CL removing inheritance of SkDevice from PlatformDevice. Flavours of PlatformDevice classes now ...

skia/ext/vector_platform_device_emf_win.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 SKIA_EXT_VECTOR_PLATFORM_DEVICE_EMF_WIN_H_
 #define SKIA_EXT_VECTOR_PLATFORM_DEVICE_EMF_WIN_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "skia/ext/platform_device.h"
 #include "third_party/skia/include/core/SkMatrix.h"
 #include "third_party/skia/include/core/SkRegion.h"
 
 namespace skia {
 
 // A device is basically a wrapper around SkBitmap that provides a surface for
 // SkCanvas to draw into. This specific device is not not backed by a surface
 // and is thus unreadable. This is because the backend is completely vectorial.
 // This device is a simple wrapper over a Windows device context (HDC) handle.
-class VectorPlatformDeviceEmf : public PlatformDevice {
+class VectorPlatformDeviceEmf : public PlatformDevice, public SkDevice {

[vandebo (ex-Chrome), 2011/08/15 19:52:10]

Would it make sense to rename this to EmfDevice that only inherits SkDevice and
then create a new VectorPlatformDeviceEmf (one that mirrors
VectorPlatformDeviceSkia) ?

[Jeff Timanus, 2011/08/15 20:06:25]

Yes.  That would make sense for all of the classes that truly need to override
SkDevice.  It would also remove the need for the logic to specify the ownership
parameters of the PlatformDevice instance during assignment to a SkDevice.

  public:
-  SK_API static PlatformDevice* CreateDevice(int width, int height,
-                                             bool isOpaque,
-                                             HANDLE shared_section);
+  SK_API static SkDevice* CreateDevice(int width, int height, bool isOpaque,
+                                       HANDLE shared_section);
 
   // Factory function. The DC is kept as the output context.
-  static VectorPlatformDeviceEmf* create(HDC dc, int width, int height);
+  static SkDevice* create(HDC dc, int width, int height);
 
   VectorPlatformDeviceEmf(HDC dc, const SkBitmap& bitmap);
   virtual ~VectorPlatformDeviceEmf();
 
   // PlatformDevice methods
   virtual PlatformSurface BeginPlatformPaint() OVERRIDE;
   virtual void DrawToNativeContext(HDC dc, int x, int y,
                                    const RECT* src_rect) OVERRIDE;
   virtual bool AlphaBlendUsed() const OVERRIDE { return alpha_blend_used_; }
 
@@ skipping 92 matching lines @@
   // True if AlphaBlend() was called during this print.
   bool alpha_blend_used_;
 
   DISALLOW_COPY_AND_ASSIGN(VectorPlatformDeviceEmf);
 };
 
 }  // namespace skia
 
 #endif  // SKIA_EXT_VECTOR_PLATFORM_DEVICE_EMF_WIN_H_