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// Copyright 2014 The Chromium Authors. All rights reserved.
// Copyright (C) 2016 Apple Inc. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "config.h"
#include "SizesAttributeParser.h"
#include "CSSPrimitiveNumericUnits.h"
#include "CSSToLengthConversionData.h"
#include "CSSTokenizer.h"
#include "FontCascade.h"
#include "MediaQueryEvaluator.h"
#include "MediaQueryParser.h"
#include "MediaQueryParserContext.h"
#include "RenderView.h"
#include "SizesCalcParser.h"
#include "StyleLengthResolution.h"
#include "StyleScope.h"
namespace WebCore {
float SizesAttributeParser::computeLength(double value, CSS::LengthUnit unit, const Document& document)
{
auto* renderer = document.renderView();
if (!renderer)
return 0;
auto& style = renderer->style();
CSSToLengthConversionData conversionData(style, &style, renderer->parentStyle(), renderer);
// Because we evaluate "sizes" at parse time (before style has been resolved), the font metrics used for these specific units
// are not available. The font selector's internal consistency isn't guaranteed just yet, so we can just temporarily clear
// the pointer to it for the duration of the unit evaluation. This is acceptable because the style always comes from the
// RenderView, which has its font information hardcoded in resolveForDocument() to be -webkit-standard, whose operations
// don't require a font selector.
if (unit == CSS::LengthUnit::Ex || unit == CSS::LengthUnit::Cap || unit == CSS::LengthUnit::Ch || unit == CSS::LengthUnit::Ic) {
RefPtr<FontSelector> fontSelector = style.fontCascade().fontSelector();
style.fontCascade().update(nullptr);
float result = clampTo<float>(Style::computeNonCalcLengthDouble(value, unit, conversionData));
style.fontCascade().update(fontSelector.get());
return result;
}
return clampTo<float>(Style::computeNonCalcLengthDouble(value, unit, conversionData));
}
SizesAttributeParser::SizesAttributeParser(const String& attribute, const Document& document)
: m_document(document)
{
m_isValid = parse(CSSTokenizer(attribute).tokenRange(), CSSParserContext(document));
}
float SizesAttributeParser::length()
{
if (m_isValid)
return effectiveSize();
return effectiveSizeDefaultValue();
}
std::optional<float> SizesAttributeParser::calculateLengthInPixels(CSSParserTokenRange range)
{
const CSSParserToken& startToken = range.peek();
CSSParserTokenType type = startToken.type();
if (type == DimensionToken) {
auto lengthUnit = CSS::toLengthUnit(startToken.unitType());
if (!lengthUnit)
return std::nullopt;
float result = computeLength(startToken.numericValue(), *lengthUnit, protectedDocument());
if (result >= 0)
return result;
} else if (type == FunctionToken) {
SizesCalcParser calcParser(range, protectedDocument());
if (!calcParser.isValid())
return std::nullopt;
return calcParser.result();
} else if (type == NumberToken && !startToken.numericValue())
return 0;
return std::nullopt;
}
bool SizesAttributeParser::mediaConditionMatches(const MQ::MediaQuery& mediaCondition)
{
// A Media Condition cannot have a media type other than screen.
auto document = protectedDocument();
auto* renderer = document->renderView();
if (!renderer)
return false;
auto& style = renderer->style();
return MQ::MediaQueryEvaluator { screenAtom(), document, &style }.evaluate(mediaCondition);
}
bool SizesAttributeParser::parse(CSSParserTokenRange range, const CSSParserContext& context)
{
// Split on a comma token and parse the result tokens as (media-condition, length) pairs
while (!range.atEnd()) {
auto mediaConditionStart = range;
// The length is the last component value before the comma which isn't whitespace or a comment
auto lengthTokenStart = range;
auto lengthTokenEnd = range;
while (!range.atEnd() && range.peek().type() != CommaToken) {
lengthTokenStart = range;
range.consumeComponentValue();
lengthTokenEnd = range;
range.consumeWhitespace();
}
range.consume();
auto length = calculateLengthInPixels(lengthTokenStart.rangeUntil(lengthTokenEnd));
if (!length)
continue;
auto mediaCondition = MQ::MediaQueryParser::parseCondition(mediaConditionStart.rangeUntil(lengthTokenStart), MediaQueryParserContext(context));
if (!mediaCondition)
continue;
bool matches = mediaConditionMatches(*mediaCondition);
MQ::MediaQueryEvaluator evaluator { screenAtom() };
if (!evaluator.collectDynamicDependencies(*mediaCondition).isEmpty())
m_dynamicMediaQueryResults.append({ MQ::MediaQueryList { *mediaCondition }, matches });
if (!matches)
continue;
m_length = *length;
m_lengthWasSet = true;
return true;
}
return false;
}
float SizesAttributeParser::effectiveSize()
{
if (m_lengthWasSet)
return m_length;
return effectiveSizeDefaultValue();
}
unsigned SizesAttributeParser::effectiveSizeDefaultValue()
{
auto* renderer = protectedDocument()->renderView();
if (!renderer)
return 0;
auto& style = renderer->style();
return clampTo<float>(Style::computeNonCalcLengthDouble(100.0, CSS::LengthUnit::Vw, { style, &style, renderer->parentStyle(), renderer }));
}
Ref<const Document> SizesAttributeParser::protectedDocument() const
{
return m_document.get();
}
} // namespace WebCore
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