/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.axiom.om.impl.common;
import java.util.HashSet;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Set;
import org.apache.axiom.om.OMContainer;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMNamespace;
/**
* Iterator implementation used by {@link OMElement#getNamespacesInScope()}.
*/
public class NamespaceIterator implements Iterator {
private final Set/*<String>*/ seenPrefixes = new HashSet();
private OMElement element;
private Iterator declaredNamespaces;
private boolean hasNextCalled;
private OMNamespace next;
public NamespaceIterator(OMElement element) {
this.element = element;
}
public boolean hasNext() {
if (!hasNextCalled) {
while (true) {
if (declaredNamespaces == null) {
declaredNamespaces = element.getAllDeclaredNamespaces();
} else if (declaredNamespaces.hasNext()) {
OMNamespace namespace = (OMNamespace)declaredNamespaces.next();
// We only return a namespace declaration if it has not been overridden (i.e. if
// we have not seen another declaration with the same prefix yet) and if the namespace
// URI is not empty. The second part of the condition covers the case of namespace
// declarations such as xmlns="" (for which no OMNamespace object is returned, as
// described in the Javadoc of the getNamespacesInScope method) as well as undeclared
// prefixes (XML 1.1 only).
if (seenPrefixes.add(namespace.getPrefix()) && namespace.getNamespaceURI().length() > 0) {
next = namespace;
break;
}
} else {
declaredNamespaces = null;
OMContainer parent = element.getParent();
if (parent instanceof OMElement) {
element = (OMElement)parent;
} else {
next = null;
break;
}
}
}
hasNextCalled = true;
}
return next != null;
}
public Object next() {
if (hasNext()) {
OMNamespace result = next;
hasNextCalled = false;
next = null;
return result;
} else {
throw new NoSuchElementException();
}
}
// TODO: document that remove is not supported
public void remove() {
throw new UnsupportedOperationException();
}
}