Toggle spoken feedback if two fingers are held down.

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/aura/wm_root_window_controller_aura.h"
 #include "ash/common/accessibility_delegate.h"
 #include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/wm_shell.h"
@@ skipping 84 matching lines @@
 void AshTouchExplorationManager::OnDisplayMetricsChanged(
     const display::Display& display,
     uint32_t changed_metrics) {
   if (root_window_controller_->wm_root_window_controller()
           ->GetWindow()
           ->GetDisplayNearestWindow()
           .id() == display.id())
     UpdateTouchExplorationState();
 }
 
+void AshTouchExplorationManager::PlaySpokenFeedbackToggleCountdown(
+    int tick_count) {
+  WmShell::Get()->accessibility_delegate()->PlaySpokenFeedbackToggleCountdown(
+      tick_count);
+}
+
+void AshTouchExplorationManager::ToggleSpokenFeedback() {
+  WmShell::Get()->accessibility_delegate()->ToggleSpokenFeedback(
+      ash::A11Y_NOTIFICATION_SHOW);
+}
+
 void AshTouchExplorationManager::OnWindowActivated(
     aura::client::ActivationChangeObserver::ActivationReason reason,
     aura::Window* gained_active,
     aura::Window* lost_active) {
   UpdateTouchExplorationState();
 }
 
 void AshTouchExplorationManager::SetTouchAccessibilityAnchorPoint(
     const gfx::Point& anchor_point) {
   if (touch_exploration_controller_) {
     touch_exploration_controller_->SetTouchAccessibilityAnchorPoint(
         anchor_point);
   }
 }
 
 void AshTouchExplorationManager::UpdateTouchExplorationState() {
   // Comes from components/exo/shell_surface.cc.
   const char kExoShellSurfaceWindowName[] = "ExoShellSurface";
 
   // See crbug.com/603745 for more details.
   const bool pass_through_surface =
       wm::GetActiveWindow() &&
       wm::GetActiveWindow()->name() == kExoShellSurfaceWindowName;
 
   const bool spoken_feedback_enabled =
       WmShell::Get()->accessibility_delegate()->IsSpokenFeedbackEnabled();
 
+  if (!touch_accessibility_enabler_) {
+    // Always enable gesture to toggle spoken feedback.
+    touch_accessibility_enabler_.reset(new ui::TouchAccessibilityEnabler(
+        root_window_controller_->GetRootWindow(), this));
+  }
+
   if (spoken_feedback_enabled) {
     if (!touch_exploration_controller_.get()) {
       touch_exploration_controller_ =
           base::MakeUnique<ui::TouchExplorationController>(
-              root_window_controller_->GetRootWindow(), this);
+              root_window_controller_->GetRootWindow(), this,
+              touch_accessibility_enabler_.get());
     }
     if (pass_through_surface) {
       const gfx::Rect& work_area =
           root_window_controller_->wm_root_window_controller()
               ->GetWindow()
               ->GetDisplayNearestWindow()
               .work_area();
       touch_exploration_controller_->SetExcludeBounds(work_area);
       SilenceSpokenFeedback();
       WmShell::Get()->accessibility_delegate()->ClearFocusHighlight();
     } else {
       touch_exploration_controller_->SetExcludeBounds(gfx::Rect());
     }
   } else {
     touch_exploration_controller_.reset();
   }
 }
 
 bool AshTouchExplorationManager::VolumeAdjustSoundEnabled() {
   return !base::CommandLine::ForCurrentProcess()->HasSwitch(
       chromeos::switches::kDisableVolumeAdjustSound);
 }
 
 }  // namespace ash