Allow the creation of a skia::PlatformCanvas from a CGContextRef.

skia/ext/platform_canvas.h

 // Copyright (c) 2006-2008 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_PLATFORM_CANVAS_H_
 #define SKIA_EXT_PLATFORM_CANVAS_H_
 #pragma once
 
 // The platform-specific device will include the necessary platform headers
 // to get the surface type.
@@ skipping 30 matching lines @@
 
 #elif defined(__APPLE__)
   // Mac -----------------------------------------------------------------------
 
   PlatformCanvas(int width, int height, bool is_opaque,
                  CGContextRef context);
   PlatformCanvas(int width, int height, bool is_opaque, uint8_t* context);
 
   // For two-part init, call if you use the no-argument constructor above
   bool initialize(int width, int height, bool is_opaque, uint8_t* data = NULL);
+  bool initialize(CGContextRef context, int width, int height, bool is_opaque);

[brettw, 2010/12/29 21:03:52]

Can you move this before the other one to match the order of the platformCanvas
constructors?

[sjl, 2010/12/31 05:55:49]

Done.

 
 #elif defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__) || \
       defined(__Solaris__)
   // Linux ---------------------------------------------------------------------
 
   // Construct a canvas from the given memory region. The memory is not cleared
   // first. @data must be, at least, @height * StrideForWidth(@width) bytes.
   PlatformCanvas(int width, int height, bool is_opaque, uint8_t* data);
 
   // For two-part init, call if you use the no-argument constructor above
@@ skipping 38 matching lines @@
 
  private:
   // Unimplemented. This is to try to prevent people from calling this function
   // on SkCanvas. SkCanvas' version is not virtual, so we can't prevent this
   // 100%, but hopefully this will make people notice and not use the function.
   // Calling SkCanvas' version will create a new device which is not compatible
   // with us and we will crash if somebody tries to draw into it with
   // CoreGraphics.
   virtual SkDevice* setBitmapDevice(const SkBitmap& bitmap);
 
+  // Internal helper.
+  bool initialize(SkDevice* device);

[brettw, 2010/12/29 21:03:52]

We should avoid overloading the initialize function like this. How about calling
it initWithDevice(). Can the comment also say that it's used internally by the
initialize() functions?

Also, you declare this for every platform but only define/use it on Mac. It
looks like this code is copied into all other platforms. Can you move the
implementation to the shared platform_canvas.cc file and make all the platforms
use it instead of the device setting and unrefing code?

[sjl, 2010/12/31 05:55:49]

Done.

+
   // Disallow copy and assign.
   PlatformCanvas(const PlatformCanvas&);
   PlatformCanvas& operator=(const PlatformCanvas&);
 };
 
 }  // namespace skia
 
 #endif  // SKIA_EXT_PLATFORM_CANVAS_H_