com.sun.glass.ui.Timer Maven / Gradle / Ivy
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* published by the Free Software Foundation. Oracle designates this
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*
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* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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package com.sun.glass.ui;
import java.lang.annotation.Native;
/**
* A high-resolution timer.
*
* An application may either override its run() method, or pass a Runnable
* object to the constructor of the Timer class.
*
* The run() method may be invoked on a thread other than the UI thread. If
* a developer wants to process timer events on the UI thread, they can use
* the Application.invokeLater/invokeAndWait() API.
*/
public abstract class Timer {
@Native private final static double UNSET_PERIOD = -1.0; // 0 is valid value, so can't use it here
@Native private final static double SET_PERIOD = -2.0; // token value for vsync timer
private final Runnable runnable;
private long ptr;
private double period = UNSET_PERIOD;
protected abstract long _start(Runnable runnable);
protected abstract long _start(Runnable runnable, int period);
protected abstract void _stop(long timer);
/**
* Constructs a new timer.
*
* If the application overrides the Timer.run(), it should call super.run()
* in order to run the runnable passed to the constructor.
*/
protected Timer(Runnable runnable) {
if (runnable == null) {
throw new IllegalArgumentException("runnable shouldn't be null");
}
this.runnable = runnable;
}
/**
* Returns the minimum timer period supported by the native system.
*/
public static int getMinPeriod() {
return Application.GetApplication().staticTimer_getMinPeriod();
}
/**
* Returns the maximum timer period supported by the native system.
*/
public static int getMaxPeriod() {
return Application.GetApplication().staticTimer_getMaxPeriod();
}
/**
* Starts the timer.
* The period must be in the range getMinPeriod() .. getMaxPeriod().
* If the timer is currently started, it gets stopped before re-starting.
* If starting the timer fails, the RuntimeException is thrown.
*/
public synchronized void start(int period) {
if (period < getMinPeriod() || period > getMaxPeriod()) {
throw new IllegalArgumentException("period is out of range");
}
if (this.ptr != 0L) {
stop();
}
this.ptr = _start(this.runnable, period);
if (this.ptr == 0L) {
this.period = UNSET_PERIOD;
throw new RuntimeException("Failed to start the timer");
} else {
this.period = (double)period;
}
}
/**
* Start a vsync-based timer if the system supports it.
*
* A RuntimeException is thrown if the system does not support
* vsync-based timer or if there was an issue starting the timer.
*/
public synchronized void start() {
if (this.ptr != 0L) {
stop();
}
this.ptr = _start(this.runnable);
if (this.ptr == 0L) {
this.period = UNSET_PERIOD;
throw new RuntimeException("Failed to start the timer");
} else {
this.period = SET_PERIOD;
}
}
/**
* Stops the timer. If a vsync-based timer is stopped, all of the
* vsync timers currently running will be stopped.
*/
public synchronized void stop() {
if (this.ptr != 0L) {
_stop(this.ptr);
this.ptr = 0L;
this.period = UNSET_PERIOD;
}
}
/**
* Returns true if the timer is currently running
* (convenience API: might not need it)
*/
public synchronized boolean isRunning() {
return (this.period != UNSET_PERIOD);
}
}