GTK: give the findbox curvy edges....

chrome/browser/gtk/nine_box.h

 // Copyright (c) 2009 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 CHROME_BROWSER_GTK_NINE_BOX_H_
 #define CHROME_BROWSER_GTK_NINE_BOX_H_
 
 #include <gtk/gtk.h>
 
 // A NineBox manages a set of source images representing a 3x3 grid, where
@@ skipping 10 matching lines @@
 class NineBox {
  public:
   // Construct a NineBox with nine images.  Images are specified using resource
   // ids that will be passed to the resource bundle.  Use 0 for no image.
   NineBox(int top_left, int top, int top_right, int left, int center, int right,
           int bottom_left, int bottom, int bottom_right);
   ~NineBox();
 
   // Render the NineBox to |dst|.
   // The images will be tiled to fit into the widget.
-  void RenderToWidget(GtkWidget* dst);
+  void RenderToWidget(GtkWidget* dst) const;
 
   // Render the top row of images to |dst| between |x1| and |x2|.
   // This is split from RenderToWidget so the toolbar can use it.
-  void RenderTopCenterStrip(GtkWidget* dst, int x1, int x2, int y1);
+  void RenderTopCenterStrip(GtkWidget* dst, int x1, int x2, int y1) const;
+
+  // Change all pixels that are white in |images_| to have 0 opacity.
+  void ChangeWhiteToTransparent();
+
+  // Set the shape of |widget| to match that of the ninebox. Note that |widget|
+  // must have its own window and be allocated. Also, currently only the top
+  // three images are used.
+  // TODO(estade): extend this function to use all 9 images (if it's ever
+  // needed).
+  void ContourWidget(GtkWidget* widget) const;
 
  private:
   // Repeatedly stamp src across dst.
   void TileImage(GtkWidget* dst, GdkPixbuf* src,
-                 int x1, int y1, int x2, int y2);
+                 int x1, int y1, int x2, int y2) const;
 
   GdkPixbuf* images_[9];
 };
 
 #endif  // CHROME_BROWSER_GTK_NINE_BOX_H_