Two Finger Tap

ash/ash_touch_exploration_manager_chromeos.cc

 // Copyright 2014 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 "ash/ash_touch_exploration_manager_chromeos.h"
 
+#include "ash/accelerators/accelerator_controller.h"
 #include "ash/accessibility_delegate.h"
 #include "ash/audio/sounds.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
 #include "ash/system/tray/system_tray_notifier.h"
 #include "base/command_line.h"
+#include "base/metrics/user_metrics.h"
 #include "chromeos/audio/chromeos_sounds.h"
 #include "chromeos/audio/cras_audio_handler.h"
 #include "chromeos/chromeos_switches.h"
 #include "ui/chromeos/touch_exploration_controller.h"
 
 namespace ash {
 
 AshTouchExplorationManager::AshTouchExplorationManager(
     RootWindowController* root_window_controller)
     : root_window_controller_(root_window_controller),
@@ skipping 27 matching lines @@
     if (audio_handler_->IsOutputMuted()) {
       audio_handler_->SetOutputMute(false);
     }
   }
   audio_handler_->SetOutputVolumePercent(volume);
   // Avoid negative volume.
   if (audio_handler_->IsOutputVolumeBelowDefaultMuteLevel())
     audio_handler_->SetOutputMute(true);
 }
 
+void AshTouchExplorationManager::SilenceSpokenFeedback() {

[lisayin, 2014/07/31 16:33:50]

This is the code that accelerator_controller uses to silence spoken feedback.
I'm not sure why this only pauses spoken feedback. However, I did notice that
when spoken feedback was silenced natively using control, it had the same issues
where it only paused it and skipped over a few words before continuing spoken
feedback.

+  AccessibilityDelegate* delegate =
+    Shell::GetInstance()->accessibility_delegate();
+  if (!delegate->IsSpokenFeedbackEnabled())
+    return;
+  delegate->SilenceSpokenFeedback();
+}
+
 void AshTouchExplorationManager::UpdateTouchExplorationState() {
   AccessibilityDelegate* delegate =
       Shell::GetInstance()->accessibility_delegate();
   bool enabled = delegate->IsSpokenFeedbackEnabled();
 
   if (enabled && !touch_exploration_controller_.get()) {
     touch_exploration_controller_.reset(new ui::TouchExplorationController(
         root_window_controller_->GetRootWindow(), this));
   } else if (!enabled) {
     touch_exploration_controller_.reset();
   }
 }
 
 bool AshTouchExplorationManager::VolumeAdjustSoundEnabled() {
   return !CommandLine::ForCurrentProcess()->HasSwitch(
       chromeos::switches::kDisableVolumeAdjustSound);
 }
 
 }  // namespace ash