skia::PlatformCanvas is being deprecated. Going forward we will use gfx::Canvas wherever we need ...

ui/gfx/canvas_skia.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_GFX_CANVAS_SKIA_H_
 #define UI_GFX_CANVAS_SKIA_H_
 #pragma once
 
 #include "base/basictypes.h"
+#include "base/scoped_ptr.h"
 #include "base/string16.h"
-#include "skia/ext/platform_canvas.h"
 #include "ui/gfx/canvas.h"
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 typedef struct _GdkPixbuf GdkPixbuf;
 #endif
 
 namespace gfx {
 
 class Canvas;
 
-// CanvasSkia is a SkCanvas subclass that provides a number of methods for
-// common operations used throughout an application built using base/gfx and
-// app/gfx.
+// CanvasSkia is a Canvas subclass implemented using skia canvas.
+// It provides a number of methods for common operations used throughout an
+// application built using base/gfx and app/gfx.
 //
 // All methods that take integer arguments (as is used throughout views)
 // end with Int. If you need to use methods provided by the superclass
 // you'll need to do a conversion. In particular you'll need to use
 // macro SkIntToScalar(xxx), or if converting from a scalar to an integer
 // SkScalarRound.
 //
 // A handful of methods in this class are overloaded providing an additional
 // argument of type SkXfermode::Mode. SkXfermode::Mode specifies how the
 // source and destination colors are combined. Unless otherwise specified,
 // the variant that does not take a SkXfermode::Mode uses a transfer mode
 // of kSrcOver_Mode.
-class CanvasSkia : public skia::PlatformCanvas,
-                   public Canvas {
+class CanvasSkia : public Canvas {
  public:
   enum TruncateFadeMode {
     TruncateFadeTail,
     TruncateFadeHead,
     TruncateFadeHeadAndTail,
   };
 
-  // Creates an empty Canvas. Callers must use initialize before using the
-  // canvas.
+  // Creates an empty Canvas.
+  // Callers must use Init before using the canvas.
   CanvasSkia();
-
-  CanvasSkia(int width, int height, bool is_opaque);
-
   virtual ~CanvasSkia();
 
   // Compute the size required to draw some text with the provided font.
   // Attempts to fit the text with the provided width and height. Increases
   // height and then width as needed to make the text fit. This method
   // supports multiple lines.
   static void SizeStringInt(const string16& text,
                             const gfx::Font& font,
                             int* width, int* height,
                             int flags);
 
   // Returns the default text alignment to be used when drawing text on a
   // gfx::CanvasSkia based on the directionality of the system locale language.
   // This function is used by gfx::Canvas::DrawStringInt when the text alignment
   // is not specified.
   //
   // This function returns either gfx::Canvas::TEXT_ALIGN_LEFT or
   // gfx::Canvas::TEXT_ALIGN_RIGHT.
   static int DefaultCanvasTextAlignment();
 
+  bool Init(int width, int height, bool is_opaque);
+
+  // Returns the underlying skia canvas.
+  SkCanvas* skia_canvas() { return skia_canvas_.get(); }
+
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
   // Draw the pixbuf in its natural size at (x, y).
   void DrawGdkPixbuf(GdkPixbuf* pixbuf, int x, int y);
 #endif
 
 #if defined(OS_WIN) || (defined(OS_POSIX) && !defined(OS_MACOSX))
   // Draws text with a 1-pixel halo around it of the given color.
   // On Windows, it allows ClearType to be drawn to an otherwise transparenct
   //   bitmap for drag images. Drag images have only 1-bit of transparency, so
   //   we don't do any fancy blurring.
@@ skipping 74 matching lines @@
   virtual void TileImageInt(const SkBitmap& bitmap,
                             int src_x, int src_y,
                             int dest_x, int dest_y, int w, int h);
   virtual gfx::NativeDrawingContext BeginPlatformPaint();
   virtual void EndPlatformPaint();
   virtual void Transform(const ui::Transform& transform);
   virtual ui::TextureID GetTextureID();
   virtual CanvasSkia* AsCanvasSkia();
   virtual const CanvasSkia* AsCanvasSkia() const;
 
+  // Blits a rectangle from this canvas into the destination context.
+  // This function uses two blit modes to achieve the final color:
+  // 1. Copy: If the source canvas is opaque the color data in the source
+  //          rectangle is simply copied to the destination rectangle.
+  // 2. Blend: If the source canvas is translucent, the color data in the
+  //           source rectangle is blended with that in the destination
+  //           rectangle.
+  void BlitToNativeContext(const Rect& src_rect,
+                           const Point& dst_origin,
+                           NativeDrawingContext dst_context);
+
  private:
   // Test whether the provided rectangle intersects the current clip rect.
   bool IntersectsClipRectInt(int x, int y, int w, int h);
 
 #if defined(OS_WIN)
   // Draws text with the specified color, font and location. The text is
   // aligned to the left, vertically centered, clipped to the region. If the
   // text is too big, it is truncated and '...' is added to the end.
   void DrawStringInt(const string16& text,
                      HFONT font,
                      const SkColor& color,
                      int x, int y, int w, int h,
                      int flags);
 #endif
 
+  scoped_ptr<SkCanvas> skia_canvas_;
   DISALLOW_COPY_AND_ASSIGN(CanvasSkia);
 };
 
 }  // namespace gfx;
 
 #endif  // UI_GFX_CANVAS_SKIA_H_