| // 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_BITMAP_PLATFORM_DEVICE_WIN_H_ |
| #define SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_ |
| #pragma once |
| |
| #include "base/basictypes.h" |
| #include "base/compiler_specific.h" |
| #include "skia/ext/platform_device.h" |
| |
| namespace skia { |
| |
| // A device is basically a wrapper around SkBitmap that provides a surface for |
| // SkCanvas to draw into. Our device provides a surface Windows can also write |
| // to. BitmapPlatformDevice creates a bitmap using CreateDIBSection() in a |
| // format that Skia supports and can then use this to draw ClearType into, etc. |
| // This pixel data is provided to the bitmap that the device contains so that it |
| // can be shared. |
| // |
| // The device owns the pixel data, when the device goes away, the pixel data |
| // also becomes invalid. THIS IS DIFFERENT THAN NORMAL SKIA which uses |
| // reference counting for the pixel data. In normal Skia, you could assign |
| // another bitmap to this device's bitmap and everything will work properly. |
| // For us, that other bitmap will become invalid as soon as the device becomes |
| // invalid, which may lead to subtle bugs. Therefore, DO NOT ASSIGN THE |
| // DEVICE'S PIXEL DATA TO ANOTHER BITMAP, make sure you copy instead. |
| class SK_API BitmapPlatformDevice : public PlatformDevice, public SkDevice { |
| public: |
| // Factory function. The screen DC is used to create the bitmap, and will not |
| // be stored beyond this function. is_opaque should be set if the caller |
| // knows the bitmap will be completely opaque and allows some optimizations. |
| // |
| // The shared_section parameter is optional (pass NULL for default behavior). |
| // If shared_section is non-null, then it must be a handle to a file-mapping |
| // object returned by CreateFileMapping. See CreateDIBSection for details. |
| static BitmapPlatformDevice* create(HDC screen_dc, int width, int height, |
| bool is_opaque, HANDLE shared_section); |
| |
| // This version is the same as above but will get the screen DC itself. |
| static BitmapPlatformDevice* create(int width, int height, bool is_opaque, |
| HANDLE shared_section); |
| |
| virtual ~BitmapPlatformDevice(); |
| |
| // PlatformDevice overrides |
| // Retrieves the bitmap DC, which is the memory DC for our bitmap data. The |
| // bitmap DC is lazy created. |
| virtual PlatformSurface BeginPlatformPaint() OVERRIDE; |
| virtual void EndPlatformPaint() OVERRIDE; |
| |
| virtual void DrawToNativeContext(HDC dc, int x, int y, |
| const RECT* src_rect) OVERRIDE; |
| |
| // Loads the given transform and clipping region into the HDC. This is |
| // overridden from SkDevice. |
| virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region, |
| const SkClipStack&) OVERRIDE; |
| |
| protected: |
| // Flushes the Windows device context so that the pixel data can be accessed |
| // directly by Skia. Overridden from SkDevice, this is called when Skia |
| // starts accessing pixel data. |
| virtual void onAccessBitmap(SkBitmap* bitmap) OVERRIDE; |
| |
| virtual SkDevice* onCreateCompatibleDevice(SkBitmap::Config, int width, |
| int height, bool isOpaque, |
| Usage usage) OVERRIDE; |
| |
| private: |
| // Reference counted data that can be shared between multiple devices. This |
| // allows copy constructors and operator= for devices to work properly. The |
| // bitmaps used by the base device class are already refcounted and copyable. |
| class BitmapPlatformDeviceData; |
| |
| // Private constructor. The data should already be ref'ed for us. |
| BitmapPlatformDevice(BitmapPlatformDeviceData* data, |
| const SkBitmap& bitmap); |
| |
| // Data associated with this device, guaranteed non-null. We hold a reference |
| // to this object. |
| BitmapPlatformDeviceData* data_; |
| |
| #ifdef SK_DEBUG |
| int begin_paint_count_; |
| #endif |
| |
| DISALLOW_COPY_AND_ASSIGN(BitmapPlatformDevice); |
| }; |
| |
| } // namespace skia |
| |
| #endif // SKIA_EXT_BITMAP_PLATFORM_DEVICE_WIN_H_ |