gecko-dev/layout/style/nsStyleUtil.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2012-05-21 15:12:37 +04:00
/* 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/. */
1998-07-23 22:04:24 +04:00
#include "nsStyleUtil.h"
#include "nsStyleConsts.h"
#include "nsIContent.h"
#include "nsCSSProps.h"
#include "nsRuleNode.h"
#include "nsROCSSPrimitiveValue.h"
#include "nsIContentPolicy.h"
#include "nsIContentSecurityPolicy.h"
#include "nsIURI.h"
#include "nsPrintfCString.h"
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;
}
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 && *in < 0xA0)) {
// Escape U+0000 through U+001F and U+007F through U+009F numerically.
aReturn.AppendPrintf("\\%hX ", *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 */ bool
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 true;
// 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 true;
}
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("\\%hX ", *in);
++in;
}
for (; in != end; ++in) {
char16_t ch = *in;
if (ch == 0x00) {
return false;
}
if (ch < 0x20 || (0x7F <= ch && ch < 0xA0)) {
// Escape U+0000 through U+001F and U+007F through U+009F numerically.
aReturn.AppendPrintf("\\%hX ", *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);
}
}
return true;
}
// 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 mozilla::FontFamilyList& aFamilyList,
nsAString& aResult)
{
const nsTArray<FontFamilyName>& fontlist = aFamilyList.GetFontlist();
size_t i, len = fontlist.Length();
for (i = 0; i < len; i++) {
if (i != 0) {
aResult.Append(',');
}
const FontFamilyName& name = fontlist[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::AppendBitmaskCSSValue(nsCSSProperty 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(' '));
}
}
}
NS_ABORT_IF_FALSE(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)
{
Bug 895322 - Part 1: Replace the usages of MOZ_STATIC_ASSERT with C++11 static_assert; r=Waldo This patch was mostly generated by running the following scripts on the codebase, with some manual changes made afterwards: # static_assert.sh #!/bin/bash # Command to convert an NSPR integer type to the equivalent standard integer type function convert() { echo "Converting $1 to $2..." find . ! -wholename "*nsprpub*" \ ! -wholename "*security/nss*" \ ! -wholename "*/.hg*" \ ! -wholename "obj-ff-dbg*" \ ! -name nsXPCOMCID.h \ ! -name prtypes.h \ -type f \ \( -iname "*.cpp" \ -o -iname "*.h" \ -o -iname "*.cc" \ -o -iname "*.mm" \) | \ xargs -n 1 `dirname $0`/assert_replacer.py #sed -i -e "s/\b$1\b/$2/g" } convert MOZ_STATIC_ASSERT static_assert hg rev --no-backup mfbt/Assertions.h \ media/webrtc/signaling/src/sipcc/core/includes/ccapi.h \ modules/libmar/src/mar_private.h \ modules/libmar/src/mar.h # assert_replacer.py #!/usr/bin/python import sys import re pattern = re.compile(r"\bMOZ_STATIC_ASSERT\b") def replaceInPlace(fname): print fname f = open(fname, "rw+") lines = f.readlines() for i in range(0, len(lines)): while True: index = re.search(pattern, lines[i]) if index != None: index = index.start() lines[i] = lines[i][0:index] + "static_assert" + lines[i][index+len("MOZ_STATIC_ASSERT"):] for j in range(i + 1, len(lines)): if lines[j].find(" ", index) == index: lines[j] = lines[j][0:index] + lines[j][index+4:] else: break else: break f.seek(0, 0) f.truncate() f.write("".join(lines)) f.close() argc = len(sys.argv) for i in range(1, argc): replaceInPlace(sys.argv[i]) --HG-- extra : rebase_source : 4b4a4047d82f2c205b9fad8d56dfc3f1afc0b045
2013-07-18 21:59:53 +04:00
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.
Bug 895322 - Part 1: Replace the usages of MOZ_STATIC_ASSERT with C++11 static_assert; r=Waldo This patch was mostly generated by running the following scripts on the codebase, with some manual changes made afterwards: # static_assert.sh #!/bin/bash # Command to convert an NSPR integer type to the equivalent standard integer type function convert() { echo "Converting $1 to $2..." find . ! -wholename "*nsprpub*" \ ! -wholename "*security/nss*" \ ! -wholename "*/.hg*" \ ! -wholename "obj-ff-dbg*" \ ! -name nsXPCOMCID.h \ ! -name prtypes.h \ -type f \ \( -iname "*.cpp" \ -o -iname "*.h" \ -o -iname "*.cc" \ -o -iname "*.mm" \) | \ xargs -n 1 `dirname $0`/assert_replacer.py #sed -i -e "s/\b$1\b/$2/g" } convert MOZ_STATIC_ASSERT static_assert hg rev --no-backup mfbt/Assertions.h \ media/webrtc/signaling/src/sipcc/core/includes/ccapi.h \ modules/libmar/src/mar_private.h \ modules/libmar/src/mar.h # assert_replacer.py #!/usr/bin/python import sys import re pattern = re.compile(r"\bMOZ_STATIC_ASSERT\b") def replaceInPlace(fname): print fname f = open(fname, "rw+") lines = f.readlines() for i in range(0, len(lines)): while True: index = re.search(pattern, lines[i]) if index != None: index = index.start() lines[i] = lines[i][0:index] + "static_assert" + lines[i][index+len("MOZ_STATIC_ASSERT"):] for j in range(i + 1, len(lines)): if lines[j].find(" ", index) == index: lines[j] = lines[j][0:index] + lines[j][index+4:] else: break else: break f.seek(0, 0) f.truncate() f.write("".join(lines)) f.close() argc = len(sys.argv) for i in range(1, argc): replaceInPlace(sys.argv[i]) --HG-- extra : rebase_source : 4b4a4047d82f2c205b9fad8d56dfc3f1afc0b045
2013-07-18 21:59:53 +04:00
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::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(", ");
}
// output tag
char tag[7];
tag[0] = '"';
tag[1] = (feat.mTag >> 24) & 0xff;
tag[2] = (feat.mTag >> 16) & 0xff;
tag[3] = (feat.mTag >> 8) & 0xff;
tag[4] = feat.mTag & 0xff;
tag[5] = '"';
tag[6] = 0;
aResult.AppendASCII(tag);
// output value, if necessary
if (feat.mValue == 0) {
// 0 ==> off
aResult.AppendLiteral(" off");
} else if (feat.mValue > 1) {
aResult.Append(' ');
aResult.AppendInt(feat.mValue);
}
// else, omit value if 1, implied by default
}
}
/* 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;
nsRuleNode::ComputeFontFeatures(aSrc.GetPairListValue(), featureSettings);
AppendFontFeatureSettings(featureSettings, 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 (key == eCSSKeyword_UNKNOWN ||
!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);
}
}
}
// print all characters with at least four hex digits
static void
AppendSerializedUnicodePoint(uint32_t aCode, nsACString& aBuf)
{
aBuf.Append(nsPrintfCString("%04X", 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;
NS_ABORT_IF_FALSE(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(");
nsDependentString url(sources[i].GetOriginalURLValue());
nsStyleUtil::AppendEscapedCSSString(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 */ 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 aTextIsSignificant,
bool aWhitespaceIsSignificant)
{
NS_ASSERTION(!aWhitespaceIsSignificant || aTextIsSignificant,
"Nonsensical arguments");
bool isText = aChild->IsNodeOfType(nsINode::eTEXT);
if (!isText && !aChild->IsNodeOfType(nsINode::eCOMMENT) &&
!aChild->IsNodeOfType(nsINode::ePROCESSING_INSTRUCTION)) {
return true;
}
return aTextIsSignificant && isText && aChild->TextLength() != 0 &&
(aWhitespaceIsSignificant ||
!aChild->TextIsOnlyWhitespace());
}
/* static */ bool
nsStyleUtil::IsFlexBasisMainSize(const nsStyleCoord& aFlexBasis,
bool aIsMainAxisHorizontal)
{
// "main-size" is stored as an enumerated value; so if we're not enumerated,
// we're not "main-size".
if (aFlexBasis.GetUnit() != eStyleUnit_Enumerated) {
return false;
}
if (!aIsMainAxisHorizontal) {
// Special case for vertical flex items: We don't support any enumerated
// values (e.g. "-moz-max-content") for "height"-flavored properties
// yet. So, if our computed flex-basis is *any* enumerated value, we'll
// just behave as if it were "main-size" (the initial value of flex-basis).
// NOTE: Once we support intrinsic sizing keywords for "height",
// we can remove this special-case.
return true;
}
return aFlexBasis.GetIntValue() == NS_STYLE_FLEX_BASIS_MAIN_SIZE;
}
/* static */ bool
nsStyleUtil::CSPAllowsInlineStyle(nsIContent* aContent,
nsIPrincipal* aPrincipal,
nsIURI* aSourceURI,
uint32_t aLineNumber,
const nsSubstring& aStyleText,
nsresult* aRv)
{
nsresult rv;
if (aRv) {
*aRv = NS_OK;
}
MOZ_ASSERT(!aContent || aContent->Tag() == nsGkAtoms::style,
"aContent passed to CSPAllowsInlineStyle "
"for an element that is not <style>");
nsCOMPtr<nsIContentSecurityPolicy> csp;
rv = aPrincipal->GetCsp(getter_AddRefs(csp));
if (NS_FAILED(rv)) {
if (aRv)
*aRv = rv;
return false;
}
if (!csp) {
// No CSP --> the style is allowed
return true;
}
// An inline style can be allowed because all inline styles are allowed,
// or else because it is whitelisted by a nonce-source or hash-source. This
// is a logical OR between whitelisting methods, so the allowInlineStyle
// outparam can be reused for each check as long as we stop checking as soon
// as it is set to true. This also optimizes performance by avoiding the
// overhead of unnecessary checks.
bool allowInlineStyle = true;
nsAutoTArray<unsigned short, 3> violations;
bool reportInlineViolation;
rv = csp->GetAllowsInlineStyle(&reportInlineViolation, &allowInlineStyle);
if (NS_FAILED(rv)) {
if (aRv)
*aRv = rv;
return false;
}
if (reportInlineViolation) {
violations.AppendElement(static_cast<unsigned short>(
nsIContentSecurityPolicy::VIOLATION_TYPE_INLINE_STYLE));
}
nsAutoString nonce;
if (!allowInlineStyle) {
// We can only find a nonce if aContent is provided
bool foundNonce = !!aContent &&
aContent->GetAttr(kNameSpaceID_None, nsGkAtoms::nonce, nonce);
if (foundNonce) {
bool reportNonceViolation;
rv = csp->GetAllowsNonce(nonce, nsIContentPolicy::TYPE_STYLESHEET,
&reportNonceViolation, &allowInlineStyle);
if (NS_FAILED(rv)) {
if (aRv)
*aRv = rv;
return false;
}
if (reportNonceViolation) {
violations.AppendElement(static_cast<unsigned short>(
nsIContentSecurityPolicy::VIOLATION_TYPE_NONCE_STYLE));
}
}
}
if (!allowInlineStyle) {
bool reportHashViolation;
rv = csp->GetAllowsHash(aStyleText, nsIContentPolicy::TYPE_STYLESHEET,
&reportHashViolation, &allowInlineStyle);
if (NS_FAILED(rv)) {
if (aRv)
*aRv = rv;
return false;
}
if (reportHashViolation) {
violations.AppendElement(static_cast<unsigned short>(
nsIContentSecurityPolicy::VIOLATION_TYPE_HASH_STYLE));
}
}
// What violation(s) should be reported?
//
// 1. If the style tag has a nonce attribute, and the nonce does not match
// the policy, report VIOLATION_TYPE_NONCE_STYLE.
// 2. If the policy has at least one hash-source, and the hashed contents of
// the style tag did not match any of them, report VIOLATION_TYPE_HASH_STYLE
// 3. Otherwise, report VIOLATION_TYPE_INLINE_STYLE if appropriate.
//
// 1 and 2 may occur together, 3 should only occur by itself. Naturally,
// every VIOLATION_TYPE_NONCE_STYLE and VIOLATION_TYPE_HASH_STYLE are also
// VIOLATION_TYPE_INLINE_STYLE, but reporting the
// VIOLATION_TYPE_INLINE_STYLE is redundant and does not help the developer.
if (!violations.IsEmpty()) {
MOZ_ASSERT(violations[0] == nsIContentSecurityPolicy::VIOLATION_TYPE_INLINE_STYLE,
"How did we get any violations without an initial inline style violation?");
// This inline style is not allowed by CSP, so report the violation
nsAutoCString asciiSpec;
aSourceURI->GetAsciiSpec(asciiSpec);
nsAutoString styleSample(aStyleText);
// cap the length of the style sample at 40 chars.
if (styleSample.Length() > 40) {
styleSample.Truncate(40);
styleSample.AppendLiteral("...");
}
for (uint32_t i = 0; i < violations.Length(); i++) {
// Skip reporting the redundant inline style violation if there are
// other (nonce and/or hash violations) as well.
if (i > 0 || violations.Length() == 1) {
csp->LogViolationDetails(violations[i], NS_ConvertUTF8toUTF16(asciiSpec),
styleSample, aLineNumber, nonce, aStyleText);
}
}
}
if (!allowInlineStyle) {
NS_ASSERTION(!violations.IsEmpty(),
"CSP blocked inline style but is not reporting a violation");
// The inline style should be blocked.
return false;
}
// CSP allows inline styles.
return true;
}