org.eclipse.mylyn.web.tasks/src/org/eclipse/mylyn/internal/web/tasks/WebImages.java

/*******************************************************************************
 * Copyright (c) 2004, 2008 Tasktop Technologies and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Tasktop Technologies - initial API and implementation
 *******************************************************************************/

package org.eclipse.mylyn.internal.web.tasks;

import java.net.MalformedURLException;
import java.net.URL;

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

/**
 * @author Mik Kersten
 */
public class WebImages {

	private static ImageRegistry imageRegistry;

	private static final String T_OBJ = "obj16"; //$NON-NLS-1$

	private static final URL baseURL = TasksWebPlugin.getDefault().getBundle().getEntry("/icons/"); //$NON-NLS-1$

	public static final ImageDescriptor OVERLAY_TASK_WEB = create(T_OBJ, "overlay-web.gif"); //$NON-NLS-1$

	public static ImageDescriptor create(String prefix, String name) {
		try {
			return ImageDescriptor.createFromURL(makeIconFileURL(prefix, name));
		} catch (MalformedURLException e) {
			return ImageDescriptor.getMissingImageDescriptor();
		}
	}

	private static URL makeIconFileURL(String prefix, String name) throws MalformedURLException {
		if (baseURL == null) {
			throw new MalformedURLException();
		}

		StringBuilder buffer = new StringBuilder(prefix);
		buffer.append('/');
		buffer.append(name);
		return new URL(baseURL, buffer.toString());
	}

	private static ImageRegistry getImageRegistry() {
		if (imageRegistry == null) {
			imageRegistry = new ImageRegistry();
		}

		return imageRegistry;
	}

	/**
	 * Lazily initializes image map.
	 */
	public static Image getImage(ImageDescriptor imageDescriptor) {
		ImageRegistry imageRegistry = getImageRegistry();

		Image image = imageRegistry.get("" + imageDescriptor.hashCode()); //$NON-NLS-1$
		if (image == null) {
			image = imageDescriptor.createImage();
			imageRegistry.put("" + imageDescriptor.hashCode(), image); //$NON-NLS-1$
		}
		return image;
	}

}