imagecache.java

Python Development Environment (Python IDE plugin for Eclipse). Features editor, code completion, re

/*
 * Author: atotic
 * Created: Jul 29, 2003
 * License: Common Public License v1.0
 */
package org.python.pydev.core.bundle;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.graphics.Image;

/**
 * Caches images, releases all on dispose
 */
public class ImageCache {
	
	
	private Map<String, Image> imageHash = new HashMap<String, Image>(10);
	private URL baseURL; 
	private Image missing = null;
	
	public ImageCache(URL baseURL) {
		this.baseURL = baseURL;
	}
	
	
	protected ImageCache() {
    }


    public void dispose() {
		Iterator e = imageHash.values().iterator();
		while (e.hasNext())
			 ((Image) e.next()).dispose();
		if (missing != null) {
			missing.dispose();
		}
	}

	/**
	 * @param key - relative path to the plugin directory
	 * @return the image
	 */
	public Image get(String key) {
		Image image = (Image)imageHash.get(key);
		if (image == null) {
			ImageDescriptor desc;
			try {
				desc = getDescriptor(key);
				image = desc.createImage();
				imageHash.put(key, image);
			} catch (NoClassDefFoundError e) {
				//we're in tests...
				return null;
			} catch (UnsatisfiedLinkError e) {
				//we're in tests...
				return null;
			} catch (MalformedURLException e) {
				// If image is missing, create a default missing one
				System.err.println("ERROR: Missing image: " + key);
				if (missing == null) {
					desc =  ImageDescriptor.getMissingImageDescriptor();
					missing = desc.createImage();
				}
				image = missing;
			}			
		}
		return image;
	}

	/**
	 * like get, but returns ImageDescription instead of image
	 */
	public ImageDescriptor getDescriptor(String key) throws MalformedURLException {
		URL url = new URL(baseURL, key);
		return ImageDescriptor.createFromURL(url);
	}
}