SVGImage.cpp   [plain text]

/*
 * 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"

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

#include "CachedPage.h"
#include "DocumentLoader.h"
#include "EmptyClients.h"
#include "FileChooser.h"
#include "FileIconLoader.h"
#include "FloatRect.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "FrameView.h"
#include "GraphicsContext.h"
#include "HTMLFormElement.h"
#include "ImageBuffer.h"
#include "ImageObserver.h"
#include "Length.h"
#include "Page.h"
#include "RenderSVGRoot.h"
#include "RenderView.h"
#include "ResourceError.h"
#include "SVGDocument.h"
#include "SVGLength.h"
#include "SVGRenderSupport.h"
#include "SVGSVGElement.h"
#include "Settings.h"

namespace WebCore {

class SVGImageChromeClient : public EmptyChromeClient {
    WTF_MAKE_NONCOPYABLE(SVGImageChromeClient); WTF_MAKE_FAST_ALLOCATED;
public:
    SVGImageChromeClient(SVGImage* image)
        : m_image(image)
    {
    }

    virtual bool isSVGImageChromeClient() const { return true; }
    SVGImage* image() const { return m_image; }

private:
    virtual void chromeDestroyed()
    {
        m_image = 0;
    }

    virtual void invalidateContentsAndRootView(const IntRect& r, bool)
    {
        // If m_image->m_page is null, we're being destructed, don't fire changedInRect() in that case.
        if (m_image && m_image->imageObserver() && m_image->m_page)
            m_image->imageObserver()->changedInRect(m_image, r);
    }

    SVGImage* m_image;
};

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());
}

void SVGImage::setContainerSize(const IntSize&)
{
    // SVGImageCache already intercepted this call, as it stores & caches the desired container sizes & zoom levels.
    ASSERT_NOT_REACHED();
}

IntSize SVGImage::size() const
{
    if (!m_page)
        return IntSize();
    Frame* frame = m_page->mainFrame();
    SVGSVGElement* rootElement = static_cast<SVGDocument*>(frame->document())->rootElement();
    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::drawSVGToImageBuffer(ImageBuffer* buffer, const IntSize& size, float zoom, float scale, ShouldClearBuffer shouldClear)
{
    // FIXME: This doesn't work correctly with animations. If an image contains animations, that say run for 2 seconds,
    // and we currently have one <img> that displays us. If we open another document referencing the same SVGImage it
    // will display the document at a time where animations already ran - even though it has its own ImageBuffer.
    // We currently don't implement SVGSVGElement::setCurrentTime, and can NOT go back in time, once animations started.
    // There's no way to fix this besides avoiding style/attribute mutations from SVGAnimationElement.
    ASSERT(buffer);
    ASSERT(!size.isEmpty());

    if (!m_page)
        return;

    Frame* frame = m_page->mainFrame();
    SVGSVGElement* rootElement = static_cast<SVGDocument*>(frame->document())->rootElement();
    if (!rootElement)
        return;
    RenderSVGRoot* renderer = toRenderSVGRoot(rootElement->renderer());
    if (!renderer)
        return;

    // Draw image at requested size.
    ImageObserver* observer = imageObserver();
    ASSERT(observer);

    // Temporarily reset image observer, we don't want to receive any changeInRect() calls due to this relayout.
    setImageObserver(0);

    // Disable repainting; we don't want deferred repaints to schedule any timers due to this relayout.
    frame->view()->beginDisableRepaints();

    renderer->setContainerSize(size);
    frame->view()->resize(this->size());

    if (zoom != 1)
        frame->setPageZoomFactor(zoom);

    // Eventually clear image buffer.
    IntRect rect(IntPoint(), size);
    if (shouldClear == ClearImageBuffer)
        buffer->context()->clearRect(rect);

    FloatRect scaledRect(rect);
    scaledRect.scale(scale);

    // Draw SVG on top of ImageBuffer.
    draw(buffer->context(), enclosingIntRect(scaledRect), rect, ColorSpaceDeviceRGB, CompositeSourceOver);

    // Reset container size & zoom to initial state. Otherwhise the size() of this
    // image would return whatever last size was set by drawSVGToImageBuffer().
    if (zoom != 1)
        frame->setPageZoomFactor(1);

    // Renderer may have been recreated by frame->setPageZoomFactor(zoom). So fetch it again.
    renderer = toRenderSVGRoot(rootElement->renderer());
    if (renderer)
        renderer->setContainerSize(IntSize());

    frame->view()->resize(this->size());
    if (frame->view()->needsLayout())
        frame->view()->layout();

    setImageObserver(observer);

    frame->view()->endDisableRepaints();
}

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

    FrameView* view = frameView();

    GraphicsContextStateSaver stateSaver(*context);
    context->setCompositeOperation(compositeOp);
    context->clip(enclosingIntRect(dstRect));
    if (compositeOp != CompositeSourceOver)
        context->beginTransparencyLayer(1);

    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);

    view->resize(size());

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

    view->paint(context, IntRect(0, 0, view->width(), view->height()));

    if (compositeOp != CompositeSourceOver)
        context->endTransparencyLayer();

    stateSaver.restore();

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

RenderBox* SVGImage::embeddedContentBox() const
{
    if (!m_page)
        return 0;
    Frame* frame = m_page->mainFrame();
    SVGSVGElement* rootElement = static_cast<SVGDocument*>(frame->document())->rootElement();
    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
{
    if (!m_page)
        return false;
    Frame* frame = m_page->mainFrame();
    SVGSVGElement* rootElement = static_cast<SVGDocument*>(frame->document())->rootElement();
    if (!rootElement)
        return false;
    return rootElement->intrinsicWidth().isPercent();
}

bool SVGImage::hasRelativeHeight() const
{
    if (!m_page)
        return false;
    Frame* frame = m_page->mainFrame();
    SVGSVGElement* rootElement = static_cast<SVGDocument*>(frame->document())->rootElement();
    if (!rootElement)
        return false;
    return rootElement->intrinsicHeight().isPercent();
}

void SVGImage::computeIntrinsicDimensions(Length& intrinsicWidth, Length& intrinsicHeight, FloatSize& intrinsicRatio)
{
    if (!m_page)
        return;
    Frame* frame = m_page->mainFrame();
    SVGSVGElement* rootElement = static_cast<SVGDocument*>(frame->document())->rootElement();
    if (!rootElement)
        return;

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

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

NativeImagePtr SVGImage::nativeImageForCurrentFrame()
{
    // FIXME: In order to support dynamic SVGs we need to have a way to invalidate this
    // frame cache, or better yet, not use a cache for tiled drawing at all, instead
    // having a tiled drawing callback (hopefully non-virtual).
    if (!m_frameCache) {
        if (!m_page)
            return 0;
        OwnPtr<ImageBuffer> buffer = ImageBuffer::create(size(), 1);
        if (!buffer) // failed to allocate image
            return 0;
        draw(buffer->context(), rect(), rect(), ColorSpaceDeviceRGB, CompositeSourceOver);
        m_frameCache = buffer->copyImage(CopyBackingStore);
    }
    return m_frameCache->nativeImageForCurrentFrame();
}

bool SVGImage::dataChanged(bool allDataReceived)
{
    // 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 CachedImages 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.
        m_page = adoptPtr(new Page(pageClients));
        m_page->settings()->setMediaEnabled(false);
        m_page->settings()->setScriptEnabled(false);
        m_page->settings()->setPluginsEnabled(false);

        RefPtr<Frame> frame = Frame::create(m_page.get(), 0, dummyFrameLoaderClient);
        frame->setView(FrameView::create(frame.get()));
        frame->init();
        FrameLoader* loader = frame->loader();
        loader->forceSandboxFlags(SandboxAll);

        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.

        ASSERT(loader->activeDocumentLoader()); // DocumentLoader should have been created by frame->init().
        loader->activeDocumentLoader()->writer()->setMIMEType("image/svg+xml");
        loader->activeDocumentLoader()->writer()->begin(KURL()); // create the empty document
        loader->activeDocumentLoader()->writer()->addData(data()->data(), data()->size());
        loader->activeDocumentLoader()->writer()->end();
    }

    return m_page;
}

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

}

#endif // ENABLE(SVG)