/*******************************************************************************
* Copyright (c) 2000, 2011 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
*******************************************************************************/
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.
*
* @see <a href="http://www.eclipse.org/swt/snippets/#busyindicator">BusyIndicator snippets</a>
* @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
*/
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>
*/
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);
}
}
}
}
}