/* * $Id: Flag.java,v 1.2 2007/12/20 18:33:33 rbair Exp $ * * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle, * Santa Clara, California 95054, U.S.A. All rights reserved. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ package com.sun.pdfview; /** * A generic synchronized flag, because Java doesn't have one. */ public class Flag { private boolean isSet; /** * Sets the flag. Any pending waitForFlag calls will now return. */ public synchronized void set() { isSet= true; notifyAll(); } /** * Clears the flag. Do this before calling waitForFlag. */ public synchronized void clear() { isSet= false; } /** * Waits for the flag to be set, if it is not set already. * This method catches InterruptedExceptions, so if you want * notification of interruptions, use interruptibleWaitForFlag * instead. */ public synchronized void waitForFlag() { if (!isSet) { try { wait(); } catch (InterruptedException ie) {} } } /** * Waits for the flag to be set, if it is not set already. */ public synchronized void interruptibleWaitForFlag() throws InterruptedException { if (!isSet) { wait(); } } }