LiveGraphUIImages.java

/*******************************************************************************
 * Copyright (c) 2016 Spring IDE Developers
 * 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:
 *     Spring IDE Developers - initial API and implementation
 *******************************************************************************/
package org.springframework.ide.eclipse.beans.ui.livegraph;

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

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

public class LiveGraphUIImages {

	private static final String ICON_PATH_PREFIX = "icons/full/";
	private static final String NAME_PREFIX = LiveGraphUiPlugin.PLUGIN_ID + '.';
	private static final int NAME_PREFIX_LENGTH = NAME_PREFIX.length();

	/* Declare Common paths */
	private static URL ICON_BASE_URL = null;

	static {
		try {
			ICON_BASE_URL = new URL(LiveGraphUiPlugin.getDefault().getBundle()
					.getEntry("/"), ICON_PATH_PREFIX);
		} catch (MalformedURLException e) {
			LiveGraphUiPlugin.log(e);
		}
	}
	
	/** A table of all the <code>ImageDescriptor</code>s. */
	private static Map<String, ImageDescriptor> imageDescriptors;

	/*
	 * Available cached Images in the Spring Beans UI plugin image registry.
	 */
	public static final String IMG_OBJS_BEAN = NAME_PREFIX + "bean_obj.gif";
	public static final String IMG_OBJS_BEAN_REF = NAME_PREFIX + "beanref_obj.gif";
	public static final String IMG_OBJS_CONFIG = NAME_PREFIX + "config_obj.gif";
	public static final String IMG_OBJS_COLLECTION = NAME_PREFIX + "collection_obj.gif";
	public static final String IMG_OBJS_REFRESH = NAME_PREFIX + "refresh_obj.gif";

	// Use IPath and toOSString to build the names to ensure they have the slashes correct
	private final static String OBJECT = "obj16/"; //basic colors - size 16x16

	public static final ImageDescriptor DESC_OBJS_BEAN_REF = createManaged(OBJECT, IMG_OBJS_BEAN_REF);
	public static final ImageDescriptor DESC_OBJS_COLLECTION = createManaged(OBJECT, IMG_OBJS_COLLECTION);
	public static final ImageDescriptor DESC_OBJS_BEAN = createManaged(OBJECT, IMG_OBJS_BEAN);
	public static final ImageDescriptor DESC_OBJS_CONFIG = createManaged(OBJECT, IMG_OBJS_CONFIG);
	public static final ImageDescriptor REFRESH = createManaged(OBJECT, IMG_OBJS_REFRESH);

	/*
	 * Helper method to initialize the image registry from the BeansUIPlugin
	 * class.
	 */
	/* package */ static void initializeImageRegistry(ImageRegistry registry) {
		for (String key : imageDescriptors.keySet()) {
			registry.put(key, imageDescriptors.get(key));
		}
	}

	/**
	 * Returns the {@link Image} identified by the given key,
	 * or <code>null</code> if it does not exist.
	 */
	public static Image getImage(String key) {
		return LiveGraphUiPlugin.getDefault().getImageRegistry().get(key);
	}
	
	private static ImageDescriptor createManaged(String prefix, String name) {
		try {
			ImageDescriptor result = ImageDescriptor.createFromURL(
				   makeIconFileURL(prefix, name.substring(NAME_PREFIX_LENGTH)));
			if (imageDescriptors == null) {
				imageDescriptors = new HashMap<String, ImageDescriptor>();
			}
			imageDescriptors.put(name, result);
			return result;
		} catch (MalformedURLException e) {
			LiveGraphUiPlugin.log(e);
			return ImageDescriptor.getMissingImageDescriptor();
		}
	}

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

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