Allow CanvasSkia to bind to an existing SkCanvas.

skia/ext/canvas_paint_mac.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 SKIA_EXT_CANVAS_PAINT_MAC_H_
 #define SKIA_EXT_CANVAS_PAINT_MAC_H_
 #pragma once
 
+#include "skia/ext/canvas_paint_common.h"
 #include "skia/ext/platform_canvas.h"
 
 #import <Cocoa/Cocoa.h>
 
 namespace skia {
 
 // A class designed to translate skia painting into a region to the current
 // graphics context.  On construction, it will set up a context for painting
 // into, and on destruction, it will commit it to the current context.
 template <class T>
 class CanvasPaintT : public T {
  public:
   // This constructor assumes the result is opaque.
   explicit CanvasPaintT(NSRect dirtyRect)
       : context_(NULL),
         rectangle_(dirtyRect),
         composite_alpha_(false) {
     init(true);
   }
 
   CanvasPaintT(NSRect dirtyRect, bool opaque)
       : context_(NULL),
         rectangle_(dirtyRect),
         composite_alpha_(false) {
     init(opaque);
   }
 
   virtual ~CanvasPaintT() {
     if (!is_empty()) {
-      T::restoreToCount(1);
+      GetPlatformCanvas(this)->restoreToCount(1);
 
       // Blit the dirty rect to the current context.
       CGImageRef image = CGBitmapContextCreateImage(context_);
       CGRect destRect = NSRectToCGRect(rectangle_);
 
       CGContextRef destinationContext =
           (CGContextRef)[[NSGraphicsContext currentContext] graphicsPort];
       CGContextSaveGState(destinationContext);
       CGContextSetBlendMode(
           destinationContext,
@@ skipping 24 matching lines @@
   bool is_empty() const {
     return rectangle_.size.width == 0 || rectangle_.size.height == 0;
   }
 
   const NSRect& rectangle() const {
     return rectangle_;
   }
 
  private:
   void init(bool opaque) {
-    if (!T::initialize(rectangle_.size.width, rectangle_.size.height,
-                       opaque, NULL)) {
+    PlatformCanvas* canvas = GetPlatformCanvas(this);
+    if (!canvas->initialize(rectangle_.size.width,
+                            rectangle_.size.height,
+                            opaque, NULL)) {
       // Cause a deliberate crash;
       *(volatile char*) 0 = 0;
     }
 
     // Need to translate so that the dirty region appears at the origin of the
     // surface.
-    T::translate(-SkDoubleToScalar(rectangle_.origin.x),
-                 -SkDoubleToScalar(rectangle_.origin.y));
+    canvas->translate(-SkDoubleToScalar(rectangle_.origin.x),
+                      -SkDoubleToScalar(rectangle_.origin.y));
 
-    context_ = GetBitmapContext(GetTopDevice(*this));
+    context_ = GetBitmapContext(GetTopDevice(*canvas));
   }
 
   CGContext* context_;
   NSRect rectangle_;
   // See description above setter.
   bool composite_alpha_;
 
   // Disallow copy and assign.
   CanvasPaintT(const CanvasPaintT&);
   CanvasPaintT& operator=(const CanvasPaintT&);
 };
 
 typedef CanvasPaintT<PlatformCanvas> PlatformCanvasPaint;
 
 }  // namespace skia
 
 
 #endif  // SKIA_EXT_CANVAS_PAINT_MAC_H_