Package com.google.gwt.user.client
Class Timer
java.lang.Object
com.google.gwt.user.client.Timer
A simplified, browser-safe timer class. This class serves the same purpose as
java.util.Timer, but is simplified because of the single-threaded
environment.
To schedule a timer, simply create a subclass of it (overriding run()
)
and call schedule(int)
or scheduleRepeating(int)
.
NOTE: If you are using a timer to schedule a UI animation, use
AnimationScheduler
instead. The
browser can optimize your animation for maximum performance.
Example
public class TimerExample implements EntryPoint, ClickHandler { public void onModuleLoad() { Button b = new Button("Click and wait 5 seconds"); b.addClickHandler(this); RootPanel.get().add(b); } public void onClick(ClickEvent event) { // Create a new timer that calls Window.alert(). Timer t = new Timer() { @Override public void run() { Window.alert("Nifty, eh?"); } }; // Schedule the timer to run once in 5 seconds. t.schedule(5000); } }
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionvoid
cancel()
Cancels this timer.(package private) final void
fire
(int scheduleCancelCounter) final boolean
Returnstrue
if the timer is running.abstract void
run()
This method will be called when a timer fires.void
schedule
(int delayMillis) Schedules a timer to elapse in the future.void
scheduleRepeating
(int periodMillis) Schedules a timer that elapses repeatedly.
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Constructor Details
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Timer
public Timer()
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Method Details
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isRunning
public final boolean isRunning()Returnstrue
if the timer is running. Timer is running if and only if it is scheduled but it is not expired or cancelled. -
cancel
public void cancel()Cancels this timer. If the timer is not running, this is a no-op. -
run
public abstract void run()This method will be called when a timer fires. Override it to implement the timer's logic. -
schedule
public void schedule(int delayMillis) Schedules a timer to elapse in the future. If the timer is already running then it will be first canceled before re-scheduling.- Parameters:
delayMillis
- how long to wait before the timer elapses, in milliseconds
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scheduleRepeating
public void scheduleRepeating(int periodMillis) Schedules a timer that elapses repeatedly. If the timer is already running then it will be first canceled before re-scheduling.- Parameters:
periodMillis
- how long to wait before the timer elapses, in milliseconds, between each repetition
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fire
final void fire(int scheduleCancelCounter)
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