Show an a11y notification only if the feature was enabled by its shortcut key

Currently, only spoken feedback has a shortcut key, so this CL supports only it.

Major Changes:
- Add a |notify| argument to ToggleSpokenFeedback() methods to pass the flag whether the tray should show a notification or not.
- (in ash_system_tray_delegate.cc) Use chrome notifications instead of watching pref change to observe the accessibility feature status change.

BUG=158288
TEST=manual
R=zork@chromium.org,derat@chromium.org
TBR=darin@chromium.org,dbeam@chromium.org
#TBRing for small changes in chrome/browser/automation and chrome/browser/ui/webui/options

Review URL: https://codereview.chromium.org/11510005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@172821 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 68 insertions, 36 deletions

diff --git a/ash/accelerators/accelerator_controller.cc b/ash/accelerators/accelerator_controller.cc
index 22c0e2c..fbe39d1 100644
--- a/ash/accelerators/accelerator_controller.cc
+++ b/ash/accelerators/accelerator_controller.cc
@@ -113,9 +113,11 @@ bool HandleCrosh() {
 }
 
 bool HandleToggleSpokenFeedback() {
-  Shell::GetInstance()->delegate()->ToggleSpokenFeedback();
+  Shell::GetInstance()->delegate()->
+      ToggleSpokenFeedback(A11Y_NOTIFICATION_SHOW);
   return true;
 }
+
 void HandleCycleDisplayMode() {
   Shell* shell = Shell::GetInstance();
   if (!base::chromeos::IsRunningOnChromeOS()) {
diff --git a/ash/accelerators/accelerator_controller_unittest.cc b/ash/accelerators/accelerator_controller_unittest.cc
index d75d75d..1c5b9bb6 100644
--- a/ash/accelerators/accelerator_controller_unittest.cc
+++ b/ash/accelerators/accelerator_controller_unittest.cc
@@ -905,12 +905,12 @@ TEST_F(AcceleratorControllerTest,
   EXPECT_TRUE(ash::Shell::GetInstance()->GetAppListTargetVisibility());
 
   // When spoken feedback is on, the AppList should not toggle.
-  delegate->ToggleSpokenFeedback();
+  delegate->ToggleSpokenFeedback(A11Y_NOTIFICATION_NONE);
   EXPECT_FALSE(ProcessWithContext(
       ui::Accelerator(ui::VKEY_LWIN, ui::EF_NONE)));
   EXPECT_FALSE(ProcessWithContext(
       ReleaseAccelerator(ui::VKEY_LWIN, ui::EF_NONE)));
-  delegate->ToggleSpokenFeedback();
+  delegate->ToggleSpokenFeedback(A11Y_NOTIFICATION_NONE);
   EXPECT_TRUE(ash::Shell::GetInstance()->GetAppListTargetVisibility());
 
   EXPECT_TRUE(ProcessWithContext(
@@ -920,12 +920,12 @@ TEST_F(AcceleratorControllerTest,
   EXPECT_FALSE(ash::Shell::GetInstance()->GetAppListTargetVisibility());
 
   // When spoken feedback is on, the AppList should not toggle.
-  delegate->ToggleSpokenFeedback();
+  delegate->ToggleSpokenFeedback(A11Y_NOTIFICATION_NONE);
   EXPECT_FALSE(ProcessWithContext(
       ui::Accelerator(ui::VKEY_LWIN, ui::EF_NONE)));
   EXPECT_FALSE(ProcessWithContext(
       ReleaseAccelerator(ui::VKEY_LWIN, ui::EF_NONE)));
-  delegate->ToggleSpokenFeedback();
+  delegate->ToggleSpokenFeedback(A11Y_NOTIFICATION_NONE);
   EXPECT_FALSE(ash::Shell::GetInstance()->GetAppListTargetVisibility());
 }
 
@@ -948,12 +948,12 @@ TEST_F(AcceleratorControllerTest,
   EXPECT_TRUE(ash::Shell::GetInstance()->GetAppListTargetVisibility());
 
   // When spoken feedback is on, the AppList should not toggle.
-  delegate->ToggleSpokenFeedback();
+  delegate->ToggleSpokenFeedback(A11Y_NOTIFICATION_NONE);
   EXPECT_FALSE(ProcessWithContext(
       ui::Accelerator(ui::VKEY_LWIN, ui::EF_NONE)));
   EXPECT_FALSE(ProcessWithContext(
       ReleaseAccelerator(ui::VKEY_LWIN, ui::EF_NONE)));
-  delegate->ToggleSpokenFeedback();
+  delegate->ToggleSpokenFeedback(A11Y_NOTIFICATION_NONE);
   EXPECT_TRUE(ash::Shell::GetInstance()->GetAppListTargetVisibility());
 
   EXPECT_FALSE(ProcessWithContext(
@@ -963,12 +963,12 @@ TEST_F(AcceleratorControllerTest,
   EXPECT_FALSE(ash::Shell::GetInstance()->GetAppListTargetVisibility());
 
   // When spoken feedback is on, the AppList should not toggle.
-  delegate->ToggleSpokenFeedback();
+  delegate->ToggleSpokenFeedback(A11Y_NOTIFICATION_NONE);
   EXPECT_FALSE(ProcessWithContext(
       ui::Accelerator(ui::VKEY_LWIN, ui::EF_NONE)));
   EXPECT_FALSE(ProcessWithContext(
       ReleaseAccelerator(ui::VKEY_LWIN, ui::EF_NONE)));
-  delegate->ToggleSpokenFeedback();
+  delegate->ToggleSpokenFeedback(A11Y_NOTIFICATION_NONE);
   EXPECT_FALSE(ash::Shell::GetInstance()->GetAppListTargetVisibility());
 }
 
diff --git a/ash/shell/shell_delegate_impl.cc b/ash/shell/shell_delegate_impl.cc
index 8cf97ba..d53fe07 100644
--- a/ash/shell/shell_delegate_impl.cc
+++ b/ash/shell/shell_delegate_impl.cc
@@ -116,7 +116,8 @@ content::BrowserContext* ShellDelegateImpl::GetCurrentBrowserContext() {
   return Shell::GetInstance()->browser_context();
 }
 
-void ShellDelegateImpl::ToggleSpokenFeedback() {
+void ShellDelegateImpl::ToggleSpokenFeedback(
+    AccessibilityNotificationVisibility notify) {
   spoken_feedback_enabled_ = !spoken_feedback_enabled_;
 }
 
diff --git a/ash/shell/shell_delegate_impl.h b/ash/shell/shell_delegate_impl.h
index 6e0b7c0..ea26561 100644
--- a/ash/shell/shell_delegate_impl.h
+++ b/ash/shell/shell_delegate_impl.h
@@ -41,7 +41,8 @@ class ShellDelegateImpl : public ash::ShellDelegate {
   virtual void ShowKeyboardOverlay() OVERRIDE;
   virtual void ShowTaskManager() OVERRIDE;
   virtual content::BrowserContext* GetCurrentBrowserContext() OVERRIDE;
-  virtual void ToggleSpokenFeedback() OVERRIDE;
+  virtual void ToggleSpokenFeedback(
+      AccessibilityNotificationVisibility notify) OVERRIDE;
   virtual bool IsSpokenFeedbackEnabled() const OVERRIDE;
   virtual void ToggleHighContrast() OVERRIDE;
   virtual bool IsHighContrastEnabled() const OVERRIDE;
diff --git a/ash/shell_delegate.h b/ash/shell_delegate.h
index 26b54a1..96064e5 100644
--- a/ash/shell_delegate.h
+++ b/ash/shell_delegate.h
@@ -60,6 +60,11 @@ enum UserMetricsAction {
   UMA_TOUCHSCREEN_TAP_DOWN,
 };
 
+enum AccessibilityNotificationVisibility {
+  A11Y_NOTIFICATION_NONE,
+  A11Y_NOTIFICATION_SHOW,
+};
+
 // Delegate of the Shell.
 class ASH_EXPORT ShellDelegate {
  public:
@@ -131,7 +136,8 @@ class ASH_EXPORT ShellDelegate {
   virtual content::BrowserContext* GetCurrentBrowserContext() = 0;
 
   // Invoked to toggle spoken feedback for accessibility
-  virtual void ToggleSpokenFeedback() = 0;
+  virtual void ToggleSpokenFeedback(
+      AccessibilityNotificationVisibility notify) = 0;
 
   // Returns true if spoken feedback is enabled.
   virtual bool IsSpokenFeedbackEnabled() const = 0;
diff --git a/ash/system/tray/system_tray_notifier.cc b/ash/system/tray/system_tray_notifier.cc
index 09704c8..e865550 100644
--- a/ash/system/tray/system_tray_notifier.cc
+++ b/ash/system/tray/system_tray_notifier.cc
@@ -149,11 +149,12 @@ void SystemTrayNotifier::RemoveSmsObserver(SmsObserver* observer) {
 }
 #endif
 
-void SystemTrayNotifier::NotifyAccessibilityModeChanged() {
+void SystemTrayNotifier::NotifyAccessibilityModeChanged(
+    AccessibilityNotificationVisibility notify) {
   FOR_EACH_OBSERVER(
       AccessibilityObserver,
       accessibility_observers_,
-      OnAccessibilityModeChanged());
+      OnAccessibilityModeChanged(notify));
 }
 
 void SystemTrayNotifier::NotifyVolumeChanged(float level) {
diff --git a/ash/system/tray/system_tray_notifier.h b/ash/system/tray/system_tray_notifier.h
index 9cfddd2..895d929 100644
--- a/ash/system/tray/system_tray_notifier.h
+++ b/ash/system/tray/system_tray_notifier.h
@@ -88,7 +88,8 @@ public:
   void RemoveSmsObserver(SmsObserver* observer);
 #endif
 
-  void NotifyAccessibilityModeChanged();
+  void NotifyAccessibilityModeChanged(
+      AccessibilityNotificationVisibility notify);
   void NotifyVolumeChanged(float level);
   void NotifyMuteToggled();
   void NotifyRefreshBluetooth();
diff --git a/ash/system/tray_accessibility.cc b/ash/system/tray_accessibility.cc
index 9f468ad..9b161f5 100644
--- a/ash/system/tray_accessibility.cc
+++ b/ash/system/tray_accessibility.cc
@@ -30,12 +30,23 @@ namespace internal {
 namespace {
 const int kPaddingAroundBottomRow = 5;
 
-bool IsAnyAccessibilityFeatureEnabled() {
+enum AccessibilityState {
+  A11Y_NONE             = 0,
+  A11Y_SPOKEN_FEEDBACK  = 1 << 0,
+  A11Y_HIGH_CONTRAST    = 1 << 1,
+  A11Y_SCREEN_MAGNIFIER = 1 << 2,
+};
+
+uint32 GetAccessibilityState() {
   ShellDelegate* shell_delegate = Shell::GetInstance()->delegate();
-  return shell_delegate &&
-      (shell_delegate->IsSpokenFeedbackEnabled() ||
-       shell_delegate->IsHighContrastEnabled() ||
-       shell_delegate->GetMagnifierType() != ash::MAGNIFIER_OFF);
+  uint32 state = A11Y_NONE;
+  if (shell_delegate->IsSpokenFeedbackEnabled())
+    state |= A11Y_SPOKEN_FEEDBACK;
+  if (shell_delegate->IsHighContrastEnabled())
+    state |= A11Y_HIGH_CONTRAST;
+  if (shell_delegate->GetMagnifierType() != ash::MAGNIFIER_OFF)
+    state |= A11Y_SCREEN_MAGNIFIER;
+  return state;
 }
 
 user::LoginStatus GetCurrentLoginStatus() {
@@ -168,7 +179,7 @@ class AccessibilityDetailedView : public TrayDetailsView,
     if (sender == footer()->content()) {
       owner()->system_tray()->ShowDefaultView(BUBBLE_USE_EXISTING);
     } else if (sender == spoken_feedback_view_) {
-      shell_delegate->ToggleSpokenFeedback();
+      shell_delegate->ToggleSpokenFeedback(A11Y_NOTIFICATION_NONE);
     } else if (sender == high_contrast_view_) {
       shell_delegate->ToggleHighContrast();
     } else if (sender == screen_magnifier_view_) {
@@ -225,8 +236,8 @@ TrayAccessibility::TrayAccessibility(SystemTray* system_tray)
       default_(NULL),
       detailed_(NULL),
       request_popup_view_(false),
-      accessibility_previously_enabled_(IsAnyAccessibilityFeatureEnabled()),
-      login_(GetCurrentLoginStatus()) {
+      login_(GetCurrentLoginStatus()),
+      previous_accessibility_state_(GetAccessibilityState()) {
   DCHECK(Shell::GetInstance()->delegate());
   DCHECK(system_tray);
   Shell::GetInstance()->system_tray_notifier()->AddAccessibilityObserver(this);
@@ -240,7 +251,7 @@ TrayAccessibility::~TrayAccessibility() {
 bool TrayAccessibility::GetInitialVisibility() {
   // Shows accessibility icon if any accessibility feature is enabled.
   // Otherwise, doen't show it.
-  return IsAnyAccessibilityFeatureEnabled();
+  return GetAccessibilityState() != A11Y_NONE;
 }
 
 views::View* TrayAccessibility::CreateDefaultView(user::LoginStatus status) {
@@ -256,7 +267,7 @@ views::View* TrayAccessibility::CreateDefaultView(user::LoginStatus status) {
   ShellDelegate* delegate = Shell::GetInstance()->delegate();
   if (login_ != user::LOGGED_IN_NONE &&
       !delegate->ShouldAlwaysShowAccessibilityMenu() &&
-      !IsAnyAccessibilityFeatureEnabled())
+      GetAccessibilityState() == A11Y_NONE)
     return NULL;
 
   CHECK(default_ == NULL);
@@ -295,21 +306,23 @@ void TrayAccessibility::UpdateAfterLoginStatusChange(user::LoginStatus status) {
     tray_view()->SetVisible(GetInitialVisibility());
 }
 
-void TrayAccessibility::OnAccessibilityModeChanged() {
+void TrayAccessibility::OnAccessibilityModeChanged(
+    AccessibilityNotificationVisibility notify) {
   if (tray_view())
     tray_view()->SetVisible(GetInitialVisibility());
 
-  bool accessibility_enabled = IsAnyAccessibilityFeatureEnabled();
-  if (!accessibility_previously_enabled_ && accessibility_enabled) {
-    // Shows popup if the accessibilty status is being changed to true from
-    // false.
+  uint32 accessibility_state = GetAccessibilityState();
+  if ((notify == ash::A11Y_NOTIFICATION_SHOW)&&
+      !(previous_accessibility_state_ & A11Y_SPOKEN_FEEDBACK) &&
+      (accessibility_state & A11Y_SPOKEN_FEEDBACK)) {
+    // Shows popup if |notify| is true and the spoken feedback is being enabled.
     request_popup_view_ = true;
     PopupDetailedView(kTrayPopupAutoCloseDelayForTextInSeconds, false);
   } else if (detailed_) {
     detailed_->GetWidget()->Close();
   }
 
-  accessibility_previously_enabled_ = accessibility_enabled;
+  previous_accessibility_state_ = accessibility_state;
 }
 
 }  // namespace internal
diff --git a/ash/system/tray_accessibility.h b/ash/system/tray_accessibility.h
index e0162f5..1000b65 100644
--- a/ash/system/tray_accessibility.h
+++ b/ash/system/tray_accessibility.h
@@ -5,6 +5,7 @@
 #ifndef ASH_SYSTEM_TRAY_ACCESSIBILITY_H_
 #define ASH_SYSTEM_TRAY_ACCESSIBILITY_H_
 
+#include "ash/shell_delegate.h"
 #include "ash/shell_observer.h"
 #include "ash/system/tray/tray_image_item.h"
 
@@ -20,7 +21,8 @@ class ASH_EXPORT AccessibilityObserver {
   virtual ~AccessibilityObserver() {}
 
   // Notifies when accessibilty mode changes.
-  virtual void OnAccessibilityModeChanged() = 0;
+  virtual void OnAccessibilityModeChanged(
+      AccessibilityNotificationVisibility notify) = 0;
 };
 
 namespace internal {
@@ -41,15 +43,18 @@ class TrayAccessibility : public TrayImageItem,
   virtual void UpdateAfterLoginStatusChange(user::LoginStatus status) OVERRIDE;
 
   // Overridden from AccessibilityObserver.
-  virtual void OnAccessibilityModeChanged() OVERRIDE;
+  virtual void OnAccessibilityModeChanged(
+      AccessibilityNotificationVisibility notify) OVERRIDE;
 
   views::View* default_;
   views::View* detailed_;
 
   bool request_popup_view_;
-  bool accessibility_previously_enabled_;
   user::LoginStatus login_;
 
+  // Bitmap of values from AccessibilityState enum.
+  uint32 previous_accessibility_state_;
+
   DISALLOW_COPY_AND_ASSIGN(TrayAccessibility);
 };
 
diff --git a/ash/test/test_shell_delegate.cc b/ash/test/test_shell_delegate.cc
index 066a14b..c57e41e 100644
--- a/ash/test/test_shell_delegate.cc
+++ b/ash/test/test_shell_delegate.cc
@@ -107,7 +107,8 @@ content::BrowserContext* TestShellDelegate::GetCurrentBrowserContext() {
   return current_browser_context_.get();
 }
 
-void TestShellDelegate::ToggleSpokenFeedback() {
+void TestShellDelegate::ToggleSpokenFeedback(
+    AccessibilityNotificationVisibility notify) {
   spoken_feedback_enabled_ = !spoken_feedback_enabled_;
 }
 
diff --git a/ash/test/test_shell_delegate.h b/ash/test/test_shell_delegate.h
index c35d116..398e0f4 100644
--- a/ash/test/test_shell_delegate.h
+++ b/ash/test/test_shell_delegate.h
@@ -40,7 +40,8 @@ class TestShellDelegate : public ShellDelegate {
   virtual void ShowKeyboardOverlay() OVERRIDE;
   virtual void ShowTaskManager() OVERRIDE;
   virtual content::BrowserContext* GetCurrentBrowserContext() OVERRIDE;
-  virtual void ToggleSpokenFeedback() OVERRIDE;
+  virtual void ToggleSpokenFeedback(
+      AccessibilityNotificationVisibility notify) OVERRIDE;
   virtual bool IsSpokenFeedbackEnabled() const OVERRIDE;
   virtual void ToggleHighContrast() OVERRIDE;
   virtual bool IsHighContrastEnabled() const OVERRIDE;