static void parseImageCandidatesFromSrcsetAttribute(const String& attribute, const CharType* attributeStart, unsigned length, Vector<ImageCandidate>& imageCandidates, Document* document)
{
const CharType* position = attributeStart;
const CharType* attributeEnd = position + length;
while (position < attributeEnd) {
// 4. Splitting loop: Collect a sequence of characters that are space characters or U+002C COMMA characters.
skipWhile<CharType, isHTMLSpaceOrComma<CharType>>(position, attributeEnd);
if (position == attributeEnd) {
// Contrary to spec language - descriptor parsing happens on each candidate, so when we reach the attributeEnd, we can exit.
break;
}
const CharType* imageURLStart = position;
// 6. Collect a sequence of characters that are not space characters, and let that be url.
skipUntil<CharType, isHTMLSpace<CharType>>(position, attributeEnd);
const CharType* imageURLEnd = position;
DescriptorParsingResult result;
// 8. If url ends with a U+002C COMMA character (,)
if (isComma(*(position - 1))) {
// Remove all trailing U+002C COMMA characters from url.
imageURLEnd = position - 1;
reverseSkipWhile<CharType, isComma>(imageURLEnd, imageURLStart);
++imageURLEnd;
// If url is empty, then jump to the step labeled splitting loop.
if (imageURLStart == imageURLEnd)
continue;
} else {
skipWhile<CharType, isHTMLSpace<CharType>>(position, attributeEnd);
Vector<DescriptorToken> descriptorTokens;
tokenizeDescriptors(attributeStart, position, attributeEnd, descriptorTokens);
// Contrary to spec language - descriptor parsing happens on each candidate.
// This is a black-box equivalent, to avoid storing descriptor lists for each candidate.
if (!parseDescriptors(attribute, descriptorTokens, result, document)) {
if (document) {
UseCounter::count(document, UseCounter::SrcsetDroppedCandidate);
if (document->frame())
document->frame()->console().addMessage(ConsoleMessage::create(OtherMessageSource, ErrorMessageLevel, String("Dropped srcset candidate ") + String(imageURLStart, imageURLEnd - imageURLStart)));
}
continue;
}
}
ASSERT(imageURLEnd > attributeStart);
unsigned imageURLStartingPosition = imageURLStart - attributeStart;
ASSERT(imageURLEnd > imageURLStart);
unsigned imageURLLength = imageURLEnd - imageURLStart;
imageCandidates.append(ImageCandidate(attribute, imageURLStartingPosition, imageURLLength, result, ImageCandidate::SrcsetOrigin));
// 11. Return to the step labeled splitting loop.
}
}
static Vector<ImageCandidate> parseImageCandidatesFromSrcsetAttribute(const CharType* attributeStart, unsigned length)
{
Vector<ImageCandidate> imageCandidates;
const CharType* attributeEnd = attributeStart + length;
for (const CharType* position = attributeStart; position < attributeEnd;) {
// 4. Splitting loop: Collect a sequence of characters that are space characters or U+002C COMMA characters.
skipWhile<CharType, isHTMLSpaceOrComma<CharType> >(position, attributeEnd);
if (position == attributeEnd) {
// Contrary to spec language - descriptor parsing happens on each candidate, so when we reach the attributeEnd, we can exit.
break;
}
const CharType* imageURLStart = position;
// 6. Collect a sequence of characters that are not space characters, and let that be url.
skipUntil<CharType, isHTMLSpace<CharType> >(position, attributeEnd);
const CharType* imageURLEnd = position;
DescriptorParsingResult result;
// 8. If url ends with a U+002C COMMA character (,)
if (isComma(*(position - 1))) {
// Remove all trailing U+002C COMMA characters from url.
imageURLEnd = position - 1;
reverseSkipWhile<CharType, isComma>(imageURLEnd, imageURLStart);
++imageURLEnd;
// If url is empty, then jump to the step labeled splitting loop.
if (imageURLStart == imageURLEnd)
continue;
} else {
// Advancing position here (contrary to spec) to avoid an useless extra state machine step.
// Filed a spec bug: https://github.com/ResponsiveImagesCG/picture-element/issues/189
++position;
Vector<StringView> descriptorTokens;
tokenizeDescriptors(position, attributeEnd, descriptorTokens);
// Contrary to spec language - descriptor parsing happens on each candidate.
// This is a black-box equivalent, to avoid storing descriptor lists for each candidate.
if (!parseDescriptors(descriptorTokens, result))
continue;
}
ASSERT(imageURLEnd > imageURLStart);
unsigned imageURLLength = imageURLEnd - imageURLStart;
imageCandidates.append(ImageCandidate(StringView(imageURLStart, imageURLLength), result, ImageCandidate::SrcsetOrigin));
// 11. Return to the step labeled splitting loop.
}
return imageCandidates;
}
