/*
 * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
 *
 * 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 SVGPaintServerGradient_h
#define SVGPaintServerGradient_h

#if ENABLE(SVG)

#include "AffineTransform.h"
#include "SVGPaintServer.h"

#include <wtf/RefCounted.h>
#include <wtf/RefPtr.h>

#if PLATFORM(QT)
#include <qglobal.h>
QT_BEGIN_NAMESPACE
class QGradient;
QT_END_NAMESPACE
#endif

namespace WebCore
{

class ImageBuffer;
class SVGGradientElement;

// FIXME: Remove the spread method enum in SVGGradientElement
enum SVGGradientSpreadMethod {
    SPREADMETHOD_PAD = 1,
    SPREADMETHOD_REFLECT = 2,
    SPREADMETHOD_REPEAT = 3
};

typedef std::pair<float, QColor> SVGGradientStop;

class SVGPaintServerGradient : public SVGPaintServer
{
public:
    virtual ~SVGPaintServerGradient();

    const Vector<SVGGradientStop> &gradientStops() const;
    void setGradientStops(const Vector<SVGGradientStop> &);

    SVGGradientSpreadMethod spreadMethod() const;
    void setGradientSpreadMethod(const SVGGradientSpreadMethod &);

    // Gradient start and end points are percentages when used in boundingBox mode.
    // For instance start point with value (0,0) is top-left and end point with
    // value (100, 100) is bottom-right. BoundingBox mode is enabled by default.
    bool boundingBoxMode() const;
    void setBoundingBoxMode(bool mode = true);

    AffineTransform gradientTransform() const;
    void setGradientTransform(const AffineTransform &);

    /*virtual TextStream& externalRepresentation(TextStream&) const;*/

    virtual bool setup(QPainter *painter, QPainterPath *path, const RenderObject *, SVGPaintTargetType, bool isPaintingText) const;
#if PLATFORM(CG)
    virtual void teardown(GraphicsContext *&, const RenderObject *, SVGPaintTargetType, bool isPaintingText) const;
    virtual void renderPath(GraphicsContext *&, const RenderObject *, SVGPaintTargetType) const;

    virtual void invalidate();

    // Helpers
    void updateQuartzGradientStopsCache(const Vector<SVGGradientStop> &);
    void updateQuartzGradientCache(const SVGPaintServerGradient *);
    void handleBoundingBoxModeAndGradientTransformation(GraphicsContext *, const FloatRect &targetRect) const;
#endif

#if PLATFORM(QT)
protected:
    void fillColorArray(QGradient &, const Vector<SVGGradientStop> &, float opacity) const;
    virtual QGradient setupGradient(QPainter *painter, QPainterPath *painterPath, const RenderObject *) const = 0;
#endif

protected:
    SVGPaintServerGradient(const SVGGradientElement *owner);

private:
    Vector<SVGGradientStop> m_stops;
    SVGGradientSpreadMethod m_spreadMethod;
    bool m_boundingBoxMode;
    AffineTransform m_gradientTransform;
    const SVGGradientElement *m_ownerElement;

#if PLATFORM(CG)
public:
    typedef struct {
        CGFloat colorArray[4];
        CGFloat offset;
        CGFloat previousDeltaInverse;
    } QuartzGradientStop;

    struct SharedStopCache : public RefCounted<SharedStopCache> {
    public:
        static PassRefPtr<SharedStopCache> create()
        {
            return adoptRef(new SharedStopCache);
        }

        Vector<QuartzGradientStop> m_stops;

    private:
        SharedStopCache() { }
    };

    RefPtr<SharedStopCache> m_stopsCache;

    CGShadingRef m_shadingCache;
    mutable GraphicsContext *m_savedContext;
    mutable ImageBuffer *m_imageBuffer;
#endif
};

inline SVGGradientStop makeGradientStop(float offset, const QColor &color)
{
    return std::make_pair(offset, color);
}

} // namespace WebCore

#endif

#endif // SVGPaintServerGradient_h
