/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/**
* Fires one or more {@code ActionEvent}s at specified
* intervals. An example use is an animation object that uses a
* <code>Timer</code> as the trigger for drawing its frames.
*<p>
* Setting up a timer
* involves creating a <code>Timer</code> object,
* registering one or more action listeners on it,
* and starting the timer using
* the <code>start</code> method.
* For example,
* the following code creates and starts a timer
* that fires an action event once per second
* (as specified by the first argument to the <code>Timer</code> constructor).
* The second argument to the <code>Timer</code> constructor
* specifies a listener to receive the timer's action events.
*
*<pre>
* int delay = 1000; //milliseconds
* ActionListener taskPerformer = new ActionListener() {
* public void actionPerformed(ActionEvent evt) {
* <em>//...Perform a task...</em>
* }
* };
* new Timer(delay, taskPerformer).start();</pre>
*
* <p>
* {@code Timers} are constructed by specifying both a delay parameter
* and an {@code ActionListener}. The delay parameter is used
* to set both the initial delay and the delay between event
* firing, in milliseconds. Once the timer has been started,
* it waits for the initial delay before firing its
* first <code>ActionEvent</code> to registered listeners.
* After this first event, it continues to fire events
* every time the between-event delay has elapsed, until it
* is stopped.
* <p>
* After construction, the initial delay and the between-event
* delay can be changed independently, and additional
* <code>ActionListeners</code> may be added.
* <p>
* If you want the timer to fire only the first time and then stop,
* invoke <code>setRepeats(false)</code> on the timer.
* <p>
* Although all <code>Timer</code>s perform their waiting
* using a single, shared thread
* (created by the first <code>Timer</code> object that executes),
* the action event handlers for <code>Timer</code>s
* execute on another thread -- the event-dispatching thread.
* This means that the action handlers for <code>Timer</code>s
* can safely perform operations on Swing components.
* However, it also means that the handlers must execute quickly
* to keep the GUI responsive.
*
* <p>
* In v 1.3, another <code>Timer</code> class was added
* to the Java platform: <code>java.util.Timer</code>.
* Both it and <code>javax.swing.Timer</code>
* provide the same basic functionality,
* but <code>java.util.Timer</code>
* is more general and has more features.
* The <code>javax.swing.Timer</code> has two features
* that can make it a little easier to use with GUIs.
* First, its event handling metaphor is familiar to GUI programmers
* and can make dealing with the event-dispatching thread
* a bit simpler.
* Second, its
* automatic thread sharing means that you don't have to
* take special steps to avoid spawning
* too many threads.
* Instead, your timer uses the same thread
* used to make cursors blink,
* tool tips appear,
* and so on.
*
* <p>
* You can find further documentation
* and several examples of using timers by visiting
* target = "_top">How to Use Timers</a>,
* a section in <em>The Java Tutorial.</em>
* For more examples and help in choosing between
* this <code>Timer</code> class and
* <code>java.util.Timer</code>,
* see
* target="_top">Using Timers in Swing Applications</a>,
* an article in <em>The Swing Connection.</em>
* <p>
* <strong>Warning:</strong>
* Serialized objects of this class will not be compatible with
* future Swing releases. The current serialization support is
* appropriate for short term storage or RMI between applications running
* the same version of Swing. As of 1.4, support for long term storage
* of all JavaBeans<sup><font size="-2">TM</font></sup>
* has been added to the <code>java.beans</code> package.
* Please see {@link java.beans.XMLEncoder}.
*
* @see java.util.Timer <code>java.util.Timer</code>
*
*
* @author Dave Moore
*/
{
/*
* NOTE: all fields need to be handled in readResolve
*/
// The following field strives to maintain the following:
// If coalesce is true, only allow one Runnable to be queued on the
// EventQueue and be pending (ie in the process of notifying the
// ActionListener). If we didn't do this it would allow for a
// situation where the app is taking too long to process the
// actionPerformed, and thus we'ld end up queing a bunch of Runnables
// and the app would never return: not good. This of course implies
// you can get dropped events, but such is life.
// notify is used to indicate if the ActionListener can be notified, when
// the Runnable is processed if this is true it will notify the listeners.
// notify is set to true when the Timer fires and the Runnable is queued.
// It will be set to false after notifying the listeners (if coalesce is
// true) or if the developer invokes stop.
private static volatile boolean logTimers;
// This field is maintained by TimerQueue.
// eventQueued can also be reset by the TimerQueue, but will only ever
// happen in applet case when TimerQueues thread is destroyed.
// access to this field is synchronized on getLock() lock.
/**
* Creates a {@code Timer} and initializes both the initial delay and
* between-event delay to {@code delay} milliseconds. If {@code delay}
* is less than or equal to zero, the timer fires as soon as it
* is started. If <code>listener</code> is not <code>null</code>,
* it's registered as an action listener on the timer.
*
* @param delay milliseconds for the initial and between-event delay
* @param listener an initial listener; can be <code>null</code>
*
* @see #addActionListener
* @see #setInitialDelay
* @see #setRepeats
*/
super();
this.initialDelay = delay;
doPostEvent = new DoPostEvent();
}
}
/*
* The timer's AccessControlContext.
*/
/**
* Returns the acc this timer was constructed with.
*/
throw new SecurityException(
"Timer is missing AccessControlContext");
}
return acc;
}
/**
* DoPostEvent is a runnable class that fires actionEvents to
* the listeners on the EventDispatchThread, via invokeLater.
* @see Timer#post
*/
{
public void run() {
if (logTimers) {
}
0));
if (coalesce) {
cancelEvent();
}
}
}
return Timer.this;
}
}
/**
* Adds an action listener to the <code>Timer</code>.
*
* @param listener the listener to add
*
* @see #Timer
*/
}
/**
* Removes the specified action listener from the <code>Timer</code>.
*
* @param listener the listener to remove
*/
}
/**
* Returns an array of all the action listeners registered
* on this timer.
*
* @return all of the timer's <code>ActionListener</code>s or an empty
* array if no action listeners are currently registered
*
* @see #addActionListener
* @see #removeActionListener
*
* @since 1.4
*/
}
/**
* Notifies all listeners that have registered interest for
* notification on this event type.
*
* @param e the action event to fire
* @see EventListenerList
*/
// Guaranteed to return a non-null array
// Process the listeners last to first, notifying
// those that are interested in this event
if (listeners[i]==ActionListener.class) {
}
}
}
/**
* Returns an array of all the objects currently registered as
* <code><em>Foo</em>Listener</code>s
* upon this <code>Timer</code>.
* <code><em>Foo</em>Listener</code>s
* are registered using the <code>add<em>Foo</em>Listener</code> method.
* <p>
* You can specify the <code>listenerType</code> argument
* with a class literal, such as <code><em>Foo</em>Listener.class</code>.
* For example, you can query a <code>Timer</code>
* instance <code>t</code>
* for its action listeners
* with the following code:
*
* <pre>ActionListener[] als = (ActionListener[])(t.getListeners(ActionListener.class));</pre>
*
* If no such listeners exist,
* this method returns an empty array.
*
* @param listenerType the type of listeners requested;
* this parameter should specify an interface
* that descends from <code>java.util.EventListener</code>
* @return an array of all objects registered as
* <code><em>Foo</em>Listener</code>s
* on this timer,
* or an empty array if no such
* listeners have been added
* @exception ClassCastException if <code>listenerType</code> doesn't
* specify a class or interface that implements
* <code>java.util.EventListener</code>
*
* @see #getActionListeners
* @see #addActionListener
* @see #removeActionListener
*
* @since 1.3
*/
}
/**
* Returns the timer queue.
*/
return TimerQueue.sharedInstance();
}
/**
* Enables or disables the timer log. When enabled, a message
* is posted to <code>System.out</code> whenever the timer goes off.
*
* @param flag <code>true</code> to enable logging
* @see #getLogTimers
*/
}
/**
* Returns <code>true</code> if logging is enabled.
*
* @return <code>true</code> if logging is enabled; otherwise, false
* @see #setLogTimers
*/
public static boolean getLogTimers() {
return logTimers;
}
/**
* Sets the <code>Timer</code>'s between-event delay, the number of milliseconds
* between successive action events. This does not affect the initial delay
* property, which can be set by the {@code setInitialDelay} method.
*
* @param delay the delay in milliseconds
* @see #setInitialDelay
*/
if (delay < 0) {
}
else {
}
}
/**
* Returns the delay, in milliseconds,
* between firings of action events.
*
* @see #setDelay
* @see #getInitialDelay
*/
public int getDelay() {
return delay;
}
/**
* Sets the <code>Timer</code>'s initial delay, the time
* in milliseconds to wait after the timer is started
* before firing the first event. Upon construction, this
* is set to be the same as the between-event delay,
* but then its value is independent and remains unaffected
* by changes to the between-event delay.
*
* @param initialDelay the initial delay, in milliseconds
* @see #setDelay
*/
if (initialDelay < 0) {
throw new IllegalArgumentException("Invalid initial delay: " +
}
else {
this.initialDelay = initialDelay;
}
}
/**
* Returns the <code>Timer</code>'s initial delay.
*
* @see #setInitialDelay
* @see #setDelay
*/
public int getInitialDelay() {
return initialDelay;
}
/**
* If <code>flag</code> is <code>false</code>,
* instructs the <code>Timer</code> to send only one
* action event to its listeners.
*
* @param flag specify <code>false</code> to make the timer
* stop after sending its first action event
*/
}
/**
* Returns <code>true</code> (the default)
* if the <code>Timer</code> will send
* an action event
* to its listeners multiple times.
*
* @see #setRepeats
*/
public boolean isRepeats() {
return repeats;
}
/**
* Sets whether the <code>Timer</code> coalesces multiple pending
* <code>ActionEvent</code> firings.
* A busy application may not be able
* to keep up with a <code>Timer</code>'s event generation,
* causing multiple
* action events to be queued. When processed,
* the application sends these events one after the other, causing the
* <code>Timer</code>'s listeners to receive a sequence of
* events with no delay between them. Coalescing avoids this situation
* by reducing multiple pending events to a single event.
* <code>Timer</code>s
* coalesce events by default.
*
* @param flag specify <code>false</code> to turn off coalescing
*/
// We must do this as otherwise if the Timer once notified
// in !coalese mode notify will be stuck to true and never
// become false.
cancelEvent();
}
}
/**
* Returns <code>true</code> if the <code>Timer</code> coalesces
* multiple pending action events.
*
* @see #setCoalesce
*/
public boolean isCoalesce() {
return coalesce;
}
/**
* Sets the string that will be delivered as the action command
* in <code>ActionEvent</code>s fired by this timer.
* <code>null</code> is an acceptable value.
*
* @param command the action command
* @since 1.6
*/
this.actionCommand = command;
}
/**
* Returns the string that will be delivered as the action command
* in <code>ActionEvent</code>s fired by this timer. May be
* <code>null</code>, which is also the default.
*
* @return the action command used in firing events
* @since 1.6
*/
return actionCommand;
}
/**
* Starts the <code>Timer</code>,
* causing it to start sending action events
* to its listeners.
*
* @see #stop
*/
public void start() {
}
/**
* Returns <code>true</code> if the <code>Timer</code> is running.
*
* @see #start
*/
public boolean isRunning() {
return timerQueue().containsTimer(this);
}
/**
* Stops the <code>Timer</code>,
* causing it to stop sending action events
* to its listeners.
*
* @see #start
*/
public void stop() {
try {
cancelEvent();
timerQueue().removeTimer(this);
} finally {
}
}
/**
* Restarts the <code>Timer</code>,
* canceling any pending firings and causing
* it to fire with its initial delay.
*/
public void restart() {
try {
stop();
start();
} finally {
}
}
/**
* Resets the internal state to indicate this Timer shouldn't notify
* any of its listeners. This does not stop a repeatable Timer from
* firing again, use <code>stop</code> for that.
*/
void cancelEvent() {
}
void post() {
return null;
}
}, getAccessControlContext());
}
}
return lock;
}
throws ClassNotFoundException, IOException
{
}
/*
* We have to use readResolve because we can not initialize final
* fields for deserialized object otherwise
*/
return timer;
}
}