package org.deftserver.io.callback;
import org.deftserver.io.IOLoop;
import org.deftserver.io.timeout.Timeout;
import org.deftserver.web.AsyncCallback;
public class PeriodicCallback {
private final AsyncCallback cb;
private final long period;
private boolean active = true;
/**
* A periodic callback that will execute its callback once every period.
* @param cb
* @param period The period in ms
*/
public PeriodicCallback(AsyncCallback cb, long period) {
this.cb = cb;
this.period = period;
}
/**
* Start the {@code PeriodicCallback}
*/
public void start() {
IOLoop.INSTANCE.addTimeout(
new Timeout(
System.currentTimeMillis() + period,
new AsyncCallback() { @Override public void onCallback() { run(); }}
)
);
}
private void run() {
if (active) {
cb.onCallback();
start(); // reschedule
}
}
/**
* Cancel the {@code PeriodicCallback}. (No way to resume the cancellation, you will need to create a new
* {@code PeriodicCallback}).
*/
public void cancel() {
this.active = false;
}
}