityService::CreateHTMLLabelAccessible(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 nsHTMLLabelAccessible(node, weakShell);
+  if (! *_retval) 
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  NS_ADDREF(*_retval);
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsAccessibilityService::CreateHTMLHRAccessible(nsISupports *aFrame, nsIAccessible **_retval)
 {

accessible/src/base/nsAccessible.cpp

@@ -1483,6 +1483,9 @@ NS_IMETHODIMP nsAccessible::AppendLabelFor(nsIContent *aLookNode, const nsAStrin
   */
 NS_IMETHODIMP nsAccessible::GetHTMLAccName(nsAString& _retval)
 {
+  if (!mDOMNode) {
+    return NS_ERROR_FAILURE;
+  }
   nsCOMPtr<nsIContent> walkUpContent(do_QueryInterface(mDOMNode));
   nsCOMPtr<nsIDOMHTMLLabelElement> labelElement;
   nsCOMPtr<nsIDOMHTMLFormElement> formElement;
@@ -1490,20 +1493,25 @@ NS_IMETHODIMP nsAccessible::GetHTMLAccName(nsAString& _retval)
 
   nsAutoString label;
   // go up tree get name of ancestor label if there is one. Don't go up farther than form element
-  while (walkUpContent && label.IsEmpty() && !formElement) {
+  while (label.IsEmpty() && !formElement) {
     labelElement = do_QueryInterface(walkUpContent);
     if (labelElement) 
       rv = AppendFlatStringFromSubtree(walkUpContent, &label);
     formElement = do_QueryInterface(walkUpContent); // reached top ancestor in form
+    if (formElement) {
+      break;
+    }
     nsCOMPtr<nsIContent> nextParent;
     walkUpContent->GetParent(*getter_AddRefs(nextParent));
+    if (!nextParent) {
+      break;
+    }
     walkUpContent = nextParent;
   }
   
 
   // There can be a label targeted at this control using the for="control_id" attribute
   // To save computing time, only look for those inside of a form element
-  walkUpContent = do_QueryInterface(formElement);
   
   if (walkUpContent) {
     nsCOMPtr<nsIDOMElement> elt(do_QueryInterface(mDOMNode));

accessible/src/html/nsHTMLTextAccessible.cpp

@@ -97,3 +97,59 @@ NS_IMETHODIMP nsHTMLBlockAccessible::GetAccState(PRUint32 *aState)
   *aState &= ~STATE_FOCUSABLE;
   return NS_OK;
 }
+
+nsHTMLLabelAccessible::nsHTMLLabelAccessible(nsIDOMNode* aDomNode, nsIWeakReference* aShell):
+nsTextAccessible(aDomNode, aShell)
+{ 
+}
+
+NS_IMETHODIMP nsHTMLLabelAccessible::GetAccName(nsAString& aReturn)
+{ 
+  nsresult rv = NS_ERROR_FAILURE;
+  nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
+
+  nsAutoString name;
+  if (content)
+    rv = AppendFlatStringFromSubtree(content, &name);
+
+  if (NS_SUCCEEDED(rv)) {
+    // Temp var needed until CompressWhitespace built for nsAString
+    name.CompressWhitespace();
+    aReturn = name;
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP nsHTMLLabelAccessible::GetAccRole(PRUint32 *aRole)
+{
+  *aRole = ROLE_STATICTEXT;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsHTMLLabelAccessible::GetAccState(PRUint32 *aState)
+{
+  nsTextAccessible::GetAccState(aState);
+  *aState &= (STATE_LINKED|STATE_TRAVERSED);  // Only use link states
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsHTMLLabelAccessible::GetAccFirstChild(nsIAccessible **aAccFirstChild) 
+{  
+  // A <label> is not necessarily a leaf!
+  return nsAccessible::GetAccFirstChild(aAccFirstChild);
+}
+
+  /* readonly attribute nsIAccessible accFirstChild; */
+NS_IMETHODIMP nsHTMLLabelAccessible::GetAccLastChild(nsIAccessible **aAccLastChild)
+{  
+  // A <label> is not necessarily a leaf!
+  return nsAccessible::GetAccLastChild(aAccLastChild);
+}
+
+/* readonly attribute long accChildCount; */
+NS_IMETHODIMP nsHTMLLabelAccessible::GetAccChildCount(PRInt32 *aAccChildCount) 
+{
+  // A <label> is not necessarily a leaf!
+  return nsAccessible::GetAccChildCount(aAccChildCount);
+}

accessible/src/html/nsHTMLTextAccessible.h

@@ -72,4 +72,17 @@ public:
   NS_IMETHOD GetAccState(PRUint32 *aState); 
 };
 
+class nsHTMLLabelAccessible : public nsTextAccessible 
+{
+
+public:
+  nsHTMLLabelAccessible(nsIDOMNode* aDomNode, nsIWeakReference* aShell);
+  NS_IMETHOD GetAccName(nsAString& _retval);
+  NS_IMETHOD GetAccRole(PRUint32 *_retval); 
+  NS_IMETHOD GetAccState(PRUint32 *_retval); 
+  NS_IMETHOD GetAccFirstChild(nsIAccessible **aAccFirstChild);
+  NS_IMETHOD GetAccLastChild(nsIAccessible **aAccLastChild);
+  NS_IMETHOD GetAccChildCount(PRInt32 *aAccChildCount);
+};
+
 #endif  

layout/generic/nsInlineFrame.cpp

@@ -919,7 +919,8 @@ NS_IMETHODIMP nsInlineFrame::GetAccessible(nsIAccessible** aAccessible)
   *aAccessible = nsnull;
   nsCOMPtr<nsIAtom> tagAtom;
   mContent->GetTag(*getter_AddRefs(tagAtom));
-  if (tagAtom == nsHTMLAtoms::img || tagAtom == nsHTMLAtoms::input || tagAtom == nsHTMLAtoms::hr) {
+  if (tagAtom == nsHTMLAtoms::img || tagAtom == nsHTMLAtoms::input || 
+     tagAtom == nsHTMLAtoms::label || tagAtom == nsHTMLAtoms::hr) {
     // Only get accessibility service if we're going to use it
     nsCOMPtr<nsIAccessibilityService> accService(do_GetService("@mozilla.org/accessibilityService;1"));
     if (!accService)
@@ -928,6 +929,8 @@ NS_IMETHODIMP nsInlineFrame::GetAccessible(nsIAccessible** aAccessible)
       return accService->CreateHTML4ButtonAccessible(NS_STATIC_CAST(nsIFrame*, this), aAccessible);
     else if (tagAtom == nsHTMLAtoms::img)  // Create accessible for broken <img>
       return accService->CreateHTMLImageAccessible(NS_STATIC_CAST(nsIFrame*, this), aAccessible);
+    else if (tagAtom == nsHTMLAtoms::label)  // Creat accessible for <label>
+      return accService->CreateHTMLLabelAccessible(NS_STATIC_CAST(nsIFrame*, this), aAccessible);
     // Create accessible for <hr>
     return accService->CreateHTMLHRAccessible(NS_STATIC_CAST(nsIFrame*, this), aAccessible);
   }

layout/html/base/src/nsInlineFrame.cpp

@@ -919,7 +919,8 @@ NS_IMETHODIMP nsInlineFrame::GetAccessible(nsIAccessible** aAccessible)
   *aAccessible = nsnull;
   nsCOMPtr<nsIAtom> tagAtom;
   mContent->GetTag(*getter_AddRefs(tagAtom));
-  if (tagAtom == nsHTMLAtoms::img || tagAtom == nsHTMLAtoms::input || tagAtom == nsHTMLAtoms::hr) {
+  if (tagAtom == nsHTMLAtoms::img || tagAtom == nsHTMLAtoms::input || 
+     tagAtom == nsHTMLAtoms::label || tagAtom == nsHTMLAtoms::hr) {
     // Only get accessibility service if we're going to use it
     nsCOMPtr<nsIAccessibilityService> accService(do_GetService("@mozilla.org/accessibilityService;1"));
     if (!accService)
@@ -928,6 +929,8 @@ NS_IMETHODIMP nsInlineFrame::GetAccessible(nsIAccessible** aAccessible)
       return accService->CreateHTML4ButtonAccessible(NS_STATIC_CAST(nsIFrame*, this), aAccessible);
     else if (tagAtom == nsHTMLAtoms::img)  // Create accessible for broken <img>
       return accService->CreateHTMLImageAccessible(NS_STATIC_CAST(nsIFrame*, this), aAccessible);
+    else if (tagAtom == nsHTMLAtoms::label)  // Creat accessible for <label>
+      return accService->CreateHTMLLabelAccessible(NS_STATIC_CAST(nsIFrame*, this), aAccessible);
     // Create accessible for <hr>
     return accService->CreateHTMLHRAccessible(NS_STATIC_CAST(nsIFrame*, this), aAccessible);
   }