Element* AccessibilitySVGElement::childElementWithMatchingLanguage(ChildrenType& children) const
{
String languageCode = language();
if (languageCode.isEmpty())
languageCode = defaultLanguage();
// The best match for a group of child SVG2 'title' or 'desc' elements may be the one
// which lacks a 'lang' attribute value. However, indexOfBestMatchingLanguageInList()
// currently bases its decision on non-empty strings. Furthermore, we cannot count on
// that child element having a given position. So we'll look for such an element while
// building the language list and save it as our fallback.
Element* fallback = nullptr;
Vector<String> childLanguageCodes;
Vector<Element*> elements;
for (auto& child : children) {
auto& lang = child.attributeWithoutSynchronization(SVGNames::langAttr);
childLanguageCodes.append(lang);
elements.append(&child);
// The current draft of the SVG2 spec states if there are multiple equally-valid
// matches, the first match should be used.
if (lang.isEmpty() && !fallback)
fallback = &child;
}
bool exactMatch;
size_t index = indexOfBestMatchingLanguageInList(languageCode, childLanguageCodes, exactMatch);
if (index < childLanguageCodes.size())
return elements[index];
return fallback;
}
static int textTrackLanguageSelectionScore(const TextTrack& track)
{
if (track.language().isEmpty())
return 0;
Vector<AtomicString> languages = userPreferredLanguages();
size_t languageMatchIndex = indexOfBestMatchingLanguageInList(track.language(), languages);
if (languageMatchIndex >= languages.size())
return 0;
return languages.size() - languageMatchIndex;
}
int CaptionUserPreferences::textTrackLanguageSelectionScore(TextTrack* track, const Vector<String>& preferredLanguages) const
{
if (track->language().isEmpty())
return 0;
size_t languageMatchIndex = indexOfBestMatchingLanguageInList(track->language(), preferredLanguages);
if (languageMatchIndex >= preferredLanguages.size())
return 0;
// Matching a track language is more important than matching track type, so this multiplier must be
// greater than the maximum value returned by textTrackSelectionScore.
return (preferredLanguages.size() - languageMatchIndex) * 10;
}
