public String[] knownNamespaces() {
final PsiElement parentElement = getParent();
BidirectionalMap<String, String> map = initNamespaceMaps(parentElement);
Set<String> known = Collections.emptySet();
if (map != null) {
known = new HashSet<String>(map.values());
}
if (parentElement instanceof XmlTag) {
if (known.isEmpty()) return ((XmlTag) parentElement).knownNamespaces();
ContainerUtil.addAll(known, ((XmlTag) parentElement).knownNamespaces());
} else {
XmlExtension xmlExtension = XmlExtension.getExtensionByElement(this);
if (xmlExtension != null) {
final XmlFile xmlFile = xmlExtension.getContainingFile(this);
if (xmlFile != null) {
final XmlTag rootTag = xmlFile.getRootTag();
if (rootTag != null && rootTag != this) {
if (known.isEmpty()) return rootTag.knownNamespaces();
ContainerUtil.addAll(known, rootTag.knownNamespaces());
}
}
}
}
return ArrayUtil.toStringArray(known);
}
@Nullable
private PsiMetaOwner retrieveOwner(final XmlFile file, final String namespace) {
if (file == null) {
return namespace.equals(XmlUtil.getTargetSchemaNsFromTag(this)) ? this : null;
}
return file.getDocument();
}
@Nullable
private static XmlNSDescriptor getDtdDescriptor(@NotNull XmlFile containingFile) {
final XmlDocument document = containingFile.getDocument();
if (document == null) {
return null;
}
final String url = XmlUtil.getDtdUri(document);
if (url == null) {
return null;
}
return document.getDefaultNSDescriptor(url, true);
}