Side Slide Gestures for Accessibility

ash/ash_touch_exploration_manager_chromeos.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.

[James Cook, 2014/07/15 19:58:10]

"Copyright 2014" please (and no (c) for 2014)

[lisayin, 2014/07/15 21:46:45]

Done.

+// 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/audio/sounds.h"
+#include "ash/shell.h"
+#include "ash/shell_delegate.h"
+#include "ash/system/tray/system_tray_notifier.h"
+#include "base/command_line.h"
+#include "chromeos/audio/chromeos_sounds.h"
+#include "chromeos/chromeos_switches.h"
+#include "ui/chromeos/touch_exploration_controller.h"
+
+namespace ash {
+
+AshTouchExplorationManagerChromeOS::AshTouchExplorationManagerChromeOS(
+    RootWindowController* root_window_controller)
+    : root_window_controller_(root_window_controller),
+      audio_handler_(chromeos::CrasAudioHandler::Get()) {
+  Shell::GetInstance()->system_tray_notifier()->
+      AddAccessibilityObserver(this);
+  UpdateTouchExplorationState();
+}
+
+AshTouchExplorationManagerChromeOS::~AshTouchExplorationManagerChromeOS() {
+  SystemTrayNotifier* system_tray_notifier =
+      Shell::GetInstance()->system_tray_notifier();
+  if (system_tray_notifier)

[James Cook, 2014/07/15 19:58:10]

Why is this needed? Are you sure you are always removing the observer?

[lisayin, 2014/07/15 21:46:45]

The original code included this in its deconstructor. Should it belong in a
deconstructor in the root window instead?

[James Cook, 2014/07/15 22:40:36]

Hmm. OK. If it was in the destructor in the old code, you should keep it. Pity
we don't know why it needs to be there.

+    system_tray_notifier->RemoveAccessibilityObserver(this);
+}
+
+bool AshTouchExplorationManagerChromeOS::VolumeAdjustSoundEnabled() {
+  return !CommandLine::ForCurrentProcess()->HasSwitch(
+      chromeos::switches::kDisableVolumeAdjustSound);
+}
+
+void const AshTouchExplorationManagerChromeOS::PlayVolumeAdjustSound() {
+  if (!VolumeAdjustSoundEnabled())
+    return;
+  if (!audio_handler_->IsOutputMuted() ||
+      !audio_handler_->GetOutputVolumePercent() == 100)
+    PlaySystemSoundIfSpokenFeedback(chromeos::SOUND_VOLUME_ADJUST);
+}
+
+void AshTouchExplorationManagerChromeOS::SetOutputLevel(float 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);
+}
+
+void AshTouchExplorationManagerChromeOS::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();
+  }
+}
+
+// Overridden from AccessibilityObserver.

[James Cook, 2014/07/15 19:58:10]

Either remove this comment or add one for the other interface.

Also, reorder functions in .cc file to match .h

[lisayin, 2014/07/15 21:46:45]

Done.

+void AshTouchExplorationManagerChromeOS::OnAccessibilityModeChanged(
+    AccessibilityNotificationVisibility notify) {
+  UpdateTouchExplorationState();
+}
+
+}  // namespace ash