Index: Source/core/html/parser/HTMLSrcsetParser.cpp |
diff --git a/Source/core/html/parser/HTMLSrcsetParser.cpp b/Source/core/html/parser/HTMLSrcsetParser.cpp |
new file mode 100644 |
index 0000000000000000000000000000000000000000..71debbf0ddd9c528536dbf1dfeb7211543521b32 |
--- /dev/null |
+++ b/Source/core/html/parser/HTMLSrcsetParser.cpp |
@@ -0,0 +1,142 @@ |
+// Copyright 2013 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
abarth-chromium
2013/09/19 18:09:52
Same problem with the license block.
|
+ |
+#include "config.h" |
+#include "core/html/parser/HTMLSrcsetParser.h" |
+ |
+#include "core/html/parser/HTMLParserIdioms.h" |
+#include "core/platform/ParsingUtilities.h" |
+ |
+namespace WebCore { |
+ |
+static inline bool compareByScaleFactor(const ImageCandidate& first, const ImageCandidate& second) |
abarth-chromium
2013/09/19 18:09:52
The |static| and |inline| keywords are redundant h
|
+{ |
+ return first.scaleFactor() < second.scaleFactor(); |
+} |
+ |
+// http://www.whatwg.org/specs/web-apps/current-work/multipage/embedded-content-1.html#processing-the-image-candidates |
+template<typename CharType> |
+static void parseImageCandidatesFromSrcsetAttribute(const String& attribute, const CharType* attributeStart, unsigned length, Vector<ImageCandidate>& imageCandidates) |
+{ |
+ const CharType* position = attributeStart; |
+ const CharType* attributeEnd = position + length; |
+ |
+ while (position < attributeEnd) { |
+ float imgScaleFactor = 1.0; |
+ // 4. Splitting loop: Skip whitespace. |
+ skipWhile<CharType, isHTMLSpace<CharType> >(position, attributeEnd); |
+ if (position == attributeEnd) |
+ break; |
+ const CharType* imageURLStart = position; |
+ |
+ // If The current candidate is either totally empty or only contains space, skipping. |
+ if (*position == ',') { |
+ ++position; |
+ continue; |
+ } |
+ // 5. Collect a sequence of characters that are not space characters, and let that be url. |
+ ++position; |
+ skipWhile<CharType, isNotHTMLSpace<CharType> >(position, attributeEnd); |
abarth-chromium
2013/09/19 18:09:52
skipUntil<CharType, isHTMLSpaceOrComma<CharType> >
Yoav Weiss
2013/09/20 07:31:36
skipUntil<CharType, isHTMLSpace<CharType> >
The a
|
+ const CharType* imageURLEnd = position; |
+ |
+ if (position != attributeEnd && *(position - 1) == ',') { |
+ --imageURLEnd; |
+ } else { |
+ // 7. Collect a sequence of characters that are not "," (U+002C) characters, and let that be descriptors. |
+ skipWhile<CharType, isHTMLSpace<CharType> >(position, attributeEnd); |
+ const CharType* qualifierStart = position; |
+ if (position != attributeEnd && *position != ',') { |
+ // This part differs from the spec as the current implementation only supports pixel density descriptors for now. |
+ skipUntil<CharType, isHTMLSpaceOrComma<CharType> >(position, attributeEnd); |
+ const CharType* qualifierEnd = position; |
+ // Make sure there are no other descriptors |
+ skipWhile<CharType, isHTMLSpace<CharType> >(position, attributeEnd); |
+ // If the first non-html-space character after the scale modifier is not a comma, |
+ // the current candidate is an invalid input. |
+ if (position != attributeEnd && *position != ',') { |
+ skipUntil<CharType>(position, attributeEnd, ','); |
+ ++position; |
+ continue; |
+ } |
+ // If the current qualifier is not an 'x', the resource is ignored |
+ if (*(qualifierEnd - 1) != 'x') |
abarth-chromium
2013/09/19 18:09:52
How do we know qualifierEnd - 1 is a valid address
Yoav Weiss
2013/09/20 07:31:36
When going into the skipUntil at line 51, we know
abarth-chromium
2013/09/20 16:08:07
I think an ASSERT is probably enough.
|
+ continue; |
+ |
+ bool validScaleFactor = false; |
+ unsigned scaleFactorLengthWithoutUnit = qualifierEnd - qualifierStart - 1; |
+ imgScaleFactor = charactersToFloat(qualifierStart, scaleFactorLengthWithoutUnit, &validScaleFactor); |
+ |
+ if (!validScaleFactor) |
+ continue; |
+ } |
+ } |
+ |
+ imageCandidates.append(ImageCandidate(attribute, imageURLStart - attributeStart, imageURLEnd - imageURLStart, imgScaleFactor)); |
+ // 11. Return to the step labeled splitting loop. |
+ } |
+} |
+ |
+static void parseImageCandidatesFromSrcsetAttribute(const String& attribute, Vector<ImageCandidate>& imageCandidates) |
+{ |
+ if (attribute.is8Bit()) |
abarth-chromium
2013/09/19 18:09:52
What if attribute.isNull() ? Calling is8Bit() on
|
+ parseImageCandidatesFromSrcsetAttribute<LChar>(attribute, attribute.characters8(), attribute.length(), imageCandidates); |
+ else |
+ parseImageCandidatesFromSrcsetAttribute<UChar>(attribute, attribute.characters16(), attribute.length(), imageCandidates); |
+} |
+ |
+static ImageCandidate pickBestImageCandidate(float deviceScaleFactor, Vector<ImageCandidate>& imageCandidates) |
+{ |
+ std::stable_sort(imageCandidates.begin(), imageCandidates.end(), compareByScaleFactor); |
+ |
+ unsigned i; |
+ for (i = 0; i < imageCandidates.size() - 1; ++i) { |
+ if (imageCandidates[i].scaleFactor() >= deviceScaleFactor) |
+ break; |
+ } |
+ return imageCandidates[i]; |
abarth-chromium
2013/09/19 18:09:52
This will crash if imageCandidates is empty.
Rath
|
+} |
+ |
+ImageCandidate bestFitSourceForSrcsetAttribute(float deviceScaleFactor, const String& srcsetAttribute) |
+{ |
+ Vector<ImageCandidate> imageCandidates; |
+ |
+ parseImageCandidatesFromSrcsetAttribute(srcsetAttribute, imageCandidates); |
+ if (imageCandidates.isEmpty()) |
+ return ImageCandidate(); |
+ return pickBestImageCandidate(deviceScaleFactor, imageCandidates); |
+} |
+ |
+String bestFitSourceForImageAttributes(float deviceScaleFactor, const String& srcAttribute, const String& srcsetAttribute) |
+{ |
+ if (srcsetAttribute.isNull()) |
+ return srcAttribute; |
abarth-chromium
2013/09/19 18:09:52
Or just:
return String()
cbiesinger
2013/09/19 23:01:44
But that's not equivalent, right? If srcset is emp
abarth-chromium
2013/09/20 16:08:07
In this case, you're testing for isNull(). There'
abarth-chromium
2013/09/20 16:08:58
Oh, you're totally right. Please ignore me.
|
+ |
+ Vector<ImageCandidate> imageCandidates; |
+ |
+ parseImageCandidatesFromSrcsetAttribute(srcsetAttribute, imageCandidates); |
+ |
+ if (!srcAttribute.isEmpty()) |
+ imageCandidates.append(ImageCandidate(srcAttribute, 0, srcAttribute.length(), 1.0)); |
+ |
+ if (imageCandidates.isEmpty()) |
+ return String(); |
+ |
+ return pickBestImageCandidate(deviceScaleFactor, imageCandidates).toString(); |
+} |
+ |
+String bestFitSourceForImageAttributes(float deviceScaleFactor, const String& srcAttribute, ImageCandidate& srcsetImageCandidate) |
+{ |
+ if (srcsetImageCandidate.isEmpty()) |
+ return srcAttribute; |
+ |
+ Vector<ImageCandidate> imageCandidates; |
+ imageCandidates.append(srcsetImageCandidate); |
+ |
+ if (!srcAttribute.isEmpty()) |
+ imageCandidates.append(ImageCandidate(srcAttribute, 0, srcAttribute.length(), 1.0)); |
+ |
+ return pickBestImageCandidate(deviceScaleFactor, imageCandidates).toString(); |
+} |
+ |
+} |