IconPool.java

/**
 * L2FProd.com Common Components 7.3 License.
 *
 * Copyright 2005-2007 L2FProd.com
 *
 * 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 com.l2fprod.common.swing;

import javax.swing.*;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;

/**
 * IconPool.<br>
 */
public class IconPool {

  private static IconPool iconPool = new IconPool();

  private Map pool;

  public IconPool() {
    pool = new HashMap();
  }

  public static IconPool shared() {
    return iconPool;
  }

  /**
   * Gets the icon denoted by url.
   * If url is relative, it is relative to the caller.
   *
   * @param url
   * @return an icon
   */
  public Icon get(String url) {
    StackTraceElement[] stacks = new Exception().getStackTrace();
    try {
      Class callerClazz = Class.forName(stacks[1].getClassName());
      return get(callerClazz.getResource(url));
    } catch (ClassNotFoundException e) {
      throw new RuntimeException(e);
    }
  }

  public synchronized Icon get(URL url) {
    if (url == null) {
      return null;
    }

    Icon icon = (Icon) pool.get(url.toString());
    if (icon == null) {
      icon = new ImageIcon(url);
      pool.put(url.toString(), icon);
    }
    return icon;
  }

  public synchronized void clear() {
    pool.clear();
  }

}