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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 "CSSPrimitiveValue.h"
#include "CSSToLengthConversionData.h"
#include "CSSTokenizer.h"
#include "FontCascade.h"
#include "MediaList.h"
#include "MediaQueryEvaluator.h"
#include "MediaQueryParser.h"
#include "MediaQueryParserContext.h"
#include "RenderView.h"
#include "SizesCalcParser.h"
#include "StyleScope.h"
namespace WebCore {
float SizesAttributeParser::computeLength(double value, CSSPrimitiveValue::UnitType type, const Document& document)
{
auto* renderer = document.renderView();
if (!renderer)
return 0;
auto& style = renderer->style();
CSSToLengthConversionData conversionData(&style, &style, 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 acceptible 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 (type == CSSPrimitiveValue::CSS_EXS || type == CSSPrimitiveValue::CSS_CHS) {
RefPtr<FontSelector> fontSelector = style.fontCascade().fontSelector();
style.fontCascade().update(nullptr);
float result = CSSPrimitiveValue::computeNonCalcLengthDouble(conversionData, type, value);
style.fontCascade().update(fontSelector.get());
return result;
}
return clampTo<float>(CSSPrimitiveValue::computeNonCalcLengthDouble(conversionData, type, value));
}
SizesAttributeParser::SizesAttributeParser(const String& attribute, const Document& document)
: m_document(document)
, m_length(0)
, m_lengthWasSet(false)
{
m_isValid = parse(CSSTokenizer(attribute).tokenRange());
}
float SizesAttributeParser::length()
{
if (m_isValid)
return effectiveSize();
return effectiveSizeDefaultValue();
}
bool SizesAttributeParser::calculateLengthInPixels(CSSParserTokenRange range, float& result)
{
const CSSParserToken& startToken = range.peek();
CSSParserTokenType type = startToken.type();
if (type == DimensionToken) {
if (!CSSPrimitiveValue::isLength(startToken.unitType()))
return false;
result = computeLength(startToken.numericValue(), startToken.unitType(), m_document);
if (result >= 0)
return true;
} else if (type == FunctionToken) {
SizesCalcParser calcParser(range, m_document);
if (!calcParser.isValid())
return false;
result = calcParser.result();
return true;
} else if (type == NumberToken && !startToken.numericValue()) {
result = 0;
return true;
}
return false;
}
bool SizesAttributeParser::mediaConditionMatches(const MediaQuerySet& mediaCondition)
{
// A Media Condition cannot have a media type other than screen.
auto* renderer = m_document.renderView();
if (!renderer)
return false;
auto& style = renderer->style();
return MediaQueryEvaluator { "screen", m_document, &style }.evaluate(mediaCondition, const_cast<Style::Scope&>(m_document.styleScope()).resolverIfExists());
}
bool SizesAttributeParser::parse(CSSParserTokenRange range)
{
// Split on a comma token and parse the result tokens as (media-condition, length) pairs
while (!range.atEnd()) {
const CSSParserToken* mediaConditionStart = &range.peek();
// The length is the last component value before the comma which isn't whitespace or a comment
const CSSParserToken* lengthTokenStart = &range.peek();
const CSSParserToken* lengthTokenEnd = &range.peek();
while (!range.atEnd() && range.peek().type() != CommaToken) {
lengthTokenStart = &range.peek();
range.consumeComponentValue();
lengthTokenEnd = &range.peek();
range.consumeWhitespace();
}
range.consume();
float length;
if (!calculateLengthInPixels(range.makeSubRange(lengthTokenStart, lengthTokenEnd), length))
continue;
RefPtr<MediaQuerySet> mediaCondition = MediaQueryParser::parseMediaCondition(range.makeSubRange(mediaConditionStart, lengthTokenStart), MediaQueryParserContext(m_document));
if (!mediaCondition || !mediaConditionMatches(*mediaCondition))
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 = m_document.renderView();
if (!renderer)
return 0;
auto& style = renderer->style();
return clampTo<float>(CSSPrimitiveValue::computeNonCalcLengthDouble({ &style, &style, renderer }, CSSPrimitiveValue::CSS_VW, 100.0));
}
} // namespace WebCore