package ca.ubc.cs.spl.aspectPatterns.examples.flyweight.java;
/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This file is part of the design patterns project at UBC
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* either http://www.mozilla.org/MPL/ or http://aspectj.org/MPL/.
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is ca.ubc.cs.spl.aspectPatterns.
*
* For more details and the latest version of this code, please see:
* http://www.cs.ubc.ca/labs/spl/projects/aodps.html
*
* Contributor(s):
*/
import java.util.Hashtable;
/**
* Implements a <i>FlyweightFactory</i> that employs a creation-on-demand
* policy.
*
* @author Jan Hannemann
* @author Gregor Kiczales
* @version 1.1, 02/11/04
*
* @see PrintableFlyweight
*/
public class PrintableFlyweightFactory {
/**
* stores the existing flyweights by character they represent
*/
private Hashtable printables = new Hashtable();
/**
* Returns the flyweight representing the argument character.
* If the appropriate flyweight does not yet exist, it is created
* on demand.
*
* @param c the character for which the the flyweight is returned
* @return the <i>Flyweight</i> representing the argument character
*/
public PrintableFlyweight getPrintableFlyweight(char c) {
Character ch = new Character(c);
if (printables.containsKey(ch)) {
return (PrintableFlyweight) printables.get(ch);
} else {
PrintableFlyweight flyweight = null;
if (Character.isWhitespace(c)) {
flyweight = new WhitespaceFlyweight(c);
} else {
flyweight = new CharacterFlyweight(c);
}
printables.put(ch, flyweight);
return flyweight;
}
}
}