M20 Ash: Animate window header transition from active to inactive

ash/wm/frame_painter.h

Index: ash/wm/frame_painter.h
diff --git a/ash/wm/frame_painter.h b/ash/wm/frame_painter.h
index 5be8ca14652a5b4b6a14dde0657dabac4b1f5976..df22a209694361f5db38d5fc78a6d13fc0a2e47e 100644
--- a/ash/wm/frame_painter.h
+++ b/ash/wm/frame_painter.h
@@ -8,15 +8,20 @@
 
 #include "ash/ash_export.h"
 #include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "ui/base/animation/animation_delegate.h"
+#include "ui/gfx/rect.h"
 
 class SkBitmap;
 namespace gfx {
 class Canvas;
 class Font;
-class Rect;
 class Point;
 class Size;
 }
+namespace ui {
+class SlideAnimation;
+}
 namespace views {
 class ImageButton;
 class NonClientFrameView;
@@ -29,10 +34,10 @@ namespace ash {
 // Helper class for painting window frames.  Exists to share code between
 // various implementations of views::NonClientFrameView.  Canonical source of
 // layout constants for Ash window frames.
-class ASH_EXPORT FramePainter {
+class ASH_EXPORT FramePainter : public ui::AnimationDelegate {
  public:
   FramePainter();
-  ~FramePainter();
+  virtual ~FramePainter();
 
   // |frame| and buttons are used for layout and are not owned.
   void Init(views::Widget* frame,
@@ -74,6 +79,9 @@ class ASH_EXPORT FramePainter {
   // |maximized_layout| appearance.
   void LayoutHeader(views::NonClientFrameView* view, bool maximized_layout);
 
+  // Overridden from ui::AnimationDelegate
+  void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
+
  private:
   // Sets the images for a button base on IDs from the |frame_| theme provider.
   void SetButtonImages(views::ImageButton* button,
@@ -98,6 +106,14 @@ class ASH_EXPORT FramePainter {
   const SkBitmap* header_left_edge_;
   const SkBitmap* header_right_edge_;
 
+  // The bitmap last used for painting header.
+  const SkBitmap* previous_theme_frame_;
+  // The bitmap we are crossfading from.
+  const SkBitmap* crossfade_theme_frame_;
+
+  gfx::Rect header_frame_bounds_;
+  scoped_ptr<ui::SlideAnimation> crossfade_animation_;
+
   DISALLOW_COPY_AND_ASSIGN(FramePainter);
 };