Side Slide Gestures for Accessibility

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/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 "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),
+      audio_handler_(chromeos::CrasAudioHandler::Get()) {
+  Shell::GetInstance()->system_tray_notifier()->AddAccessibilityObserver(this);
+  UpdateTouchExplorationState();
+}
+
+AshTouchExplorationManager::~AshTouchExplorationManager() {
+  SystemTrayNotifier* system_tray_notifier =
+      Shell::GetInstance()->system_tray_notifier();
+  if (system_tray_notifier)
+    system_tray_notifier->RemoveAccessibilityObserver(this);
+}
+
+void AshTouchExplorationManager::OnAccessibilityModeChanged(
+    AccessibilityNotificationVisibility notify) {
+  UpdateTouchExplorationState();
+}
+
+void AshTouchExplorationManager::PlayVolumeAdjustSound() {
+  if (!VolumeAdjustSoundEnabled())
+    return;
+  if ((!audio_handler_->IsOutputMuted()) ||
+      !(audio_handler_->GetOutputVolumePercent() == 100))
+    PlaySystemSoundIfSpokenFeedback(chromeos::SOUND_VOLUME_ADJUST);
+}
+
+void AshTouchExplorationManager::SetOutputLevel(int volume) {
+  if (volume > 0) {
+    if (audio_handler_->IsOutputMuted()) {
+      audio_handler_->SetOutputMute(false);
+    }
+  }
+  audio_handler_->SetOutputVolumePercent(volume);
+  // Avoid negative volume.
+  if (audio_handler_->IsOutputVolumeBelowDefaultMuteLevel())
+    audio_handler_->SetOutputMute(true);

[aboxhall, 2014/07/22 17:20:41]

Does SetOutputMute set the volume back to 0/DefaultMuteLevel ?

[lisayin, 2014/07/22 18:06:25]

Yes.

+}
+
+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