/*
 * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Rob Buis <buis@kde.org>
 * Copyright (C) 2007 Apple Inc. All rights reserved.
 *
 * 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"

#include "core/svg/SVGSVGElement.h"

#include "HTMLNames.h"
#include "SVGNames.h"
#include "bindings/v8/ScriptEventListener.h"
#include "core/css/CSSHelper.h"
#include "core/dom/Document.h"
#include "core/dom/ElementTraversal.h"
#include "core/dom/NodeTraversal.h"
#include "core/dom/StaticNodeList.h"
#include "core/editing/FrameSelection.h"
#include "core/events/EventListener.h"
#include "core/events/ThreadLocalEventNames.h"
#include "core/frame/Frame.h"
#include "core/page/FrameTree.h"
#include "core/frame/FrameView.h"
#include "core/frame/UseCounter.h"
#include "core/rendering/RenderObject.h"
#include "core/rendering/RenderPart.h"
#include "core/rendering/svg/RenderSVGModelObject.h"
#include "core/rendering/svg/RenderSVGResource.h"
#include "core/rendering/svg/RenderSVGRoot.h"
#include "core/rendering/svg/RenderSVGViewportContainer.h"
#include "core/svg/SVGAngle.h"
#include "core/svg/SVGElementInstance.h"
#include "core/svg/SVGPreserveAspectRatio.h"
#include "core/svg/SVGTransform.h"
#include "core/svg/SVGTransformList.h"
#include "core/svg/SVGViewElement.h"
#include "core/svg/SVGViewSpec.h"
#include "core/svg/animation/SMILTimeContainer.h"
#include "platform/FloatConversion.h"
#include "platform/LengthFunctions.h"
#include "platform/geometry/FloatRect.h"
#include "platform/transforms/AffineTransform.h"
#include "wtf/StdLibExtras.h"

namespace WebCore {

// Animated property definitions
DEFINE_ANIMATED_LENGTH(SVGSVGElement, SVGNames::xAttr, X, x)
DEFINE_ANIMATED_LENGTH(SVGSVGElement, SVGNames::yAttr, Y, y)
DEFINE_ANIMATED_LENGTH(SVGSVGElement, SVGNames::widthAttr, Width, width)
DEFINE_ANIMATED_LENGTH(SVGSVGElement, SVGNames::heightAttr, Height, height)
DEFINE_ANIMATED_BOOLEAN(SVGSVGElement, SVGNames::externalResourcesRequiredAttr, ExternalResourcesRequired, externalResourcesRequired)
DEFINE_ANIMATED_PRESERVEASPECTRATIO(SVGSVGElement, SVGNames::preserveAspectRatioAttr, PreserveAspectRatio, preserveAspectRatio)
DEFINE_ANIMATED_RECT(SVGSVGElement, SVGNames::viewBoxAttr, ViewBox, viewBox)

BEGIN_REGISTER_ANIMATED_PROPERTIES(SVGSVGElement)
    REGISTER_LOCAL_ANIMATED_PROPERTY(x)
    REGISTER_LOCAL_ANIMATED_PROPERTY(y)
    REGISTER_LOCAL_ANIMATED_PROPERTY(width)
    REGISTER_LOCAL_ANIMATED_PROPERTY(height)
    REGISTER_LOCAL_ANIMATED_PROPERTY(externalResourcesRequired)
    REGISTER_LOCAL_ANIMATED_PROPERTY(viewBox)
    REGISTER_LOCAL_ANIMATED_PROPERTY(preserveAspectRatio)
    REGISTER_PARENT_ANIMATED_PROPERTIES(SVGGraphicsElement)
END_REGISTER_ANIMATED_PROPERTIES

inline SVGSVGElement::SVGSVGElement(Document& doc)
    : SVGGraphicsElement(SVGNames::svgTag, doc)
    , m_x(LengthModeWidth)
    , m_y(LengthModeHeight)
    , m_width(LengthModeWidth, "100%")
    , m_height(LengthModeHeight, "100%")
    , m_useCurrentView(false)
    , m_zoomAndPan(SVGZoomAndPanMagnify)
    , m_timeContainer(SMILTimeContainer::create(this))
    , m_weakFactory(this)
{
    ScriptWrappable::init(this);
    registerAnimatedPropertiesForSVGSVGElement();

    UseCounter::count(doc, UseCounter::SVGSVGElement);
}

PassRefPtr<SVGSVGElement> SVGSVGElement::create(Document& document)
{
    return adoptRef(new SVGSVGElement(document));
}

SVGSVGElement::~SVGSVGElement()
{
    // There are cases where removedFromDocument() is not called.
    // see ContainerNode::removeAllChildren, called by its destructor.
    document().accessSVGExtensions()->removeTimeContainer(this);

    ASSERT(inDocument() || !accessDocumentSVGExtensions()->isSVGRootWithRelativeLengthDescendents(this));
}

const AtomicString& SVGSVGElement::contentScriptType() const
{
    DEFINE_STATIC_LOCAL(const AtomicString, defaultValue, ("text/ecmascript", AtomicString::ConstructFromLiteral));
    const AtomicString& n = fastGetAttribute(SVGNames::contentScriptTypeAttr);
    return n.isNull() ? defaultValue : n;
}

void SVGSVGElement::setContentScriptType(const AtomicString& type)
{
    setAttribute(SVGNames::contentScriptTypeAttr, type);
}

const AtomicString& SVGSVGElement::contentStyleType() const
{
    DEFINE_STATIC_LOCAL(const AtomicString, defaultValue, ("text/css", AtomicString::ConstructFromLiteral));
    const AtomicString& n = fastGetAttribute(SVGNames::contentStyleTypeAttr);
    return n.isNull() ? defaultValue : n;
}

void SVGSVGElement::setContentStyleType(const AtomicString& type)
{
    setAttribute(SVGNames::contentStyleTypeAttr, type);
}

SVGRect SVGSVGElement::viewport() const
{
    // FIXME: This method doesn't follow the spec and is basically untested. Parent documents are not considered here.
    // As we have no test coverage for this, we're going to disable it completly for now.
    return SVGRect();
}

float SVGSVGElement::pixelUnitToMillimeterX() const
{
    return 1 / cssPixelsPerMillimeter;
}

float SVGSVGElement::pixelUnitToMillimeterY() const
{
    return 1 / cssPixelsPerMillimeter;
}

float SVGSVGElement::screenPixelToMillimeterX() const
{
    return pixelUnitToMillimeterX();
}

float SVGSVGElement::screenPixelToMillimeterY() const
{
    return pixelUnitToMillimeterY();
}

SVGViewSpec* SVGSVGElement::currentView()
{
    if (!m_viewSpec)
        m_viewSpec = SVGViewSpec::create(m_weakFactory.createWeakPtr());
    return m_viewSpec.get();
}

float SVGSVGElement::currentScale() const
{
    if (!inDocument() || !isOutermostSVGSVGElement())
        return 1;

    Frame* frame = document().frame();
    if (!frame)
        return 1;

    const FrameTree& frameTree = frame->tree();

    // The behaviour of currentScale() is undefined, when we're dealing with non-standalone SVG documents.
    // If the svg is embedded, the scaling is handled by the host renderer, so when asking from inside
    // the SVG document, a scale value of 1 seems reasonable, as it doesn't know anything about the parent scale.
    return frameTree.parent() ? 1 : frame->pageZoomFactor();
}

void SVGSVGElement::setCurrentScale(float scale)
{
    if (!inDocument() || !isOutermostSVGSVGElement())
        return;

    Frame* frame = document().frame();
    if (!frame)
        return;

    const FrameTree& frameTree = frame->tree();

    // The behaviour of setCurrentScale() is undefined, when we're dealing with non-standalone SVG documents.
    // We choose the ignore this call, it's pretty useless to support calling setCurrentScale() from within
    // an embedded SVG document, for the same reasons as in currentScale() - needs resolution by SVG WG.
    if (frameTree.parent())
        return;

    frame->setPageZoomFactor(scale);
}

void SVGSVGElement::setCurrentTranslate(const FloatPoint& translation)
{
    m_translation = translation;
    updateCurrentTranslate();
}

void SVGSVGElement::updateCurrentTranslate()
{
    if (RenderObject* object = renderer())
        object->setNeedsLayout();

    if (parentNode() == document() && document().renderer())
        document().renderer()->repaint();
}

void SVGSVGElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
{
    SVGParsingError parseError = NoError;

    if (!nearestViewportElement()) {
        bool setListener = true;

        // Only handle events if we're the outermost <svg> element
        if (name == HTMLNames::onunloadAttr)
            document().setWindowAttributeEventListener(EventTypeNames::unload, createAttributeEventListener(document().frame(), name, value));
        else if (name == HTMLNames::onresizeAttr)
            document().setWindowAttributeEventListener(EventTypeNames::resize, createAttributeEventListener(document().frame(), name, value));
        else if (name == HTMLNames::onscrollAttr)
            document().setWindowAttributeEventListener(EventTypeNames::scroll, createAttributeEventListener(document().frame(), name, value));
        else if (name == SVGNames::onzoomAttr)
            document().setWindowAttributeEventListener(EventTypeNames::zoom, createAttributeEventListener(document().frame(), name, value));
        else
            setListener = false;

        if (setListener)
            return;
    }

    if (name == HTMLNames::onabortAttr)
        document().setWindowAttributeEventListener(EventTypeNames::abort, createAttributeEventListener(document().frame(), name, value));
    else if (name == HTMLNames::onerrorAttr)
        document().setWindowAttributeEventListener(EventTypeNames::error, createAttributeEventListener(document().frame(), name, value));
    else if (name == SVGNames::xAttr)
        setXBaseValue(SVGLength::construct(LengthModeWidth, value, parseError));
    else if (name == SVGNames::yAttr)
        setYBaseValue(SVGLength::construct(LengthModeHeight, value, parseError));
    else if (name == SVGNames::widthAttr)
        setWidthBaseValue(SVGLength::construct(LengthModeWidth, value, parseError, ForbidNegativeLengths));
    else if (name == SVGNames::heightAttr)
        setHeightBaseValue(SVGLength::construct(LengthModeHeight, value, parseError, ForbidNegativeLengths));
    else if (SVGExternalResourcesRequired::parseAttribute(name, value)
               || SVGFitToViewBox::parseAttribute(this, name, value)
               || SVGZoomAndPan::parseAttribute(this, name, value)) {
    } else
        SVGGraphicsElement::parseAttribute(name, value);

    reportAttributeParsingError(parseError, name, value);
}

void SVGSVGElement::svgAttributeChanged(const QualifiedName& attrName)
{
    bool updateRelativeLengthsOrViewBox = false;
    bool widthChanged = attrName == SVGNames::widthAttr;
    if (widthChanged
        || attrName == SVGNames::heightAttr
        || attrName == SVGNames::xAttr
        || attrName == SVGNames::yAttr) {
        updateRelativeLengthsOrViewBox = true;
        updateRelativeLengthsInformation();
        invalidateRelativeLengthClients();

        // At the SVG/HTML boundary (aka RenderSVGRoot), the width attribute can
        // affect the replaced size so we need to mark it for updating.
        if (widthChanged) {
            RenderObject* renderObject = renderer();
            if (renderObject && renderObject->isSVGRoot())
                toRenderSVGRoot(renderObject)->setNeedsLayoutAndPrefWidthsRecalc();
        }
    }

    if (SVGFitToViewBox::isKnownAttribute(attrName)) {
        updateRelativeLengthsOrViewBox = true;
        if (RenderObject* object = renderer())
            object->setNeedsTransformUpdate();
    }

    SVGElementInstance::InvalidationGuard invalidationGuard(this);

    if (updateRelativeLengthsOrViewBox
        || SVGExternalResourcesRequired::isKnownAttribute(attrName)
        || SVGZoomAndPan::isKnownAttribute(attrName)) {
        if (renderer())
            RenderSVGResource::markForLayoutAndParentResourceInvalidation(renderer());
        return;
    }

    SVGGraphicsElement::svgAttributeChanged(attrName);
}

unsigned SVGSVGElement::suspendRedraw(unsigned /* maxWaitMilliseconds */)
{
    // FIXME: Implement me (see bug 11275)
    return 0;
}

void SVGSVGElement::unsuspendRedraw(unsigned /* suspendHandleId */)
{
    // FIXME: Implement me (see bug 11275)
}

void SVGSVGElement::unsuspendRedrawAll()
{
    // FIXME: Implement me (see bug 11275)
}

void SVGSVGElement::forceRedraw()
{
    // FIXME: Implement me (see bug 11275)
}

PassRefPtr<NodeList> SVGSVGElement::collectIntersectionOrEnclosureList(const SVGRect& rect, SVGElement* referenceElement, CollectIntersectionOrEnclosure collect) const
{
    Vector<RefPtr<Node> > nodes;
    Element* element = ElementTraversal::next(*(referenceElement ? referenceElement : this));
    while (element) {
        if (element->isSVGElement()) {
            SVGElement* svgElement = toSVGElement(element);
            if (collect == CollectIntersectionList) {
                if (checkIntersection(svgElement, rect))
                    nodes.append(element);
            } else {
                if (checkEnclosure(svgElement, rect))
                    nodes.append(element);
            }
        }

        element = ElementTraversal::next(*element, referenceElement ? referenceElement : this);
    }
    return StaticNodeList::adopt(nodes);
}

PassRefPtr<NodeList> SVGSVGElement::getIntersectionList(const SVGRect& rect, SVGElement* referenceElement) const
{
    return collectIntersectionOrEnclosureList(rect, referenceElement, CollectIntersectionList);
}

PassRefPtr<NodeList> SVGSVGElement::getEnclosureList(const SVGRect& rect, SVGElement* referenceElement) const
{
    return collectIntersectionOrEnclosureList(rect, referenceElement, CollectEnclosureList);
}

bool SVGSVGElement::checkIntersection(SVGElement* element, const SVGRect& rect) const
{
    if (!element)
        return false;
    return RenderSVGModelObject::checkIntersection(element->renderer(), rect);
}

bool SVGSVGElement::checkEnclosure(SVGElement* element, const SVGRect& rect) const
{
    if (!element)
        return false;
    return RenderSVGModelObject::checkEnclosure(element->renderer(), rect);
}

void SVGSVGElement::deselectAll()
{
    if (Frame* frame = document().frame())
        frame->selection().clear();
}

float SVGSVGElement::createSVGNumber()
{
    return 0.0f;
}

SVGLength SVGSVGElement::createSVGLength()
{
    return SVGLength();
}

SVGAngle SVGSVGElement::createSVGAngle()
{
    return SVGAngle();
}

SVGPoint SVGSVGElement::createSVGPoint()
{
    return SVGPoint();
}

SVGMatrix SVGSVGElement::createSVGMatrix()
{
    return SVGMatrix();
}

SVGRect SVGSVGElement::createSVGRect()
{
    return SVGRect();
}

SVGTransform SVGSVGElement::createSVGTransform()
{
    return SVGTransform(SVGTransform::SVG_TRANSFORM_MATRIX);
}

SVGTransform SVGSVGElement::createSVGTransformFromMatrix(const SVGMatrix& matrix)
{
    return SVGTransform(static_cast<const AffineTransform&>(matrix));
}

AffineTransform SVGSVGElement::localCoordinateSpaceTransform(SVGElement::CTMScope mode) const
{
    AffineTransform viewBoxTransform;
    if (!hasEmptyViewBox()) {
        FloatSize size = currentViewportSize();
        viewBoxTransform = viewBoxToViewTransform(size.width(), size.height());
    }

    AffineTransform transform;
    if (!isOutermostSVGSVGElement()) {
        SVGLengthContext lengthContext(this);
        transform.translate(xCurrentValue().value(lengthContext), yCurrentValue().value(lengthContext));
    } else if (mode == SVGElement::ScreenScope) {
        if (RenderObject* renderer = this->renderer()) {
            FloatPoint location;
            float zoomFactor = 1;

            // At the SVG/HTML boundary (aka RenderSVGRoot), we apply the localToBorderBoxTransform
            // to map an element from SVG viewport coordinates to CSS box coordinates.
            // RenderSVGRoot's localToAbsolute method expects CSS box coordinates.
            // We also need to adjust for the zoom level factored into CSS coordinates (bug #96361).
            if (renderer->isSVGRoot()) {
                location = toRenderSVGRoot(renderer)->localToBorderBoxTransform().mapPoint(location);
                zoomFactor = 1 / renderer->style()->effectiveZoom();
            }

            // Translate in our CSS parent coordinate space
            // FIXME: This doesn't work correctly with CSS transforms.
            location = renderer->localToAbsolute(location, UseTransforms);
            location.scale(zoomFactor, zoomFactor);

            // Be careful here! localToBorderBoxTransform() included the x/y offset coming from the viewBoxToViewTransform(),
            // so we have to subtract it here (original cause of bug #27183)
            transform.translate(location.x() - viewBoxTransform.e(), location.y() - viewBoxTransform.f());

            // Respect scroll offset.
            if (FrameView* view = document().view()) {
                LayoutSize scrollOffset = view->scrollOffset();
                scrollOffset.scale(zoomFactor);
                transform.translate(-scrollOffset.width(), -scrollOffset.height());
            }
        }
    }

    return transform.multiply(viewBoxTransform);
}

bool SVGSVGElement::rendererIsNeeded(const RenderStyle& style)
{
    // FIXME: We should respect display: none on the documentElement svg element
    // but many things in FrameView and SVGImage depend on the RenderSVGRoot when
    // they should instead depend on the RenderView.
    // https://bugs.webkit.org/show_bug.cgi?id=103493
    if (document().documentElement() == this)
        return true;
    return Element::rendererIsNeeded(style);
}

RenderObject* SVGSVGElement::createRenderer(RenderStyle*)
{
    if (isOutermostSVGSVGElement())
        return new RenderSVGRoot(this);

    return new RenderSVGViewportContainer(this);
}

Node::InsertionNotificationRequest SVGSVGElement::insertedInto(ContainerNode* rootParent)
{
    if (rootParent->inDocument()) {
        document().accessSVGExtensions()->addTimeContainer(this);

        // Animations are started at the end of document parsing and after firing the load event,
        // but if we miss that train (deferred programmatic element insertion for example) we need
        // to initialize the time container here.
        if (!document().parsing() && !document().processingLoadEvent() && document().loadEventFinished() && !timeContainer()->isStarted())
            timeContainer()->begin();
    }
    return SVGGraphicsElement::insertedInto(rootParent);
}

void SVGSVGElement::removedFrom(ContainerNode* rootParent)
{
    if (rootParent->inDocument()) {
        SVGDocumentExtensions* svgExtensions = document().accessSVGExtensions();
        svgExtensions->removeTimeContainer(this);
        svgExtensions->removeSVGRootWithRelativeLengthDescendents(this);
    }

    SVGGraphicsElement::removedFrom(rootParent);
}

void SVGSVGElement::pauseAnimations()
{
    if (!m_timeContainer->isPaused())
        m_timeContainer->pause();
}

void SVGSVGElement::unpauseAnimations()
{
    if (m_timeContainer->isPaused())
        m_timeContainer->resume();
}

bool SVGSVGElement::animationsPaused() const
{
    return m_timeContainer->isPaused();
}

float SVGSVGElement::getCurrentTime() const
{
    return narrowPrecisionToFloat(m_timeContainer->elapsed().value());
}

void SVGSVGElement::setCurrentTime(float seconds)
{
    if (std::isnan(seconds))
        return;
    seconds = max(seconds, 0.0f);
    m_timeContainer->setElapsed(seconds);
}

bool SVGSVGElement::selfHasRelativeLengths() const
{
    return xCurrentValue().isRelative()
        || yCurrentValue().isRelative()
        || widthCurrentValue().isRelative()
        || heightCurrentValue().isRelative()
        || hasAttribute(SVGNames::viewBoxAttr);
}

SVGRect SVGSVGElement::currentViewBoxRect() const
{
    if (m_useCurrentView)
        return m_viewSpec ? m_viewSpec->viewBoxCurrentValue() : SVGRect();

    FloatRect useViewBox = viewBoxCurrentValue();
    if (!useViewBox.isEmpty())
        return useViewBox;
    if (!renderer() || !renderer()->isSVGRoot())
        return SVGRect();
    if (!toRenderSVGRoot(renderer())->isEmbeddedThroughSVGImage())
        return SVGRect();

    Length intrinsicWidth = this->intrinsicWidth();
    Length intrinsicHeight = this->intrinsicHeight();
    if (!intrinsicWidth.isFixed() || !intrinsicHeight.isFixed())
        return SVGRect();

    // If no viewBox is specified but non-relative width/height values, then we
    // should always synthesize a viewBox if we're embedded through a SVGImage.
    return SVGRect(FloatPoint(), FloatSize(floatValueForLength(intrinsicWidth, 0, 0), floatValueForLength(intrinsicHeight, 0, 0)));
}

FloatSize SVGSVGElement::currentViewportSize() const
{
    Length intrinsicWidth = this->intrinsicWidth();
    Length intrinsicHeight = this->intrinsicHeight();
    if (intrinsicWidth.isFixed() && intrinsicHeight.isFixed())
        return FloatSize(floatValueForLength(intrinsicWidth, 0), floatValueForLength(intrinsicHeight, 0));

    if (!renderer())
        return FloatSize();

    if (renderer()->isSVGRoot()) {
        LayoutRect contentBoxRect = toRenderSVGRoot(renderer())->contentBoxRect();
        return FloatSize(contentBoxRect.width() / renderer()->style()->effectiveZoom(), contentBoxRect.height() / renderer()->style()->effectiveZoom());
    }

    FloatRect viewportRect = toRenderSVGViewportContainer(renderer())->viewport();
    return FloatSize(viewportRect.width(), viewportRect.height());
}

bool SVGSVGElement::widthAttributeEstablishesViewport() const
{
    if (!renderer() || renderer()->isSVGViewportContainer())
        return true;

    // Spec: http://www.w3.org/TR/SVG/coords.html#ViewportSpace
    // The ‘width’ attribute on the outermost svg element establishes the viewport's width, unless the following conditions are met:
    // - the SVG content is a separately stored resource that is embedded by reference (such as the ‘object’ element in XHTML [XHTML]), or
    //   the SVG content is embedded inline within a containing document;
    // - and the referencing element or containing document is styled using CSS [CSS2] or XSL [XSL];
    // - and there are CSS-compatible positioning properties ([CSS2], section 9.3) specified on the referencing element (e.g., the ‘object’ element)
    //   or on the containing document's outermost svg element that are sufficient to establish the width of the viewport. Under these conditions,
    //   the positioning properties establish the viewport's width.
    RenderSVGRoot* root = toRenderSVGRoot(renderer());

    // SVG embedded through object/embed/iframe.
    if (root->isEmbeddedThroughFrameContainingSVGDocument())
        return !root->hasReplacedLogicalWidth() && !document().frame()->ownerRenderer()->hasReplacedLogicalWidth();

    // SVG embedded via SVGImage (background-image/border-image/etc) / Inline SVG.
    if (root->isEmbeddedThroughSVGImage() || document().documentElement() != this)
        return !root->hasReplacedLogicalWidth();

    return true;
}

bool SVGSVGElement::heightAttributeEstablishesViewport() const
{
    if (!renderer() || renderer()->isSVGViewportContainer())
        return true;

    // Spec: http://www.w3.org/TR/SVG/coords.html#IntrinsicSizing
    // Similarly, if there are positioning properties specified on the referencing element or on the outermost svg element
    // that are sufficient to establish the height of the viewport, then these positioning properties establish the viewport's
    // height; otherwise, the ‘height’ attribute on the outermost svg element establishes the viewport's height.
    RenderSVGRoot* root = toRenderSVGRoot(renderer());

    // SVG embedded through object/embed/iframe.
    if (root->isEmbeddedThroughFrameContainingSVGDocument())
        return !root->hasReplacedLogicalHeight() && !document().frame()->ownerRenderer()->hasReplacedLogicalHeight();

    // SVG embedded via SVGImage (background-image/border-image/etc) / Inline SVG.
    if (root->isEmbeddedThroughSVGImage() || document().documentElement() != this)
        return !root->hasReplacedLogicalHeight();

    return true;
}

Length SVGSVGElement::intrinsicWidth(ConsiderCSSMode mode) const
{
    if (widthAttributeEstablishesViewport() || mode == IgnoreCSSProperties) {
        if (widthCurrentValue().unitType() == LengthTypePercentage)
            return Length(widthCurrentValue().valueAsPercentage() * 100, Percent);

        SVGLengthContext lengthContext(this);
        return Length(widthCurrentValue().value(lengthContext), Fixed);
    }

    ASSERT(renderer());
    return renderer()->style()->width();
}

Length SVGSVGElement::intrinsicHeight(ConsiderCSSMode mode) const
{
    if (heightAttributeEstablishesViewport() || mode == IgnoreCSSProperties) {
        if (heightCurrentValue().unitType() == LengthTypePercentage)
            return Length(heightCurrentValue().valueAsPercentage() * 100, Percent);

        SVGLengthContext lengthContext(this);
        return Length(heightCurrentValue().value(lengthContext), Fixed);
    }

    ASSERT(renderer());
    return renderer()->style()->height();
}

AffineTransform SVGSVGElement::viewBoxToViewTransform(float viewWidth, float viewHeight) const
{
    if (!m_useCurrentView || !m_viewSpec)
        return SVGFitToViewBox::viewBoxToViewTransform(currentViewBoxRect(), preserveAspectRatioCurrentValue(), viewWidth, viewHeight);

    AffineTransform ctm = SVGFitToViewBox::viewBoxToViewTransform(currentViewBoxRect(), m_viewSpec->preserveAspectRatioCurrentValue(), viewWidth, viewHeight);
    const SVGTransformList& transformList = m_viewSpec->transformBaseValue();
    if (transformList.isEmpty())
        return ctm;

    AffineTransform transform;
    if (transformList.concatenate(transform))
        ctm *= transform;

    return ctm;
}

void SVGSVGElement::setupInitialView(const String& fragmentIdentifier, Element* anchorNode)
{
    RenderObject* renderer = this->renderer();
    SVGViewSpec* view = m_viewSpec.get();
    if (view)
        view->reset();

    bool hadUseCurrentView = m_useCurrentView;
    m_useCurrentView = false;

    if (fragmentIdentifier.startsWith("xpointer(")) {
        // FIXME: XPointer references are ignored (https://bugs.webkit.org/show_bug.cgi?id=17491)
        if (renderer && hadUseCurrentView)
            RenderSVGResource::markForLayoutAndParentResourceInvalidation(renderer);
        return;
    }

    if (fragmentIdentifier.startsWith("svgView(")) {
        if (!view)
            view = currentView(); // Create the SVGViewSpec.

        if (view->parseViewSpec(fragmentIdentifier))
            m_useCurrentView = true;
        else
            view->reset();

        if (renderer && (hadUseCurrentView || m_useCurrentView))
            RenderSVGResource::markForLayoutAndParentResourceInvalidation(renderer);
        return;
    }

    // Spec: If the SVG fragment identifier addresses a ‘view’ element within an SVG document (e.g., MyDrawing.svg#MyView
    // or MyDrawing.svg#xpointer(id('MyView'))) then the closest ancestor ‘svg’ element is displayed in the viewport.
    // Any view specification attributes included on the given ‘view’ element override the corresponding view specification
    // attributes on the closest ancestor ‘svg’ element.
    if (anchorNode && anchorNode->hasTagName(SVGNames::viewTag)) {
        SVGViewElement* viewElement = toSVGViewElement(anchorNode);
        if (!viewElement)
            return;

        if (SVGSVGElement* svg = viewElement->ownerSVGElement()) {
            svg->inheritViewAttributes(viewElement);

            if (RenderObject* renderer = svg->renderer())
                RenderSVGResource::markForLayoutAndParentResourceInvalidation(renderer);
        }
    }

    // FIXME: We need to decide which <svg> to focus on, and zoom to it.
    // FIXME: We need to actually "highlight" the viewTarget(s).
}

void SVGSVGElement::inheritViewAttributes(SVGViewElement* viewElement)
{
    SVGViewSpec* view = currentView();
    m_useCurrentView = true;

    if (viewElement->hasAttribute(SVGNames::viewBoxAttr))
        view->setViewBoxBaseValue(viewElement->viewBoxCurrentValue());
    else
        view->setViewBoxBaseValue(viewBoxCurrentValue());

    if (viewElement->hasAttribute(SVGNames::preserveAspectRatioAttr))
        view->setPreserveAspectRatioBaseValue(viewElement->preserveAspectRatioBaseValue());
    else
        view->setPreserveAspectRatioBaseValue(preserveAspectRatioBaseValue());

    if (viewElement->hasAttribute(SVGNames::zoomAndPanAttr))
        view->setZoomAndPanBaseValue(viewElement->zoomAndPan());
    else
        view->setZoomAndPanBaseValue(zoomAndPan());
}

// getElementById on SVGSVGElement is restricted to only the child subtree defined by the <svg> element.
// See http://www.w3.org/TR/SVG11/struct.html#InterfaceSVGSVGElement
Element* SVGSVGElement::getElementById(const AtomicString& id) const
{
    Element* element = treeScope().getElementById(id);
    if (element && element->isDescendantOf(this))
        return element;

    // Fall back to traversing our subtree. Duplicate ids are allowed, the first found will
    // be returned.
    for (Node* node = firstChild(); node; node = NodeTraversal::next(*node, this)) {
        if (!node->isElementNode())
            continue;

        Element* element = toElement(node);
        if (element->getIdAttribute() == id)
            return element;
    }
    return 0;
}

}