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// Copyright (c) 2012 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_MAC_H_
#define SKIA_EXT_BITMAP_PLATFORM_DEVICE_MAC_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 CoreGraphics can also
// write to. BitmapPlatformDevice creates a bitmap using
// CGCreateBitmapContext() in a format that Skia supports and can then use this
// to draw text 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:
// Creates a BitmapPlatformDevice instance. |is_opaque| should be set if the
// caller knows the bitmap will be completely opaque and allows some
// optimizations.
// |context| may be NULL. If |context| is NULL, then the bitmap backing store
// is not initialized.
static BitmapPlatformDevice* Create(CGContextRef context,
int width, int height,
bool is_opaque);
// Creates a BitmapPlatformDevice instance. If |is_opaque| is false,
// then the bitmap is initialzed to 0.
static BitmapPlatformDevice* CreateAndClear(int width, int height,
bool is_opaque);
// Creates a context for |data| and calls Create.
// If |data| is NULL, then the bitmap backing store is not initialized.
static BitmapPlatformDevice* CreateWithData(uint8_t* data,
int width, int height,
bool is_opaque);
virtual ~BitmapPlatformDevice();
// PlatformDevice overrides
virtual CGContextRef GetBitmapContext() OVERRIDE;
virtual void DrawToNativeContext(CGContextRef context, int x, int y,
const CGRect* src_rect) OVERRIDE;
// SkDevice overrides
virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
const SkClipStack&) OVERRIDE;
protected:
// 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;
BitmapPlatformDevice(BitmapPlatformDeviceData* data,
const SkBitmap& bitmap);
// Flushes the CoreGraphics 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 const SkBitmap& onAccessBitmap(SkBitmap*) OVERRIDE;
virtual SkDevice* onCreateCompatibleDevice(SkBitmap::Config, int width,
int height, bool isOpaque,
Usage usage) OVERRIDE;
// Data associated with this device, guaranteed non-null. We hold a reference
// to this object.
BitmapPlatformDeviceData* data_;
DISALLOW_COPY_AND_ASSIGN(BitmapPlatformDevice);
};
} // namespace skia
#endif // SKIA_EXT_BITMAP_PLATFORM_DEVICE_MAC_H_
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