Fix Chrome OS virtual keyboard accessibility

chrome/browser/chromeos/accessibility/select_to_speak_event_handler.cc

 // Copyright 2016 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/chromeos/accessibility/select_to_speak_event_handler.h"
 
 #include "ash/shell.h"
 #include "base/logging.h"
 #include "chrome/browser/speech/tts_controller.h"
 #include "chrome/browser/ui/aura/accessibility/automation_manager_aura.h"
@@ skipping 107 matching lines @@
     case ui::ET_MOUSE_ENTERED:
     case ui::ET_MOUSE_EXITED:
       ax_event = ui::AX_EVENT_MOUSE_MOVED;
       break;
     default:
       return;
   }
 
   CancelEvent(event);
 
-  // Find the View to post the accessibility event on.
   aura::Window* event_target = static_cast<aura::Window*>(event->target());
-  aura::Window* hit_window = event_target;
-  if (!hit_window)
-    return;
-
-  views::Widget* hit_widget = views::Widget::GetWidgetForNativeView(hit_window);
-  while (!hit_widget) {
-    hit_window = hit_window->parent();
-    if (!hit_window)
-      break;
-
-    hit_widget = views::Widget::GetWidgetForNativeView(hit_window);
-  }
-
-  if (!hit_window || !hit_widget)
-    return;
-
-  gfx::Point window_location = event->location();
-  aura::Window::ConvertPointToTarget(event_target, hit_window,
-                                     &window_location);
-
-  views::View* root_view = hit_widget->GetRootView();
-  views::View* hit_view = root_view->GetEventHandlerForPoint(window_location);
-
-  if (hit_view) {
-    // Send the accessibility event, then save the view so we can post the
-    // cancel event on the same view if possible.
-    hit_view->NotifyAccessibilityEvent(ax_event, true);
-    if (!last_view_storage_id_) {
-      last_view_storage_id_ =
-          views::ViewStorage::GetInstance()->CreateStorageID();
-    }
-    views::ViewStorage::GetInstance()->RemoveView(last_view_storage_id_);
-    views::ViewStorage::GetInstance()->StoreView(last_view_storage_id_,
-                                                 hit_view);
-  }
+  views::AXAuraObjCache* cache = views::AXAuraObjCache::GetInstance();
+  views::AXAuraObjWrapper* ax_obj = cache->GetOrCreate(event_target);
+  ui::AXActionData action;
+  action.action = ui::AX_ACTION_HIT_TEST;
+  action.target_point = event->location();
+  action.hit_test_event_to_fire = ax_event;
+  ax_obj->HandleAccessibleAction(action);

[David Tseng, 2017/04/05 23:43:43]

I think this should happen inside of the extension using the automation bindings
in js. There are other clients like ChromeVox that might optionally want this
type of behavior for speak what's under the mouse.

[dmazzoni, 2017/04/07 23:34:08]

I spend all day trying to make this work. It's slightly
harder to forward a mouse event than a keyboard event
due to coordinate transformations, but it works, for
mouse down and mouse up. But mouse move just doesn't work,
there's some throttling code, probably designed to keep
background pages from wasting processing on mouse move
events.

There may be a way around it, but I'm thinking this might
be the wrong approach.

Options:
* Use a private API to send the mouse event to the extension
* Keep this existing code for now

 }
 
 void SelectToSpeakEventHandler::CancelEvent(ui::Event* event) {
   DCHECK(event);
   if (event->cancelable()) {
     event->SetHandled();
     event->StopPropagation();
   }
 }
 
 void SelectToSpeakEventHandler::SendCancelAXEvent() {
   // If the user releases Search while the button is still down, cancel
-  // the Select-to-speak gesture. Try to post it on the same View that
-  // was last targeted, but if that's impossible, post it on the desktop.
-  views::View* last_view =
-      last_view_storage_id_
-          ? views::ViewStorage::GetInstance()->RetrieveView(
-                last_view_storage_id_)
-          : nullptr;
-  if (last_view) {
-    last_view->NotifyAccessibilityEvent(ui::AX_EVENT_MOUSE_CANCELED, true);
-  } else {
-    AutomationManagerAura::GetInstance()->HandleEvent(
-        nullptr, nullptr, ui::AX_EVENT_MOUSE_CANCELED);
-  }
+  // the Select-to-speak gesture.
+  AutomationManagerAura::GetInstance()->HandleEvent(
+      nullptr, nullptr, ui::AX_EVENT_MOUSE_CANCELED);

[David Tseng, 2017/04/06 16:45:43]

Btw, it seems like a hack to do this via ax events. There's no node associated
with the event and no browser context. I know I'm guilty of this as well, but it
does seem like ax events are being used for everything now when there are
existing apis already serving this purpose. You could forward mouse events
directly to the extension as DOM events.

 }
 
 }  // namespace chromeos