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/*
* Copyright (C) 2010 Sencha, Inc.
* Copyright (C) 2010 Igalia S.L.
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef ContextShadow_h
#define ContextShadow_h
#include "Color.h"
#include "FloatRect.h"
#include "IntRect.h"
#include "RefCounted.h"
#if PLATFORM(CAIRO)
typedef struct _cairo cairo_t;
typedef struct _cairo_surface cairo_surface_t;
typedef cairo_surface_t* PlatformImage;
typedef cairo_t* PlatformContext;
#elif PLATFORM(QT)
#include <QImage>
class QPainter;
typedef QImage PlatformImage;
typedef QPainter* PlatformContext;
#endif
namespace WebCore {
// This is to track and keep the shadow state. We use this rather than
// using GraphicsContextState to allow possible optimizations (right now
// only to determine the shadow type, but in future it might covers things
// like cached scratch image, persistent shader, etc).
// This class should be copyable since GraphicsContextQt keeps a stack of
// the shadow state for savePlatformState and restorePlatformState.
class ContextShadow {
public:
enum {
NoShadow,
SolidShadow,
BlurShadow
} m_type;
Color m_color;
int m_blurRadius;
FloatSize m_offset;
ContextShadow();
ContextShadow(const Color&, float radius, const FloatSize& offset);
void clear();
// The pair beginShadowLayer and endShadowLayer creates a temporary image
// where the caller can draw onto, using the returned context. This context
// must be used only to draw between the call to beginShadowLayer and
// endShadowLayer.
//
// Note: multiple/nested shadow layers are NOT allowed.
//
// The current clip region will be used to optimize the size of the
// temporary image. Thus, the original context should not change any
// clipping until endShadowLayer. If the shadow will be completely outside
// the clipping region, beginShadowLayer will return 0.
//
// The returned context will have the transformation matrix and clipping
// properly initialized to start doing the painting (no need to account for
// the shadow offset), however it will not have the same render hints, pen,
// brush, etc as the passed context. This is intentional, usually shadows
// have different properties than the shapes which cast them.
//
// Once endShadowLayer is called, the temporary image will be drawn with the
// original context. If blur radius is specified, the shadow will be
// filtered first.
PlatformContext beginShadowLayer(PlatformContext, const FloatRect& layerArea);
void endShadowLayer(PlatformContext);
static void purgeScratchBuffer();
#if PLATFORM(QT)
QPointF offset() { return QPointF(m_offset.width(), m_offset.height()); }
#endif
private:
IntRect m_layerRect;
PlatformImage m_layerImage;
PlatformContext m_layerContext;
void blurLayerImage(unsigned char*, const IntSize& imageSize, int stride);
void calculateLayerBoundingRect(const FloatRect& layerArea, const IntRect& clipRect);
};
} // namespace WebCore
#endif // ContextShadow_h
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