Revert 46842 - Reimplement accessibility of web content by caching the entire...

chrome/browser/renderer_host/render_widget_host_view_win.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/renderer_host/render_widget_host_view_win.h"
 
 #include "app/l10n_util.h"
 #include "app/l10n_util_win.h"
 #include "app/resource_bundle.h"
 #include "base/command_line.h"
 #include "base/histogram.h"
 #include "base/i18n/rtl.h"
 #include "base/process_util.h"
 #include "base/thread.h"
 #include "base/win_util.h"
-#include "chrome/browser/browser_accessibility.h"
 #include "chrome/browser/browser_accessibility_manager.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_trial.h"
 #include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/plugin_process_host.h"
 #include "chrome/browser/renderer_host/backing_store.h"
 #include "chrome/browser/renderer_host/backing_store_win.h"
 #include "chrome/browser/renderer_host/gpu_view_host.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
 #include "chrome/browser/renderer_host/render_widget_host.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/native_web_keyboard_event.h"
-#include "chrome/common/notification_service.h"
 #include "chrome/common/plugin_messages.h"
 #include "chrome/common/render_messages.h"
 #include "gfx/canvas.h"
 #include "gfx/gdi_util.h"
 #include "gfx/rect.h"
 #include "grit/webkit_resources.h"
 #include "skia/ext/skia_utils_win.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebInputEvent.h"
 #include "third_party/WebKit/WebKit/chromium/public/win/WebInputEventFactory.h"
 #include "views/accessibility/view_accessibility.h"
@@ skipping 239 matching lines @@
       tooltip_hwnd_(NULL),
       tooltip_showing_(false),
       shutdown_factory_(this),
       parent_hwnd_(NULL),
       is_loading_(false),
       visually_deemphasized_(false) {
   render_widget_host_->set_view(this);
   renderer_accessible_ =
       CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableRendererAccessibility);
-  registrar_.Add(this,
-                 NotificationType::RENDERER_PROCESS_TERMINATED,
-                 NotificationService::AllSources());
 }
 
 RenderWidgetHostViewWin::~RenderWidgetHostViewWin() {
   ResetTooltip();
 }
 
 void RenderWidgetHostViewWin::CreateWnd(HWND parent) {
   Create(parent);  // ATL function to create the window.
 
   // Add a property indicating that a particular renderer is associated with
@@ skipping 1167 matching lines @@
         child_window = ::GetWindow(child_window, GW_CHILD);
 
       ::SetFocus(child_window);
       return MA_NOACTIVATE;
     }
   }
   handled = FALSE;
   return MA_ACTIVATE;
 }
 
-void RenderWidgetHostViewWin::UpdateAccessibilityTree(
-    const webkit_glue::WebAccessibility& tree) {
-  browser_accessibility_manager_.reset(
-      new BrowserAccessibilityManager(m_hWnd, tree));
-}
-
-void RenderWidgetHostViewWin::OnAccessibilityFocusChange(int acc_obj_id) {
-  if (browser_accessibility_manager_.get()) {
-    browser_accessibility_manager_->OnAccessibilityFocusChange(acc_obj_id);
-  }
-}
-
-void RenderWidgetHostViewWin::OnAccessibilityObjectStateChange(int acc_obj_id) {
-  if (browser_accessibility_manager_.get()) {
-    browser_accessibility_manager_->OnAccessibilityObjectStateChange(
-        acc_obj_id);
-  }
-}
-
-void RenderWidgetHostViewWin::Observe(NotificationType type,
-                                      const NotificationSource& source,
-                                      const NotificationDetails& details) {
-  DCHECK(type == NotificationType::RENDERER_PROCESS_TERMINATED);
-
-  // Get the RenderProcessHost that posted this notification, and exit
-  // if it's not the one associated with this host view.
-  RenderProcessHost* render_process_host =
-      Source<RenderProcessHost>(source).ptr();
-  DCHECK(render_process_host);
-  if (!render_widget_host_ ||
-      render_process_host != render_widget_host_->process())
-    return;
-
-  // If it was our RenderProcessHost that posted the notification,
-  // clear the BrowserAccessibilityManager, because the renderer is
-  // dead and any accessibility information we have is now stale.
-  browser_accessibility_manager_.reset(NULL);
-}
-
 LRESULT RenderWidgetHostViewWin::OnGetObject(UINT message, WPARAM wparam,
                                              LPARAM lparam, BOOL& handled) {
-  // TODO(dmazzoni): http://crbug.com/25564 Disabling accessibility in the
+  LRESULT reference_result = static_cast<LRESULT>(0L);
+  // TODO(jcampan): http://b/issue?id=1432077 Disabling accessibility in the
   // renderer is a temporary work-around until that bug is fixed.
-  if (!renderer_accessible_) {
-    handled = false;
-    return static_cast<LRESULT>(0L);
+  if (!renderer_accessible_)
+    return reference_result;
+
+  // Accessibility readers will send an OBJID_CLIENT message.
+  if (OBJID_CLIENT == lparam) {
+    // If our MSAA DOM root is already created, reuse that pointer. Otherwise,
+    // create a new one.
+    if (!browser_accessibility_root_) {
+      // Create a new instance of IAccessible. Root id is 1000, to avoid
+      // conflicts with the ids used by MSAA.
+      BrowserAccessibilityManager::GetInstance()->CreateAccessibilityInstance(
+          IID_IAccessible, 1000,
+          render_widget_host_->routing_id(),
+          render_widget_host_->process()->id(),
+          m_hWnd,
+          reinterpret_cast<void **>(browser_accessibility_root_.Receive()));
+
+      if (!browser_accessibility_root_) {
+        // No valid root found, return with failure.
+        return static_cast<LRESULT>(0L);
+      }
+    }
+
+    // Create a reference to BrowserAccessibility which MSAA will marshall to
+    // the client.
+    reference_result = LresultFromObject(IID_IAccessible, wparam,
+        static_cast<IAccessible*>(browser_accessibility_root_));
   }
-
-  if (lparam == OBJID_CLIENT && browser_accessibility_manager_.get()) {
-    BrowserAccessibility* root = browser_accessibility_manager_->GetRoot();
-    if (root) {
-      return LresultFromObject(IID_IAccessible, wparam,
-                               static_cast<IAccessible*>(root->NewReference()));
-    }
-  }
-
-  handled = false;
-  return static_cast<LRESULT>(0L);
+  return reference_result;
 }
 
 void RenderWidgetHostViewWin::OnFinalMessage(HWND window) {
   // When the render widget host is being destroyed, it ends up calling
   // WillDestroyRenderWidget (through the RENDER_WIDGET_HOST_DESTROYED
   // notification) which NULLs render_widget_host_.
   // Note: the following bug http://crbug.com/24248 seems to report that
   // OnFinalMessage is called with a deleted |render_widget_host_|. It is not
   // clear how this could happen, hence the NULLing of render_widget_host_
   // above.
@@ skipping 109 matching lines @@
     RenderWidgetHostView::GetRenderWidgetHostViewFromNativeView(
         gfx::NativeView native_view) {
   if (::IsWindow(native_view)) {
     HANDLE raw_render_host_view = ::GetProp(native_view,
                                             kRenderWidgetHostViewKey);
     if (raw_render_host_view)
       return reinterpret_cast<RenderWidgetHostView*>(raw_render_host_view);
   }
   return NULL;
 }