gecko-dev/dom/svg/SVGContentUtils.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:
// This is also necessary to ensure our definition of M_SQRT1_2 is picked up
#include "SVGContentUtils.h"
// Keep others in (case-insensitive) order:
#include "gfx2DGlue.h"
#include "gfxMatrix.h"
#include "gfxPlatform.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/dom/SVGSVGElement.h"
#include "mozilla/PresShell.h"
#include "mozilla/RefPtr.h"
#include "mozilla/SVGContextPaint.h"
#include "mozilla/TextUtils.h"
#include "nsComputedDOMStyle.h"
#include "nsContainerFrame.h"
#include "nsFontMetrics.h"
#include "nsIFrame.h"
#include "nsIScriptError.h"
#include "nsLayoutUtils.h"
#include "nsMathUtils.h"
#include "nsSVGUtils.h"
#include "nsWhitespaceTokenizer.h"
#include "SVGAnimationElement.h"
#include "SVGAnimatedPreserveAspectRatio.h"
#include "SVGGeometryProperty.h"
#include "nsContentUtils.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/Types.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/ComputedStyle.h"
#include "SVGPathDataParser.h"
#include "SVGPathData.h"
#include "SVGPathElement.h"
using namespace mozilla;
using namespace mozilla::dom;
using namespace mozilla::dom::SVGPreserveAspectRatio_Binding;
using namespace mozilla::gfx;
static bool ParseNumber(RangedPtr<const char16_t>& aIter,
const RangedPtr<const char16_t>& aEnd, double& aValue) {
int32_t sign;
if (!SVGContentUtils::ParseOptionalSign(aIter, aEnd, sign)) {
return false;
}
// Absolute value of the integer part of the mantissa.
double intPart = 0.0;
bool gotDot = *aIter == '.';
if (!gotDot) {
if (!mozilla::IsAsciiDigit(*aIter)) {
return false;
}
do {
intPart = 10.0 * intPart + mozilla::AsciiAlphanumericToNumber(*aIter);
++aIter;
} while (aIter != aEnd && mozilla::IsAsciiDigit(*aIter));
if (aIter != aEnd) {
gotDot = *aIter == '.';
}
}
// Fractional part of the mantissa.
double fracPart = 0.0;
if (gotDot) {
++aIter;
if (aIter == aEnd || !mozilla::IsAsciiDigit(*aIter)) {
return false;
}
// Power of ten by which we need to divide the fraction
double divisor = 1.0;
do {
fracPart = 10.0 * fracPart + mozilla::AsciiAlphanumericToNumber(*aIter);
divisor *= 10.0;
++aIter;
} while (aIter != aEnd && mozilla::IsAsciiDigit(*aIter));
fracPart /= divisor;
}
bool gotE = false;
int32_t exponent = 0;
int32_t expSign;
if (aIter != aEnd && (*aIter == 'e' || *aIter == 'E')) {
RangedPtr<const char16_t> expIter(aIter);
++expIter;
if (expIter != aEnd) {
expSign = *expIter == '-' ? -1 : 1;
if (*expIter == '-' || *expIter == '+') {
++expIter;
}
if (expIter != aEnd && mozilla::IsAsciiDigit(*expIter)) {
// At this point we're sure this is an exponent
// and not the start of a unit such as em or ex.
gotE = true;
}
}
if (gotE) {
aIter = expIter;
do {
exponent = 10.0 * exponent + mozilla::AsciiAlphanumericToNumber(*aIter);
++aIter;
} while (aIter != aEnd && mozilla::IsAsciiDigit(*aIter));
}
}
// Assemble the number
aValue = sign * (intPart + fracPart);
if (gotE) {
aValue *= pow(10.0, expSign * exponent);
}
return true;
}
namespace mozilla {
SVGSVGElement* SVGContentUtils::GetOuterSVGElement(SVGElement* aSVGElement) {
Element* element = nullptr;
Element* ancestor = aSVGElement->GetParentElementCrossingShadowRoot();
while (ancestor && ancestor->IsSVGElement() &&
!ancestor->IsSVGElement(nsGkAtoms::foreignObject)) {
element = ancestor;
ancestor = element->GetParentElementCrossingShadowRoot();
}
if (element && element->IsSVGElement(nsGkAtoms::svg)) {
return static_cast<SVGSVGElement*>(element);
}
return nullptr;
}
void SVGContentUtils::ActivateByHyperlink(nsIContent* aContent) {
MOZ_ASSERT(aContent->IsNodeOfType(nsINode::eANIMATION),
"Expecting an animation element");
static_cast<SVGAnimationElement*>(aContent)->ActivateByHyperlink();
}
enum DashState {
eDashedStroke,
eContinuousStroke, //< all dashes, no gaps
eNoStroke //< all gaps, no dashes
};
static DashState GetStrokeDashData(
SVGContentUtils::AutoStrokeOptions* aStrokeOptions, SVGElement* aElement,
const nsStyleSVG* aStyleSVG, SVGContextPaint* aContextPaint) {
size_t dashArrayLength;
Float totalLengthOfDashes = 0.0, totalLengthOfGaps = 0.0;
Float pathScale = 1.0;
if (aStyleSVG->mStrokeDasharray.IsContextValue()) {
if (!aContextPaint) {
return eContinuousStroke;
}
const FallibleTArray<Float>& dashSrc = aContextPaint->GetStrokeDashArray();
dashArrayLength = dashSrc.Length();
if (dashArrayLength <= 0) {
return eContinuousStroke;
}
Float* dashPattern = aStrokeOptions->InitDashPattern(dashArrayLength);
if (!dashPattern) {
return eContinuousStroke;
}
for (size_t i = 0; i < dashArrayLength; i++) {
if (dashSrc[i] < 0.0) {
return eContinuousStroke; // invalid
}
dashPattern[i] = Float(dashSrc[i]);
(i % 2 ? totalLengthOfGaps : totalLengthOfDashes) += dashSrc[i];
}
} else {
const auto dasharray = aStyleSVG->mStrokeDasharray.AsValues().AsSpan();
dashArrayLength = dasharray.Length();
if (dashArrayLength <= 0) {
return eContinuousStroke;
}
if (aElement->IsNodeOfType(nsINode::eSHAPE)) {
pathScale =
static_cast<SVGGeometryElement*>(aElement)->GetPathLengthScale(
SVGGeometryElement::eForStroking);
if (pathScale <= 0) {
return eContinuousStroke;
}
}
Float* dashPattern = aStrokeOptions->InitDashPattern(dashArrayLength);
if (!dashPattern) {
return eContinuousStroke;
}
for (uint32_t i = 0; i < dashArrayLength; i++) {
Float dashLength =
SVGContentUtils::CoordToFloat(aElement, dasharray[i]) * pathScale;
if (dashLength < 0.0) {
return eContinuousStroke; // invalid
}
dashPattern[i] = dashLength;
(i % 2 ? totalLengthOfGaps : totalLengthOfDashes) += dashLength;
}
}
// Now that aStrokeOptions.mDashPattern is fully initialized (we didn't
// return early above) we can safely set mDashLength:
aStrokeOptions->mDashLength = dashArrayLength;
if ((dashArrayLength % 2) == 1) {
// If we have a dash pattern with an odd number of lengths the pattern
// repeats a second time, per the SVG spec., and as implemented by Moz2D.
// When deciding whether to return eNoStroke or eContinuousStroke below we
// need to take into account that in the repeat pattern the dashes become
// gaps, and the gaps become dashes.
Float origTotalLengthOfDashes = totalLengthOfDashes;
totalLengthOfDashes += totalLengthOfGaps;
totalLengthOfGaps += origTotalLengthOfDashes;
}
// Stroking using dashes is much slower than stroking a continuous line
// (see bug 609361 comment 40), and much, much slower than not stroking the
// line at all. Here we check for cases when the dash pattern causes the
// stroke to essentially be continuous or to be nonexistent in which case
// we can avoid expensive stroking operations (the underlying platform
// graphics libraries don't seem to optimize for this).
if (totalLengthOfGaps <= 0) {
return eContinuousStroke;
}
// We can only return eNoStroke if the value of stroke-linecap isn't
// adding caps to zero length dashes.
if (totalLengthOfDashes <= 0 &&
aStyleSVG->mStrokeLinecap == StyleStrokeLinecap::Butt) {
return eNoStroke;
}
if (aStyleSVG->mStrokeDashoffset.IsContextValue()) {
aStrokeOptions->mDashOffset =
Float(aContextPaint ? aContextPaint->GetStrokeDashOffset() : 0);
} else {
aStrokeOptions->mDashOffset =
SVGContentUtils::CoordToFloat(
aElement, aStyleSVG->mStrokeDashoffset.AsLengthPercentage()) *
pathScale;
}
return eDashedStroke;
}
void SVGContentUtils::GetStrokeOptions(AutoStrokeOptions* aStrokeOptions,
SVGElement* aElement,
const ComputedStyle* aComputedStyle,
SVGContextPaint* aContextPaint,
StrokeOptionFlags aFlags) {
auto doCompute = [&](const ComputedStyle* computedStyle) {
const nsStyleSVG* styleSVG = computedStyle->StyleSVG();
bool checkedDashAndStrokeIsDashed = false;
if (aFlags != eIgnoreStrokeDashing) {
DashState dashState =
GetStrokeDashData(aStrokeOptions, aElement, styleSVG, aContextPaint);
if (dashState == eNoStroke) {
// Hopefully this will shortcircuit any stroke operations:
aStrokeOptions->mLineWidth = 0;
return;
}
if (dashState == eContinuousStroke && aStrokeOptions->mDashPattern) {
// Prevent our caller from wasting time looking at a pattern without
// gaps:
aStrokeOptions->DiscardDashPattern();
}
checkedDashAndStrokeIsDashed = (dashState == eDashedStroke);
}
aStrokeOptions->mLineWidth =
GetStrokeWidth(aElement, computedStyle, aContextPaint);
aStrokeOptions->mMiterLimit = Float(styleSVG->mStrokeMiterlimit);
switch (styleSVG->mStrokeLinejoin) {
case StyleStrokeLinejoin::Miter:
aStrokeOptions->mLineJoin = JoinStyle::MITER_OR_BEVEL;
break;
case StyleStrokeLinejoin::Round:
aStrokeOptions->mLineJoin = JoinStyle::ROUND;
break;
case StyleStrokeLinejoin::Bevel:
aStrokeOptions->mLineJoin = JoinStyle::BEVEL;
break;
}
if (ShapeTypeHasNoCorners(aElement) && !checkedDashAndStrokeIsDashed) {
// Note: if aFlags == eIgnoreStrokeDashing then we may be returning the
// wrong linecap value here, since the actual linecap used on render in
// this case depends on whether the stroke is dashed or not.
aStrokeOptions->mLineCap = CapStyle::BUTT;
} else {
switch (styleSVG->mStrokeLinecap) {
case StyleStrokeLinecap::Butt:
aStrokeOptions->mLineCap = CapStyle::BUTT;
break;
case StyleStrokeLinecap::Round:
aStrokeOptions->mLineCap = CapStyle::ROUND;
break;
case StyleStrokeLinecap::Square:
aStrokeOptions->mLineCap = CapStyle::SQUARE;
break;
}
}
};
if (aComputedStyle) {
doCompute(aComputedStyle);
} else {
SVGGeometryProperty::DoForComputedStyle(aElement, doCompute);
}
}
Float SVGContentUtils::GetStrokeWidth(SVGElement* aElement,
const ComputedStyle* aComputedStyle,
SVGContextPaint* aContextPaint) {
Float res = 0.0;
auto doCompute = [&](ComputedStyle const* computedStyle) {
const nsStyleSVG* styleSVG = computedStyle->StyleSVG();
if (styleSVG->mStrokeWidth.IsContextValue()) {
res = aContextPaint ? aContextPaint->GetStrokeWidth() : 1.0;
} else {
res = SVGContentUtils::CoordToFloat(
aElement, styleSVG->mStrokeWidth.AsLengthPercentage());
}
};
if (aComputedStyle) {
doCompute(aComputedStyle);
} else {
SVGGeometryProperty::DoForComputedStyle(aElement, doCompute);
}
return res;
}
float SVGContentUtils::GetFontSize(Element* aElement) {
if (!aElement) {
return 1.0f;
}
nsPresContext* pc = nsContentUtils::GetContextForContent(aElement);
if (!pc) {
return 1.0f;
}
if (auto* f = aElement->GetPrimaryFrame()) {
return GetFontSize(f->Style(), pc);
}
if (RefPtr<ComputedStyle> style =
nsComputedDOMStyle::GetComputedStyleNoFlush(aElement, nullptr)) {
return GetFontSize(style, pc);
}
// ReportToConsole
NS_WARNING("Couldn't get ComputedStyle for content in GetFontStyle");
return 1.0f;
}
float SVGContentUtils::GetFontSize(nsIFrame* aFrame) {
MOZ_ASSERT(aFrame, "NULL frame in GetFontSize");
return GetFontSize(aFrame->Style(), aFrame->PresContext());
}
float SVGContentUtils::GetFontSize(ComputedStyle* aComputedStyle,
nsPresContext* aPresContext) {
MOZ_ASSERT(aComputedStyle);
MOZ_ASSERT(aPresContext);
nscoord fontSize = aComputedStyle->StyleFont()->mSize;
return nsPresContext::AppUnitsToFloatCSSPixels(fontSize) /
aPresContext->EffectiveTextZoom();
}
float SVGContentUtils::GetFontXHeight(Element* aElement) {
if (!aElement) {
return 1.0f;
}
nsPresContext* pc = nsContentUtils::GetContextForContent(aElement);
if (!pc) {
return 1.0f;
}
if (auto* f = aElement->GetPrimaryFrame()) {
return GetFontXHeight(f->Style(), pc);
}
if (RefPtr<ComputedStyle> style =
nsComputedDOMStyle::GetComputedStyleNoFlush(aElement, nullptr)) {
return GetFontXHeight(style, pc);
}
// ReportToConsole
NS_WARNING("Couldn't get ComputedStyle for content in GetFontStyle");
return 1.0f;
}
float SVGContentUtils::GetFontXHeight(nsIFrame* aFrame) {
MOZ_ASSERT(aFrame, "NULL frame in GetFontXHeight");
return GetFontXHeight(aFrame->Style(), aFrame->PresContext());
}
float SVGContentUtils::GetFontXHeight(ComputedStyle* aComputedStyle,
nsPresContext* aPresContext) {
MOZ_ASSERT(aComputedStyle && aPresContext);
RefPtr<nsFontMetrics> fontMetrics =
nsLayoutUtils::GetFontMetricsForComputedStyle(aComputedStyle,
aPresContext);
if (!fontMetrics) {
// ReportToConsole
NS_WARNING("no FontMetrics in GetFontXHeight()");
return 1.0f;
}
nscoord xHeight = fontMetrics->XHeight();
return nsPresContext::AppUnitsToFloatCSSPixels(xHeight) /
aPresContext->EffectiveTextZoom();
}
nsresult SVGContentUtils::ReportToConsole(Document* doc, const char* aWarning,
const nsTArray<nsString>& aParams) {
return nsContentUtils::ReportToConsole(
nsIScriptError::warningFlag, NS_LITERAL_CSTRING("SVG"), doc,
nsContentUtils::eSVG_PROPERTIES, aWarning, aParams);
}
bool SVGContentUtils::EstablishesViewport(nsIContent* aContent) {
// Although SVG 1.1 states that <image> is an element that establishes a
// viewport, this is really only for the document it references, not
// for any child content, which is what this function is used for.
return aContent &&
aContent->IsAnyOfSVGElements(nsGkAtoms::svg, nsGkAtoms::foreignObject,
nsGkAtoms::symbol);
}
SVGViewportElement* SVGContentUtils::GetNearestViewportElement(
const nsIContent* aContent) {
nsIContent* element = aContent->GetFlattenedTreeParent();
while (element && element->IsSVGElement()) {
if (EstablishesViewport(element)) {
if (element->IsSVGElement(nsGkAtoms::foreignObject)) {
return nullptr;
}
MOZ_ASSERT(element->IsAnyOfSVGElements(nsGkAtoms::svg, nsGkAtoms::symbol),
"upcoming static_cast is only valid for "
"SVGViewportElement subclasses");
return static_cast<SVGViewportElement*>(element);
}
element = element->GetFlattenedTreeParent();
}
return nullptr;
}
static gfx::Matrix GetCTMInternal(SVGElement* aElement, bool aScreenCTM,
bool aHaveRecursed) {
auto getLocalTransformHelper =
[](SVGElement const* e, bool shouldIncludeChildToUserSpace) -> gfxMatrix {
gfxMatrix ret;
if (auto* f = e->GetPrimaryFrame()) {
ret = nsSVGUtils::GetTransformMatrixInUserSpace(f);
} else {
// FIXME: Ideally we should also return the correct matrix
// for display:none, but currently transform related code relies
// heavily on the present of a frame.
// For now we just fall back to |PrependLocalTransformsTo| which
// doesn't account for CSS transform.
ret = e->PrependLocalTransformsTo({}, eUserSpaceToParent);
}
if (shouldIncludeChildToUserSpace) {
ret = e->PrependLocalTransformsTo({}, eChildToUserSpace) * ret;
}
return ret;
};
gfxMatrix matrix = getLocalTransformHelper(aElement, aHaveRecursed);
SVGElement* element = aElement;
nsIContent* ancestor = aElement->GetFlattenedTreeParent();
while (ancestor && ancestor->IsSVGElement() &&
!ancestor->IsSVGElement(nsGkAtoms::foreignObject)) {
element = static_cast<SVGElement*>(ancestor);
matrix *= getLocalTransformHelper(element, true);
if (!aScreenCTM && SVGContentUtils::EstablishesViewport(element)) {
if (!element->NodeInfo()->Equals(nsGkAtoms::svg, kNameSpaceID_SVG) &&
!element->NodeInfo()->Equals(nsGkAtoms::symbol, kNameSpaceID_SVG)) {
NS_ERROR("New (SVG > 1.1) SVG viewport establishing element?");
return gfx::Matrix(0.0, 0.0, 0.0, 0.0, 0.0, 0.0); // singular
}
// XXX spec seems to say x,y translation should be undone for IsInnerSVG
return gfx::ToMatrix(matrix);
}
ancestor = ancestor->GetFlattenedTreeParent();
}
if (!aScreenCTM) {
// didn't find a nearestViewportElement
return gfx::Matrix(0.0, 0.0, 0.0, 0.0, 0.0, 0.0); // singular
}
if (!element->IsSVGElement(nsGkAtoms::svg)) {
// Not a valid SVG fragment
return gfx::Matrix(0.0, 0.0, 0.0, 0.0, 0.0, 0.0); // singular
}
if (element == aElement && !aHaveRecursed) {
// We get here when getScreenCTM() is called on an outer-<svg>.
// Consistency with other elements would have us include only the
// eFromUserSpace transforms, but we include the eAllTransforms
// transforms in this case since that's what we've been doing for
// a while, and it keeps us consistent with WebKit and Opera (if not
// really with the ambiguous spec).
matrix = getLocalTransformHelper(aElement, true);
}
if (auto* f = element->GetPrimaryFrame()) {
if (f->IsSVGOuterSVGFrame()) {
nsMargin bp = f->GetUsedBorderAndPadding();
matrix.PostTranslate(
NSAppUnitsToFloatPixels(bp.left, AppUnitsPerCSSPixel()),
NSAppUnitsToFloatPixels(bp.top, AppUnitsPerCSSPixel()));
}
}
if (!ancestor || !ancestor->IsElement()) {
return gfx::ToMatrix(matrix);
}
if (ancestor->IsSVGElement()) {
return gfx::ToMatrix(matrix) *
GetCTMInternal(static_cast<SVGElement*>(ancestor), true, true);
}
// XXX this does not take into account CSS transform, or that the non-SVG
// content that we've hit may itself be inside an SVG foreignObject higher up
Document* currentDoc = aElement->GetComposedDoc();
float x = 0.0f, y = 0.0f;
if (currentDoc &&
element->NodeInfo()->Equals(nsGkAtoms::svg, kNameSpaceID_SVG)) {
PresShell* presShell = currentDoc->GetPresShell();
if (presShell) {
nsIFrame* frame = element->GetPrimaryFrame();
nsIFrame* ancestorFrame = presShell->GetRootFrame();
if (frame && ancestorFrame) {
nsPoint point = frame->GetOffsetTo(ancestorFrame);
x = nsPresContext::AppUnitsToFloatCSSPixels(point.x);
y = nsPresContext::AppUnitsToFloatCSSPixels(point.y);
}
}
}
return ToMatrix(matrix).PostTranslate(x, y);
}
gfx::Matrix SVGContentUtils::GetCTM(SVGElement* aElement, bool aScreenCTM) {
return GetCTMInternal(aElement, aScreenCTM, false);
}
void SVGContentUtils::RectilinearGetStrokeBounds(
const Rect& aRect, const Matrix& aToBoundsSpace,
const Matrix& aToNonScalingStrokeSpace, float aStrokeWidth, Rect* aBounds) {
MOZ_ASSERT(aToBoundsSpace.IsRectilinear(),
"aToBoundsSpace must be rectilinear");
MOZ_ASSERT(aToNonScalingStrokeSpace.IsRectilinear(),
"aToNonScalingStrokeSpace must be rectilinear");
Matrix nonScalingToSource = aToNonScalingStrokeSpace.Inverse();
Matrix nonScalingToBounds = nonScalingToSource * aToBoundsSpace;
*aBounds = aToBoundsSpace.TransformBounds(aRect);
// Compute the amounts dx and dy that nonScalingToBounds scales a half-width
// stroke in the x and y directions, and then inflate aBounds by those amounts
// so that when aBounds is transformed back to non-scaling-stroke space
// it will map onto the correct stroked bounds.
Float dx = 0.0f;
Float dy = 0.0f;
// nonScalingToBounds is rectilinear, so either _12 and _21 are zero or _11
// and _22 are zero, and in each case the non-zero entries (from among _11,
// _12, _21, _22) simply scale the stroke width in the x and y directions.
if (FuzzyEqual(nonScalingToBounds._12, 0) &&
FuzzyEqual(nonScalingToBounds._21, 0)) {
dx = (aStrokeWidth / 2.0f) * std::abs(nonScalingToBounds._11);
dy = (aStrokeWidth / 2.0f) * std::abs(nonScalingToBounds._22);
} else {
dx = (aStrokeWidth / 2.0f) * std::abs(nonScalingToBounds._21);
dy = (aStrokeWidth / 2.0f) * std::abs(nonScalingToBounds._12);
}
aBounds->Inflate(dx, dy);
}
double SVGContentUtils::ComputeNormalizedHypotenuse(double aWidth,
double aHeight) {
return NS_hypot(aWidth, aHeight) / M_SQRT2;
}
float SVGContentUtils::AngleBisect(float a1, float a2) {
float delta = std::fmod(a2 - a1, static_cast<float>(2 * M_PI));
if (delta < 0) {
delta += static_cast<float>(2 * M_PI);
}
/* delta is now the angle from a1 around to a2, in the range [0, 2*M_PI) */
float r = a1 + delta / 2;
if (delta >= M_PI) {
/* the arc from a2 to a1 is smaller, so use the ray on that side */
r += static_cast<float>(M_PI);
}
return r;
}
gfx::Matrix SVGContentUtils::GetViewBoxTransform(
float aViewportWidth, float aViewportHeight, float aViewboxX,
float aViewboxY, float aViewboxWidth, float aViewboxHeight,
const SVGAnimatedPreserveAspectRatio& aPreserveAspectRatio) {
return GetViewBoxTransform(aViewportWidth, aViewportHeight, aViewboxX,
aViewboxY, aViewboxWidth, aViewboxHeight,
aPreserveAspectRatio.GetAnimValue());
}
gfx::Matrix SVGContentUtils::GetViewBoxTransform(
float aViewportWidth, float aViewportHeight, float aViewboxX,
float aViewboxY, float aViewboxWidth, float aViewboxHeight,
const SVGPreserveAspectRatio& aPreserveAspectRatio) {
NS_ASSERTION(aViewportWidth >= 0, "viewport width must be nonnegative!");
NS_ASSERTION(aViewportHeight >= 0, "viewport height must be nonnegative!");
NS_ASSERTION(aViewboxWidth > 0, "viewBox width must be greater than zero!");
NS_ASSERTION(aViewboxHeight > 0, "viewBox height must be greater than zero!");
uint16_t align = aPreserveAspectRatio.GetAlign();
uint16_t meetOrSlice = aPreserveAspectRatio.GetMeetOrSlice();
// default to the defaults
if (align == SVG_PRESERVEASPECTRATIO_UNKNOWN)
align = SVG_PRESERVEASPECTRATIO_XMIDYMID;
if (meetOrSlice == SVG_MEETORSLICE_UNKNOWN)
meetOrSlice = SVG_MEETORSLICE_MEET;
float a, d, e, f;
a = aViewportWidth / aViewboxWidth;
d = aViewportHeight / aViewboxHeight;
e = 0.0f;
f = 0.0f;
if (align != SVG_PRESERVEASPECTRATIO_NONE && a != d) {
if ((meetOrSlice == SVG_MEETORSLICE_MEET && a < d) ||
(meetOrSlice == SVG_MEETORSLICE_SLICE && d < a)) {
d = a;
switch (align) {
case SVG_PRESERVEASPECTRATIO_XMINYMIN:
case SVG_PRESERVEASPECTRATIO_XMIDYMIN:
case SVG_PRESERVEASPECTRATIO_XMAXYMIN:
break;
case SVG_PRESERVEASPECTRATIO_XMINYMID:
case SVG_PRESERVEASPECTRATIO_XMIDYMID:
case SVG_PRESERVEASPECTRATIO_XMAXYMID:
f = (aViewportHeight - a * aViewboxHeight) / 2.0f;
break;
case SVG_PRESERVEASPECTRATIO_XMINYMAX:
case SVG_PRESERVEASPECTRATIO_XMIDYMAX:
case SVG_PRESERVEASPECTRATIO_XMAXYMAX:
f = aViewportHeight - a * aViewboxHeight;
break;
default:
MOZ_ASSERT_UNREACHABLE("Unknown value for align");
}
} else if ((meetOrSlice == SVG_MEETORSLICE_MEET && d < a) ||
(meetOrSlice == SVG_MEETORSLICE_SLICE && a < d)) {
a = d;
switch (align) {
case SVG_PRESERVEASPECTRATIO_XMINYMIN:
case SVG_PRESERVEASPECTRATIO_XMINYMID:
case SVG_PRESERVEASPECTRATIO_XMINYMAX:
break;
case SVG_PRESERVEASPECTRATIO_XMIDYMIN:
case SVG_PRESERVEASPECTRATIO_XMIDYMID:
case SVG_PRESERVEASPECTRATIO_XMIDYMAX:
e = (aViewportWidth - a * aViewboxWidth) / 2.0f;
break;
case SVG_PRESERVEASPECTRATIO_XMAXYMIN:
case SVG_PRESERVEASPECTRATIO_XMAXYMID:
case SVG_PRESERVEASPECTRATIO_XMAXYMAX:
e = aViewportWidth - a * aViewboxWidth;
break;
default:
MOZ_ASSERT_UNREACHABLE("Unknown value for align");
}
} else
MOZ_ASSERT_UNREACHABLE("Unknown value for meetOrSlice");
}
if (aViewboxX) e += -a * aViewboxX;
if (aViewboxY) f += -d * aViewboxY;
return gfx::Matrix(a, 0.0f, 0.0f, d, e, f);
}
template <class floatType>
bool SVGContentUtils::ParseNumber(RangedPtr<const char16_t>& aIter,
const RangedPtr<const char16_t>& aEnd,
floatType& aValue) {
RangedPtr<const char16_t> iter(aIter);
double value;
if (!::ParseNumber(iter, aEnd, value)) {
return false;
}
floatType floatValue = floatType(value);
if (!IsFinite(floatValue)) {
return false;
}
aValue = floatValue;
aIter = iter;
return true;
}
template bool SVGContentUtils::ParseNumber<float>(
RangedPtr<const char16_t>& aIter, const RangedPtr<const char16_t>& aEnd,
float& aValue);
template bool SVGContentUtils::ParseNumber<double>(
RangedPtr<const char16_t>& aIter, const RangedPtr<const char16_t>& aEnd,
double& aValue);
RangedPtr<const char16_t> SVGContentUtils::GetStartRangedPtr(
const nsAString& aString) {
return RangedPtr<const char16_t>(aString.Data(), aString.Length());
}
RangedPtr<const char16_t> SVGContentUtils::GetEndRangedPtr(
const nsAString& aString) {
return RangedPtr<const char16_t>(aString.Data() + aString.Length(),
aString.Data(), aString.Length());
}
template <class floatType>
bool SVGContentUtils::ParseNumber(const nsAString& aString, floatType& aValue) {
RangedPtr<const char16_t> iter = GetStartRangedPtr(aString);
const RangedPtr<const char16_t> end = GetEndRangedPtr(aString);
return ParseNumber(iter, end, aValue) && iter == end;
}
template bool SVGContentUtils::ParseNumber<float>(const nsAString& aString,
float& aValue);
template bool SVGContentUtils::ParseNumber<double>(const nsAString& aString,
double& aValue);
/* static */
bool SVGContentUtils::ParseInteger(RangedPtr<const char16_t>& aIter,
const RangedPtr<const char16_t>& aEnd,
int32_t& aValue) {
RangedPtr<const char16_t> iter(aIter);
int32_t sign;
if (!ParseOptionalSign(iter, aEnd, sign)) {
return false;
}
if (!mozilla::IsAsciiDigit(*iter)) {
return false;
}
int64_t value = 0;
do {
if (value <= std::numeric_limits<int32_t>::max()) {
value = 10 * value + mozilla::AsciiAlphanumericToNumber(*iter);
}
++iter;
} while (iter != aEnd && mozilla::IsAsciiDigit(*iter));
aIter = iter;
aValue = int32_t(clamped(sign * value,
int64_t(std::numeric_limits<int32_t>::min()),
int64_t(std::numeric_limits<int32_t>::max())));
return true;
}
/* static */
bool SVGContentUtils::ParseInteger(const nsAString& aString, int32_t& aValue) {
RangedPtr<const char16_t> iter = GetStartRangedPtr(aString);
const RangedPtr<const char16_t> end = GetEndRangedPtr(aString);
return ParseInteger(iter, end, aValue) && iter == end;
}
float SVGContentUtils::CoordToFloat(SVGElement* aContent,
const LengthPercentage& aLength) {
float result = aLength.ResolveToCSSPixelsWith([&] {
SVGViewportElement* ctx = aContent->GetCtx();
return CSSCoord(ctx ? ctx->GetLength(SVGContentUtils::XY) : 0.0f);
});
if (aLength.IsCalc()) {
auto& calc = aLength.AsCalc();
if (calc.clamping_mode == StyleAllowedNumericType::NonNegative) {
result = std::max(result, 0.0f);
} else {
MOZ_ASSERT(calc.clamping_mode == StyleAllowedNumericType::All);
}
}
return result;
}
already_AddRefed<gfx::Path> SVGContentUtils::GetPath(
const nsAString& aPathString) {
SVGPathData pathData;
SVGPathDataParser parser(aPathString, &pathData);
if (!parser.Parse()) {
return nullptr;
}
RefPtr<DrawTarget> drawTarget =
gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
RefPtr<PathBuilder> builder =
drawTarget->CreatePathBuilder(FillRule::FILL_WINDING);
return pathData.BuildPath(builder, StyleStrokeLinecap::Butt, 1);
}
bool SVGContentUtils::ShapeTypeHasNoCorners(const nsIContent* aContent) {
return aContent &&
aContent->IsAnyOfSVGElements(nsGkAtoms::circle, nsGkAtoms::ellipse);
}
nsDependentSubstring SVGContentUtils::GetAndEnsureOneToken(
const nsAString& aString, bool& aSuccess) {
nsWhitespaceTokenizerTemplate<nsContentUtils::IsHTMLWhitespace> tokenizer(
aString);
aSuccess = false;
if (!tokenizer.hasMoreTokens()) {
return {};
}
auto token = tokenizer.nextToken();
if (tokenizer.hasMoreTokens()) {
return {};
}
aSuccess = true;
return token;
}
} // namespace mozilla