imageloader.java

一个用于排队系统仿真的开源软件,有非常形象的图象仿真过程!

/**    
  * Copyright (C) 2006, Laboratorio di Valutazione delle Prestazioni - Politecnico di Milano

  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.

  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.

  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
  
package jmt.gui.common.resources;

import javax.swing.*;
import java.awt.*;
import java.util.HashMap;

/** Loads images to create icons.

 * @author Federico Granata
 * Date: 4-giu-2003
 * Time: 17.14.13

 * @author Bertoli Marco
 * added caching support (11-lug-2005)

 */
public class ImageLoader {
    // Used to cache already used icons (this speeds up a lot)
    protected static HashMap iconcache = new HashMap();

	/**  Loads the image from this directory, please put all images in the class
	 * package.
	 *
	 * @param imageName string containing the image name
	 * @return the icon  of the image
     *
     * Modified by Bertoli Marco to support caching
	 */
	public static ImageIcon loadImage(String imageName) {
		String internalName = imageName + ".gif";
        if (!iconcache.containsKey(internalName)) {
            java.net.URL imageURL = ImageLoader.class.getResource(internalName);
            
            if (imageURL == null) {
                return null;
            } else {
                ImageIcon tmp = new ImageIcon(imageURL);
                iconcache.put(internalName, tmp);
                return tmp;
            }
        }
        else
            return (ImageIcon)iconcache.get(internalName);
	}

    /**  Loads the image from this directory, please put all images in the class
     * package.
     *
     * @param imageName string containing the image name
     * @param size specific size for the image to be returned
     * @return the icon  of the image
     *
     */
    public static ImageIcon loadImage(String imageName, Dimension size){
        ImageIcon im = ImageLoader.loadImage(imageName);
        if(im != null) {
            Image scaled = im.getImage();
            scaled = scaled.getScaledInstance(size.width, size.height, Image.SCALE_SMOOTH);
            return new ImageIcon(scaled);
        }else return im;
    }

	/**  Loads the image from this directory, please put all images in the class
	 * package.
	 *
	 * @param imageName string containing the image name
	 * @return the image
	 */
	public static Image loadImageAwt(String imageName) {
		String internalName = imageName + ".gif";
		Image image = Toolkit.getDefaultToolkit().getImage(ImageLoader.class.getResource(internalName));
		if (image == null) {
			return null;
		} else {
			return image;
		}
	}
}