| /******************************************************************************* |
| * Copyright (c) 2000, 2011 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * 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 = Integer.valueOf(nextBusyId); |
| nextBusyId++; |
| Cursor cursor = display.getSystemCursor(SWT.CURSOR_WAIT); |
| Shell[] shells = display.getShells(); |
| for (Shell shell : shells) { |
| Integer id = (Integer)shell.getData(BUSYID_NAME); |
| if (id == null) { |
| setCursorAndId(shell, cursor, busyId); |
| } |
| } |
| |
| try { |
| runnable.run(); |
| } finally { |
| shells = display.getShells(); |
| for (Shell shell : shells) { |
| Integer id = (Integer)shell.getData(BUSYID_NAME); |
| if (id == busyId) { |
| setCursorAndId(shell, null, null); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Paranoia code to make sure we don't break UI because of one shell disposed, see bug 532632 comment 20 |
| */ |
| private static void setCursorAndId(Shell shell, Cursor cursor, Integer busyId) { |
| if (!shell.isDisposed()) { |
| shell.setCursor(cursor); |
| } |
| if (!shell.isDisposed()) { |
| shell.setData(BUSYID_NAME, busyId); |
| } |
| } |
| } |