ActionUtil.java

/* AWE - Amanzi Wireless Explorer
 * http://awe.amanzi.org
 * (C) 2008-2009, AmanziTel AB
 *
 * This library is provided under the terms of the Eclipse Public License
 * as described at http://www.eclipse.org/legal/epl-v10.html. Any use,
 * reproduction or distribution of the library constitutes recipient's
 * acceptance of this agreement.
 *
 * This library is distributed WITHOUT ANY WARRANTY; without even the
 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 */
package org.amanzi.awe.ui.util;

import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.PlatformUI;

/**
 * Utility class that provides running actions from Display. Since the code that calls this also
 * runs in non-GUI unit and system tests, we support a fallback mechanism where if the workbench
 * cannot be created (headless tests), we run the runnables in the current thread instead.
 * 
 * @author Lagutko_N
 */
public class ActionUtil {

    /*
     * Display for running
     */
    private Display display;

    /*
     * Instance of ActionUtil
     */
    private static ActionUtil util;

    /**
     * Constructor.
     */
    protected ActionUtil() {
        try {
            this.display = PlatformUI.getWorkbench().getDisplay();
        } catch (RuntimeException e) {
            // We are probably running unit tests, log and error and continue
            System.err.println("Failed to get display: " + e);
        }
    }

    /**
     * Returns an instance of ActionUtil
     * 
     * @return instance of ActionUtil
     */

    public static ActionUtil getInstance() {
        if (util == null) {
            util = new ActionUtil();
        }

        return util;
    }

    /**
     * Runs a Task
     * 
     * @param task task for running
     * @param async is this task must be ran asyncrhonically
     */

    public void runTask(final Runnable task, final boolean async) {
        if (display != null) {
            if (async) {
                display.asyncExec(task);
            } else {
                display.syncExec(task);
            }
        } else {
            task.run();
        }
    }
}