GraphicsContextCG.h

/*
 * Copyright (C) 2006, 2007, 2010 Apple 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 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 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 GraphicsContextCG_h
#define GraphicsContextCG_h

#include "GraphicsContext.h"

typedef struct CGColorSpace *CGColorSpaceRef;

namespace WebCore {

CGColorSpaceRef deviceRGBColorSpaceRef();
WEBCORE_EXPORT CGColorSpaceRef sRGBColorSpaceRef();
CGColorSpaceRef linearRGBColorSpaceRef();

inline CGAffineTransform getUserToBaseCTM(CGContextRef context)
{
    return CGAffineTransformConcat(CGContextGetCTM(context), CGAffineTransformInvert(CGContextGetBaseCTM(context)));
}

static inline CGColorSpaceRef cachedCGColorSpace(ColorSpace colorSpace)
{
    switch (colorSpace) {
    case ColorSpaceDeviceRGB:
        return deviceRGBColorSpaceRef();
    case ColorSpaceSRGB:
        return sRGBColorSpaceRef();
    case ColorSpaceLinearRGB:
        return linearRGBColorSpaceRef();
    }
    ASSERT_NOT_REACHED();
    return deviceRGBColorSpaceRef();
}

class CGContextStateSaver {
public:
    CGContextStateSaver(CGContextRef context, bool saveAndRestore = true)
        : m_context(context)
        , m_saveAndRestore(saveAndRestore)
    {
        if (m_saveAndRestore)
            CGContextSaveGState(m_context);
    }
    
    ~CGContextStateSaver()
    {
        if (m_saveAndRestore)
            CGContextRestoreGState(m_context);
    }
    
    void save()
    {
        ASSERT(!m_saveAndRestore);
        CGContextSaveGState(m_context);
        m_saveAndRestore = true;
    }

    void restore()
    {
        ASSERT(m_saveAndRestore);
        CGContextRestoreGState(m_context);
        m_saveAndRestore = false;
    }
    
    bool didSave() const
    {
        return m_saveAndRestore;
    }
    
private:
    CGContextRef m_context;
    bool m_saveAndRestore;
};

}

#endif