/* See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* Esri Inc. 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 com.esri.gpt.framework.resource.adapters;
import com.esri.gpt.framework.resource.api.Resource;
import com.esri.gpt.framework.util.ReadOnlyIterator;
import java.util.Arrays;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.NoSuchElementException;
/**
* Flattes collection of resources.
*/
public class FlatResourcesAdapter implements Iterable<Resource> {
/** collection of resources */
private Iterable<? extends Resource> resources;
/**
* Creates instance of the adapter.
* @param resources collection of resources
*/
public FlatResourcesAdapter(Iterable<? extends Resource> resources) {
this.resources = resources;
}
/**
* Creates instance of the adapter.
* @param resource collection of resources
*/
public FlatResourcesAdapter(Resource resource) {
this(Arrays.asList(new Resource[]{resource}));
}
@Override
public Iterator<Resource> iterator() {
return new FlatResourcesIterator();
}
/**
* Flat resources iterator.
*/
private class FlatResourcesIterator extends ReadOnlyIterator<Resource> {
/** stack of iterators */
private LinkedList<Iterator<? extends Resource>> stack = new LinkedList<Iterator<? extends Resource>>();
{
Iterator<? extends Resource> iter = resources.iterator();
if (iter.hasNext()) {
stack.addLast(iter);
}
}
@Override
public boolean hasNext() {
if (stack.size()==0) return false;
if (stack.getLast().hasNext()) return true;
stack.removeLast();
return hasNext();
}
@Override
public Resource next() {
if (!hasNext()) {
throw new NoSuchElementException("No more resources.");
}
Resource resource = stack.getLast().next();
while (stack.size()>0 && !stack.getLast().hasNext()) {
stack.removeLast();
}
Iterator<Resource> iter = resource.getNodes().iterator();
if (iter.hasNext()) {
stack.addLast(iter);
}
return resource;
}
}
}