Bug 705179 - Implement initial canvas accessible and baseline test. r=surkov,ehsan

accessible/src/base/nsAccessibilityService.cpp

@@ -50,6 +50,7 @@
 #include "nsIContentViewer.h"
 #include "nsCURILoader.h"
 #include "nsDocAccessible.h"
+#include "nsHTMLCanvasAccessible.h"
 #include "nsHTMLImageMapAccessible.h"
 #include "nsHTMLLinkAccessible.h"
 #include "nsHTMLSelectAccessible.h"
@@ -275,6 +276,16 @@ nsAccessibilityService::CreateHTMLComboboxAccessible(nsIContent* aContent,
   return accessible;
 }
 
+already_AddRefed<nsAccessible>
+nsAccessibilityService::CreateHTMLCanvasAccessible(nsIContent* aContent,
+                                                   nsIPresShell* aPresShell)
+{
+  nsCOMPtr<nsIWeakReference> weakShell(do_GetWeakReference(aPresShell));
+  nsAccessible* accessible = new nsHTMLCanvasAccessible(aContent, weakShell);
+  NS_IF_ADDREF(accessible);
+  return accessible;
+}
+
 already_AddRefed<nsAccessible>
 nsAccessibilityService::CreateHTMLImageAccessible(nsIContent* aContent,
                                                   nsIPresShell* aPresShell)

accessible/src/base/nsAccessibilityService.h

@@ -83,6 +83,8 @@ public:
     CreateHTML4ButtonAccessible(nsIContent* aContent, nsIPresShell* aPresShell);
   virtual already_AddRefed<nsAccessible>
     CreateHTMLButtonAccessible(nsIContent* aContent, nsIPresShell* aPresShell);
+  already_AddRefed<nsAccessible>
+    CreateHTMLCanvasAccessible(nsIContent* aContent, nsIPresShell* aPresShell);
   virtual already_AddRefed<nsAccessible>
     CreateHTMLCaptionAccessible(nsIContent* aContent, nsIPresShell* aPresShell);
   virtual already_AddRefed<nsAccessible>

accessible/src/html/Makefile.in

@@ -50,6 +50,7 @@ LIBXUL_LIBRARY = 1
 
 
 CPPSRCS = \
+  nsHTMLCanvasAccessible.cpp \
   nsHTMLFormControlAccessible.cpp \
   nsHTMLImageAccessible.cpp \
   nsHTMLImageMapAccessible.cpp \

accessible/src/html/nsHTMLCanvasAccessible.cpp

@@ -0,0 +1,52 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Foundation
+ * Portions created by the Initial Developer are Copyright (C) 2011
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include "nsHTMLCanvasAccessible.h"
+
+using namespace mozilla::a11y;
+
+nsHTMLCanvasAccessible::
+  nsHTMLCanvasAccessible(nsIContent* aContent, nsIWeakReference* aShell) :
+  nsHyperTextAccessible(aContent, aShell)
+{
+}
+
+PRUint32
+nsHTMLCanvasAccessible::NativeRole()
+{
+  return nsIAccessibleRole::ROLE_CANVAS;
+}

accessible/src/html/nsHTMLCanvasAccessible.h

@@ -0,0 +1,56 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Foundation
+ * Portions created by the Initial Developer are Copyright (C) 2011
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include "nsHyperTextAccessible.h"
+
+#ifndef _nsHTMLCanvasAccessible_H_
+#define _nsHTMLCanvasAccessible_H_
+
+/**
+ * HTML canvas accessible (html:canvas).
+ */
+class nsHTMLCanvasAccessible : public nsHyperTextAccessible
+{
+public:
+  nsHTMLCanvasAccessible(nsIContent* aContent, nsIWeakReference* aShell);
+  virtual ~nsHTMLCanvasAccessible() { }
+
+  // nsAccessible
+  virtual PRUint32 NativeRole();
+};
+
+#endif

accessible/tests/mochitest/role.js

@@ -7,6 +7,7 @@ const ROLE_APPLICATION = nsIAccessibleRole.ROLE_APPLICATION;
 const ROLE_APP_ROOT = nsIAccessibleRole.ROLE_APP_ROOT;
 const ROLE_AUTOCOMPLETE = nsIAccessibleRole.ROLE_AUTOCOMPLETE;
 const ROLE_BUTTONDROPDOWNGRID = nsIAccessibleRole.ROLE_BUTTONDROPDOWNGRID;
+const ROLE_CANVAS = nsIAccessibleRole.ROLE_CANVAS;
 const ROLE_CAPTION = nsIAccessibleRole.ROLE_CAPTION;
 const ROLE_CELL = nsIAccessibleRole.ROLE_CELL;
 const ROLE_CHECKBUTTON = nsIAccessibleRole.ROLE_CHECKBUTTON;

accessible/tests/mochitest/tree/Makefile.in

@@ -52,6 +52,7 @@ _TEST_FILES =\
 		test_aria_imgmap.html \
 		test_aria_presentation.html \
 		test_button.xul \
+		test_canvas.html \
 		test_combobox.xul \
 		test_cssoverflow.html \
 		test_dochierarchy.html \

accessible/tests/mochitest/tree/test_canvas.html

@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=495912
+-->
+<head>
+  <title>File Input Control tests</title>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css" />
+
+  <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">
+    function doTest()
+    {
+      var accTree = {
+        role: ROLE_CANVAS,
+        children: [
+        ]
+      };
+      testAccessibleTree("canvas", accTree);
+
+      SimpleTest.finish();
+    }
+
+    SimpleTest.waitForExplicitFinish();
+    addA11yLoadEvent(doTest);
+  </script>
+</head>
+<body>
+
+  <a target="_blank"
+     title="Expose alternative content in Canvas element to ATs"
+     href="https://bugzilla.mozilla.org/show_bug.cgi?id=495912">Mozilla Bug 495912</a>
+  <p id="display"></p>
+  <div id="content" style="display: none"></div>
+  <pre id="test">
+  </pre>
+
+  <canvas id="canvas" tabindex="0">
+    fallback content.
+  </canvas>
+
+  <script type="text/javascript">
+    var c=document.getElementById("canvas");
+    var cxt=c.getContext("2d");
+    cxt.fillStyle="#005500";
+    cxt.fillRect(0,0,150,75);
+  </script>  
+
+</body>
+</html>

layout/generic/nsHTMLCanvasFrame.cpp

@@ -52,6 +52,10 @@
 
 #include "gfxContext.h"
 
+#ifdef ACCESSIBILITY
+#include "nsAccessibilityService.h"
+#endif
+
 using namespace mozilla;
 using namespace mozilla::layers;
 
@@ -360,6 +364,10 @@ nsHTMLCanvasFrame::GetContinuationOffset(nscoord* aWidth) const
 already_AddRefed<nsAccessible>
 nsHTMLCanvasFrame::CreateAccessible()
 {
+  nsAccessibilityService* accService = nsIPresShell::AccService();
+  if (accService) {
+    return accService->CreateHTMLCanvasAccessible(mContent, PresContext()->PresShell());
+  }
   return nsnull;
 }
 #endif