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/*
* Copyright (C) 2010 Sencha, Inc.
*
* 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 <QPainter>
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,
OpaqueSolidShadow,
AlphaSolidShadow,
BlurShadow
} type;
QColor color;
int blurRadius;
QPointF offset;
ContextShadow();
ContextShadow(const QColor& c, float r, qreal dx, qreal dy);
void clear();
// The pair beginShadowLayer and endShadowLayer creates a temporary image
// where the caller can draw onto, using the returned QPainter. This
// QPainter instance must be used only to draw between the call to
// beginShadowLayer and endShadowLayer.
//
// Note: multiple/nested shadow layer is NOT allowed.
//
// The current clip region will be used to optimize the size of the
// temporary image. Thus, the original painter should not change any
// clipping until endShadowLayer.
// If the shadow will be completely outside the clipping region,
// beginShadowLayer will return 0.
//
// The returned QPainter 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 QPainter. This is intentional, usually
// shadow has different properties than the shape which casts the shadow.
//
// Once endShadowLayer is called, the temporary image will be drawn
// with the original painter. If blur radius is specified, the shadow
// will be filtered first.
QPainter* beginShadowLayer(QPainter* p, const QRectF& rect);
void endShadowLayer(QPainter* p);
private:
QRect m_layerRect;
QImage m_layerImage;
QPainter* m_layerPainter;
};
} // namespace WebCore
#endif // ContextShadow_h
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