root/Source/platform/graphics/Image.h

INCLUDED FROM

/*
 * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
 * Copyright (C) 2004, 2005, 2006 Apple Computer, 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 Image_h
#define Image_h

#include "platform/PlatformExport.h"
#include "platform/geometry/IntRect.h"
#include "platform/graphics/Color.h"
#include "platform/graphics/GraphicsTypes.h"
#include "platform/graphics/ImageOrientation.h"
#include "platform/graphics/skia/NativeImageSkia.h"
#include "third_party/skia/include/core/SkXfermode.h"
#include "wtf/PassRefPtr.h"
#include "wtf/RefCounted.h"
#include "wtf/RefPtr.h"
#include "wtf/RetainPtr.h"
#include "wtf/text/WTFString.h"

namespace WebCore {

class FloatPoint;
class FloatRect;
class FloatSize;
class GraphicsContext;
class Length;
class SharedBuffer;

// This class gets notified when an image creates or destroys decoded frames and when it advances animation frames.
class ImageObserver;

class PLATFORM_EXPORT Image : public RefCounted<Image> {
    friend class GeneratedImage;
    friend class CrossfadeGeneratedImage;
    friend class GradientGeneratedImage;
    friend class GraphicsContext;

public:
    virtual ~Image();

    static PassRefPtr<Image> loadPlatformResource(const char* name);
    static bool supportsType(const String&);

    virtual bool isSVGImage() const { return false; }
    virtual bool isBitmapImage() const { return false; }
    virtual bool currentFrameKnownToBeOpaque() = 0;

    // Derived classes should override this if they can assure that the current
    // image frame contains only resources from its own security origin.
    virtual bool currentFrameHasSingleSecurityOrigin() const { return false; }

    static Image* nullImage();
    bool isNull() const { return size().isEmpty(); }

    virtual void setContainerSize(const IntSize&) { }
    virtual bool usesContainerSize() const { return false; }
    virtual bool hasRelativeWidth() const { return false; }
    virtual bool hasRelativeHeight() const { return false; }
    virtual void computeIntrinsicDimensions(Length& intrinsicWidth, Length& intrinsicHeight, FloatSize& intrinsicRatio);

    virtual IntSize size() const = 0;
    IntRect rect() const { return IntRect(IntPoint(), size()); }
    int width() const { return size().width(); }
    int height() const { return size().height(); }
    virtual bool getHotSpot(IntPoint&) const { return false; }

    bool setData(PassRefPtr<SharedBuffer> data, bool allDataReceived);
    virtual bool dataChanged(bool /*allDataReceived*/) { return false; }

    virtual String filenameExtension() const { return String(); } // null string if unknown

    virtual void destroyDecodedData(bool destroyAll) = 0;

    SharedBuffer* data() { return m_encodedImageData.get(); }

    // Animation begins whenever someone draws the image, so startAnimation() is not normally called.
    // It will automatically pause once all observers no longer want to render the image anywhere.
    virtual void startAnimation(bool /*catchUpIfNecessary*/ = true) { }
    virtual void stopAnimation() {}
    virtual void resetAnimation() {}

    // True if this image can potentially animate.
    virtual bool maybeAnimated() { return false; }

    // Typically the ImageResource that owns us.
    ImageObserver* imageObserver() const { return m_imageObserver; }
    void setImageObserver(ImageObserver* observer) { m_imageObserver = observer; }

    enum TileRule { StretchTile, RoundTile, SpaceTile, RepeatTile };

    virtual PassRefPtr<NativeImageSkia> nativeImageForCurrentFrame() { return nullptr; }

    virtual void drawPattern(GraphicsContext*, const FloatRect&,
        const FloatSize&, const FloatPoint& phase, CompositeOperator,
        const FloatRect&, blink::WebBlendMode = blink::WebBlendModeNormal, const IntSize& repeatSpacing = IntSize());

#if !ASSERT_DISABLED
    virtual bool notSolidColor() { return true; }
#endif

protected:
    Image(ImageObserver* = 0);

    static void fillWithSolidColor(GraphicsContext*, const FloatRect& dstRect, const Color&, CompositeOperator);
    static FloatRect adjustForNegativeSize(const FloatRect&); // A helper method for translating negative width and height values.

    virtual void draw(GraphicsContext*, const FloatRect& dstRect, const FloatRect& srcRect, CompositeOperator, blink::WebBlendMode) = 0;
    virtual void draw(GraphicsContext*, const FloatRect& dstRect, const FloatRect& srcRect, CompositeOperator, blink::WebBlendMode, RespectImageOrientationEnum);
    void drawTiled(GraphicsContext*, const FloatRect& dstRect, const FloatPoint& srcPoint, const FloatSize& tileSize,
        CompositeOperator, blink::WebBlendMode, const IntSize& repeatSpacing);
    void drawTiled(GraphicsContext*, const FloatRect& dstRect, const FloatRect& srcRect, const FloatSize& tileScaleFactor, TileRule hRule, TileRule vRule, CompositeOperator);

    // Supporting tiled drawing
    virtual bool mayFillWithSolidColor() { return false; }
    virtual Color solidColor() const { return Color(); }

private:
    RefPtr<SharedBuffer> m_encodedImageData;
    ImageObserver* m_imageObserver;
};

#define DEFINE_IMAGE_TYPE_CASTS(typeName) \
    DEFINE_TYPE_CASTS(typeName, Image, image, image->is##typeName(), image.is##typeName())

}

#endif