gecko-dev/layout/svg/nsSVGGradientFrame.cpp

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// Main header first:
#include "nsSVGGradientFrame.h"
#include <algorithm>
// Keep others in (case-insensitive) order:
#include "AutoReferenceChainGuard.h"
#include "gfxPattern.h"
#include "mozilla/PresShell.h"
#include "mozilla/dom/SVGGradientElement.h"
#include "mozilla/dom/SVGGradientElementBinding.h"
#include "mozilla/dom/SVGStopElement.h"
#include "mozilla/dom/SVGUnitTypesBinding.h"
#include "nsContentUtils.h"
#include "SVGObserverUtils.h"
#include "SVGAnimatedTransformList.h"
// XXX Tight coupling with content classes ahead!
using namespace mozilla;
using namespace mozilla::dom;
using namespace mozilla::dom::SVGGradientElement_Binding;
using namespace mozilla::dom::SVGUnitTypes_Binding;
using namespace mozilla::gfx;
//----------------------------------------------------------------------
// Implementation
nsSVGGradientFrame::nsSVGGradientFrame(ComputedStyle* aStyle,
nsPresContext* aPresContext, ClassID aID)
: nsSVGPaintServerFrame(aStyle, aPresContext, aID),
mSource(nullptr),
mLoopFlag(false),
mNoHRefURI(false) {}
//----------------------------------------------------------------------
// nsIFrame methods:
nsresult nsSVGGradientFrame::AttributeChanged(int32_t aNameSpaceID,
nsAtom* aAttribute,
int32_t aModType) {
if (aNameSpaceID == kNameSpaceID_None &&
(aAttribute == nsGkAtoms::gradientUnits ||
aAttribute == nsGkAtoms::gradientTransform ||
aAttribute == nsGkAtoms::spreadMethod)) {
SVGObserverUtils::InvalidateDirectRenderingObservers(this);
} else if ((aNameSpaceID == kNameSpaceID_XLink ||
aNameSpaceID == kNameSpaceID_None) &&
aAttribute == nsGkAtoms::href) {
// Blow away our reference, if any
SVGObserverUtils::RemoveTemplateObserver(this);
mNoHRefURI = false;
// And update whoever references us
SVGObserverUtils::InvalidateDirectRenderingObservers(this);
}
return nsSVGPaintServerFrame::AttributeChanged(aNameSpaceID, aAttribute,
aModType);
}
//----------------------------------------------------------------------
uint16_t nsSVGGradientFrame::GetEnumValue(uint32_t aIndex,
nsIContent* aDefault) {
const SVGAnimatedEnumeration& thisEnum =
static_cast<dom::SVGGradientElement*>(GetContent())
->mEnumAttributes[aIndex];
if (thisEnum.IsExplicitlySet()) {
return thisEnum.GetAnimValue();
}
// Before we recurse, make sure we'll break reference loops and over long
// reference chains:
static int16_t sRefChainLengthCounter = AutoReferenceChainGuard::noChain;
AutoReferenceChainGuard refChainGuard(this, &mLoopFlag,
&sRefChainLengthCounter);
if (MOZ_UNLIKELY(!refChainGuard.Reference())) {
// Break reference chain
return static_cast<dom::SVGGradientElement*>(aDefault)
->mEnumAttributes[aIndex]
.GetAnimValue();
}
nsSVGGradientFrame* next = GetReferencedGradient();
return next ? next->GetEnumValue(aIndex, aDefault)
: static_cast<dom::SVGGradientElement*>(aDefault)
->mEnumAttributes[aIndex]
.GetAnimValue();
}
uint16_t nsSVGGradientFrame::GetGradientUnits() {
// This getter is called every time the others are called - maybe cache it?
return GetEnumValue(dom::SVGGradientElement::GRADIENTUNITS);
}
uint16_t nsSVGGradientFrame::GetSpreadMethod() {
return GetEnumValue(dom::SVGGradientElement::SPREADMETHOD);
}
const SVGAnimatedTransformList* nsSVGGradientFrame::GetGradientTransformList(
nsIContent* aDefault) {
SVGAnimatedTransformList* thisTransformList =
static_cast<dom::SVGGradientElement*>(GetContent())
->GetAnimatedTransformList();
if (thisTransformList && thisTransformList->IsExplicitlySet())
return thisTransformList;
// Before we recurse, make sure we'll break reference loops and over long
// reference chains:
static int16_t sRefChainLengthCounter = AutoReferenceChainGuard::noChain;
AutoReferenceChainGuard refChainGuard(this, &mLoopFlag,
&sRefChainLengthCounter);
if (MOZ_UNLIKELY(!refChainGuard.Reference())) {
// Break reference chain
return static_cast<const dom::SVGGradientElement*>(aDefault)
->mGradientTransform.get();
}
nsSVGGradientFrame* next = GetReferencedGradient();
return next ? next->GetGradientTransformList(aDefault)
: static_cast<const dom::SVGGradientElement*>(aDefault)
->mGradientTransform.get();
}
gfxMatrix nsSVGGradientFrame::GetGradientTransform(
nsIFrame* aSource, const gfxRect* aOverrideBounds) {
gfxMatrix bboxMatrix;
uint16_t gradientUnits = GetGradientUnits();
if (gradientUnits != SVG_UNIT_TYPE_USERSPACEONUSE) {
NS_ASSERTION(gradientUnits == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX,
"Unknown gradientUnits type");
// objectBoundingBox is the default anyway
gfxRect bbox = aOverrideBounds
? *aOverrideBounds
: nsSVGUtils::GetBBox(
aSource, nsSVGUtils::eUseFrameBoundsForOuterSVG |
nsSVGUtils::eBBoxIncludeFillGeometry);
bboxMatrix =
gfxMatrix(bbox.Width(), 0, 0, bbox.Height(), bbox.X(), bbox.Y());
}
const SVGAnimatedTransformList* animTransformList =
GetGradientTransformList(GetContent());
if (!animTransformList) {
return bboxMatrix;
}
gfxMatrix gradientTransform =
animTransformList->GetAnimValue().GetConsolidationMatrix();
return bboxMatrix.PreMultiply(gradientTransform);
}
dom::SVGLinearGradientElement* nsSVGGradientFrame::GetLinearGradientWithLength(
uint32_t aIndex, dom::SVGLinearGradientElement* aDefault) {
// If this was a linear gradient with the required length, we would have
// already found it in nsSVGLinearGradientFrame::GetLinearGradientWithLength.
// Since we didn't find the length, continue looking down the chain.
// Before we recurse, make sure we'll break reference loops and over long
// reference chains:
static int16_t sRefChainLengthCounter = AutoReferenceChainGuard::noChain;
AutoReferenceChainGuard refChainGuard(this, &mLoopFlag,
&sRefChainLengthCounter);
if (MOZ_UNLIKELY(!refChainGuard.Reference())) {
// Break reference chain
return aDefault;
}
nsSVGGradientFrame* next = GetReferencedGradient();
return next ? next->GetLinearGradientWithLength(aIndex, aDefault) : aDefault;
}
dom::SVGRadialGradientElement* nsSVGGradientFrame::GetRadialGradientWithLength(
uint32_t aIndex, dom::SVGRadialGradientElement* aDefault) {
// If this was a radial gradient with the required length, we would have
// already found it in nsSVGRadialGradientFrame::GetRadialGradientWithLength.
// Since we didn't find the length, continue looking down the chain.
// Before we recurse, make sure we'll break reference loops and over long
// reference chains:
static int16_t sRefChainLengthCounter = AutoReferenceChainGuard::noChain;
AutoReferenceChainGuard refChainGuard(this, &mLoopFlag,
&sRefChainLengthCounter);
if (MOZ_UNLIKELY(!refChainGuard.Reference())) {
// Break reference chain
return aDefault;
}
nsSVGGradientFrame* next = GetReferencedGradient();
return next ? next->GetRadialGradientWithLength(aIndex, aDefault) : aDefault;
}
//----------------------------------------------------------------------
// nsSVGPaintServerFrame methods:
// helper
static void GetStopInformation(nsIFrame* aStopFrame, float* aOffset,
nscolor* aStopColor, float* aStopOpacity) {
nsIContent* stopContent = aStopFrame->GetContent();
MOZ_ASSERT(stopContent && stopContent->IsSVGElement(nsGkAtoms::stop));
static_cast<SVGStopElement*>(stopContent)
->GetAnimatedNumberValues(aOffset, nullptr);
const nsStyleSVGReset* styleSVGReset = aStopFrame->StyleSVGReset();
*aOffset = mozilla::clamped(*aOffset, 0.0f, 1.0f);
*aStopColor = styleSVGReset->mStopColor.CalcColor(aStopFrame);
*aStopOpacity = styleSVGReset->mStopOpacity;
}
already_AddRefed<gfxPattern> nsSVGGradientFrame::GetPaintServerPattern(
nsIFrame* aSource, const DrawTarget* aDrawTarget,
const gfxMatrix& aContextMatrix, nsStyleSVGPaint nsStyleSVG::*aFillOrStroke,
float aGraphicOpacity, imgDrawingParams& aImgParams,
const gfxRect* aOverrideBounds) {
uint16_t gradientUnits = GetGradientUnits();
MOZ_ASSERT(gradientUnits == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX ||
gradientUnits == SVG_UNIT_TYPE_USERSPACEONUSE);
if (gradientUnits == SVG_UNIT_TYPE_USERSPACEONUSE) {
// Set mSource for this consumer.
// If this gradient is applied to text, our caller will be the glyph, which
// is not an element, so we need to get the parent
mSource = aSource->GetContent()->IsText() ? aSource->GetParent() : aSource;
}
AutoTArray<nsIFrame*, 8> stopFrames;
GetStopFrames(&stopFrames);
uint32_t nStops = stopFrames.Length();
// SVG specification says that no stops should be treated like
// the corresponding fill or stroke had "none" specified.
if (nStops == 0) {
RefPtr<gfxPattern> pattern = new gfxPattern(Color());
return do_AddRef(new gfxPattern(Color()));
}
if (nStops == 1 || GradientVectorLengthIsZero()) {
auto lastStopFrame = stopFrames[nStops - 1];
auto svgReset = lastStopFrame->StyleSVGReset();
// The gradient paints a single colour, using the stop-color of the last
// gradient step if there are more than one.
float stopOpacity = svgReset->mStopOpacity;
nscolor stopColor = svgReset->mStopColor.CalcColor(lastStopFrame);
Color stopColor2 = Color::FromABGR(stopColor);
stopColor2.a *= stopOpacity * aGraphicOpacity;
return do_AddRef(new gfxPattern(stopColor2));
}
// Get the transform list (if there is one). We do this after the returns
// above since this call can be expensive when "gradientUnits" is set to
// "objectBoundingBox" (since that requiring a GetBBox() call).
gfxMatrix patternMatrix = GetGradientTransform(aSource, aOverrideBounds);
if (patternMatrix.IsSingular()) {
return nullptr;
}
// revert any vector effect transform so that the gradient appears unchanged
if (aFillOrStroke == &nsStyleSVG::mStroke) {
gfxMatrix userToOuterSVG;
if (nsSVGUtils::GetNonScalingStrokeTransform(aSource, &userToOuterSVG)) {
patternMatrix *= userToOuterSVG;
}
}
if (!patternMatrix.Invert()) {
return nullptr;
}
RefPtr<gfxPattern> gradient = CreateGradient();
if (!gradient) {
return nullptr;
}
uint16_t aSpread = GetSpreadMethod();
if (aSpread == SVG_SPREADMETHOD_PAD)
gradient->SetExtend(ExtendMode::CLAMP);
else if (aSpread == SVG_SPREADMETHOD_REFLECT)
gradient->SetExtend(ExtendMode::REFLECT);
else if (aSpread == SVG_SPREADMETHOD_REPEAT)
gradient->SetExtend(ExtendMode::REPEAT);
gradient->SetMatrix(patternMatrix);
// setup stops
float lastOffset = 0.0f;
for (uint32_t i = 0; i < nStops; i++) {
float offset, stopOpacity;
nscolor stopColor;
GetStopInformation(stopFrames[i], &offset, &stopColor, &stopOpacity);
if (offset < lastOffset)
offset = lastOffset;
else
lastOffset = offset;
Color stopColor2 = Color::FromABGR(stopColor);
stopColor2.a *= stopOpacity * aGraphicOpacity;
gradient->AddColorStop(offset, stopColor2);
}
return gradient.forget();
}
// Private (helper) methods
nsSVGGradientFrame* nsSVGGradientFrame::GetReferencedGradient() {
if (mNoHRefURI) {
return nullptr;
}
auto GetHref = [this](nsAString& aHref) {
dom::SVGGradientElement* grad =
static_cast<dom::SVGGradientElement*>(this->GetContent());
if (grad->mStringAttributes[dom::SVGGradientElement::HREF]
.IsExplicitlySet()) {
grad->mStringAttributes[dom::SVGGradientElement::HREF].GetAnimValue(aHref,
grad);
} else {
grad->mStringAttributes[dom::SVGGradientElement::XLINK_HREF].GetAnimValue(
aHref, grad);
}
this->mNoHRefURI = aHref.IsEmpty();
};
nsIFrame* tframe = SVGObserverUtils::GetAndObserveTemplate(this, GetHref);
if (tframe) {
LayoutFrameType frameType = tframe->Type();
if (frameType == LayoutFrameType::SVGLinearGradient ||
frameType == LayoutFrameType::SVGRadialGradient) {
return static_cast<nsSVGGradientFrame*>(tframe);
}
// We don't call SVGObserverUtils::RemoveTemplateObserver and set
// `mNoHRefURI = false` here since we want to be invalidated if the ID
// specified by our href starts resolving to a different/valid element.
}
return nullptr;
}
void nsSVGGradientFrame::GetStopFrames(nsTArray<nsIFrame*>* aStopFrames) {
nsIFrame* stopFrame = nullptr;
for (stopFrame = mFrames.FirstChild(); stopFrame;
stopFrame = stopFrame->GetNextSibling()) {
if (stopFrame->IsSVGStopFrame()) {
aStopFrames->AppendElement(stopFrame);
}
}
if (aStopFrames->Length() > 0) {
return;
}
// Our gradient element doesn't have stops - try to "inherit" them
// Before we recurse, make sure we'll break reference loops and over long
// reference chains:
static int16_t sRefChainLengthCounter = AutoReferenceChainGuard::noChain;
AutoReferenceChainGuard refChainGuard(this, &mLoopFlag,
&sRefChainLengthCounter);
if (MOZ_UNLIKELY(!refChainGuard.Reference())) {
// Break reference chain
return;
}
nsSVGGradientFrame* next = GetReferencedGradient();
if (next) {
next->GetStopFrames(aStopFrames);
}
}
// -------------------------------------------------------------------------
// Linear Gradients
// -------------------------------------------------------------------------
#ifdef DEBUG
void nsSVGLinearGradientFrame::Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) {
NS_ASSERTION(aContent->IsSVGElement(nsGkAtoms::linearGradient),
"Content is not an SVG linearGradient");
nsSVGGradientFrame::Init(aContent, aParent, aPrevInFlow);
}
#endif /* DEBUG */
nsresult nsSVGLinearGradientFrame::AttributeChanged(int32_t aNameSpaceID,
nsAtom* aAttribute,
int32_t aModType) {
if (aNameSpaceID == kNameSpaceID_None &&
(aAttribute == nsGkAtoms::x1 || aAttribute == nsGkAtoms::y1 ||
aAttribute == nsGkAtoms::x2 || aAttribute == nsGkAtoms::y2)) {
SVGObserverUtils::InvalidateDirectRenderingObservers(this);
}
return nsSVGGradientFrame::AttributeChanged(aNameSpaceID, aAttribute,
aModType);
}
//----------------------------------------------------------------------
float nsSVGLinearGradientFrame::GetLengthValue(uint32_t aIndex) {
dom::SVGLinearGradientElement* lengthElement = GetLinearGradientWithLength(
aIndex, static_cast<dom::SVGLinearGradientElement*>(GetContent()));
// We passed in mContent as a fallback, so, assuming mContent is non-null, the
// return value should also be non-null.
MOZ_ASSERT(lengthElement,
"Got unexpected null element from GetLinearGradientWithLength");
const SVGAnimatedLength& length = lengthElement->mLengthAttributes[aIndex];
// Object bounding box units are handled by setting the appropriate
// transform in GetGradientTransform, but we need to handle user
// space units as part of the individual Get* routines. Fixes 323669.
uint16_t gradientUnits = GetGradientUnits();
if (gradientUnits == SVG_UNIT_TYPE_USERSPACEONUSE) {
return nsSVGUtils::UserSpace(mSource, &length);
}
NS_ASSERTION(gradientUnits == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX,
"Unknown gradientUnits type");
return length.GetAnimValue(static_cast<SVGViewportElement*>(nullptr));
}
dom::SVGLinearGradientElement*
nsSVGLinearGradientFrame::GetLinearGradientWithLength(
uint32_t aIndex, dom::SVGLinearGradientElement* aDefault) {
dom::SVGLinearGradientElement* thisElement =
static_cast<dom::SVGLinearGradientElement*>(GetContent());
const SVGAnimatedLength& length = thisElement->mLengthAttributes[aIndex];
if (length.IsExplicitlySet()) {
return thisElement;
}
return nsSVGGradientFrame::GetLinearGradientWithLength(aIndex, aDefault);
}
bool nsSVGLinearGradientFrame::GradientVectorLengthIsZero() {
return GetLengthValue(dom::SVGLinearGradientElement::ATTR_X1) ==
GetLengthValue(dom::SVGLinearGradientElement::ATTR_X2) &&
GetLengthValue(dom::SVGLinearGradientElement::ATTR_Y1) ==
GetLengthValue(dom::SVGLinearGradientElement::ATTR_Y2);
}
already_AddRefed<gfxPattern> nsSVGLinearGradientFrame::CreateGradient() {
float x1, y1, x2, y2;
x1 = GetLengthValue(dom::SVGLinearGradientElement::ATTR_X1);
y1 = GetLengthValue(dom::SVGLinearGradientElement::ATTR_Y1);
x2 = GetLengthValue(dom::SVGLinearGradientElement::ATTR_X2);
y2 = GetLengthValue(dom::SVGLinearGradientElement::ATTR_Y2);
RefPtr<gfxPattern> pattern = new gfxPattern(x1, y1, x2, y2);
return pattern.forget();
}
// -------------------------------------------------------------------------
// Radial Gradients
// -------------------------------------------------------------------------
#ifdef DEBUG
void nsSVGRadialGradientFrame::Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) {
NS_ASSERTION(aContent->IsSVGElement(nsGkAtoms::radialGradient),
"Content is not an SVG radialGradient");
nsSVGGradientFrame::Init(aContent, aParent, aPrevInFlow);
}
#endif /* DEBUG */
nsresult nsSVGRadialGradientFrame::AttributeChanged(int32_t aNameSpaceID,
nsAtom* aAttribute,
int32_t aModType) {
if (aNameSpaceID == kNameSpaceID_None &&
(aAttribute == nsGkAtoms::r || aAttribute == nsGkAtoms::cx ||
aAttribute == nsGkAtoms::cy || aAttribute == nsGkAtoms::fx ||
aAttribute == nsGkAtoms::fy)) {
SVGObserverUtils::InvalidateDirectRenderingObservers(this);
}
return nsSVGGradientFrame::AttributeChanged(aNameSpaceID, aAttribute,
aModType);
}
//----------------------------------------------------------------------
float nsSVGRadialGradientFrame::GetLengthValue(uint32_t aIndex) {
dom::SVGRadialGradientElement* lengthElement = GetRadialGradientWithLength(
aIndex, static_cast<dom::SVGRadialGradientElement*>(GetContent()));
// We passed in mContent as a fallback, so, assuming mContent is non-null,
// the return value should also be non-null.
MOZ_ASSERT(lengthElement,
"Got unexpected null element from GetRadialGradientWithLength");
return GetLengthValueFromElement(aIndex, *lengthElement);
}
float nsSVGRadialGradientFrame::GetLengthValue(uint32_t aIndex,
float aDefaultValue) {
dom::SVGRadialGradientElement* lengthElement =
GetRadialGradientWithLength(aIndex, nullptr);
return lengthElement ? GetLengthValueFromElement(aIndex, *lengthElement)
: aDefaultValue;
}
float nsSVGRadialGradientFrame::GetLengthValueFromElement(
uint32_t aIndex, dom::SVGRadialGradientElement& aElement) {
const SVGAnimatedLength& length = aElement.mLengthAttributes[aIndex];
// Object bounding box units are handled by setting the appropriate
// transform in GetGradientTransform, but we need to handle user
// space units as part of the individual Get* routines. Fixes 323669.
uint16_t gradientUnits = GetGradientUnits();
if (gradientUnits == SVG_UNIT_TYPE_USERSPACEONUSE) {
return nsSVGUtils::UserSpace(mSource, &length);
}
NS_ASSERTION(gradientUnits == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX,
"Unknown gradientUnits type");
return length.GetAnimValue(static_cast<SVGViewportElement*>(nullptr));
}
dom::SVGRadialGradientElement*
nsSVGRadialGradientFrame::GetRadialGradientWithLength(
uint32_t aIndex, dom::SVGRadialGradientElement* aDefault) {
dom::SVGRadialGradientElement* thisElement =
static_cast<dom::SVGRadialGradientElement*>(GetContent());
const SVGAnimatedLength& length = thisElement->mLengthAttributes[aIndex];
if (length.IsExplicitlySet()) {
return thisElement;
}
return nsSVGGradientFrame::GetRadialGradientWithLength(aIndex, aDefault);
}
bool nsSVGRadialGradientFrame::GradientVectorLengthIsZero() {
return GetLengthValue(dom::SVGRadialGradientElement::ATTR_R) == 0;
}
already_AddRefed<gfxPattern> nsSVGRadialGradientFrame::CreateGradient() {
float cx, cy, r, fx, fy, fr;
cx = GetLengthValue(dom::SVGRadialGradientElement::ATTR_CX);
cy = GetLengthValue(dom::SVGRadialGradientElement::ATTR_CY);
r = GetLengthValue(dom::SVGRadialGradientElement::ATTR_R);
// If fx or fy are not set, use cx/cy instead
fx = GetLengthValue(dom::SVGRadialGradientElement::ATTR_FX, cx);
fy = GetLengthValue(dom::SVGRadialGradientElement::ATTR_FY, cy);
fr = GetLengthValue(dom::SVGRadialGradientElement::ATTR_FR);
if (fx != cx || fy != cy) {
// The focal point (fFx and fFy) must be clamped to be *inside* - not on -
// the circumference of the gradient or we'll get rendering anomalies. We
// calculate the distance from the focal point to the gradient center and
// make sure it is *less* than the gradient radius.
// 1/128 is the limit of the fractional part of cairo's 24.8 fixed point
// representation divided by 2 to ensure that we get different cairo
// fractions
double dMax = std::max(0.0, r - 1.0 / 128);
double dx = fx - cx;
double dy = fy - cy;
double d = std::sqrt((dx * dx) + (dy * dy));
if (d > dMax) {
double angle = std::atan2(dy, dx);
fx = float(dMax * std::cos(angle)) + cx;
fy = float(dMax * std::sin(angle)) + cy;
}
}
RefPtr<gfxPattern> pattern = new gfxPattern(fx, fy, fr, cx, cy, r);
return pattern.forget();
}
// -------------------------------------------------------------------------
// Public functions
// -------------------------------------------------------------------------
nsIFrame* NS_NewSVGLinearGradientFrame(mozilla::PresShell* aPresShell,
ComputedStyle* aStyle) {
return new (aPresShell)
nsSVGLinearGradientFrame(aStyle, aPresShell->GetPresContext());
}
NS_IMPL_FRAMEARENA_HELPERS(nsSVGLinearGradientFrame)
nsIFrame* NS_NewSVGRadialGradientFrame(mozilla::PresShell* aPresShell,
ComputedStyle* aStyle) {
return new (aPresShell)
nsSVGRadialGradientFrame(aStyle, aPresShell->GetPresContext());
}
NS_IMPL_FRAMEARENA_HELPERS(nsSVGRadialGradientFrame)