Refactor window frame painting into a window background class

ui/views/window/frame_background.h

+// 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_VIEWS_WINDOW_FRAME_BACKGROUND_H_
+#define UI_VIEWS_WINDOW_FRAME_BACKGROUND_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "third_party/skia/include/core/SkColor.h"
+#include "ui/views/views_export.h"
+
+class SkBitmap;
+namespace gfx {
+class Canvas;
+}
+
+namespace views {
+
+class View;
+
+// FrameBackground handles painting for all the various window frames we
+// support in Chrome. It intends to consolidate paint code that historically
+// was copied. One frame to rule them all!
+class VIEWS_EXPORT FrameBackground {
+ public:
+  FrameBackground();
+  ~FrameBackground();
+
+  // Sets the color to draw under the frame bitmaps.
+  void set_frame_color(SkColor color) { frame_color_ = color; }
+
+  // Sets the theme bitmap for the top of the window.  May be NULL.
+  // Memory is owned by the caller.
+  void set_theme_bitmap(SkBitmap* bitmap) { theme_bitmap_ = bitmap; }
+
+  // Sets an image that overlays the top window bitmap.  Usually used to add
+  // edge highlighting to provide the illusion of depth.  May be NULL.
+  // Memory is owned by the caller.
+  void set_theme_overlay_bitmap(SkBitmap* bitmap) {
+    theme_overlay_bitmap_ = bitmap;
+  }
+
+  // Sets the height of the top area to fill with the default frame color,
+  // which must extend behind the tab strip.
+  void set_top_area_height(int height) { top_area_height_ = height; }
+
+  // Only used if we have an overlay image for the theme.
+  void set_theme_background_y(int y) { theme_background_y_ = y; }
+
+  // Vertical offset for theme image when drawing maximized.
+  void set_maximized_top_offset(int offset) { maximized_top_offset_ = offset; }
+
+  // Sets images used when drawing the sides of the frame.
+  // Caller owns the memory.
+  void SetSideImages(SkBitmap* left,
+                     SkBitmap* top,
+                     SkBitmap* right,
+                     SkBitmap* bottom);
+
+  // Sets images used when drawing the corners of the frame.
+  // Caller owns the memory.
+  void SetCornerImages(SkBitmap* top_left,
+                       SkBitmap* top_right,
+                       SkBitmap* bottom_left,
+                       SkBitmap* bottom_right);
+
+  // Sets attributes to paint top-left and top-right corners for maximized
+  // windows.  Use 0 and NULL if you don't want special corners.
+  // TODO(jamescook): This is the remnant of a ChromeOS window hack, and should
+  // be removed.
+  void SetMaximizedCorners(SkBitmap* top_left,
+                           SkBitmap* top_right,
+                           int top_offset);
+
+  // Paints the border for a standard, non-maximized window.  Also paints the
+  // background of the title bar area, since the top frame border and the
+  // title bar background are a contiguous component.
+  void PaintRestored(gfx::Canvas* canvas, View* view) const;
+
+  // Paints the border for a maximized window, which does not include the
+  // window edges.
+  void PaintMaximized(gfx::Canvas* canvas, View* view) const;
+
+ private:
+  // Fills the frame area with the frame color.
+  void PaintFrameColor(gfx::Canvas* canvas, View* view) const;
+
+  SkColor frame_color_;
+  SkBitmap* theme_bitmap_;
+  SkBitmap* theme_overlay_bitmap_;
+  int top_area_height_;
+
+  // Images for the sides of the frame.
+  SkBitmap* left_edge_;
+  SkBitmap* top_edge_;
+  SkBitmap* right_edge_;
+  SkBitmap* bottom_edge_;
+
+  // Images for the corners of the frame.
+  SkBitmap* top_left_corner_;
+  SkBitmap* top_right_corner_;
+  SkBitmap* bottom_left_corner_;
+  SkBitmap* bottom_right_corner_;
+
+  // Attributes for maximized window painting.
+  // TODO(jamescook): Remove all these.
+  SkBitmap* maximized_top_left_;
+  SkBitmap* maximized_top_right_;
+  int maximized_top_offset_;
+  int theme_background_y_;
+
+  DISALLOW_COPY_AND_ASSIGN(FrameBackground);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_WINDOW_FRAME_BACKGROUND_H_