CSSVariableData.cpp [plain text]
#include "config.h"
#include "CSSVariableData.h"
#include "CSSCustomPropertyValue.h"
#include "CSSParserTokenRange.h"
#include <wtf/text/AtomicStringHash.h>
#include <wtf/text/StringBuilder.h>
#include <wtf/text/StringView.h>
namespace WebCore {
template<typename CharacterType> void CSSVariableData::updateTokens(const CSSParserTokenRange& range)
{
const CharacterType* currentOffset = m_backingString.characters<CharacterType>();
for (const CSSParserToken& token : range) {
if (token.hasStringBacking()) {
unsigned length = token.value().length();
StringView string(currentOffset, length);
m_tokens.append(token.copyWithUpdatedString(string));
currentOffset += length;
} else
m_tokens.append(token);
}
ASSERT(currentOffset == m_backingString.characters<CharacterType>() + m_backingString.length());
}
bool CSSVariableData::operator==(const CSSVariableData& other) const
{
return tokens() == other.tokens();
}
void CSSVariableData::consumeAndUpdateTokens(const CSSParserTokenRange& range)
{
StringBuilder stringBuilder;
CSSParserTokenRange localRange = range;
while (!localRange.atEnd()) {
CSSParserToken token = localRange.consume();
if (token.hasStringBacking())
stringBuilder.append(token.value());
}
m_backingString = stringBuilder.toString();
if (m_backingString.is8Bit())
updateTokens<LChar>(range);
else
updateTokens<UChar>(range);
}
CSSVariableData::CSSVariableData(const CSSParserTokenRange& range, bool needsVariableResolution)
: m_needsVariableResolution(needsVariableResolution)
{
ASSERT(!range.atEnd());
consumeAndUpdateTokens(range);
}
bool CSSVariableData::checkVariablesForCycles(const AtomicString& name, CustomPropertyValueMap& customProperties, HashSet<AtomicString>& seenProperties, HashSet<AtomicString>& invalidProperties) const
{
if (invalidProperties.contains(name))
return false;
HashSet<AtomicString> newSeenProperties = seenProperties;
newSeenProperties.add(name);
bool valid = checkVariablesForCyclesWithRange(m_tokens, customProperties, newSeenProperties, invalidProperties);
if (!valid)
invalidProperties.add(name);
return valid;
}
bool CSSVariableData::checkVariablesForCyclesWithRange(CSSParserTokenRange range, CustomPropertyValueMap& customProperties, HashSet<AtomicString>& seenProperties, HashSet<AtomicString>& invalidProperties) const
{
while (!range.atEnd()) {
if (range.peek().functionId() == CSSValueVar || range.peek().functionId() == CSSValueEnv) {
CSSParserTokenRange block = range.consumeBlock();
block.consumeWhitespace();
ASSERT(block.peek().type() == IdentToken);
AtomicString variableName = block.consumeIncludingWhitespace().value().toAtomicString();
ASSERT(block.atEnd() || block.peek().type() == CommaToken);
if (seenProperties.contains(variableName))
return false;
RefPtr<CSSCustomPropertyValue> value = customProperties.get(variableName);
if (value && value->containsVariables() && !value->checkVariablesForCycles(variableName, customProperties, seenProperties, invalidProperties))
return false;
if (range.peek().type() == CommaToken) {
range.consume();
return checkVariablesForCyclesWithRange(block, customProperties, seenProperties, invalidProperties);
}
} else
range.consume();
}
return true;
}
bool CSSVariableData::resolveVariableFallback(const CustomPropertyValueMap& customProperties, CSSParserTokenRange range, Vector<CSSParserToken>& result) const
{
if (range.atEnd())
return false;
ASSERT(range.peek().type() == CommaToken);
range.consume();
return resolveTokenRange(customProperties, range, result);
}
bool CSSVariableData::resolveVariableReference(const CustomPropertyValueMap& customProperties, CSSParserTokenRange range, Vector<CSSParserToken>& result) const
{
range.consumeWhitespace();
ASSERT(range.peek().type() == IdentToken);
AtomicString variableName = range.consumeIncludingWhitespace().value().toAtomicString();
ASSERT(range.atEnd() || (range.peek().type() == CommaToken));
RefPtr<CSSCustomPropertyValue> property = customProperties.get(variableName);
if (!property || !property->value())
return resolveVariableFallback(customProperties, range, result);
if (property->containsVariables()) {
RefPtr<CSSVariableData> resolvedData = property->value()->resolveVariableReferences(customProperties);
if (!resolvedData)
return false;
result.appendVector(resolvedData->tokens());
} else
result.appendVector(property->value()->tokens());
return true;
}
RefPtr<CSSVariableData> CSSVariableData::resolveVariableReferences(const CustomPropertyValueMap& customProperties) const
{
Vector<CSSParserToken> resolvedTokens;
CSSParserTokenRange range = m_tokens;
if (!resolveTokenRange(customProperties, range, resolvedTokens))
return nullptr;
return CSSVariableData::createResolved(resolvedTokens, *this);
}
bool CSSVariableData::resolveTokenRange(const CustomPropertyValueMap& customProperties, CSSParserTokenRange range, Vector<CSSParserToken>& result) const
{
bool success = true;
while (!range.atEnd()) {
if (range.peek().functionId() == CSSValueVar || range.peek().functionId() == CSSValueEnv)
success &= resolveVariableReference(customProperties, range.consumeBlock(), result);
else
result.append(range.consume());
}
return success;
}
}