ash: Update app list button.

- Update the icons assets;
- Make app list button a ToggleImageButton and wire its
  toggle state with app list UI visibility;
- Make app list button icon vertically center aligned and
  get rid of the special handling;
- Expose toggled state from ToggleImageButton so that it
  could be checked in test;

BUG=235994
R=sky@chromium.org

Review URL: https://codereview.chromium.org/13993027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@197366 0039d316-1c4b-4281-b951-d872f2087c98

16 files changed, 201 insertions, 63 deletions

diff --git a/ash/launcher/app_list_button.cc b/ash/launcher/app_list_button.cc
index 8879a38..bd7bfcf 100644
--- a/ash/launcher/app_list_button.cc
+++ b/ash/launcher/app_list_button.cc
@@ -8,8 +8,11 @@
 
 #include "ash/launcher/launcher_button_host.h"
 #include "ash/launcher/launcher_types.h"
+#include "ash/shell.h"
+#include "ash/wm/app_list_controller.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
+#include "ui/aura/window.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
@@ -17,6 +20,7 @@
 #include "ui/compositor/layer_animation_element.h"
 #include "ui/compositor/layer_animation_sequence.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/views/widget/widget.h"
 
 namespace ash {
 namespace internal {
@@ -30,7 +34,7 @@ const int kBorderSize = 9;
 
 AppListButton::AppListButton(views::ButtonListener* listener,
                              LauncherButtonHost* host)
-    : views::ImageButton(listener),
+    : views::ToggleImageButton(listener),
       host_(host) {
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   SetImage(
@@ -44,12 +48,23 @@ AppListButton::AppListButton(views::ButtonListener* listener,
       views::CustomButton::STATE_PRESSED,
       rb.GetImageNamed(IDR_AURA_LAUNCHER_ICON_APPLIST_PUSHED).
           ToImageSkia());
+
+  const gfx::ImageSkia* toggled_image =
+      rb.GetImageNamed(IDR_AURA_LAUNCHER_ICON_APPLIST_PUSHED).
+          ToImageSkia();
+  SetToggledImage(views::CustomButton::STATE_NORMAL, toggled_image);
+  SetToggledImage(views::CustomButton::STATE_HOVERED, toggled_image);
+  SetToggledImage(views::CustomButton::STATE_PRESSED, toggled_image);
+
   SetAccessibleName(l10n_util::GetStringUTF16(IDS_AURA_APP_LIST_TITLE));
   SetSize(gfx::Size(kLauncherPreferredSize, kLauncherPreferredSize));
-  SetImageAlignment(ImageButton::ALIGN_CENTER, ImageButton::ALIGN_TOP);
+  SetImageAlignment(ImageButton::ALIGN_CENTER, ImageButton::ALIGN_MIDDLE);
+
+  Shell::GetInstance()->app_list_controller()->AddObserver(this);
 }
 
 AppListButton::~AppListButton() {
+  Shell::GetInstance()->app_list_controller()->RemoveObserver(this);
 }
 
 void AppListButton::StartLoadingAnimation() {
@@ -130,5 +145,15 @@ void AppListButton::GetAccessibleState(ui::AccessibleViewState* state) {
   state->name = host_->GetAccessibleName(this);
 }
 
+void AppListButton::OnAppLauncherVisibilityChanged(
+    bool visible, const aura::RootWindow* root_window) {
+  if (!GetWidget() ||
+      GetWidget()->GetNativeView()->GetRootWindow() != root_window) {
+    return;
+  }
+
+  SetToggled(visible);
+}
+
 }  // namespace internal
 }  // namespace ash
diff --git a/ash/launcher/app_list_button.h b/ash/launcher/app_list_button.h
index 4d25254..4d1cd63 100644
--- a/ash/launcher/app_list_button.h
+++ b/ash/launcher/app_list_button.h
@@ -5,6 +5,7 @@
 #ifndef ASH_LAUNCHER_APP_LIST_BUTTON_H_
 #define ASH_LAUNCHER_APP_LIST_BUTTON_H_
 
+#include "ash/wm/app_list_controller_observer.h"
 #include "ui/views/controls/button/image_button.h"
 
 namespace ash {
@@ -13,7 +14,8 @@ namespace internal {
 class LauncherButtonHost;
 
 // Button used for the AppList icon on the launcher.
-class AppListButton : public views::ImageButton {
+class AppListButton : public views::ToggleImageButton,
+                      public AppListControllerObserver {
  public:
   AppListButton(views::ButtonListener* listener,
                 LauncherButtonHost* host);
@@ -34,6 +36,11 @@ class AppListButton : public views::ImageButton {
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
 
  private:
+  // AppListControllerObserver overrides:
+  virtual void OnAppLauncherVisibilityChanged(
+      bool visible,
+      const aura::RootWindow* root_window) OVERRIDE;
+
   LauncherButtonHost* host_;
 
   DISALLOW_COPY_AND_ASSIGN(AppListButton);
diff --git a/ash/launcher/launcher_unittest.cc b/ash/launcher/launcher_unittest.cc
index 59d6a67..06b77ba 100644
--- a/ash/launcher/launcher_unittest.cc
+++ b/ash/launcher/launcher_unittest.cc
@@ -3,10 +3,13 @@
 // found in the LICENSE file.
 
 #include "ash/launcher/launcher.h"
+
+#include <vector>
+
+#include "ash/launcher/app_list_button.h"
 #include "ash/launcher/launcher_button.h"
 #include "ash/launcher/launcher_model.h"
 #include "ash/launcher/launcher_view.h"
-
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
@@ -24,6 +27,7 @@
 #endif
 
 typedef ash::test::AshTestBase LauncherTest;
+using ash::internal::AppListButton;
 using ash::internal::LauncherView;
 using ash::internal::LauncherButton;
 
@@ -57,7 +61,7 @@ TEST_F(LauncherTest, OpenBrowser) {
 
 // Confirm that using the menu will clear the hover attribute. To avoid another
 // browser test we check this here.
-TEST_F(LauncherTest, checkHoverAfterMenu) {
+TEST_F(LauncherTest, CheckHoverAfterMenu) {
   Launcher* launcher = Launcher::ForPrimaryDisplay();
   ASSERT_TRUE(launcher);
   LauncherView* launcher_view = launcher->GetLauncherViewForTest();
@@ -116,4 +120,50 @@ TEST_F(LauncherTest, ShowOverflowBubble) {
   EXPECT_FALSE(launcher->IsShowingOverflowBubble());
 }
 
+// Tests app list button toggles when app list UI shows up.
+TEST_F(LauncherTest, AppMenuToggle) {
+  AppListButton* app_list_button = static_cast<AppListButton*>(
+      Launcher::ForPrimaryDisplay()->GetLauncherViewForTest()->
+      GetAppListButtonView());
+  Shell* shell = Shell::GetInstance();
+
+  EXPECT_FALSE(shell->GetAppListTargetVisibility());
+  EXPECT_FALSE(app_list_button->toggled());
+  shell->ToggleAppList(NULL);
+  EXPECT_TRUE(shell->GetAppListTargetVisibility());
+  EXPECT_TRUE(app_list_button->toggled());
+}
+
+// Tests only the app list button with a UI is toggled.
+TEST_F(LauncherTest, MultipleAppMenuToggle) {
+  UpdateDisplay("300x300,200x200");
+
+  std::vector<AppListButton*> app_list_buttons;
+  Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
+  for (Shell::RootWindowList::const_iterator it = root_windows.begin();
+       it != root_windows.end(); ++it) {
+    AppListButton* button = static_cast<AppListButton*>(
+        Launcher::ForWindow(*it)->GetLauncherViewForTest()->
+        GetAppListButtonView());
+    app_list_buttons.push_back(button);
+    EXPECT_FALSE(button->toggled());
+  }
+
+  Shell* shell = Shell::GetInstance();
+
+  EXPECT_FALSE(shell->GetAppListTargetVisibility());
+  shell->ToggleAppList(root_windows[0]);
+  EXPECT_TRUE(shell->GetAppListTargetVisibility());
+  EXPECT_TRUE(app_list_buttons[0]->toggled());
+  EXPECT_FALSE(app_list_buttons[1]->toggled());
+
+  shell->ToggleAppList(NULL);
+  EXPECT_FALSE(shell->GetAppListTargetVisibility());
+
+  shell->ToggleAppList(root_windows[1]);
+  EXPECT_TRUE(shell->GetAppListTargetVisibility());
+  EXPECT_FALSE(app_list_buttons[0]->toggled());
+  EXPECT_TRUE(app_list_buttons[1]->toggled());
+}
+
 }  // namespace ash
diff --git a/ash/launcher/launcher_view.cc b/ash/launcher/launcher_view.cc
index 810baed..e324624 100644
--- a/ash/launcher/launcher_view.cc
+++ b/ash/launcher/launcher_view.cc
@@ -420,22 +420,7 @@ void LauncherView::OnShelfAlignmentChanged() {
   UpdateFirstButtonPadding();
   overflow_button_->OnShelfAlignmentChanged();
   LayoutToIdealBounds();
-  for (int i=0; i < view_model_->view_size(); ++i) {
-    // TODO: remove when AppIcon is a Launcher Button.
-    if (TYPE_APP_LIST == model_->items()[i].type) {
-      ShelfLayoutManager* shelf = tooltip_->shelf_layout_manager();
-      static_cast<AppListButton*>(view_model_->view_at(i))->SetImageAlignment(
-          shelf->SelectValueForShelfAlignment(
-              views::ImageButton::ALIGN_CENTER,
-              views::ImageButton::ALIGN_LEFT,
-              views::ImageButton::ALIGN_RIGHT,
-              views::ImageButton::ALIGN_CENTER),
-          shelf->SelectValueForShelfAlignment(
-              views::ImageButton::ALIGN_TOP,
-              views::ImageButton::ALIGN_MIDDLE,
-              views::ImageButton::ALIGN_MIDDLE,
-              views::ImageButton::ALIGN_BOTTOM));
-    }
+  for (int i = 0; i < view_model_->view_size(); ++i) {
     if (i >= first_visible_index_ && i <= last_visible_index_)
       view_model_->view_at(i)->Layout();
   }
@@ -763,18 +748,6 @@ views::View* LauncherView::CreateViewForItem(const LauncherItem& item) {
     case TYPE_APP_LIST: {
       // TODO(dave): turn this into a LauncherButton too.
       AppListButton* button = new AppListButton(this, this);
-      ShelfLayoutManager* shelf = tooltip_->shelf_layout_manager();
-      button->SetImageAlignment(
-          shelf->SelectValueForShelfAlignment(
-              views::ImageButton::ALIGN_CENTER,
-              views::ImageButton::ALIGN_LEFT,
-              views::ImageButton::ALIGN_RIGHT,
-              views::ImageButton::ALIGN_CENTER),
-          shelf->SelectValueForShelfAlignment(
-              views::ImageButton::ALIGN_TOP,
-              views::ImageButton::ALIGN_MIDDLE,
-              views::ImageButton::ALIGN_MIDDLE,
-              views::ImageButton::ALIGN_BOTTOM));
       view = button;
       break;
     }
diff --git a/ash/resources/default_100_percent/common/launcher/launcher_appmenu.png b/ash/resources/default_100_percent/common/launcher/launcher_appmenu.png
index 13118c8..7e17571 100644
--- a/ash/resources/default_100_percent/common/launcher/launcher_appmenu.png
+++ b/ash/resources/default_100_percent/common/launcher/launcher_appmenu.png
diff --git a/ash/resources/default_100_percent/common/launcher/launcher_appmenu_hover.png b/ash/resources/default_100_percent/common/launcher/launcher_appmenu_hover.png
index bafb356..4b0e80f 100644
--- a/ash/resources/default_100_percent/common/launcher/launcher_appmenu_hover.png
+++ b/ash/resources/default_100_percent/common/launcher/launcher_appmenu_hover.png
diff --git a/ash/resources/default_100_percent/common/launcher/launcher_appmenu_pressed.png b/ash/resources/default_100_percent/common/launcher/launcher_appmenu_pressed.png
index c6f0ce0..87ebbc8 100644
--- a/ash/resources/default_100_percent/common/launcher/launcher_appmenu_pressed.png
+++ b/ash/resources/default_100_percent/common/launcher/launcher_appmenu_pressed.png
diff --git a/ash/resources/default_200_percent/common/launcher/launcher_appmenu.png b/ash/resources/default_200_percent/common/launcher/launcher_appmenu.png
index 8a3ba66a..d504bfc4 100644
--- a/ash/resources/default_200_percent/common/launcher/launcher_appmenu.png
+++ b/ash/resources/default_200_percent/common/launcher/launcher_appmenu.png
diff --git a/ash/resources/default_200_percent/common/launcher/launcher_appmenu_hover.png b/ash/resources/default_200_percent/common/launcher/launcher_appmenu_hover.png
index 5758ec9..4875b5b 100644
--- a/ash/resources/default_200_percent/common/launcher/launcher_appmenu_hover.png
+++ b/ash/resources/default_200_percent/common/launcher/launcher_appmenu_hover.png
diff --git a/ash/resources/default_200_percent/common/launcher/launcher_appmenu_pressed.png b/ash/resources/default_200_percent/common/launcher/launcher_appmenu_pressed.png
index dd40409..35cb32f 100644
--- a/ash/resources/default_200_percent/common/launcher/launcher_appmenu_pressed.png
+++ b/ash/resources/default_200_percent/common/launcher/launcher_appmenu_pressed.png
diff --git a/ash/shell.cc b/ash/shell.cc
index 9297b0e..93cd61f 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -259,11 +259,11 @@ Shell::~Shell() {
   // TooltipController is deleted with the Shell so removing its references.
   RemovePreTargetHandler(tooltip_controller_.get());
 
-  // AppList needs to be released before shelf layout manager, which is
-  // destroyed with launcher container in the loop below. However, app list
-  // container is now on top of launcher container and released after it.
-  // TODO(xiyuan): Move it back when app list container is no longer needed.
-  app_list_controller_.reset();
+  // AppList needs to clean up it dependency on Shell and closes its opened
+  // UI (if any) before closing all RootWindows. However, the controller
+  // instance is still needed so that sub views (e.g. app menu button on
+  // the shelf) could properly clean up.
+  app_list_controller_->Shutdown();
 
   // Destroy SystemTrayDelegate before destroying the status area(s).
   system_tray_delegate_->Shutdown();
@@ -586,6 +586,10 @@ void Shell::Init() {
   if (!system_tray_delegate_)
     system_tray_delegate_.reset(SystemTrayDelegate::CreateDummyDelegate());
 
+  // Creates app_list_controller_ before the launcher because app list
+  // button observes it for UI visibility.
+  app_list_controller_.reset(new internal::AppListController(this));
+
   // Creates StatusAreaWidget.
   root_window_controller->InitForPrimaryDisplay();
 
@@ -636,21 +640,15 @@ void Shell::ShowContextMenu(const gfx::Point& location_in_screen) {
 }
 
 void Shell::ToggleAppList(aura::Window* window) {
-  // If the context window is not given, show it on the active root window.
-  if (!window)
-    window = GetActiveRootWindow();
-  if (!app_list_controller_)
-    app_list_controller_.reset(new internal::AppListController);
-  app_list_controller_->SetVisible(!app_list_controller_->IsVisible(), window);
+  app_list_controller_->Toggle(window);
 }
 
 bool Shell::GetAppListTargetVisibility() const {
-  return app_list_controller_.get() &&
-      app_list_controller_->GetTargetVisibility();
+  return app_list_controller_->GetTargetVisibility();
 }
 
 aura::Window* Shell::GetAppListWindow() {
-  return app_list_controller_.get() ? app_list_controller_->GetWindow() : NULL;
+  return app_list_controller_->GetWindow();
 }
 
 bool Shell::IsSystemModalWindowOpen() const {
diff --git a/ash/shell.h b/ash/shell.h
index 67551c8..27e94a0 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -444,6 +444,10 @@ class ASH_EXPORT Shell
     return launcher_model_.get();
   }
 
+  internal::AppListController* app_list_controller() {
+    return app_list_controller_.get();
+  }
+
   // Returns the launcher delegate, creating if necesary.
   LauncherDelegate* GetLauncherDelegate();
 
diff --git a/ash/wm/app_list_controller.cc b/ash/wm/app_list_controller.cc
index 7fcf76c..6776b60 100644
--- a/ash/wm/app_list_controller.cc
+++ b/ash/wm/app_list_controller.cc
@@ -10,6 +10,7 @@
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
+#include "ash/wm/app_list_controller_observer.h"
 #include "ash/wm/property_util.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/pagination_model.h"
@@ -52,10 +53,11 @@ views::BubbleBorder::Arrow GetBubbleArrow(aura::Window* window) {
           views::BubbleBorder::TOP_CENTER);
 }
 
-// Offset given |rect| towards shelf.
-gfx::Rect OffsetTowardsShelf(const gfx::Rect& rect, views::Widget* widget) {
-  DCHECK(Shell::HasInstance());
-  ShelfAlignment shelf_alignment = Shell::GetInstance()->GetShelfAlignment(
+// Offsets the given |rect| towards shelf.
+gfx::Rect OffsetTowardsShelf(Shell* shell,
+                             const gfx::Rect& rect,
+                             views::Widget* widget) {
+  ShelfAlignment shelf_alignment = shell->GetShelfAlignment(
       widget->GetNativeView()->GetRootWindow());
   gfx::Rect offseted(rect);
   switch (shelf_alignment) {
@@ -81,23 +83,31 @@ gfx::Rect OffsetTowardsShelf(const gfx::Rect& rect, views::Widget* widget) {
 ////////////////////////////////////////////////////////////////////////////////
 // AppListController, public:
 
-AppListController::AppListController()
-    : pagination_model_(new app_list::PaginationModel),
+AppListController::AppListController(Shell* shell)
+    : shell_(shell),
+      pagination_model_(new app_list::PaginationModel),
       is_visible_(false),
       view_(NULL),
       should_snap_back_(false) {
-  Shell::GetInstance()->AddShellObserver(this);
+  shell_->AddShellObserver(this);
   pagination_model_->AddObserver(this);
 }
 
 AppListController::~AppListController() {
+  Shutdown();
+  pagination_model_->RemoveObserver(this);
+}
+
+void AppListController::Shutdown() {
   // Ensures app list view goes before the controller since pagination model
   // lives in the controller and app list view would access it on destruction.
   if (view_ && view_->GetWidget())
     view_->GetWidget()->CloseNow();
 
-  Shell::GetInstance()->RemoveShellObserver(this);
-  pagination_model_->RemoveObserver(this);
+  if (shell_) {
+    shell_->RemoveShellObserver(this);
+    shell_ = NULL;
+  }
 }
 
 void AppListController::SetVisible(bool visible, aura::Window* window) {
@@ -111,14 +121,18 @@ void AppListController::SetVisible(bool visible, aura::Window* window) {
   Shell::GetPrimaryRootWindowController()->GetShelfLayoutManager()->
       UpdateAutoHideState();
 
+  // Determine the root window to show the UI.
+  aura::RootWindow* root_window =
+      window ? window->GetRootWindow() : Shell::GetActiveRootWindow();
+
   if (view_) {
     ScheduleAnimation();
   } else if (is_visible_) {
     // AppListModel and AppListViewDelegate are owned by AppListView. They
     // will be released with AppListView on close.
     app_list::AppListView* view = new app_list::AppListView(
-        Shell::GetInstance()->delegate()->CreateAppListViewDelegate());
-    aura::Window* container = GetRootWindowController(window->GetRootWindow())->
+        shell_->delegate()->CreateAppListViewDelegate());
+    aura::Window* container = GetRootWindowController(root_window)->
         GetContainer(kShellWindowId_AppListContainer);
     view->InitAsBubble(
         container,
@@ -129,16 +143,32 @@ void AppListController::SetVisible(bool visible, aura::Window* window) {
         true /* border_accepts_events */);
     SetView(view);
   }
+
+  FOR_EACH_OBSERVER(AppListControllerObserver,
+                    observers_,
+                    OnAppLauncherVisibilityChanged(is_visible_, root_window));
 }
 
 bool AppListController::IsVisible() const {
   return view_ && view_->GetWidget()->IsVisible();
 }
 
+void AppListController::Toggle(aura::Window* window) {
+  SetVisible(!IsVisible(), window);
+}
+
 aura::Window* AppListController::GetWindow() {
   return is_visible_ && view_ ? view_->GetWidget()->GetNativeWindow() : NULL;
 }
 
+void AppListController::AddObserver(AppListControllerObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void AppListController::RemoveObserver(AppListControllerObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // AppListController, private:
 
@@ -149,7 +179,7 @@ void AppListController::SetView(app_list::AppListView* view) {
   view_ = view;
   views::Widget* widget = view_->GetWidget();
   widget->AddObserver(this);
-  Shell::GetInstance()->AddPreTargetHandler(this);
+  shell_->AddPreTargetHandler(this);
   Launcher::ForWindow(widget->GetNativeWindow())->AddIconObserver(this);
   widget->GetNativeView()->GetRootWindow()->AddRootWindowObserver(this);
   aura::client::GetFocusClient(widget->GetNativeView())->AddObserver(this);
@@ -164,7 +194,7 @@ void AppListController::ResetView() {
   views::Widget* widget = view_->GetWidget();
   widget->RemoveObserver(this);
   GetLayer(widget)->GetAnimator()->RemoveObserver(this);
-  Shell::GetInstance()->RemovePreTargetHandler(this);
+  shell_->RemovePreTargetHandler(this);
   Launcher::ForWindow(widget->GetNativeWindow())->RemoveIconObserver(this);
   widget->GetNativeView()->GetRootWindow()->RemoveRootWindowObserver(this);
   aura::client::GetFocusClient(widget->GetNativeView())->RemoveObserver(this);
@@ -182,9 +212,10 @@ void AppListController::ScheduleAnimation() {
   gfx::Rect target_bounds;
   if (is_visible_) {
     target_bounds = widget->GetWindowBoundsInScreen();
-    widget->SetBounds(OffsetTowardsShelf(target_bounds, widget));
+    widget->SetBounds(OffsetTowardsShelf(shell_, target_bounds, widget));
   } else {
-    target_bounds = OffsetTowardsShelf(widget->GetWindowBoundsInScreen(),
+    target_bounds = OffsetTowardsShelf(shell_,
+                                       widget->GetWindowBoundsInScreen(),
                                        widget);
   }
 
diff --git a/ash/wm/app_list_controller.h b/ash/wm/app_list_controller.h
index d2408d8..385e1e5 100644
--- a/ash/wm/app_list_controller.h
+++ b/ash/wm/app_list_controller.h
@@ -9,6 +9,7 @@
 #include "ash/shell_observer.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "base/observer_list.h"
 #include "base/timer.h"
 #include "ui/app_list/pagination_model_observer.h"
 #include "ui/aura/client/focus_change_observer.h"
@@ -28,8 +29,13 @@ class LocatedEvent;
 }
 
 namespace ash {
+
+class Shell;
+
 namespace internal {
 
+class AppListControllerObserver;
+
 // AppListController is a controller that manages app list UI for shell.
 // It creates AppListView and schedules showing/hiding animation.
 // While the UI is visible, it monitors things such as app list widget's
@@ -43,9 +49,12 @@ class AppListController : public ui::EventHandler,
                           public LauncherIconObserver,
                           public app_list::PaginationModelObserver {
  public:
-  AppListController();
+  explicit AppListController(Shell* shell);
   virtual ~AppListController();
 
+  // Closes opened app list and cleans up its dependency on shell.
+  void Shutdown();
+
   // Show/hide app list window. The |window| is used to deterime in
   // which display (in which the |window| exists) the app list should
   // be shown.
@@ -54,6 +63,10 @@ class AppListController : public ui::EventHandler,
   // Whether app list window is visible (shown or being shown).
   bool IsVisible() const;
 
+  // Convenience wrapper to toggle visibility using the SetVisible() and
+  // IsVisible().
+  void Toggle(aura::Window* window);
+
   // Returns target visibility. This differs from IsVisible() if an animation
   // is ongoing.
   bool GetTargetVisibility() const { return is_visible_; }
@@ -61,6 +74,9 @@ class AppListController : public ui::EventHandler,
   // Returns app list window or NULL if it is not visible.
   aura::Window* GetWindow();
 
+  void AddObserver(AppListControllerObserver* observer);
+  void RemoveObserver(AppListControllerObserver* observer);
+
  private:
   // Sets the app list view and attempts to show it.
   void SetView(app_list::AppListView* view);
@@ -105,6 +121,8 @@ class AppListController : public ui::EventHandler,
   virtual void SelectedPageChanged(int old_selected, int new_selected) OVERRIDE;
   virtual void TransitionChanged() OVERRIDE;
 
+  Shell* shell_;
+
   scoped_ptr<app_list::PaginationModel> pagination_model_;
 
   // Whether we should show or hide app list widget.
@@ -119,6 +137,8 @@ class AppListController : public ui::EventHandler,
   // Whether should schedule snap back animation.
   bool should_snap_back_;
 
+  ObserverList<AppListControllerObserver, true> observers_;
+
   DISALLOW_COPY_AND_ASSIGN(AppListController);
 };
 
diff --git a/ash/wm/app_list_controller_observer.h b/ash/wm/app_list_controller_observer.h
new file mode 100644
index 0000000..0ea0400
--- /dev/null
+++ b/ash/wm/app_list_controller_observer.h
@@ -0,0 +1,29 @@
+// Copyright 2013 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.
+
+#ifndef ASH_WM_APP_LIST_CONTROLLER_OBSERVER_H_
+#define ASH_WM_APP_LIST_CONTROLLER_OBSERVER_H_
+
+namespace aura {
+class RootWindow;
+}
+
+namespace ash {
+namespace internal {
+
+class AppListControllerObserver {
+ public:
+  // Invoked when app launcher bubble is toggled on the given root window.
+  virtual void OnAppLauncherVisibilityChanged(
+      bool visible,
+      const aura::RootWindow* root_window) = 0;
+
+ protected:
+  virtual ~AppListControllerObserver() {}
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_WM_APP_LIST_CONTROLLER_OBSERVER_H_
diff --git a/ui/views/controls/button/image_button.h b/ui/views/controls/button/image_button.h
index 4015def..44f5cfb 100644
--- a/ui/views/controls/button/image_button.h
+++ b/ui/views/controls/button/image_button.h
@@ -109,6 +109,7 @@ class VIEWS_EXPORT ToggleImageButton : public ImageButton {
 
   // Change the toggled state.
   void SetToggled(bool toggled);
+  bool toggled() const { return toggled_; }
 
   // Like ImageButton::SetImage(), but to set the graphics used for the
   // "has been toggled" state.  Must be called for each button state