content: /*******************************************************************************
   * Copyright (c) 2000, 2007 IBM Corporation and others.
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *     IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.internal.ui.search;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.Set;
  
  import org.eclipse.ui.IWorkingSet;
  import org.eclipse.ui.PlatformUI;
  
  public class LRUWorkingSetsList {
  
  	private final ArrayList fLRUList;
  	private final int fSize;
  	private final  WorkingSetsComparator fComparator= new WorkingSetsComparator();
  	
  	public LRUWorkingSetsList(int size) {
  		fSize= size;
  		fLRUList= new ArrayList(size);
  	}
  	
  	public void add(IWorkingSet[] workingSets) {
  		removeDeletedWorkingSets();
  		IWorkingSet[] existingWorkingSets= find(fLRUList, workingSets);
  		if (existingWorkingSets != null)
  			fLRUList.remove(existingWorkingSets);
  		else if (fLRUList.size() == fSize)
  			fLRUList.remove(fSize - 1);
  		fLRUList.add(0, workingSets);
  
  	}
  	
  	public Iterator iterator() {
  		removeDeletedWorkingSets();
  		return fLRUList.iterator();	
  	}
  
  	public Iterator sortedIterator() {
  		removeDeletedWorkingSets();
  		ArrayList sortedList= new ArrayList(fLRUList);
  		Collections.sort(sortedList, fComparator);
  		return sortedList.iterator();	
  	}
  	
  	private void removeDeletedWorkingSets() {
  		Iterator iter= new ArrayList(fLRUList).iterator();
  		while (iter.hasNext()) {
  			IWorkingSet[] workingSets= (IWorkingSet[])iter.next();
  			for (int i= 0; i < workingSets.length; i++) {
  				if (PlatformUI.getWorkbench().getWorkingSetManager().getWorkingSet(workingSets[i].getName()) == null) {
  					fLRUList.remove(workingSets);
  					break;
  				}
  			}
  		}
  	}
  	
  	private IWorkingSet[] find(ArrayList list, IWorkingSet[] workingSets) {
  		Set workingSetList= new HashSet(Arrays.asList(workingSets));
  		Iterator iter= list.iterator();
  		while (iter.hasNext()) {
  			IWorkingSet[] lruWorkingSets= (IWorkingSet[])iter.next();
  			Set lruWorkingSetList= new HashSet(Arrays.asList(lruWorkingSets));
  			if (lruWorkingSetList.equals(workingSetList))
  				return lruWorkingSets;
  		}
  		return null;
  	}
  }
  