| /* LayoutQueue.java -- |
| Copyright (C) 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package javax.swing.text; |
| |
| import java.util.LinkedList; |
| |
| /** |
| * This is a queue which holds {@link Runnable} objects. It is |
| * intended for deferring layout operations. |
| */ |
| public class LayoutQueue |
| { |
| // The default layout queue. |
| private static LayoutQueue defaultQueue = new LayoutQueue(); |
| |
| // The queue of tasks. |
| private LinkedList list = new LinkedList(); |
| |
| /** |
| * Create a new layout queue. |
| */ |
| public LayoutQueue() |
| { |
| // Nothing to do here. |
| } |
| |
| /** |
| * Add a layout task to the queue. |
| */ |
| public void addTask(Runnable task) |
| { |
| synchronized (list) |
| { |
| list.addLast(task); |
| list.notify(); |
| } |
| } |
| |
| /** |
| * Called by a worker thread to retrieve the next layout task. This |
| * will block until a new task is available. This method will |
| * return null if the thread is interrupted while waiting. |
| */ |
| protected Runnable waitForWork() |
| { |
| synchronized (list) |
| { |
| while (list.size() == 0) |
| { |
| try |
| { |
| list.wait(); |
| } |
| catch (InterruptedException _) |
| { |
| // This seemed like a good idea, but it has not been |
| // tested on the JDK. |
| return null; |
| } |
| } |
| return (Runnable) list.removeFirst(); |
| } |
| } |
| |
| /** |
| * Return the default layout queue. |
| */ |
| public static synchronized LayoutQueue getDefaultQueue() |
| { |
| return defaultQueue; |
| } |
| |
| /** |
| * Set the default layout queue. |
| */ |
| public static synchronized void setDefaultQueue(LayoutQueue q) |
| { |
| defaultQueue = q; |
| } |
| } |