BreakpointPlugin.java

/*******************************************************************************
 * Copyright (c) 2006 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *     IBM Research
 *******************************************************************************/
package com.ibm.research.tagging.breakpoint;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.ui.plugin.AbstractUIPlugin;
import org.osgi.framework.BundleContext;

/**
 * The activator class controls the plug-in life cycle
 */
public class BreakpointPlugin extends AbstractUIPlugin {

	// The plug-in ID
	public static final String PLUGIN_ID = "com.ibm.research.tagging.breakpoint";
	
	public static final String IMG_DEBUG   = "IMG_DEBUG";
	private static final String PATH_DEBUG = "icons/debug.gif";
	// The shared instance
	private static BreakpointPlugin plugin;
	
	/**
	 * The constructor
	 */
	public BreakpointPlugin() {
		plugin = this;
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.ui.plugin.AbstractUIPlugin#start(org.osgi.framework.BundleContext)
	 */
	public void start(BundleContext context) throws Exception {
		super.start(context);
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.ui.plugin.AbstractUIPlugin#stop(org.osgi.framework.BundleContext)
	 */
	public void stop(BundleContext context) throws Exception {
		plugin = null;
		super.stop(context);
	}

	/**
	 * Returns the shared instance
	 *
	 * @return the shared instance
	 */
	public static BreakpointPlugin getDefault() {
		return plugin;
	}

	/**
	 * Returns an image descriptor for the image file at the given
	 * plug-in relative path
	 *
	 * @param path the path
	 * @return the image descriptor
	 */
	public static ImageDescriptor getImageDescriptor(String path) {
		return imageDescriptorFromPlugin(PLUGIN_ID, path);
	}
	
	@Override
	protected ImageRegistry createImageRegistry() 
	{
		ImageRegistry registry = super.createImageRegistry();
		loadImageDescriptorIntoRegistry(registry,IMG_DEBUG,PATH_DEBUG);
		return registry;
	}
	
	/**
	 * Loads an image descriptor into the registry if it doesn't already exist.
	 * @param reg the image registry
	 * @param key the key for the image in the registry
	 * @param path the path to the image (relative to the plugin directory (e.g. /icons/icon.gif) 
	 */
	private void loadImageDescriptorIntoRegistry(ImageRegistry reg, String key, String path) {
		ImageDescriptor descriptor = reg.getDescriptor(key);
		if (descriptor == null) {
			descriptor = getImageDescriptor(path);
			if(descriptor != null) {
				reg.put(key, descriptor);
			}
		}
	}
}