1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * ident "%Z%%M% %I% %E% SMI" 24 * 25 * Copyright (c) 1998-1999 by Sun Microsystems, Inc. 26 * All rights reserved. 27 */ 28 package com.sun.dhcpmgr.ui; 29 30 import javax.swing.SwingUtilities; 31 32 /** 33 * An abstract class that you subclass to perform 34 * GUI-related work in a dedicated thread. 35 * For instructions on using this class, see 36 * http://java.sun.com/products/jfc/swingdoc-current/threads2.html 37 */ 38 public abstract class SwingWorker { 39 private Object value; 40 private Thread thread; 41 42 /** 43 * Compute the value to be returned by the <code>get</code> method. 44 */ 45 public abstract Object construct(); 46 47 /** 48 * Called on the event dispatching thread (not on the worker thread) 49 * after the <code>construct</code> method has returned. 50 */ 51 public void finished() { 52 } 53 54 /** 55 * A new method that interrupts the worker thread. Call this method 56 * to force the worker to abort what it's doing. 57 */ 58 public void interrupt() { 59 Thread t = thread; 60 if (t != null) { 61 t.interrupt(); 62 } 63 thread = null; 64 } 65 66 /** 67 * Return the value created by the <code>construct</code> method. 68 */ 69 public Object get() { 70 while (true) { // keep trying if we're interrupted 71 Thread t; 72 synchronized (SwingWorker.this) { 73 t = thread; 74 if (t == null) { 75 return value; 76 } 77 } 78 try { 79 t.join(); 80 } 81 catch (InterruptedException e) { 82 } 83 } 84 } 85 86 /** 87 * Start a thread that will call the <code>construct</code> method 88 * and then exit. 89 */ 90 public SwingWorker() { 91 final Runnable doFinished = new Runnable() { 92 public void run() { finished(); } 93 }; 94 95 Runnable doConstruct = new Runnable() { 96 public void run() { 97 synchronized (SwingWorker.this) { 98 value = construct(); 99 thread = null; 100 } 101 SwingUtilities.invokeLater(doFinished); 102 } 103 }; 104 105 thread = new Thread(doConstruct); 106 thread.start(); 107 } 108 }