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// Copyright (c) 2006-2008 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_PLATFORM_CANVAS_LINUX_H_
#define SKIA_EXT_PLATFORM_CANVAS_LINUX_H_
#include <unistd.h>
#include "skia/ext/platform_device_linux.h"
namespace skia {
// This class is a specialization of the regular SkCanvas that is designed to
// work with a gfx::PlatformDevice to manage platform-specific drawing. It
// allows using both Skia operations and platform-specific operations.
class PlatformCanvasLinux : public SkCanvas {
public:
// Set is_opaque if you are going to erase the bitmap and not use
// tranparency: this will enable some optimizations. The shared_section
// parameter is passed to gfx::PlatformDevice::create. See it for details.
//
// If you use the version with no arguments, you MUST call initialize()
PlatformCanvasLinux();
PlatformCanvasLinux(int width, int height, bool is_opaque);
// Construct a canvas from the given memory region. The memory is not cleared
// first. @data must be, at least, @height * StrideForWidth(@width) bytes.
PlatformCanvasLinux(int width, int height, bool is_opaque, uint8_t* data);
virtual ~PlatformCanvasLinux();
// For two-part init, call if you use the no-argument constructor above
bool initialize(int width, int height, bool is_opaque);
// Returns the platform device pointer of the topmost rect with a non-empty
// clip. Both the windows and mac versions have an equivalent of this method;
// a Linux version is added for compatibility.
PlatformDeviceLinux& getTopPlatformDevice() const;
// Return the stride (length of a line in bytes) for the given width. Because
// we use 32-bits per pixel, this will be roughly 4*width. However, for
// alignment reasons we may wish to increase that.
static size_t StrideForWidth(unsigned width);
protected:
// Creates a device store for use by the canvas. We override this so that
// the device is always our own so we know that we can use GDI operations
// on it. Simply calls into createPlatformDevice().
virtual SkDevice* createDevice(SkBitmap::Config, int width, int height,
bool is_opaque, bool isForLayer);
// Creates a device store for use by the canvas. By default, it creates a
// BitmapPlatformDevice object. Can be overridden to change the object type.
virtual SkDevice* createPlatformDevice(int width, int height, bool is_opaque);
// Disallow copy and assign.
PlatformCanvasLinux(const PlatformCanvasLinux&);
PlatformCanvasLinux& operator=(const PlatformCanvasLinux&);
};
} // namespace skia
#endif // SKIA_EXT_PLATFORM_CANVAS_LINUX_H_
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