root/Source/core/svg/graphics/SVGImage.cpp

DEFINITIONS

1. isInSVGImage
2. currentFrameHasSingleSecurityOrigin
3. svgRootElement
4. setContainerSize
5. containerSize
6. drawForContainer
7. nativeImageForCurrentFrame
8. drawPatternForContainer
9. draw
10. embeddedContentBox
11. frameView
12. hasRelativeWidth
13. hasRelativeHeight
14. computeIntrinsicDimensions
15. startAnimation
16. stopAnimation
17. resetAnimation
18. hasAnimations
19. dataChanged
20. filenameExtension

/*
 * Copyright (C) 2006 Eric Seidel <eric@webkit.org>
 * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
 * Copyright (C) Research In Motion Limited 2011. 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.
 */

#include "config.h"

#include "core/svg/graphics/SVGImage.h"

#include "core/animation/DocumentTimeline.h"
#include "core/dom/NodeTraversal.h"
#include "core/dom/shadow/ComposedTreeWalker.h"
#include "core/frame/FrameView.h"
#include "core/frame/LocalFrame.h"
#include "core/frame/Settings.h"
#include "core/loader/FrameLoadRequest.h"
#include "core/page/Chrome.h"
#include "core/rendering/style/RenderStyle.h"
#include "core/rendering/svg/RenderSVGRoot.h"
#include "core/svg/SVGDocument.h"
#include "core/svg/SVGFEImageElement.h"
#include "core/svg/SVGImageElement.h"
#include "core/svg/SVGSVGElement.h"
#include "core/svg/animation/SMILTimeContainer.h"
#include "core/svg/graphics/SVGImageChromeClient.h"
#include "platform/LengthFunctions.h"
#include "platform/geometry/IntRect.h"
#include "platform/graphics/GraphicsContextStateSaver.h"
#include "platform/graphics/ImageBuffer.h"
#include "platform/graphics/ImageObserver.h"
#include "wtf/PassRefPtr.h"

namespace WebCore {

SVGImage::SVGImage(ImageObserver* observer)
    : Image(observer)
{
}

SVGImage::~SVGImage()
{
    if (m_page) {
        // Store m_page in a local variable, clearing m_page, so that SVGImageChromeClient knows we're destructed.
        OwnPtr<Page> currentPage = m_page.release();
        currentPage->mainFrame()->loader().frameDetached(); // Break both the loader and view references to the frame
    }

    // Verify that page teardown destroyed the Chrome
    ASSERT(!m_chromeClient || !m_chromeClient->image());
}

bool SVGImage::isInSVGImage(const Element* element)
{
    ASSERT(element);

    Page* page = element->document().page();
    if (!page)
        return false;

    return page->chrome().client().isSVGImageChromeClient();
}

bool SVGImage::currentFrameHasSingleSecurityOrigin() const
{
    if (!m_page)
        return true;

    LocalFrame* frame = m_page->mainFrame();

    RELEASE_ASSERT(frame->document()->loadEventFinished());

    SVGSVGElement* rootElement = toSVGDocument(frame->document())->rootElement();
    if (!rootElement)
        return true;

    // Don't allow foreignObject elements or images that are not known to be
    // single-origin since these can leak cross-origin information.
    ComposedTreeWalker walker(rootElement);
    while (Node* node = walker.get()) {
        if (isSVGForeignObjectElement(*node))
            return false;
        if (isSVGImageElement(*node)) {
            if (!toSVGImageElement(*node).currentFrameHasSingleSecurityOrigin())
                return false;
        } else if (isSVGFEImageElement(*node)) {
            if (!toSVGFEImageElement(*node).currentFrameHasSingleSecurityOrigin())
                return false;
        }
        walker.next();
    }

    // Because SVG image rendering disallows external resources and links, these
    // images effectively are restricted to a single security origin.
    return true;
}

static SVGSVGElement* svgRootElement(Page* page)
{
    if (!page)
        return 0;
    LocalFrame* frame = page->mainFrame();
    return toSVGDocument(frame->document())->rootElement();
}

void SVGImage::setContainerSize(const IntSize& size)
{
    if (!usesContainerSize())
        return;

    SVGSVGElement* rootElement = svgRootElement(m_page.get());
    if (!rootElement)
        return;

    FrameView* view = frameView();
    view->resize(this->containerSize());

    RenderSVGRoot* renderer = toRenderSVGRoot(rootElement->renderer());
    if (!renderer)
        return;
    renderer->setContainerSize(size);
}

IntSize SVGImage::containerSize() const
{
    SVGSVGElement* rootElement = svgRootElement(m_page.get());
    if (!rootElement)
        return IntSize();

    RenderSVGRoot* renderer = toRenderSVGRoot(rootElement->renderer());
    if (!renderer)
        return IntSize();

    // If a container size is available it has precedence.
    IntSize containerSize = renderer->containerSize();
    if (!containerSize.isEmpty())
        return containerSize;

    // Assure that a container size is always given for a non-identity zoom level.
    ASSERT(renderer->style()->effectiveZoom() == 1);

    FloatSize currentSize;
    if (rootElement->intrinsicWidth().isFixed() && rootElement->intrinsicHeight().isFixed())
        currentSize = rootElement->currentViewportSize();
    else
        currentSize = rootElement->currentViewBoxRect().size();

    if (!currentSize.isEmpty())
        return IntSize(static_cast<int>(ceilf(currentSize.width())), static_cast<int>(ceilf(currentSize.height())));

    // As last resort, use CSS default intrinsic size.
    return IntSize(300, 150);
}

void SVGImage::drawForContainer(GraphicsContext* context, const FloatSize containerSize, float zoom, const FloatRect& dstRect,
    const FloatRect& srcRect, CompositeOperator compositeOp, blink::WebBlendMode blendMode)
{
    if (!m_page)
        return;

    // Temporarily disable the image observer to prevent changeInRect() calls due re-laying out the image.
    ImageObserverDisabler imageObserverDisabler(this);

    IntSize roundedContainerSize = roundedIntSize(containerSize);
    setContainerSize(roundedContainerSize);

    FloatRect scaledSrc = srcRect;
    scaledSrc.scale(1 / zoom);

    // Compensate for the container size rounding by adjusting the source rect.
    FloatSize adjustedSrcSize = scaledSrc.size();
    adjustedSrcSize.scale(roundedContainerSize.width() / containerSize.width(), roundedContainerSize.height() / containerSize.height());
    scaledSrc.setSize(adjustedSrcSize);

    draw(context, dstRect, scaledSrc, compositeOp, blendMode);
}

PassRefPtr<NativeImageSkia> SVGImage::nativeImageForCurrentFrame()
{
    if (!m_page)
        return nullptr;

    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(size());
    if (!buffer)
        return nullptr;

    drawForContainer(buffer->context(), size(), 1, rect(), rect(), CompositeSourceOver, blink::WebBlendModeNormal);

    // FIXME: WK(Bug 113657): We should use DontCopyBackingStore here.
    return buffer->copyImage(CopyBackingStore)->nativeImageForCurrentFrame();
}

void SVGImage::drawPatternForContainer(GraphicsContext* context, const FloatSize containerSize, float zoom, const FloatRect& srcRect,
    const FloatSize& scale, const FloatPoint& phase, CompositeOperator compositeOp, const FloatRect& dstRect, blink::WebBlendMode blendMode, const IntSize& repeatSpacing)
{
    FloatRect zoomedContainerRect = FloatRect(FloatPoint(), containerSize);
    zoomedContainerRect.scale(zoom);

    // The ImageBuffer size needs to be scaled to match the final resolution.
    // FIXME: No need to get the full CTM here, we just need the scale.
    AffineTransform transform = context->getCTM();
    FloatSize imageBufferScale = FloatSize(transform.xScale(), transform.yScale());
    ASSERT(imageBufferScale.width());
    ASSERT(imageBufferScale.height());

    FloatSize scaleWithoutCTM(scale.width() / imageBufferScale.width(), scale.height() / imageBufferScale.height());

    FloatRect imageBufferSize = zoomedContainerRect;
    imageBufferSize.scale(imageBufferScale.width(), imageBufferScale.height());

    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(expandedIntSize(imageBufferSize.size()));
    if (!buffer) // Failed to allocate buffer.
        return;

    drawForContainer(buffer->context(), containerSize, zoom, imageBufferSize, zoomedContainerRect, CompositeSourceOver, blink::WebBlendModeNormal);
    RefPtr<Image> image = buffer->copyImage(DontCopyBackingStore, Unscaled);

    // Adjust the source rect and transform due to the image buffer's scaling.
    FloatRect scaledSrcRect = srcRect;
    scaledSrcRect.scale(imageBufferScale.width(), imageBufferScale.height());

    image->drawPattern(context, scaledSrcRect, scaleWithoutCTM, phase, compositeOp, dstRect, blendMode, repeatSpacing);
}

void SVGImage::draw(GraphicsContext* context, const FloatRect& dstRect, const FloatRect& srcRect, CompositeOperator compositeOp, blink::WebBlendMode blendMode)
{
    if (!m_page)
        return;

    GraphicsContextStateSaver stateSaver(*context);
    context->setCompositeOperation(compositeOp, blendMode);
    context->clip(enclosingIntRect(dstRect));

    bool compositingRequiresTransparencyLayer = compositeOp != CompositeSourceOver || blendMode != blink::WebBlendModeNormal;
    float opacity = context->getNormalizedAlpha() / 255.f;
    bool requiresTransparencyLayer = compositingRequiresTransparencyLayer || opacity < 1;
    if (requiresTransparencyLayer) {
        context->beginTransparencyLayer(opacity);
        if (compositingRequiresTransparencyLayer)
            context->setCompositeOperation(CompositeSourceOver, blink::WebBlendModeNormal);
    }

    FloatSize scale(dstRect.width() / srcRect.width(), dstRect.height() / srcRect.height());

    // We can only draw the entire frame, clipped to the rect we want. So compute where the top left
    // of the image would be if we were drawing without clipping, and translate accordingly.
    FloatSize topLeftOffset(srcRect.location().x() * scale.width(), srcRect.location().y() * scale.height());
    FloatPoint destOffset = dstRect.location() - topLeftOffset;

    context->translate(destOffset.x(), destOffset.y());
    context->scale(scale);

    FrameView* view = frameView();
    view->resize(containerSize());

    if (view->needsLayout())
        view->layout();

    view->paint(context, enclosingIntRect(srcRect));
    ASSERT(!view->needsLayout());

    if (requiresTransparencyLayer)
        context->endLayer();

    stateSaver.restore();

    if (imageObserver())
        imageObserver()->didDraw(this);

    // Start any (SMIL) animations if needed. This will restart or continue
    // animations if preceded by calls to resetAnimation or stopAnimation
    // respectively.
    startAnimation();
}

RenderBox* SVGImage::embeddedContentBox() const
{
    SVGSVGElement* rootElement = svgRootElement(m_page.get());
    if (!rootElement)
        return 0;
    return toRenderBox(rootElement->renderer());
}

FrameView* SVGImage::frameView() const
{
    if (!m_page)
        return 0;

    return m_page->mainFrame()->view();
}

bool SVGImage::hasRelativeWidth() const
{
    SVGSVGElement* rootElement = svgRootElement(m_page.get());
    if (!rootElement)
        return false;
    return rootElement->intrinsicWidth().isPercent();
}

bool SVGImage::hasRelativeHeight() const
{
    SVGSVGElement* rootElement = svgRootElement(m_page.get());
    if (!rootElement)
        return false;
    return rootElement->intrinsicHeight().isPercent();
}

void SVGImage::computeIntrinsicDimensions(Length& intrinsicWidth, Length& intrinsicHeight, FloatSize& intrinsicRatio)
{
    SVGSVGElement* rootElement = svgRootElement(m_page.get());
    if (!rootElement)
        return;

    intrinsicWidth = rootElement->intrinsicWidth();
    intrinsicHeight = rootElement->intrinsicHeight();
    if (rootElement->preserveAspectRatio()->currentValue()->align() == SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_NONE)
        return;

    intrinsicRatio = rootElement->viewBox()->currentValue()->value().size();
    if (intrinsicRatio.isEmpty() && intrinsicWidth.isFixed() && intrinsicHeight.isFixed())
        intrinsicRatio = FloatSize(floatValueForLength(intrinsicWidth, 0), floatValueForLength(intrinsicHeight, 0));
}

// FIXME: support catchUpIfNecessary.
void SVGImage::startAnimation(bool /* catchUpIfNecessary */)
{
    SVGSVGElement* rootElement = svgRootElement(m_page.get());
    if (!rootElement || !rootElement->animationsPaused())
        return;
    rootElement->unpauseAnimations();
}

void SVGImage::stopAnimation()
{
    SVGSVGElement* rootElement = svgRootElement(m_page.get());
    if (!rootElement)
        return;
    rootElement->pauseAnimations();
}

void SVGImage::resetAnimation()
{
    SVGSVGElement* rootElement = svgRootElement(m_page.get());
    if (!rootElement)
        return;
    rootElement->pauseAnimations();
    rootElement->setCurrentTime(0);
}

bool SVGImage::hasAnimations() const
{
    SVGSVGElement* rootElement = svgRootElement(m_page.get());
    if (!rootElement)
        return false;
    return rootElement->timeContainer()->hasAnimations() || m_page->mainFrame()->document()->timeline().hasPendingUpdates();
}

bool SVGImage::dataChanged(bool allDataReceived)
{
    TRACE_EVENT0("webkit", "SVGImage::dataChanged");

    // Don't do anything if is an empty image.
    if (!data()->size())
        return true;

    if (allDataReceived) {
        static FrameLoaderClient* dummyFrameLoaderClient = new EmptyFrameLoaderClient;

        Page::PageClients pageClients;
        fillWithEmptyClients(pageClients);
        m_chromeClient = adoptPtr(new SVGImageChromeClient(this));
        pageClients.chromeClient = m_chromeClient.get();

        // FIXME: If this SVG ends up loading itself, we might leak the world.
        // The Cache code does not know about ImageResources holding Frames and
        // won't know to break the cycle.
        // This will become an issue when SVGImage will be able to load other
        // SVGImage objects, but we're safe now, because SVGImage can only be
        // loaded by a top-level document.
        OwnPtr<Page> page = adoptPtr(new Page(pageClients));
        page->settings().setScriptEnabled(false);
        page->settings().setPluginsEnabled(false);
        page->settings().setAcceleratedCompositingEnabled(false);

        RefPtr<LocalFrame> frame = LocalFrame::create(dummyFrameLoaderClient, &page->frameHost(), 0);
        frame->setView(FrameView::create(frame.get()));
        frame->init();
        FrameLoader& loader = frame->loader();
        loader.forceSandboxFlags(SandboxAll);

        frame->view()->setScrollbarsSuppressed(true);
        frame->view()->setCanHaveScrollbars(false); // SVG Images will always synthesize a viewBox, if it's not available, and thus never see scrollbars.
        frame->view()->setTransparent(true); // SVG Images are transparent.

        m_page = page.release();

        loader.load(FrameLoadRequest(0, blankURL(), SubstituteData(data(), "image/svg+xml", "UTF-8", KURL(), ForceSynchronousLoad)));
        // Set the intrinsic size before a container size is available.
        m_intrinsicSize = containerSize();
    }

    return m_page;
}

String SVGImage::filenameExtension() const
{
    return "svg";
}

}