ash: Animate changes in the uber tray.

ash/system/tray/tray_item_view.h

Index: ash/system/tray/tray_item_view.h
diff --git a/ash/system/tray/tray_item_view.h b/ash/system/tray/tray_item_view.h
new file mode 100644
index 0000000000000000000000000000000000000000..62f7013b75e0ddb22872a2325cd41528436e257d
--- /dev/null
+++ b/ash/system/tray/tray_item_view.h
@@ -0,0 +1,79 @@
+// 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.
+
+#ifndef ASH_SYSTEM_TRAY_TRAY_ITEM_VIEW_H_
+#define ASH_SYSTEM_TRAY_TRAY_ITEM_VIEW_H_
+#pragma once
+
+#include "ui/base/animation/animation_delegate.h"
+#include "ui/views/view.h"
+
+namespace ui {
+class SlideAnimation;
+}
+
+namespace views {
+class ImageView;
+class Label;
+}
+
+namespace ash {
+namespace internal {
+
+// Base-class for items in the tray. It makes sure the widget is updated
+// correctly when the visibility/size of the tray item changes. It also adds
+// animation when showing/hiding the item in the tray.
+class TrayItemView : public views::View,
+                     public ui::AnimationDelegate {
+ public:
+  TrayItemView();
+  virtual ~TrayItemView();
+
+  // Conveniece function for creating a child Label or ImageView.
+  void CreateLabel();
+  void CreateImageView();
+
+  views::Label* label() { return label_; }
+  views::ImageView* image_view() { return image_view_; }
+
+  // Overridden from views::View.
+  virtual void SetVisible(bool visible) OVERRIDE;
+
+ protected:
+  // Makes sure the widget relayouts after the size/visibility of the view
+  // changes.
+  void ApplyChange();
+
+  // This should return the desired size of the view. For most views, this
+  // returns GetPreferredSize. But since this class overrides GetPreferredSize
+  // for animation purposes, we allow a different way to get this size, and do
+  // not allow GetPreferredSize to be overridden.
+  virtual gfx::Size DesiredSize();
+
+  // The default animation duration is 200ms. But each view can customize this.
+  virtual int GetAnimationDurationMS();
+
+  // Overridden from views::View.
+  virtual void PreferredSizeChanged() OVERRIDE;
+
+ private:
+  // Overridden from views::View.
+  virtual gfx::Size GetPreferredSize() OVERRIDE;
+
+  // Overridden from ui::AnimationDelegate.
+  virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
+  virtual void AnimationEnded(const ui::Animation* animation) OVERRIDE;
+  virtual void AnimationCanceled(const ui::Animation* animation) OVERRIDE;
+
+  scoped_ptr<ui::SlideAnimation> animation_;
+  views::Label* label_;
+  views::ImageView* image_view_;
+
+  DISALLOW_COPY_AND_ASSIGN(TrayItemView);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_TRAY_TRAY_ITEM_VIEW_H_