/******************************************************************************* * Copyright (c) 2000, 2004 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/cpl-v10.html *  * Contributors: *     IBM Corporation - initial API and implementation *******************************************************************************/package org.eclipse.swt.custom;import org.eclipse.swt.*;import org.eclipse.swt.graphics.*;import org.eclipse.swt.widgets.*;/** * Support for showing a Busy Cursor during a long running process. */public class BusyIndicator {	static int nextBusyId = 1;	static final String BUSYID_NAME = "SWT BusyIndicator"; //$NON-NLS-1$	static final String BUSY_CURSOR = "SWT BusyIndicator Cursor"; //$NON-NLS-1$/** * Runs the given <code>Runnable</code> while providing * busy feedback using this busy indicator. *  * @param display the display on which the busy feedback should be *        displayed.  If the display is null, the Display for the current *        thread will be used.  If there is no Display for the current thread, *        the runnable code will be executed and no busy feedback will be displayed. * @param runnable the runnable for which busy feedback is to be shown. *        Must not be null. * * @exception IllegalArgumentException <ul> *    <li>ERROR_NULL_ARGUMENT - if the runnable is null</li> * </ul> *  * @see #showWhile */public static void showWhile(Display display, Runnable runnable) {	if (runnable == null)		SWT.error(SWT.ERROR_NULL_ARGUMENT);	if (display == null) {		display = Display.getCurrent();		if (display == null) {			runnable.run();			return;		}	}		Integer busyId = new Integer(nextBusyId);	nextBusyId++;	Cursor cursor = display.getSystemCursor(SWT.CURSOR_WAIT);	Shell[] shells = display.getShells();	for (int i = 0; i < shells.length; i++) {		Integer id = (Integer)shells[i].getData(BUSYID_NAME);		if (id == null) {			shells[i].setCursor(cursor);			shells[i].setData(BUSYID_NAME, busyId);		}	}			try {		runnable.run();	} finally {		shells = display.getShells();		for (int i = 0; i < shells.length; i++) {			Integer id = (Integer)shells[i].getData(BUSYID_NAME);			if (id == busyId) {				shells[i].setCursor(null);				shells[i].setData(BUSYID_NAME, null);			}		}	}}}