bool
HTMLImageElement::SourceElementMatches(nsIContent* aSourceNode)
{
MOZ_ASSERT(aSourceNode->IsHTMLElement(nsGkAtoms::source));
DebugOnly<Element *> parent(nsINode::GetParentElement());
MOZ_ASSERT(parent && parent->IsHTMLElement(nsGkAtoms::picture));
MOZ_ASSERT(IsPreviousSibling(aSourceNode, this));
MOZ_ASSERT(HTMLPictureElement::IsPictureEnabled());
// Check media and type
HTMLSourceElement *src = static_cast<HTMLSourceElement*>(aSourceNode);
if (!src->MatchesCurrentMedia()) {
return false;
}
nsAutoString type;
if (aSourceNode->GetAttr(kNameSpaceID_None, nsGkAtoms::type, type) &&
!SupportedPictureSourceType(type)) {
return false;
}
return true;
}
/* static */ bool
HTMLImageElement::SelectSourceForTagWithAttrs(nsIDocument *aDocument,
bool aIsSourceTag,
const nsAString& aSrcAttr,
const nsAString& aSrcsetAttr,
const nsAString& aSizesAttr,
const nsAString& aTypeAttr,
const nsAString& aMediaAttr,
nsAString& aResult)
{
MOZ_ASSERT(aIsSourceTag || (aTypeAttr.IsEmpty() && aMediaAttr.IsEmpty()),
"Passing type or media attrs makes no sense without aIsSourceTag");
MOZ_ASSERT(!aIsSourceTag || aSrcAttr.IsEmpty(),
"Passing aSrcAttr makes no sense with aIsSourceTag set");
bool pictureEnabled = HTMLPictureElement::IsPictureEnabled();
if (aIsSourceTag && !pictureEnabled) {
return false;
}
if (!IsSrcsetEnabled() || aSrcsetAttr.IsEmpty()) {
if (!aIsSourceTag) {
// For an <img> with no srcset, we would always select the src attr.
aResult.Assign(aSrcAttr);
return true;
}
// Otherwise, a <source> without srcset is never selected
return false;
}
// Would not consider source tags with unsupported media or type
if (aIsSourceTag &&
((!aMediaAttr.IsVoid() &&
!HTMLSourceElement::WouldMatchMediaForDocument(aMediaAttr, aDocument)) ||
(!aTypeAttr.IsVoid() &&
!SupportedPictureSourceType(aTypeAttr)))) {
return false;
}
// Using srcset or picture <source>, build a responsive selector for this tag.
RefPtr<ResponsiveImageSelector> sel =
new ResponsiveImageSelector(aDocument);
sel->SetCandidatesFromSourceSet(aSrcsetAttr);
if (pictureEnabled && !aSizesAttr.IsEmpty()) {
sel->SetSizesFromDescriptor(aSizesAttr);
}
if (!aIsSourceTag) {
sel->SetDefaultSource(aSrcAttr);
}
if (sel->GetSelectedImageURLSpec(aResult)) {
return true;
}
if (!aIsSourceTag) {
// <img> tag with no match would definitively load nothing.
aResult.Truncate();
return true;
}
// <source> tags with no match would leave source yet-undetermined.
return false;
}
bool
HTMLImageElement::TryCreateResponsiveSelector(nsIContent *aSourceNode,
const nsAString *aSrcset,
const nsAString *aSizes)
{
if (!IsSrcsetEnabled()) {
return false;
}
bool pictureEnabled = HTMLPictureElement::IsPictureEnabled();
// Skip if this is not a <source> with matching media query
bool isSourceTag = aSourceNode->IsHTMLElement(nsGkAtoms::source);
if (isSourceTag) {
DebugOnly<Element *> parent(nsINode::GetParentElement());
MOZ_ASSERT(parent && parent->IsHTMLElement(nsGkAtoms::picture));
MOZ_ASSERT(IsPreviousSibling(aSourceNode, this));
MOZ_ASSERT(pictureEnabled);
// Check media and type
HTMLSourceElement *src = static_cast<HTMLSourceElement*>(aSourceNode);
if (!src->MatchesCurrentMedia()) {
return false;
}
nsAutoString type;
if (aSourceNode->GetAttr(kNameSpaceID_None, nsGkAtoms::type, type) &&
!SupportedPictureSourceType(type)) {
return false;
}
} else if (aSourceNode->IsHTMLElement(nsGkAtoms::img)) {
// Otherwise this is the <img> tag itself
MOZ_ASSERT(aSourceNode == this);
}
// Skip if has no srcset or an empty srcset
nsString srcset;
if (aSrcset) {
srcset = *aSrcset;
} else if (!aSourceNode->GetAttr(kNameSpaceID_None, nsGkAtoms::srcset,
srcset)) {
return false;
}
if (srcset.IsEmpty()) {
return false;
}
// Try to parse
nsRefPtr<ResponsiveImageSelector> sel = new ResponsiveImageSelector(aSourceNode);
if (!sel->SetCandidatesFromSourceSet(srcset)) {
// No possible candidates, don't need to bother parsing sizes
return false;
}
if (pictureEnabled && aSizes) {
sel->SetSizesFromDescriptor(*aSizes);
} else if (pictureEnabled) {
nsAutoString sizes;
aSourceNode->GetAttr(kNameSpaceID_None, nsGkAtoms::sizes, sizes);
sel->SetSizesFromDescriptor(sizes);
}
// If this is the <img> tag, also pull in src as the default source
if (!isSourceTag) {
MOZ_ASSERT(aSourceNode == this);
nsAutoString src;
if (GetAttr(kNameSpaceID_None, nsGkAtoms::src, src) && !src.IsEmpty()) {
sel->SetDefaultSource(src);
}
}
mResponsiveSelector = sel;
return true;
}
