[Aura] Refactor and update app list window.

ui/aura_shell/app_list.h

Index: ui/aura_shell/app_list.h
diff --git a/ui/aura_shell/app_list.h b/ui/aura_shell/app_list.h
new file mode 100644
index 0000000000000000000000000000000000000000..eb2b886cfc5a2ec14c03d538c754f08c4f5c887b
--- /dev/null
+++ b/ui/aura_shell/app_list.h
@@ -0,0 +1,83 @@
+// Copyright (c) 2011 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 UI_AURA_SHELL_APP_LIST_H_
+#define UI_AURA_SHELL_APP_LIST_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/weak_ptr.h"
+#include "ui/aura/event_filter.h"
+#include "ui/gfx/compositor/layer_animation_observer.h"
+#include "views/widget/widget.h"
+
+namespace aura_shell {
+namespace internal {
+
+// AppList is a controller that manages app list UI for shell. To show the UI,
+// it requests app list widget from ShellDelegate and shows it when ready.
+// While the UI is visible, it monitors things such as app list widget's
+// activation state and desktop mouse click to auto dismiss the UI.
+class AppList : public aura::EventFilter,
+                public ui::LayerAnimationObserver,
+                public views::Widget::Observer {
+ public:
+  AppList();
+  virtual ~AppList();
+
+  // Show/hide app list window.
+  void SetVisible(bool visible);
+
+  // Whether app list window is visible (shown or being shown).
+  bool IsVisible();
+
+ private:
+  // Sets app list widget. If we are in visible mode, start showing animation.
+  // Otherwise, we just close the widget.
+  void SetWidget(views::Widget* widget);
+
+  // Forgets the widget.
+  void ResetWidget();
+
+  // Starts show/hide animation.
+  void ScheduleAnimation();
+
+  // aura::EventFilter overrides:
+  virtual bool PreHandleKeyEvent(aura::Window* target,
+                                 aura::KeyEvent* event) OVERRIDE;
+  virtual bool PreHandleMouseEvent(aura::Window* target,
+                                   aura::MouseEvent* event) OVERRIDE;
+  virtual ui::TouchStatus PreHandleTouchEvent(aura::Window* target,
+                                              aura::TouchEvent* event) OVERRIDE;
+
+  // ui::LayerAnimationObserver overrides:
+  virtual void OnLayerAnimationEnded(
+      const ui::LayerAnimationSequence* sequence) OVERRIDE;
+  virtual void OnLayerAnimationAborted(
+      const ui::LayerAnimationSequence* sequence) OVERRIDE;
+  virtual void OnLayerAnimationScheduled(
+      const ui::LayerAnimationSequence* sequence) OVERRIDE;
+
+  // views::Widget::Observer overrides:
+  virtual void OnWidgetClosing(views::Widget* widget) OVERRIDE;
+  virtual void OnWidgetActivationChanged(views::Widget* widget,
+      bool active) OVERRIDE;
+
+  // Whether we should show or hide app list widget.
+  bool is_visible_;
+
+  // App list widget we get from ShellDelegate.
+  views::Widget* widget_;
+
+  // A weak ptr factory for callbacks that ShellDelegate used to set widget.
+  base::WeakPtrFactory<AppList> set_widget_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(AppList);
+};
+
+}  // namespace internal
+}  // namespace aura_shell
+
+#endif  //  UI_AURA_SHELL_APP_LIST_H_