/* CVS: $Id: ImageCache.java,v 1.3 2001/03/08 21:08:20 gvijf Exp $ */

package gui;

import java.util.*;
import java.net.URL;
import javax.swing.ImageIcon;

/**
 * A simpel image cache.
 * The cache is of unlimited size.
 */
public class ImageCache {

    /**
     * Create a new image cache.
     * @param path The path which should be prepended to every load operation,
     * this path must be "" or contain a '/' at the end.
     */
    public ImageCache(String path) {
        this.path = path;
        cache = new HashMap();
    }

    /**
     * Create a new image cache.
     */
    public ImageCache() {
        this("");
    }

    /**
     * Get the given image.
     * If the image was already in the cache the cached version is returned,
     * otherwise the image is loaded and returned.
     * If the image was not found, null is returned, also in subsequent tries.
     */
    public ImageIcon get(String imageName) {
        if(cache.containsKey(imageName))
            return (ImageIcon) cache.get(imageName);
        URL url = ClassLoader.getSystemResource(path + imageName);
        if(url == null) {
            cache.put(imageName, null);
            return null;
        }
        ImageIcon img = new ImageIcon(url);
        cache.put(imageName, img);
        return img;
    }

    /**
     * The path which should be prepended to every load operation.
     */
    private String path;

    /**
     * A hash of image names and image icons.
     */
    private Map cache;

}