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Diffstat (limited to 'libjava/classpath/javax/swing/Timer.java')
-rw-r--r-- | libjava/classpath/javax/swing/Timer.java | 485 |
1 files changed, 485 insertions, 0 deletions
diff --git a/libjava/classpath/javax/swing/Timer.java b/libjava/classpath/javax/swing/Timer.java new file mode 100644 index 00000000000..87f420a4367 --- /dev/null +++ b/libjava/classpath/javax/swing/Timer.java @@ -0,0 +1,485 @@ +/* Timer.java -- + Copyright (C) 2002, 2004, 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; + +import java.awt.event.ActionEvent; +import java.awt.event.ActionListener; +import java.io.Serializable; +import java.util.EventListener; + +import javax.swing.event.EventListenerList; + +/** + * Fires one or more action events after the specified delay. + * @author Ronald Veldema + * @author Audrius Meskauskas (audriusa@Bionformatics.org) - bug fixes + * and documentation comments + */ +public class Timer + implements Serializable +{ + /** + * The timer thread + */ + private class Waker + extends Thread + { + /** + * Fires events, pausing for required intervals. + */ + public void run() + { + running = true; + try + { + sleep(initialDelay); + + queueEvent(); + + while (running) + { + try + { + sleep(delay); + } + catch (InterruptedException e) + { + return; + } + queueEvent(); + + if (logTimers) + System.out.println("javax.swing.Timer -> clocktick"); + + if ( ! repeats) + break; + } + running = false; + } + catch (Exception e) + { + // The timer is no longer running. + running = false; + } + } + } + + /** + * Use serialVersionUID for interoperability. + */ + private static final long serialVersionUID = -1116180831621385484L; + + /** + * The encloding class, used with {@link SwingUtilities#invokeLater} + * to invoke the {@link #drainEvents()}. + */ + private Runnable drainer = new Runnable() + { + public void run() + { + drainEvents(); + } + }; + + /** + * If <code>true</code>, the timer prints a message to + * {@link System#out} when firing each event. + */ + static boolean logTimers; + + /** + * A field to store all listeners who are listening to this timer. + */ + protected EventListenerList listenerList = new EventListenerList(); + + /** + * <code>true</code> if the timer coalesces events. + */ + boolean coalesce = true; + + /** + * <code>true</code> if the timer is firing repetetive events. + */ + boolean repeats = true; + + /** + * <code>true</code> if the timer is currently active, firing events + * as scheduled. + */ + boolean running; + + /** + * The delay between subsequent repetetive events. + */ + int delay; + + /** + * The initial delay before the first event. + */ + int initialDelay; + + /** + * The number of events that have been already fired by this timer. + * This is used as a numeric identifier for the next event that would + * be fired. + */ + int ticks; + + /** + * Stores the thread that posts events to the queue at required time + * intervals. + */ + private Waker waker; + + /** + * This object manages a "queue" of virtual actionEvents, maintained as a + * simple long counter. When the timer expires, a new event is queued, + * and a dispatcher object is pushed into the system event queue. When + * the system thread runs the dispatcher, it will fire as many + * ActionEvents as have been queued, unless the timer is set to + * coalescing mode, in which case it will fire only one ActionEvent. + */ + private long queue; + + /** + * <code>synchronized(queueLock)</code> replaces + * <code>synchronized(queue)</code> that is not supported by this language. + */ + private Object queueLock = new Object(); + + /** + * Creates a new Timer object. + * + * @param d the default value for both initial and between event delay, in + * milliseconds. + * @param listener the first action listener, can be <code>null</code>. + */ + public Timer(int d, ActionListener listener) + { + delay = d; + initialDelay = d; + + if (listener != null) + addActionListener(listener); + } + + /** + * Get the array of action listeners. + * + * @return the array of action listeners that are listening for the events, + * fired by this timer + * + * @since 1.4 + */ + public ActionListener[] getActionListeners() + { + return (ActionListener[]) listenerList.getListeners(ActionListener.class); + } + + /** + * Sets whether the Timer coalesces multiple pending event firings. + * If the coalescing is enabled, the multiple events that have not been + * fired on time are replaced by the single event. The events may not + * be fired on time if the application is busy. + * + * @param c <code>true</code> (default) to enable the event coalescing, + * <code>false</code> otherwise + */ + public void setCoalesce(boolean c) + { + coalesce = c; + } + + /** + * Checks if the Timer coalesces multiple pending event firings. + * If the coalescing is enabled, the multiple events that have not been + * fired on time are replaced by the single event. The events may not + * be fired on time if the application is busy. + * + * @return <code>true</code> if the coalescing is enabled, + * <code>false</code> otherwise + */ + public boolean isCoalesce() + { + return coalesce; + } + + /** + * Get the event listeners of the given type that are listening for the + * events, fired by this timer. + * + * @param listenerType the listener type (for example, ActionListener.class) + * + * @return the array of event listeners that are listening for the events, + * fired by this timer + * @since 1.3 + */ + public EventListener[] getListeners(Class listenerType) + { + return listenerList.getListeners(listenerType); + } + + /** + * Set the timer logging state. If it is set to <code>true</code>, the + * timer prints a message to {@link System#out} when firing each + * action event. + * + * @param lt <code>true</code> if logging is enabled, <code>false</code> + * (default value) otherwise + */ + public static void setLogTimers(boolean lt) + { + logTimers = lt; + } + + /** + * Return the logging state. + * + * @return <code>true</code> if the timer is printing a message to + * {@link System#out} + * when firing each action event + */ + public static boolean getLogTimers() + { + return logTimers; + } + + /** + * Set the delay between firing the subsequent events. + * This parameter does not change the value of the initial delay before + * firing the first event. + * + * @param d The time gap between the subsequent events, in milliseconds + */ + public void setDelay(int d) + { + delay = d; + } + + /** + * Get the delay between firing the subsequent events. + * + * @return The delay between subsequent events, in milliseconds + */ + public int getDelay() + { + return delay; + } + + /** + * Set the intial delay before firing the first event since calling + * the {@link #start()} method. If the initial delay has not been + * set, it is assumed having the same value as the delay between the + * subsequent events. + * + * @param i the initial delay, in milliseconds + */ + public void setInitialDelay(int i) + { + initialDelay = i; + } + + /** + * Get the intial delay before firing the first event since calling + * the {@link #start()} method. If the initial delay has not been + * set, returns the same value as {@link #getDelay()}. + * + * @return the initial delay before firing the first action event. + */ + public int getInitialDelay() + { + return initialDelay; + } + + /** + * Enable firing the repetetive events. + * + * @param r <code>true</code> (default value) to fire repetetive events. + * <code>false</code> to fire + * only one event after the initial delay + */ + public void setRepeats(boolean r) + { + repeats = r; + } + + /** + * Check is this timer fires repetetive events. + * + * @return <code>true</code> if the timer fires repetetive events, + * <code>false</code> if it fires + * only one event after the initial delay + */ + public boolean isRepeats() + { + return repeats; + } + + /** + * Get the timer state. + * + * @return <code>true</code> if the timer has been started and is firing + * the action events as scheduled. <code>false</code> + * if the timer is inactive. + */ + public boolean isRunning() + { + return running; + } + + /** + * Add the action listener + * + * @param listener the action listener to add + */ + public void addActionListener(ActionListener listener) + { + listenerList.add(ActionListener.class, listener); + } + + /** + * Remove the action listener. + * + * @param listener the action listener to remove + */ + public void removeActionListener(ActionListener listener) + { + listenerList.remove(ActionListener.class, listener); + } + + /** + * Cancel all pending tasks and fire the first event after the initial + * delay. + */ + public void restart() + { + stop(); + start(); + } + + /** + * Start firing the action events. + */ + public void start() + { + if (isRunning()) + return; + waker = new Waker(); + waker.start(); + } + + /** + * Stop firing the action events. + */ + public void stop() + { + running = false; + if (waker != null) + waker.interrupt(); + synchronized (queueLock) + { + queue = 0; + } + } + + /** + * Fire the given action event to the action listeners. + * + * @param event the event to fire + */ + protected void fireActionPerformed(ActionEvent event) + { + ActionListener[] listeners = getActionListeners(); + + for (int i = 0; i < listeners.length; i++) + listeners [ i ].actionPerformed(event); + } + + /** + * Fire the action event, named "Timer" and having the numeric + * identifier, equal to the numer of events that have been + * already fired before. + */ + void fireActionPerformed() + { + fireActionPerformed(new ActionEvent(this, ticks++, "Timer")); + } + + /** + * Fire the queued action events. + * In the coalescing mode, a single event is fired as a replacement + * for all queued events. In non coalescing mode, a series of + * all queued events is fired. + * This is package-private to avoid an accessor method. + */ + void drainEvents() + { + synchronized (queueLock) + { + if (isCoalesce()) + { + if (queue > 0) + fireActionPerformed(); + } + else + { + while (queue > 0) + { + fireActionPerformed(); + queue--; + } + } + queue = 0; + } + } + + /** + * Post a scheduled event to the event queue. + * Package-private to avoid an accessor method. + */ + void queueEvent() + { + synchronized (queueLock) + { + queue++; + if (queue == 1) + SwingUtilities.invokeLater(drainer); + } + } +} |