1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef SKIA_EXT_BITMAP_PLATFORM_DEVICE_MAC_H_ 6 #define SKIA_EXT_BITMAP_PLATFORM_DEVICE_MAC_H_ 7 8 #include "base/basictypes.h" 9 #include "base/compiler_specific.h" 10 #include "skia/ext/platform_device.h" 11 #include "skia/ext/refptr.h" 12 13 namespace skia { 14 15 // A device is basically a wrapper around SkBitmap that provides a surface for 16 // SkCanvas to draw into. Our device provides a surface CoreGraphics can also 17 // write to. BitmapPlatformDevice creates a bitmap using 18 // CGCreateBitmapContext() in a format that Skia supports and can then use this 19 // to draw text into, etc. This pixel data is provided to the bitmap that the 20 // device contains so that it can be shared. 21 // 22 // The device owns the pixel data, when the device goes away, the pixel data 23 // also becomes invalid. THIS IS DIFFERENT THAN NORMAL SKIA which uses 24 // reference counting for the pixel data. In normal Skia, you could assign 25 // another bitmap to this device's bitmap and everything will work properly. 26 // For us, that other bitmap will become invalid as soon as the device becomes 27 // invalid, which may lead to subtle bugs. Therefore, DO NOT ASSIGN THE 28 // DEVICE'S PIXEL DATA TO ANOTHER BITMAP, make sure you copy instead. 29 class SK_API BitmapPlatformDevice : public SkDevice, public PlatformDevice { 30 public: 31 // Creates a BitmapPlatformDevice instance. |is_opaque| should be set if the 32 // caller knows the bitmap will be completely opaque and allows some 33 // optimizations. 34 // |context| may be NULL. If |context| is NULL, then the bitmap backing store 35 // is not initialized. 36 static BitmapPlatformDevice* Create(CGContextRef context, 37 int width, int height, 38 bool is_opaque); 39 40 // Creates a BitmapPlatformDevice instance. If |is_opaque| is false, 41 // then the bitmap is initialzed to 0. 42 static BitmapPlatformDevice* CreateAndClear(int width, int height, 43 bool is_opaque); 44 45 // Creates a context for |data| and calls Create. 46 // If |data| is NULL, then the bitmap backing store is not initialized. 47 static BitmapPlatformDevice* CreateWithData(uint8_t* data, 48 int width, int height, 49 bool is_opaque); 50 51 virtual ~BitmapPlatformDevice(); 52 53 // PlatformDevice overrides 54 virtual CGContextRef GetBitmapContext() OVERRIDE; 55 virtual void DrawToNativeContext(CGContextRef context, int x, int y, 56 const CGRect* src_rect) OVERRIDE; 57 58 // SkDevice overrides 59 virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region, 60 const SkClipStack&) OVERRIDE; 61 62 protected: 63 // Reference counted data that can be shared between multiple devices. This 64 // allows copy constructors and operator= for devices to work properly. The 65 // bitmaps used by the base device class are already refcounted and copyable. 66 class BitmapPlatformDeviceData; 67 68 BitmapPlatformDevice(const skia::RefPtr<BitmapPlatformDeviceData>& data, 69 const SkBitmap& bitmap); 70 71 // Flushes the CoreGraphics context so that the pixel data can be accessed 72 // directly by Skia. Overridden from SkDevice, this is called when Skia 73 // starts accessing pixel data. 74 virtual const SkBitmap& onAccessBitmap(SkBitmap*) OVERRIDE; 75 76 virtual SkDevice* onCreateCompatibleDevice(SkBitmap::Config, int width, 77 int height, bool isOpaque, 78 Usage usage) OVERRIDE; 79 80 // Data associated with this device, guaranteed non-null. 81 skia::RefPtr<BitmapPlatformDeviceData> data_; 82 83 DISALLOW_COPY_AND_ASSIGN(BitmapPlatformDevice); 84 }; 85 86 } // namespace skia 87 88 #endif // SKIA_EXT_BITMAP_PLATFORM_DEVICE_MAC_H_ 89
