Gtk3: Render a GtkHeaderBar as the background of the tab strip

ui/views/window/frame_background.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_WINDOW_FRAME_BACKGROUND_H_
 #define UI_VIEWS_WINDOW_FRAME_BACKGROUND_H_
 
 #include "base/macros.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/image/image_skia.h"
@@ skipping 11 matching lines @@
 // 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 images.
   void set_frame_color(SkColor color) { frame_color_ = color; }
 
+  // Sets whether the frame to be drawn should have focus.

[Peter Kasting, 2017/01/12 18:53:53]

Nit: This sounds as if the frame will be given focus.  Maybe "Distinguishes
between active (foreground) and inactive (background) window frame styles", or
something.

[Tom (Use chromium acct), 2017/01/12 21:51:10]

Done.

+  void set_is_active(bool is_active) { is_active_ = is_active; }
+
   // Sets the theme image for the top of the window.  May be null (empty).
   // Memory is owned by the caller.
   void set_theme_image(const gfx::ImageSkia& image) { theme_image_ = image; }
 
   // Sets an image that overlays the top window image.  Usually used to add
   // edge highlighting to provide the illusion of depth.  May be null (empty).
   // Memory is owned by the caller.
   void set_theme_overlay_image(const gfx::ImageSkia& image) {
     theme_overlay_image_ = image;
   }
@@ skipping 25 matching lines @@
   void PaintRestored(gfx::Canvas* canvas, const View* view) const;
 
   // Paints the border for a maximized window, which does not include the
   // window edges.
   void PaintMaximized(gfx::Canvas* canvas, const View* view) const;
 
  private:
   // Fills the frame area with the frame color.
   void PaintFrameColor(gfx::Canvas* canvas, const View* view) const;
 
+  // Paints the background of the tab strip.
+  void PaintFrameTopArea(gfx::Canvas* canvas, const View* view) const;
+
   SkColor frame_color_;
+  bool is_active_;
   gfx::ImageSkia theme_image_;
   gfx::ImageSkia theme_overlay_image_;
   int top_area_height_;
 
   // Images for the sides of the frame.
   const gfx::ImageSkia* left_edge_;
   const gfx::ImageSkia* top_edge_;
   const gfx::ImageSkia* right_edge_;
   const gfx::ImageSkia* bottom_edge_;
 
   // Images for the corners of the frame.
   const gfx::ImageSkia* top_left_corner_;
   const gfx::ImageSkia* top_right_corner_;
   const gfx::ImageSkia* bottom_left_corner_;
   const gfx::ImageSkia* bottom_right_corner_;
 
   // Vertical inset for theme image when drawing maximized.
   int maximized_top_inset_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameBackground);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WINDOW_FRAME_BACKGROUND_H_