It is time.

ui/views/native_theme_delegate.h

-// 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 UI_VIEWS_NATIVE_THEME_DELEGATE_H_
-#define UI_VIEWS_NATIVE_THEME_DELEGATE_H_
-
-#include "ui/gfx/rect.h"
-#include "ui/native_theme/native_theme.h"
-#include "ui/views/views_export.h"
-
-namespace views {
-
-// A delagate that supports animating transtions between different native
-// theme states.  This delegate can be used to control a native theme Border
-// or Painter object.
-//
-// If animation is ongoing, the native theme border or painter will
-// composite the foreground state over the backgroud state using an alpha
-// between 0 and 255 based on the current value of the animation.
-class VIEWS_EXPORT NativeThemeDelegate {
- public:
-  virtual ~NativeThemeDelegate() {}
-
-  // Get the native theme part that should be drawn.
-  virtual ui::NativeTheme::Part GetThemePart() const = 0;
-
-  // Get the rectangle that should be painted.
-  virtual gfx::Rect GetThemePaintRect() const = 0;
-
-  // Get the state of the part, along with any extra data needed for drawing.
-  virtual ui::NativeTheme::State GetThemeState(
-      ui::NativeTheme::ExtraParams* params) const = 0;
-
-  // If the native theme drawign should be animated, return the Animation object
-  // that controlls it.  If no animation is ongoing, NULL may be returned.
-  virtual const gfx::Animation* GetThemeAnimation() const = 0;
-
-  // If animation is onging, this returns the background native theme state.
-  virtual ui::NativeTheme::State GetBackgroundThemeState(
-      ui::NativeTheme::ExtraParams* params) const = 0;
-
-  // If animation is onging, this returns the foreground native theme state.
-  // This state will be composited over the background using an alpha value
-  // based on the current value of the animation.
-  virtual ui::NativeTheme::State GetForegroundThemeState(
-      ui::NativeTheme::ExtraParams* params) const = 0;
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_NATIVE_THEME_DELEGATE_H_