Notify MSAA clients when a state change notification is received.

BUG=36165
TEST=The screen reader JAWS should speak the checked state of a check box when it is toggled. 

Review URL: http://codereview.chromium.org/693002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@40998 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 64 insertions, 0 deletions

diff --git a/chrome/browser/browser_accessibility_manager.cc b/chrome/browser/browser_accessibility_manager.cc
index ccbf5b8..cd53e72 100644
--- a/chrome/browser/browser_accessibility_manager.cc
+++ b/chrome/browser/browser_accessibility_manager.cc
@@ -110,6 +110,19 @@ bool BrowserAccessibilityManager::ChangeAccessibilityFocus(int acc_obj_id,
   return false;
 }
 
+bool BrowserAccessibilityManager::OnAccessibilityObjectStateChange(
+    int acc_obj_id, int process_id, int routing_id) {
+  BrowserAccessibility* browser_acc =
+      GetBrowserAccessibility(process_id, routing_id);
+  if (browser_acc) {
+    // Notify Access Technology that there was a change in state.
+    ::NotifyWinEvent(EVENT_OBJECT_STATECHANGE, browser_acc->parent_hwnd(),
+                     OBJID_CLIENT, static_cast<LONG>(acc_obj_id));
+    return true;
+  }
+  return false;
+}
+
 const WebAccessibility::OutParams& BrowserAccessibilityManager::response() {
   return out_params_;
 }
diff --git a/chrome/browser/browser_accessibility_manager.h b/chrome/browser/browser_accessibility_manager.h
index 4af1363..4850242 100644
--- a/chrome/browser/browser_accessibility_manager.h
+++ b/chrome/browser/browser_accessibility_manager.h
@@ -56,6 +56,12 @@ class BrowserAccessibilityManager : public NotificationObserver {
   // platform-specific channels.
   bool ChangeAccessibilityFocus(int acc_obj_id, int process_id, int routing_id);
 
+  // Notifies assistive technology that an object's state changed, through the
+  // platform-specific channels.
+  bool OnAccessibilityObjectStateChange(int acc_obj_id,
+                                        int process_id,
+                                        int routing_id);
+
   // Wrapper function, for cleaner code.
   const WebAccessibility::OutParams& response();
 
diff --git a/chrome/browser/renderer_host/render_view_host.cc b/chrome/browser/renderer_host/render_view_host.cc
index c6f673a..59ba321 100644
--- a/chrome/browser/renderer_host/render_view_host.cc
+++ b/chrome/browser/renderer_host/render_view_host.cc
@@ -813,6 +813,8 @@ void RenderViewHost::OnMessageReceived(const IPC::Message& msg) {
                         OnExtensionPostMessage)
     IPC_MESSAGE_HANDLER(ViewHostMsg_AccessibilityFocusChange,
                         OnAccessibilityFocusChange)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_AccessibilityObjectStateChange,
+                        OnAccessibilityObjectStateChange)
     IPC_MESSAGE_HANDLER(ViewHostMsg_OnCSSInserted, OnCSSInserted)
     IPC_MESSAGE_HANDLER(ViewHostMsg_PageContents, OnPageContents)
     IPC_MESSAGE_HANDLER(ViewHostMsg_PageTranslated, OnPageTranslated)
@@ -1815,6 +1817,15 @@ void RenderViewHost::OnAccessibilityFocusChange(int acc_obj_id) {
 #endif
 }
 
+void RenderViewHost::OnAccessibilityObjectStateChange(int acc_obj_id) {
+#if defined(OS_WIN)
+  BrowserAccessibilityManager::GetInstance()->OnAccessibilityObjectStateChange(
+      acc_obj_id, process()->id(), routing_id());
+#else
+  // TODO(port): accessibility not yet implemented. See http://crbug.com/8288.
+#endif
+}
+
 void RenderViewHost::OnCSSInserted() {
   delegate_->DidInsertCSS();
 }
diff --git a/chrome/browser/renderer_host/render_view_host.h b/chrome/browser/renderer_host/render_view_host.h
index d7ad3e9a7..e860dc2 100644
--- a/chrome/browser/renderer_host/render_view_host.h
+++ b/chrome/browser/renderer_host/render_view_host.h
@@ -607,6 +607,7 @@ class RenderViewHost : public RenderWidgetHost {
                           int request_id, bool has_callback);
   void OnExtensionPostMessage(int port_id, const std::string& message);
   void OnAccessibilityFocusChange(int acc_obj_id);
+  void OnAccessibilityObjectStateChange(int acc_obj_id);
   void OnCSSInserted();
   void OnPageContents(const GURL& url,
                       int32 page_id,
diff --git a/chrome/common/render_messages_internal.h b/chrome/common/render_messages_internal.h
index dc852f7..7c6755b 100644
--- a/chrome/common/render_messages_internal.h
+++ b/chrome/common/render_messages_internal.h
@@ -2033,6 +2033,12 @@ IPC_BEGIN_MESSAGES(ViewHost)
   IPC_MESSAGE_ROUTED1(ViewHostMsg_AccessibilityFocusChange,
                       int /* accessibility object id */)
 
+  // Send as a result of a state change in the renderer (if accessibility is
+  // enabled), to notify the browser side. Takes the id of the accessibility
+  // object that had a state change
+  IPC_MESSAGE_ROUTED1(ViewHostMsg_AccessibilityObjectStateChange,
+                      int /* accessibility object id */)
+
   // Message sent from the renderer to the browser to request that the browser
   // close all sockets.  Used for debugging/testing.
   IPC_MESSAGE_CONTROL0(ViewHostMsg_CloseCurrentConnections)
diff --git a/chrome/renderer/render_view.cc b/chrome/renderer/render_view.cc
index d511825..f18d06b 100644
--- a/chrome/renderer/render_view.cc
+++ b/chrome/renderer/render_view.cc
@@ -4411,6 +4411,31 @@ void RenderView::SendForms(WebFrame* frame) {
     Send(new ViewHostMsg_FormsSeen(routing_id_, forms));
 }
 
+void RenderView::didChangeAccessibilityObjectState(
+    const WebKit::WebAccessibilityObject& acc_obj) {
+#if defined(OS_WIN)
+  // TODO(dglazkov): Current logic implies that a state change can only be made
+  // after at least one call to RenderView::OnGetAccessibilityInfo, which is
+  // where accessibility is initialized. We should determine whether that's
+  // right.
+  if (!accessibility_.get())
+    return;
+
+  // Retrieve the accessibility object id of the AccessibilityObject.
+  int acc_obj_id = accessibility_->addOrGetId(acc_obj);
+
+  // If id is valid, alert the browser side that an accessibility object state
+  // change occurred.
+  if (acc_obj_id >= 0)
+    Send(new ViewHostMsg_AccessibilityObjectStateChange(routing_id_,
+                                                        acc_obj_id));
+
+#else  // defined(OS_WIN)
+  // TODO(port): accessibility not yet implemented
+  NOTIMPLEMENTED();
+#endif
+}
+
 void RenderView::SendPasswordForms(WebFrame* frame) {
   WebVector<WebFormElement> forms;
   frame->forms(forms);
diff --git a/chrome/renderer/render_view.h b/chrome/renderer/render_view.h
index c149320..b0db68f 100644
--- a/chrome/renderer/render_view.h
+++ b/chrome/renderer/render_view.h
@@ -259,6 +259,8 @@ class RenderView : public RenderWidget,
   virtual void didAddHistoryItem();
   virtual void focusAccessibilityObject(
       const WebKit::WebAccessibilityObject& acc_obj);
+  virtual void didChangeAccessibilityObjectState(
+      const WebKit::WebAccessibilityObject& acc_obj);
   virtual void didUpdateInspectorSettings();
   virtual void queryAutofillSuggestions(
       const WebKit::WebNode& node, const WebKit::WebString& name,