br.ufscar.dc.Dialogs.java Source code

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Here is the source code for br.ufscar.dc.Dialogs.java

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/**
 * <copyright>
 *
 * Copyright (c) 2014 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 - Initial API and implementation
 *
 * </copyright>
 *
 * $Id$
 */
package br.ufscar.dc;

import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class Dialogs {
    private static Shell tempShell;

    /**
     * Helper method for a standard ERROR MessageDialog
     * 
     * @param message
     *            Error message to display to user
     */
    public static void errorDialogMessage(final String message) {
        runOnDisplayThread(new Runnable() {
            public void run() {
                MessageDialog.openError(Display.getCurrent().getActiveShell(), "Error", message);
            }
        });
    }

    /**
     * Helper method for a standard WARNING MessageDialog
     * 
     * @param message
     *            Warning message to display to user
     */
    public static void warningDialogMessage(final String message) {
        runOnDisplayThread(new Runnable() {
            public void run() {
                MessageDialog.openWarning(Display.getCurrent().getActiveShell(), "Warning", message);
            }
        });
    }

    /**
     * Helper method to show a standard INFO MessageDialog
     * 
     * @param message
     *            Message to display to user
     */
    public static void infoDialogMessage(final String message) {
        runOnDisplayThread(new Runnable() {
            public void run() {
                MessageDialog.openInformation(Display.getCurrent().getActiveShell(), "Info", message);
            }
        });
    }

    /**
     * Ensure the specified Runnable runs on the Display thread.
     * <p>
     * If the Display or a default Shell does not exist, they are created. If a
     * default Shell has to be created, it will automatically be disposed after
     * the Runnable runs. If we are not already running on the Display thread
     * (for any reason), the Runnable will be asyncExec'd on the Display and
     * will run at the first reasonable time, but *after* this method
     * terminates. If we are already running on the Display thread, the Runnable
     * will be executed directly/synchronously.
     * 
     * @param runnable
     *            the Runnable to execute on the Display thread.
     */
    public static void runOnDisplayThread(final Runnable runnable) {
        Display display = getDisplay();

        if (display.getThread() == Thread.currentThread()) {
            //getActiveShell ensures that a shell exists, we don't actually care what it is 
            //but it just needs to be there. If you want the active shell (after calling getActiveShell() 
            //do it using standard SWT (i.e Display.getCurrent().getActiveShell() )         
            getActiveShell();
            runnable.run();
            disposeTempShell();
        } else {
            Runnable wrapped = new Runnable() {
                public void run() {
                    getActiveShell();
                    runnable.run();
                    disposeTempShell();
                }
            };

            display.asyncExec(wrapped);
        }
    }

    private static Shell getActiveShell() {
        tempShell = null;
        Display display = getDisplay();
        Shell shell = display.getActiveShell();
        if (shell != null) {
            return shell;
        }
        tempShell = new Shell(display);
        return tempShell;
    }

    private static Display getDisplay() {
        Display display = Display.getCurrent();
        if (display == null) {
            display = Display.getDefault();
        }
        return display;
    }

    protected static void disposeTempShell() {
        if (tempShell != null) {
            tempShell.dispose();
            tempShell = null;
        }
    }
}