/*******************************************************************************
 * Copyright (c) 2001, 2004 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
 *     Jens Lukowski/Innoopract - initial renaming/restructuring
 *     
 *******************************************************************************/
package org.eclipse.wst.sse.ui.edit.util;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.IActionDelegate;

public class ResourceActionDelegate implements IActionDelegate {
	protected IStructuredSelection fSelection;

	protected Job getJob() {
		// ResourceActionDelegate does not create background job
		// subclass creates the background job for the action
		return null;
	}

	protected boolean processorAvailable(IResource resource) {
		// ResourceActionDelegate returns false by default
		// subclass returns true if processor is available; false otherwise
		return false;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.IActionDelegate#run(org.eclipse.jface.action.IAction)
	 */
	public void run(IAction action) {
		if (fSelection != null && !fSelection.isEmpty()) {
			Job job = getJob();
			if (job != null)
				job.schedule();
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.IActionDelegate#selectionChanged(org.eclipse.jface.action.IAction,
	 *      org.eclipse.jface.viewers.ISelection)
	 */
	public void selectionChanged(IAction action, ISelection selection) {
		if (selection instanceof IStructuredSelection) {
			fSelection = (IStructuredSelection) selection;
			boolean available = false;

			Object[] elements = fSelection.toArray();
			for (int i = 0; i < elements.length; i++) {
				if (elements[i] instanceof IResource) {
					available = processorAvailable((IResource) elements[i]);

					if (available)
						break;
				}
			}

			action.setEnabled(available);
		}
	}

}