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gecko-dev/layout/style/nsStyleUtil.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/. */
#include "nsStyleUtil.h"
#include "nsStyleConsts.h"
#include "nsIContent.h"
#include "nsCSSProps.h"
#include "nsContentUtils.h"
#include "nsROCSSPrimitiveValue.h"
#include "nsStyleStruct.h"
#include "nsIContentPolicy.h"
#include "nsIContentSecurityPolicy.h"
#include "nsIURI.h"
#include "nsISupportsPrimitives.h"
#include "nsLayoutUtils.h"
#include "nsPrintfCString.h"
#include <cctype>
using namespace mozilla;
//------------------------------------------------------------------------------
// Font Algorithm Code
//------------------------------------------------------------------------------
// Compare two language strings
bool nsStyleUtil::DashMatchCompare(const nsAString& aAttributeValue,
const nsAString& aSelectorValue,
const nsStringComparator& aComparator)
{
bool result;
uint32_t selectorLen = aSelectorValue.Length();
uint32_t attributeLen = aAttributeValue.Length();
if (selectorLen > attributeLen) {
result = false;
}
else {
nsAString::const_iterator iter;
if (selectorLen != attributeLen &&
*aAttributeValue.BeginReading(iter).advance(selectorLen) !=
char16_t('-')) {
// to match, the aAttributeValue must have a dash after the end of
// the aSelectorValue's text (unless the aSelectorValue and the
// aAttributeValue have the same text)
result = false;
}
else {
result = StringBeginsWith(aAttributeValue, aSelectorValue, aComparator);
}
}
return result;
}
bool
nsStyleUtil::ValueIncludes(const nsAString& aValueList,
const nsAString& aValue,
const nsStringComparator& aComparator)
{
const char16_t *p = aValueList.BeginReading(),
*p_end = aValueList.EndReading();
while (p < p_end) {
// skip leading space
while (p != p_end && nsContentUtils::IsHTMLWhitespace(*p))
++p;
const char16_t *val_start = p;
// look for space or end
while (p != p_end && !nsContentUtils::IsHTMLWhitespace(*p))
++p;
const char16_t *val_end = p;
if (val_start < val_end &&
aValue.Equals(Substring(val_start, val_end), aComparator))
return true;
++p; // we know the next character is not whitespace
}
return false;
}
void nsStyleUtil::AppendEscapedCSSString(const nsAString& aString,
nsAString& aReturn,
char16_t quoteChar)
{
NS_PRECONDITION(quoteChar == '\'' || quoteChar == '"',
"CSS strings must be quoted with ' or \"");
aReturn.Append(quoteChar);
const char16_t* in = aString.BeginReading();
const char16_t* const end = aString.EndReading();
for (; in != end; in++) {
if (*in < 0x20 || *in == 0x7F) {
// Escape U+0000 through U+001F and U+007F numerically.
aReturn.AppendPrintf("\\%x ", *in);
} else {
if (*in == '"' || *in == '\'' || *in == '\\') {
// Escape backslash and quote characters symbolically.
// It's not technically necessary to escape the quote
// character that isn't being used to delimit the string,
// but we do it anyway because that makes testing simpler.
aReturn.Append(char16_t('\\'));
}
aReturn.Append(*in);
}
}
aReturn.Append(quoteChar);
}
/* static */ void
nsStyleUtil::AppendEscapedCSSIdent(const nsAString& aIdent, nsAString& aReturn)
{
// The relevant parts of the CSS grammar are:
// ident ([-]?{nmstart}|[-][-]){nmchar}*
// nmstart [_a-z]|{nonascii}|{escape}
// nmchar [_a-z0-9-]|{nonascii}|{escape}
// nonascii [^\0-\177]
// escape {unicode}|\\[^\n\r\f0-9a-f]
// unicode \\[0-9a-f]{1,6}(\r\n|[ \n\r\t\f])?
// from http://www.w3.org/TR/CSS21/syndata.html#tokenization but
// modified for idents by
// http://dev.w3.org/csswg/cssom/#serialize-an-identifier and
// http://dev.w3.org/csswg/css-syntax/#would-start-an-identifier
const char16_t* in = aIdent.BeginReading();
const char16_t* const end = aIdent.EndReading();
if (in == end)
return;
// A leading dash does not need to be escaped as long as it is not the
// *only* character in the identifier.
if (*in == '-') {
if (in + 1 == end) {
aReturn.Append(char16_t('\\'));
aReturn.Append(char16_t('-'));
return;
}
aReturn.Append(char16_t('-'));
++in;
}
// Escape a digit at the start (including after a dash),
// numerically. If we didn't escape it numerically, it would get
// interpreted as a numeric escape for the wrong character.
if (in != end && ('0' <= *in && *in <= '9')) {
aReturn.AppendPrintf("\\%x ", *in);
++in;
}
for (; in != end; ++in) {
char16_t ch = *in;
if (ch == 0x00) {
aReturn.Append(char16_t(0xFFFD));
} else if (ch < 0x20 || 0x7F == ch) {
// Escape U+0000 through U+001F and U+007F numerically.
aReturn.AppendPrintf("\\%x ", *in);
} else {
// Escape ASCII non-identifier printables as a backslash plus
// the character.
if (ch < 0x7F &&
ch != '_' && ch != '-' &&
(ch < '0' || '9' < ch) &&
(ch < 'A' || 'Z' < ch) &&
(ch < 'a' || 'z' < ch)) {
aReturn.Append(char16_t('\\'));
}
aReturn.Append(ch);
}
}
}
// unquoted family names must be a sequence of idents
// so escape any parts that require escaping
static void
AppendUnquotedFamilyName(const nsAString& aFamilyName, nsAString& aResult)
{
const char16_t *p, *p_end;
aFamilyName.BeginReading(p);
aFamilyName.EndReading(p_end);
bool moreThanOne = false;
while (p < p_end) {
const char16_t* identStart = p;
while (++p != p_end && *p != ' ')
/* nothing */ ;
nsDependentSubstring ident(identStart, p);
if (!ident.IsEmpty()) {
if (moreThanOne) {
aResult.Append(' ');
}
nsStyleUtil::AppendEscapedCSSIdent(ident, aResult);
moreThanOne = true;
}
++p;
}
}
/* static */ void
nsStyleUtil::AppendEscapedCSSFontFamilyList(
const nsTArray<mozilla::FontFamilyName>& aNames,
nsAString& aResult)
{
size_t i, len = aNames.Length();
for (i = 0; i < len; i++) {
if (i != 0) {
aResult.AppendLiteral(", ");
}
const FontFamilyName& name = aNames[i];
switch (name.mType) {
case eFamily_named:
AppendUnquotedFamilyName(name.mName, aResult);
break;
case eFamily_named_quoted:
AppendEscapedCSSString(name.mName, aResult);
break;
default:
name.AppendToString(aResult);
}
}
}
/* static */ void
nsStyleUtil::AppendEscapedCSSFontFamilyList(
const mozilla::FontFamilyList& aFamilyList,
nsAString& aResult)
{
if (aFamilyList.IsEmpty()) {
FontFamilyType defaultGeneric = aFamilyList.GetDefaultFontType();
// If the font list is empty, then serialize the default generic.
// See also: gfxFontGroup::BuildFontList()
if (defaultGeneric != eFamily_none) {
FontFamilyName(defaultGeneric).AppendToString(aResult);
} else {
NS_NOTREACHED("No fonts to serialize");
}
return;
}
AppendEscapedCSSFontFamilyList(aFamilyList.GetFontlist().get(), aResult);
}
/* static */ void
nsStyleUtil::AppendBitmaskCSSValue(nsCSSPropertyID aProperty,
int32_t aMaskedValue,
int32_t aFirstMask,
int32_t aLastMask,
nsAString& aResult)
{
for (int32_t mask = aFirstMask; mask <= aLastMask; mask <<= 1) {
if (mask & aMaskedValue) {
AppendASCIItoUTF16(nsCSSProps::LookupPropertyValue(aProperty, mask),
aResult);
aMaskedValue &= ~mask;
if (aMaskedValue) { // more left
aResult.Append(char16_t(' '));
}
}
}
MOZ_ASSERT(aMaskedValue == 0, "unexpected bit remaining in bitfield");
}
/* static */ void
nsStyleUtil::AppendAngleValue(const nsStyleCoord& aAngle, nsAString& aResult)
{
MOZ_ASSERT(aAngle.IsAngleValue(), "Should have angle value");
// Append number.
AppendCSSNumber(aAngle.GetAngleValue(), aResult);
// Append unit.
switch (aAngle.GetUnit()) {
case eStyleUnit_Degree: aResult.AppendLiteral("deg"); break;
case eStyleUnit_Grad: aResult.AppendLiteral("grad"); break;
case eStyleUnit_Radian: aResult.AppendLiteral("rad"); break;
case eStyleUnit_Turn: aResult.AppendLiteral("turn"); break;
default: NS_NOTREACHED("unrecognized angle unit");
}
}
/* static */ void
nsStyleUtil::AppendPaintOrderValue(uint8_t aValue,
nsAString& aResult)
{
static_assert
(NS_STYLE_PAINT_ORDER_BITWIDTH * NS_STYLE_PAINT_ORDER_LAST_VALUE <= 8,
"SVGStyleStruct::mPaintOrder and local variables not big enough");
if (aValue == NS_STYLE_PAINT_ORDER_NORMAL) {
aResult.AppendLiteral("normal");
return;
}
// Append the minimal value necessary for the given paint order.
static_assert(NS_STYLE_PAINT_ORDER_LAST_VALUE == 3,
"paint-order values added; check serialization");
// The following relies on the default order being the order of the
// constant values.
const uint8_t MASK = (1 << NS_STYLE_PAINT_ORDER_BITWIDTH) - 1;
uint32_t lastPositionToSerialize = 0;
for (uint32_t position = NS_STYLE_PAINT_ORDER_LAST_VALUE - 1;
position > 0;
position--) {
uint8_t component =
(aValue >> (position * NS_STYLE_PAINT_ORDER_BITWIDTH)) & MASK;
uint8_t earlierComponent =
(aValue >> ((position - 1) * NS_STYLE_PAINT_ORDER_BITWIDTH)) & MASK;
if (component < earlierComponent) {
lastPositionToSerialize = position - 1;
break;
}
}
for (uint32_t position = 0; position <= lastPositionToSerialize; position++) {
if (position > 0) {
aResult.Append(' ');
}
uint8_t component = aValue & MASK;
switch (component) {
case NS_STYLE_PAINT_ORDER_FILL:
aResult.AppendLiteral("fill");
break;
case NS_STYLE_PAINT_ORDER_STROKE:
aResult.AppendLiteral("stroke");
break;
case NS_STYLE_PAINT_ORDER_MARKERS:
aResult.AppendLiteral("markers");
break;
default:
NS_NOTREACHED("unexpected paint-order component value");
}
aValue >>= NS_STYLE_PAINT_ORDER_BITWIDTH;
}
}
/* static */ void
nsStyleUtil::AppendFontTagAsString(uint32_t aTag, nsAString& aResult)
{
// A font tag (for feature/variation settings) is a 4-char code interpreted
// as a bigendian 32-bit value and stored/processed as a uint32_t.
// To serialize it, we put the four bytes (which are all guaranteed to be
// printable ASCII values) into a string, starting from the high byte of the
// value, then append that to the result with CSS escaping and quotes.
nsAutoString tagStr;
for (int shiftAmount = 24; shiftAmount >= 0; shiftAmount -= 8) {
char c = (aTag >> shiftAmount) & 0xff;
MOZ_ASSERT(isascii(c) && isprint(c),
"parser should have restricted tag to printable ASCII chars");
tagStr.Append(c);
}
AppendEscapedCSSString(tagStr, aResult);
}
/* static */ void
nsStyleUtil::AppendFontFeatureSettings(const nsTArray<gfxFontFeature>& aFeatures,
nsAString& aResult)
{
for (uint32_t i = 0, numFeat = aFeatures.Length(); i < numFeat; i++) {
const gfxFontFeature& feat = aFeatures[i];
if (i != 0) {
aResult.AppendLiteral(", ");
}
AppendFontTagAsString(feat.mTag, aResult);
// omit value if it's 1, implied by default
if (feat.mValue != 1) {
aResult.Append(' ');
aResult.AppendInt(feat.mValue);
}
}
}
/* static */ void
nsStyleUtil::AppendFontFeatureSettings(const nsCSSValue& aSrc,
nsAString& aResult)
{
nsCSSUnit unit = aSrc.GetUnit();
if (unit == eCSSUnit_Normal) {
aResult.AppendLiteral("normal");
return;
}
NS_PRECONDITION(unit == eCSSUnit_PairList || unit == eCSSUnit_PairListDep,
"improper value unit for font-feature-settings:");
nsTArray<gfxFontFeature> featureSettings;
nsLayoutUtils::ComputeFontFeatures(aSrc.GetPairListValue(), featureSettings);
AppendFontFeatureSettings(featureSettings, aResult);
}
/* static */ void
nsStyleUtil::AppendFontVariationSettings(const nsTArray<gfxFontVariation>& aVariations,
nsAString& aResult)
{
for (uint32_t i = 0, numVars = aVariations.Length(); i < numVars; i++) {
const gfxFontVariation& var = aVariations[i];
if (i != 0) {
aResult.AppendLiteral(", ");
}
// output tag
AppendFontTagAsString(var.mTag, aResult);
// output value
aResult.Append(' ');
aResult.AppendFloat(var.mValue);
}
}
/* static */ void
nsStyleUtil::AppendFontVariationSettings(const nsCSSValue& aSrc,
nsAString& aResult)
{
nsCSSUnit unit = aSrc.GetUnit();
if (unit == eCSSUnit_Normal) {
aResult.AppendLiteral("normal");
return;
}
NS_PRECONDITION(unit == eCSSUnit_PairList || unit == eCSSUnit_PairListDep,
"improper value unit for font-variation-settings:");
nsTArray<gfxFontVariation> variationSettings;
nsLayoutUtils::ComputeFontVariations(aSrc.GetPairListValue(),
variationSettings);
AppendFontVariationSettings(variationSettings, aResult);
}
/* static */ void
nsStyleUtil::GetFunctionalAlternatesName(int32_t aFeature,
nsAString& aFeatureName)
{
aFeatureName.Truncate();
nsCSSKeyword key =
nsCSSProps::ValueToKeywordEnum(aFeature,
nsCSSProps::kFontVariantAlternatesFuncsKTable);
NS_ASSERTION(key != eCSSKeyword_UNKNOWN, "bad alternate feature type");
AppendUTF8toUTF16(nsCSSKeywords::GetStringValue(key), aFeatureName);
}
/* static */ void
nsStyleUtil::SerializeFunctionalAlternates(
const nsTArray<gfxAlternateValue>& aAlternates,
nsAString& aResult)
{
nsAutoString funcName, funcParams;
uint32_t numValues = aAlternates.Length();
uint32_t feature = 0;
for (uint32_t i = 0; i < numValues; i++) {
const gfxAlternateValue& v = aAlternates.ElementAt(i);
if (feature != v.alternate) {
feature = v.alternate;
if (!funcName.IsEmpty() && !funcParams.IsEmpty()) {
if (!aResult.IsEmpty()) {
aResult.Append(char16_t(' '));
}
// append the previous functional value
aResult.Append(funcName);
aResult.Append(char16_t('('));
aResult.Append(funcParams);
aResult.Append(char16_t(')'));
}
// function name
GetFunctionalAlternatesName(v.alternate, funcName);
NS_ASSERTION(!funcName.IsEmpty(), "unknown property value name");
// function params
funcParams.Truncate();
AppendEscapedCSSIdent(v.value, funcParams);
} else {
if (!funcParams.IsEmpty()) {
funcParams.AppendLiteral(", ");
}
AppendEscapedCSSIdent(v.value, funcParams);
}
}
// append the previous functional value
if (!funcName.IsEmpty() && !funcParams.IsEmpty()) {
if (!aResult.IsEmpty()) {
aResult.Append(char16_t(' '));
}
aResult.Append(funcName);
aResult.Append(char16_t('('));
aResult.Append(funcParams);
aResult.Append(char16_t(')'));
}
}
/* static */ void
nsStyleUtil::ComputeFunctionalAlternates(const nsCSSValueList* aList,
nsTArray<gfxAlternateValue>& aAlternateValues)
{
gfxAlternateValue v;
aAlternateValues.Clear();
for (const nsCSSValueList* curr = aList; curr != nullptr; curr = curr->mNext) {
// list contains function units
if (curr->mValue.GetUnit() != eCSSUnit_Function) {
continue;
}
// element 0 is the propval in ident form
const nsCSSValue::Array *func = curr->mValue.GetArrayValue();
// lookup propval
nsCSSKeyword key = func->Item(0).GetKeywordValue();
NS_ASSERTION(key != eCSSKeyword_UNKNOWN, "unknown alternate property value");
int32_t alternate;
if (!nsCSSProps::FindKeyword(key,
nsCSSProps::kFontVariantAlternatesFuncsKTable,
alternate)) {
NS_NOTREACHED("keyword not a font-variant-alternates value");
continue;
}
v.alternate = alternate;
// other elements are the idents associated with the propval
// append one alternate value for each one
uint32_t numElems = func->Count();
for (uint32_t i = 1; i < numElems; i++) {
const nsCSSValue& value = func->Item(i);
NS_ASSERTION(value.GetUnit() == eCSSUnit_Ident,
"weird unit found in variant alternate");
if (value.GetUnit() != eCSSUnit_Ident) {
continue;
}
value.GetStringValue(v.value);
aAlternateValues.AppendElement(v);
}
}
}
static void
AppendSerializedUnicodePoint(uint32_t aCode, nsACString& aBuf)
{
aBuf.Append(nsPrintfCString("%0X", aCode));
}
// A unicode-range: descriptor is represented as an array of integers,
// to be interpreted as a sequence of pairs: min max min max ...
// It is in source order. (Possibly it should be sorted and overlaps
// consolidated, but right now we don't do that.)
/* static */ void
nsStyleUtil::AppendUnicodeRange(const nsCSSValue& aValue, nsAString& aResult)
{
NS_PRECONDITION(aValue.GetUnit() == eCSSUnit_Null ||
aValue.GetUnit() == eCSSUnit_Array,
"improper value unit for unicode-range:");
aResult.Truncate();
if (aValue.GetUnit() != eCSSUnit_Array)
return;
nsCSSValue::Array const & sources = *aValue.GetArrayValue();
nsAutoCString buf;
MOZ_ASSERT(sources.Count() % 2 == 0,
"odd number of entries in a unicode-range: array");
for (uint32_t i = 0; i < sources.Count(); i += 2) {
uint32_t min = sources[i].GetIntValue();
uint32_t max = sources[i+1].GetIntValue();
// We don't try to replicate the U+XX?? notation.
buf.AppendLiteral("U+");
AppendSerializedUnicodePoint(min, buf);
if (min != max) {
buf.Append('-');
AppendSerializedUnicodePoint(max, buf);
}
buf.AppendLiteral(", ");
}
buf.Truncate(buf.Length() - 2); // remove the last comma-space
CopyASCIItoUTF16(buf, aResult);
}
/* static */ void
nsStyleUtil::AppendSerializedFontSrc(const nsCSSValue& aValue,
nsAString& aResult)
{
// A src: descriptor is represented as an array value; each entry in
// the array can be eCSSUnit_URL, eCSSUnit_Local_Font, or
// eCSSUnit_Font_Format. Blocks of eCSSUnit_Font_Format may appear
// only after one of the first two. (css3-fonts only contemplates
// annotating URLs with formats, but we handle the general case.)
NS_PRECONDITION(aValue.GetUnit() == eCSSUnit_Array,
"improper value unit for src:");
const nsCSSValue::Array& sources = *aValue.GetArrayValue();
size_t i = 0;
while (i < sources.Count()) {
nsAutoString formats;
if (sources[i].GetUnit() == eCSSUnit_URL) {
aResult.AppendLiteral("url(");
nsDependentCSubstring url(sources[i].GetURLStructValue()->GetString());
nsStyleUtil::AppendEscapedCSSString(NS_ConvertUTF8toUTF16(url), aResult);
aResult.Append(')');
} else if (sources[i].GetUnit() == eCSSUnit_Local_Font) {
aResult.AppendLiteral("local(");
nsDependentString local(sources[i].GetStringBufferValue());
nsStyleUtil::AppendEscapedCSSString(local, aResult);
aResult.Append(')');
} else {
NS_NOTREACHED("entry in src: descriptor with improper unit");
i++;
continue;
}
i++;
formats.Truncate();
while (i < sources.Count() &&
sources[i].GetUnit() == eCSSUnit_Font_Format) {
formats.Append('"');
formats.Append(sources[i].GetStringBufferValue());
formats.AppendLiteral("\", ");
i++;
}
if (formats.Length() > 0) {
formats.Truncate(formats.Length() - 2); // remove the last comma
aResult.AppendLiteral(" format(");
aResult.Append(formats);
aResult.Append(')');
}
aResult.AppendLiteral(", ");
}
aResult.Truncate(aResult.Length() - 2); // remove the last comma-space
}
/* static */ void
nsStyleUtil::AppendStepsTimingFunction(nsTimingFunction::Type aType,
uint32_t aSteps,
nsAString& aResult)
{
MOZ_ASSERT(aType == nsTimingFunction::Type::StepStart ||
aType == nsTimingFunction::Type::StepEnd);
aResult.AppendLiteral("steps(");
aResult.AppendInt(aSteps);
if (aType == nsTimingFunction::Type::StepStart) {
aResult.AppendLiteral(", start)");
} else {
aResult.AppendLiteral(")");
}
}
/* static */ void
nsStyleUtil::AppendFramesTimingFunction(uint32_t aFrames,
nsAString& aResult)
{
aResult.AppendLiteral("frames(");
aResult.AppendInt(aFrames);
aResult.AppendLiteral(")");
}
/* static */ void
nsStyleUtil::AppendCubicBezierTimingFunction(float aX1, float aY1,
float aX2, float aY2,
nsAString& aResult)
{
// set the value from the cubic-bezier control points
// (We could try to regenerate the keywords if we want.)
aResult.AppendLiteral("cubic-bezier(");
aResult.AppendFloat(aX1);
aResult.AppendLiteral(", ");
aResult.AppendFloat(aY1);
aResult.AppendLiteral(", ");
aResult.AppendFloat(aX2);
aResult.AppendLiteral(", ");
aResult.AppendFloat(aY2);
aResult.Append(')');
}
/* static */ void
nsStyleUtil::AppendCubicBezierKeywordTimingFunction(
nsTimingFunction::Type aType,
nsAString& aResult)
{
switch (aType) {
case nsTimingFunction::Type::Ease:
case nsTimingFunction::Type::Linear:
case nsTimingFunction::Type::EaseIn:
case nsTimingFunction::Type::EaseOut:
case nsTimingFunction::Type::EaseInOut: {
nsCSSKeyword keyword = nsCSSProps::ValueToKeywordEnum(
static_cast<int32_t>(aType),
nsCSSProps::kTransitionTimingFunctionKTable);
AppendASCIItoUTF16(nsCSSKeywords::GetStringValue(keyword),
aResult);
break;
}
default:
MOZ_ASSERT_UNREACHABLE("unexpected aType");
break;
}
}
/* static */ float
nsStyleUtil::ColorComponentToFloat(uint8_t aAlpha)
{
// Alpha values are expressed as decimals, so we should convert
// back, using as few decimal places as possible for
// round-tripping.
// First try two decimal places:
float rounded = NS_roundf(float(aAlpha) * 100.0f / 255.0f) / 100.0f;
if (FloatToColorComponent(rounded) != aAlpha) {
// Use three decimal places.
rounded = NS_roundf(float(aAlpha) * 1000.0f / 255.0f) / 1000.0f;
}
return rounded;
}
/* static */ bool
nsStyleUtil::IsSignificantChild(nsIContent* aChild,
bool aWhitespaceIsSignificant)
{
bool isText = aChild->IsText();
if (!isText && !aChild->IsNodeOfType(nsINode::eCOMMENT) &&
!aChild->IsNodeOfType(nsINode::ePROCESSING_INSTRUCTION)) {
return true;
}
return isText && aChild->TextLength() != 0 &&
(aWhitespaceIsSignificant ||
!aChild->TextIsOnlyWhitespace());
}
/* static */ bool
nsStyleUtil::ThreadSafeIsSignificantChild(const nsIContent* aChild,
bool aWhitespaceIsSignificant)
{
bool isText = aChild->IsText();
if (!isText && !aChild->IsNodeOfType(nsINode::eCOMMENT) &&
!aChild->IsNodeOfType(nsINode::ePROCESSING_INSTRUCTION)) {
return true;
}
return isText && aChild->TextLength() != 0 &&
(aWhitespaceIsSignificant ||
!aChild->ThreadSafeTextIsOnlyWhitespace());
}
// For a replaced element whose concrete object size is no larger than the
// element's content-box, this method checks whether the given
// "object-position" coordinate might cause overflow in its dimension.
static bool
ObjectPositionCoordMightCauseOverflow(const Position::Coord& aCoord)
{
// Any nonzero length in "object-position" can push us to overflow
// (particularly if our concrete object size is exactly the same size as the
// replaced element's content-box).
if (aCoord.mLength != 0) {
return true;
}
// Percentages are interpreted as a fraction of the extra space. So,
// percentages in the 0-100% range are safe, but values outside of that
// range could cause overflow.
if (aCoord.mHasPercent &&
(aCoord.mPercent < 0.0f || aCoord.mPercent > 1.0f)) {
return true;
}
return false;
}
/* static */ bool
nsStyleUtil::ObjectPropsMightCauseOverflow(const nsStylePosition* aStylePos)
{
auto objectFit = aStylePos->mObjectFit;
// "object-fit: cover" & "object-fit: none" can give us a render rect that's
// larger than our container element's content-box.
if (objectFit == NS_STYLE_OBJECT_FIT_COVER ||
objectFit == NS_STYLE_OBJECT_FIT_NONE) {
return true;
}
// (All other object-fit values produce a concrete object size that's no larger
// than the constraint region.)
// Check each of our "object-position" coords to see if it could cause
// overflow in its dimension:
const Position& objectPosistion = aStylePos->mObjectPosition;
if (ObjectPositionCoordMightCauseOverflow(objectPosistion.mXPosition) ||
ObjectPositionCoordMightCauseOverflow(objectPosistion.mYPosition)) {
return true;
}
return false;
}
/* static */ bool
nsStyleUtil::CSPAllowsInlineStyle(Element* aElement,
nsIPrincipal* aPrincipal,
nsIPrincipal* aTriggeringPrincipal,
nsIURI* aSourceURI,
uint32_t aLineNumber,
const nsAString& aStyleText,
nsresult* aRv)
{
nsresult rv;
if (aRv) {
*aRv = NS_OK;
}
MOZ_ASSERT(!aElement || aElement->NodeInfo()->NameAtom() == nsGkAtoms::style,
"aElement passed to CSPAllowsInlineStyle "
"for an element that is not <style>");
nsIPrincipal* principal = aPrincipal;
if (aTriggeringPrincipal &&
BasePrincipal::Cast(aTriggeringPrincipal)->OverridesCSP(aPrincipal)) {
principal = aTriggeringPrincipal;
}
nsCOMPtr<nsIContentSecurityPolicy> csp;
rv = principal->GetCsp(getter_AddRefs(csp));
if (NS_FAILED(rv)) {
if (aRv)
*aRv = rv;
return false;
}
if (!csp) {
// No CSP --> the style is allowed
return true;
}
// query the nonce
nsAutoString nonce;
if (aElement) {
aElement->GetAttr(kNameSpaceID_None, nsGkAtoms::nonce, nonce);
}
nsCOMPtr<nsISupportsString> styleText(do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID));
if (styleText) {
styleText->SetData(aStyleText);
}
bool allowInlineStyle = true;
rv = csp->GetAllowsInline(nsIContentPolicy::TYPE_STYLESHEET,
nonce,
false, // aParserCreated only applies to scripts
styleText, aLineNumber,
&allowInlineStyle);
NS_ENSURE_SUCCESS(rv, false);
return allowInlineStyle;
}
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