OLD | NEW |
(Empty) | |
| 1 // Copyright 2014 The Chromium Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. |
| 4 |
| 5 #include "config.h" |
| 6 #include "SizesAttributeParser.h" |
| 7 |
| 8 #include "MediaTypeNames.h" |
| 9 #include "core/css/MediaQueryEvaluator.h" |
| 10 #include "core/css/parser/MediaQueryTokenizer.h" |
| 11 |
| 12 namespace WebCore { |
| 13 |
| 14 unsigned SizesAttributeParser::findEffectiveSize(const String& attribute, PassRe
fPtr<MediaValues> mediaValues) |
| 15 { |
| 16 Vector<MediaQueryToken> tokens; |
| 17 SizesAttributeParser parser(mediaValues); |
| 18 |
| 19 MediaQueryTokenizer::tokenize(attribute, tokens); |
| 20 if (!parser.parse(tokens)) |
| 21 return parser.effectiveSizeDefaultValue(); |
| 22 return parser.effectiveSize(); |
| 23 } |
| 24 |
| 25 bool SizesAttributeParser::calculateLengthInPixels(TokenIterator startToken, Tok
enIterator endToken, unsigned& result) |
| 26 { |
| 27 MediaQueryTokenType type = startToken->type(); |
| 28 if (type == DimensionToken) { |
| 29 int length; |
| 30 if (!CSSPrimitiveValue::isLength(startToken->unitType())) |
| 31 return false; |
| 32 if (m_mediaValues->computeLength(startToken->numericValue(), startToken-
>unitType(), length)) { |
| 33 if (length > 0) { |
| 34 result = (unsigned)length; |
| 35 return true; |
| 36 } |
| 37 } |
| 38 } |
| 39 if (type == FunctionToken) { |
| 40 // FIXME - Handle calc() functions here! |
| 41 } |
| 42 return false; |
| 43 } |
| 44 |
| 45 static void reverseSkipIrrelevantTokens(TokenIterator& token, TokenIterator star
tToken) |
| 46 { |
| 47 TokenIterator endToken = token; |
| 48 while (token != startToken && (token->type() == WhitespaceToken || token->ty
pe() == CommentToken || token->type() == EOFToken)) |
| 49 --token; |
| 50 if (token != endToken) |
| 51 ++token; |
| 52 } |
| 53 |
| 54 static void reverseSkipUntilComponentStart(TokenIterator& token, TokenIterator s
tartToken) |
| 55 { |
| 56 if (token == startToken) |
| 57 return; |
| 58 --token; |
| 59 if (token->blockType() != MediaQueryToken::BlockEnd) |
| 60 return; |
| 61 unsigned blockLevel = 0; |
| 62 while (token != startToken) { |
| 63 if (token->blockType() == MediaQueryToken::BlockEnd) { |
| 64 ++blockLevel; |
| 65 } else if (token->blockType() == MediaQueryToken::BlockStart) { |
| 66 --blockLevel; |
| 67 if (!blockLevel) |
| 68 break; |
| 69 } |
| 70 |
| 71 --token; |
| 72 } |
| 73 } |
| 74 |
| 75 bool SizesAttributeParser::mediaConditionMatches(PassRefPtr<MediaQuerySet> media
Condition) |
| 76 { |
| 77 // FIXME: How do I handle non-screen media types here? |
| 78 MediaQueryEvaluator mediaQueryEvaluator(MediaTypeNames::screen, *m_mediaValu
es); |
| 79 return mediaQueryEvaluator.eval(mediaCondition.get()); |
| 80 } |
| 81 |
| 82 bool SizesAttributeParser::parseMediaConditionAndLength(TokenIterator startToken
, TokenIterator endToken) |
| 83 { |
| 84 TokenIterator lengthTokenStart; |
| 85 TokenIterator lengthTokenEnd; |
| 86 |
| 87 reverseSkipIrrelevantTokens(endToken, startToken); |
| 88 lengthTokenEnd = endToken; |
| 89 reverseSkipUntilComponentStart(endToken, startToken); |
| 90 lengthTokenStart = endToken; |
| 91 unsigned length; |
| 92 if (!calculateLengthInPixels(lengthTokenStart, lengthTokenEnd, length)) |
| 93 return false; |
| 94 RefPtr<MediaQuerySet> mediaCondition = MediaQueryParser::parseMediaCondition
(startToken, endToken); |
| 95 if (mediaCondition && mediaConditionMatches(mediaCondition)) { |
| 96 m_length = length; |
| 97 return true; |
| 98 } |
| 99 return false; |
| 100 } |
| 101 |
| 102 bool SizesAttributeParser::parse(Vector<MediaQueryToken>& tokens) |
| 103 { |
| 104 TokenIterator startToken = tokens.begin(); |
| 105 TokenIterator endToken; |
| 106 // Split on a comma token, and send the result tokens to be parsed as (media
-condition, length) pairs |
| 107 for (TokenIterator token = tokens.begin(); token != tokens.end(); ++token) { |
| 108 if (token->type() == CommaToken) { |
| 109 endToken = token; |
| 110 if (parseMediaConditionAndLength(startToken, endToken)) |
| 111 return true; |
| 112 startToken = token; |
| 113 ++startToken; |
| 114 } |
| 115 } |
| 116 endToken = tokens.end(); |
| 117 return parseMediaConditionAndLength(startToken, --endToken); |
| 118 } |
| 119 |
| 120 unsigned SizesAttributeParser::effectiveSize() |
| 121 { |
| 122 if (m_length) |
| 123 return m_length; |
| 124 return effectiveSizeDefaultValue(); |
| 125 } |
| 126 |
| 127 unsigned SizesAttributeParser::effectiveSizeDefaultValue() |
| 128 { |
| 129 // Returning the equivalent of "100%" |
| 130 return m_mediaValues->viewportWidth(); |
| 131 } |
| 132 |
| 133 } // namespace |
| 134 |
OLD | NEW |