Implement ui for re-parenting an item from an app list folder to another position or folder in the …

ui/app_list/views/top_icon_animation_view.h

+// Copyright (c) 2014 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_APP_LIST_VIEWS_TOP_ICON_ANIMATION_VIEW_H
+#define UI_APP_LIST_VIEWS_TOP_ICON_ANIMATION_VIEW_H
+
+#include "base/observer_list.h"
+#include "ui/compositor/layer_animation_observer.h"
+#include "ui/views/view.h"
+
+namespace views {
+class ImageView;
+}
+
+namespace app_list {
+
+// Observer for top icon animation completion.
+class TopIconAnimationObserver {
+ public:
+  // Called when top icon animation completes.
+  virtual void OnTopIconAnimationsComplete() {}
+
+ protected:
+  TopIconAnimationObserver() {}
+  virtual ~TopIconAnimationObserver() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TopIconAnimationObserver);
+};
+
+// Transitional view used for top item icons animation when opening or closing
+// a folder.
+class TopIconAnimationView : public views::View,
+                             public ui::ImplicitAnimationObserver {
+ public:
+  // |icon|: The icon image of the item icon of full scale size.
+  // |scaled_rect|: Bounds of the small icon inside folder icon.
+  // |open_folder|: Specify open/close folder animation to perform.
+  // The view will be self-cleaned by the end of animation.
+  TopIconAnimationView(const gfx::ImageSkia& icon,
+                       const gfx::Rect& scaled_rect,
+                       bool open_folder);
+  virtual ~TopIconAnimationView();
+
+  void AddObserver(TopIconAnimationObserver* observer);
+  void RemoveObserver(TopIconAnimationObserver* observer);
+
+  // When opening a folder, transform the top item icon from the small icon
+  // inside folder icon to the full scale icon at the target location.
+  // When closing a folder, transform the full scale item icon from its
+  // location to the small icon inside the folder icon.
+  void TransformView();
+
+ private:
+  // views::View overrides:
+  virtual gfx::Size GetPreferredSize() OVERRIDE;
+  virtual void Layout() OVERRIDE;
+
+  // ui::ImplicitAnimationObserver overrides:
+  virtual void OnImplicitAnimationsCompleted() OVERRIDE;
+
+  gfx::Size icon_size_;
+  views::ImageView* icon_;  // Owned by views hierarchy.
+  // Rect of the scaled down top item icon inside folder icon's ink bubble.
+  gfx::Rect scaled_rect_;
+  // true: opening folder; false: closing folder.
+  bool open_folder_;
+
+  ObserverList<TopIconAnimationObserver> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(TopIconAnimationView);
+};
+
+}  // namespace app_list
+
+#endif  // UI_APP_LIST_VIEWS_TOP_ICON_ANIMATION_VIEW_H