Side Slide Gestures for Accessibility

ash/ash_touch_exploration_manager_chromeos.cc

+// Copyright (c) 2012 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/audio/sounds.h"
+#include "ash/shell.h"
+#include "ash/shell_delegate.h"

[James Cook, 2014/07/15 18:21:57]

Do you need this include?  Or ash/accessibility_delegate.h?

[lisayin, 2014/07/15 21:46:44]

Done.

+#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 {
+
+CrosAccessibilityObserver::CrosAccessibilityObserver(
+    RootWindowController* root_window_controller)
+    : root_window_controller_(root_window_controller),
+      audio_handler_(chromeos::CrasAudioHandler::Get()) {
+  Shell::GetInstance()->system_tray_notifier()->
+      AddAccessibilityObserver(this);
+  UpdateTouchExplorationState();
+}
+
+CrosAccessibilityObserver::~CrosAccessibilityObserver() {
+  SystemTrayNotifier* system_tray_notifier =
+      Shell::GetInstance()->system_tray_notifier();
+  if (system_tray_notifier)

[James Cook, 2014/07/15 18:21:56]

Is this NULL in normal operation, in tests, in both?  I'm worried you might be
leaking an observer.

+    system_tray_notifier->RemoveAccessibilityObserver(this);
+

[James Cook, 2014/07/15 18:21:57]

no blank line

[lisayin, 2014/07/15 21:46:44]

Done.

+}
+
+bool CrosAccessibilityObserver::VolumeAdjustSoundEnabled() {
+  return !CommandLine::ForCurrentProcess()->HasSwitch(
+      chromeos::switches::kDisableVolumeAdjustSound);
+}
+
+void const CrosAccessibilityObserver::PlayVolumeAdjustSound() {
+  if (!VolumeAdjustSoundEnabled())
+    return;
+  if (!audio_handler_->IsOutputMuted() ||
+      !audio_handler_->GetOutputVolumePercent() == 100)
+    PlaySystemSoundIfSpokenFeedback(chromeos::SOUND_VOLUME_ADJUST);
+}
+
+void CrosAccessibilityObserver::AdjustSound(float volume) {

[James Cook, 2014/07/15 18:21:56]

Please add a unit test for this functionality. (In general, it's good to add at
least one unit test for a new class. This ensures that the class can be used in
a unit test harness and make it much easier for later maintainers to add
additional tests. The hardest test to write is always the first one. :-)

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