Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2018 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 * Lars Vogel <Lars.Vogel@vogella.com> - Bug 530764 *******************************************************************************/ package org.eclipse.swt.snippets; /* * Text example snippet: verify input (only allow digits) * * For a list of all SWT example snippets see * http://www.eclipse.org/swt/snippets/ */ import org.eclipse.swt.*; import org.eclipse.swt.events.*; import org.eclipse.swt.graphics.*; import org.eclipse.swt.widgets.*; public class Snippet19 { public static void main(String[] args) { Display display = new Display(); Shell shell = new Shell(display); shell.setText("Snippet 19"); Text text = new Text(shell, SWT.BORDER | SWT.V_SCROLL); Rectangle clientArea = shell.getClientArea(); text.setBounds(clientArea.x + 10, clientArea.y + 10, 200, 200); text.addVerifyListener(Snippet19::ensureTextContainsOnlyDigits); shell.open(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) display.sleep(); } display.dispose(); } private static void ensureTextContainsOnlyDigits(VerifyEvent e) { String string = e.text; e.doit = string.matches("\\d*"); return; } }