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/*===========================================================================
  Copyright (C) 2009 by the Okapi Framework contributors
-----------------------------------------------------------------------------
  Licensed 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 net.sf.okapi.common.ui;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.Properties;

/**
 * Provides a way to manage a list of most recently used files (MRU).
 */
public class MRUList {

	private LinkedList list;
	private int max;
	
	/**
	 * Creates a new MRUList object with a given maximum size.
	 * @param maxInList The maximum size.
	 */
	public MRUList (int maxInList) {
		if ( max < 2 ) max = 2;
		max = maxInList;
		list = new LinkedList();
	}
	
	/**
	 * Reads the list from a properties object.
	 * @param properties The properties to read from.
	 */
	public void getFromProperties (Properties properties) {
		list = new LinkedList();
		String tmp = properties.getProperty("mru.count");
		if ( tmp == null ) return;
		int count = Integer.valueOf(tmp);
		for ( int i=0; i();
	}

	/**
	 * Removes a given path from this MRU list. If the path does not
	 * exists in the list, nothing happens.
	 * @param path The path to remove.
	 */
	public void remove (String path) {
		list.remove(path);
	}
	
	/**
	 * Adds at the top of the list, pushes all the other path downward,
	 * and trim if the list gets larger than the maximum allowed.
	 * If the path exists already in the list, it is moved to the top.
	 * @param path The path to add.
	 */
	public void add (String path) {
		// Check if the path exists and if so, get its index
		int n = -1;
		for ( int i=0; i -1 ) {
			// In the list already
			if ( n == 0 ) return; // Already at the top
			// Else, remove it, so we can add it at the top
			list.remove(n);
		}
		// Add the path at the top
		list.addFirst(path);
		// Trim the list to the maximum allowed
		if ( list.size() > max ) {
			list.removeLast();
		}
	}
	
	/**
	 * Gets the first path in the list, or null if there is none.
	 * @return the first path in the list, or null if there is none.
	 */
	public String getfirst () {
		if ( list.size() > 0 ) return list.getFirst();
		else return null;
	}

	/**
	 * Gets an iterator for the paths in this MRU list.
	 * @return The iterator for the paths in this MRU list.
	 */
	public Iterator getIterator () {
		return list.iterator();
	}
	
}