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 13namespace 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. 29class SK_API BitmapPlatformDevice : public SkBitmapDevice, 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 // SkBaseDevice overrides 59 virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region, 60 const SkClipStack&) OVERRIDE; 61 62 protected: 63 BitmapPlatformDevice(CGContextRef context, 64 const SkBitmap& bitmap); 65 66 virtual SkBaseDevice* onCreateDevice(const SkImageInfo& info, 67 Usage usage) OVERRIDE; 68 69 private: 70 void ReleaseBitmapContext(); 71 72 // Sets the transform and clip operations. This will not update the CGContext, 73 // but will mark the config as dirty. The next call of LoadConfig will 74 // pick up these changes. 75 void SetMatrixClip(const SkMatrix& transform, const SkRegion& region); 76 77 // Loads the current transform and clip into the context. Can be called even 78 // when |bitmap_context_| is NULL (will be a NOP). 79 void LoadConfig(); 80 81 // Lazily-created graphics context used to draw into the bitmap. 82 CGContextRef bitmap_context_; 83 84 // True when there is a transform or clip that has not been set to the 85 // context. The context is retrieved for every text operation, and the 86 // transform and clip do not change as much. We can save time by not loading 87 // the clip and transform for every one. 88 bool config_dirty_; 89 90 // Translation assigned to the context: we need to keep track of this 91 // separately so it can be updated even if the context isn't created yet. 92 SkMatrix transform_; 93 94 // The current clipping 95 SkRegion clip_region_; 96 DISALLOW_COPY_AND_ASSIGN(BitmapPlatformDevice); 97}; 98 99} // namespace skia 100 101#endif // SKIA_EXT_BITMAP_PLATFORM_DEVICE_MAC_H_ 102