svgrendersupport.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2007, 2008 Rob Buis <[e-mail]>
 *           (C) 2007 Nikolas Zimmermann <[e-mail]>
 *           (C) 2007 Eric Seidel <[e-mail]>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#include "config.h"

#if ENABLE(SVG)
#include "SVGRenderSupport.h"

#include "TransformationMatrix.h"
#include "ImageBuffer.h"
#include "RenderObject.h"
#include "RenderSVGContainer.h"
#include "RenderView.h"
#include "SVGResourceClipper.h"
#include "SVGResourceFilter.h"
#include "SVGResourceMasker.h"
#include "SVGStyledElement.h"
#include "SVGURIReference.h"
#include <wtf/UnusedParam.h>

namespace WebCore {

void prepareToRenderSVGContent(RenderObject* object, RenderObject::PaintInfo& paintInfo, const FloatRect& boundingBox, SVGResourceFilter*& filter, SVGResourceFilter* rootFilter)
{
#if !ENABLE(SVG_FILTERS)
    UNUSED_PARAM(filter);
    UNUSED_PARAM(rootFilter);
#endif

    SVGElement* svgElement = static_cast<SVGElement*>(object->node());
    ASSERT(svgElement && svgElement->document() && svgElement->isStyled());
    ASSERT(object);

    SVGStyledElement* styledElement = static_cast<SVGStyledElement*>(svgElement);
    const RenderStyle* style = object->style();
    ASSERT(style);

    const SVGRenderStyle* svgStyle = style->svgStyle();
    ASSERT(svgStyle);

    // Setup transparency layers before setting up filters!
    float opacity = style->opacity(); 
    if (opacity < 1.0f) {
        paintInfo.context->clip(enclosingIntRect(boundingBox));
        paintInfo.context->beginTransparencyLayer(opacity);
    }

#if ENABLE(SVG_FILTERS)
    AtomicString filterId(svgStyle->filter());
#endif

    AtomicString clipperId(svgStyle->clipPath());
    AtomicString maskerId(svgStyle->maskElement());

    Document* document = object->document();

#if ENABLE(SVG_FILTERS)
    SVGResourceFilter* newFilter = getFilterById(document, filterId);
    if (newFilter == rootFilter) {
        // Catch <text filter="url(#foo)">Test<tspan filter="url(#foo)">123</tspan></text>.
        // The filter is NOT meant to be applied twice in that case!
        filter = 0;
        filterId = String();
    } else
        filter = newFilter;
#endif

    SVGResourceClipper* clipper = getClipperById(document, clipperId);
    SVGResourceMasker* masker = getMaskerById(document, maskerId);

#if ENABLE(SVG_FILTERS)
    if (filter) {
        filter->addClient(styledElement);
        filter->prepareFilter(paintInfo.context, boundingBox);
    } else if (!filterId.isEmpty())
        svgElement->document()->accessSVGExtensions()->addPendingResource(filterId, styledElement);
#endif

    if (clipper) {
        clipper->addClient(styledElement);
        clipper->applyClip(paintInfo.context, boundingBox);
    } else if (!clipperId.isEmpty())
        svgElement->document()->accessSVGExtensions()->addPendingResource(clipperId, styledElement);

    if (masker) {
        masker->addClient(styledElement);
        masker->applyMask(paintInfo.context, boundingBox);
    } else if (!maskerId.isEmpty())
        svgElement->document()->accessSVGExtensions()->addPendingResource(maskerId, styledElement);
}

void finishRenderSVGContent(RenderObject* object, RenderObject::PaintInfo& paintInfo, const FloatRect& boundingBox, SVGResourceFilter*& filter, GraphicsContext* savedContext)
{
#if !ENABLE(SVG_FILTERS)
    UNUSED_PARAM(boundingBox);
    UNUSED_PARAM(filter);
    UNUSED_PARAM(savedContext);
#endif

    ASSERT(object);

    const RenderStyle* style = object->style();
    ASSERT(style);

#if ENABLE(SVG_FILTERS)
    if (filter) {
        filter->applyFilter(paintInfo.context, boundingBox);
        paintInfo.context = savedContext;
    }
#endif

    float opacity = style->opacity();    
    if (opacity < 1.0f)
        paintInfo.context->endTransparencyLayer();
}

void renderSubtreeToImage(ImageBuffer* image, RenderObject* item)
{
    ASSERT(item);
    ASSERT(image);
    ASSERT(image->context());
    RenderObject::PaintInfo info(image->context(), IntRect(), PaintPhaseForeground, 0, 0, 0);

    RenderSVGContainer* svgContainer = 0;
    if (item && item->isSVGContainer())
        svgContainer = static_cast<RenderSVGContainer*>(item);

    bool drawsContents = svgContainer ? svgContainer->drawsContents() : false;
    if (svgContainer && !drawsContents)
        svgContainer->setDrawsContents(true);

    item->layoutIfNeeded();
    item->paint(info, 0, 0);

    if (svgContainer && !drawsContents)
        svgContainer->setDrawsContents(false);
}

void clampImageBufferSizeToViewport(RenderObject* object, IntSize& size)
{
    if (!object || !object->isRenderView())
        return;

    RenderView* view = toRenderView(object);
    if (!view->frameView())
        return;

    int viewWidth = view->frameView()->visibleWidth();
    int viewHeight = view->frameView()->visibleHeight();

    if (size.width() > viewWidth)
        size.setWidth(viewWidth);

    if (size.height() > viewHeight)
        size.setHeight(viewHeight);
}

} // namespace WebCore

#endif // ENABLE(SVG)