/** Creates a timer if one doesn't already exist, then starts the timer thread. */
private void start(int interval) {
previousDelay = interval;
lastCall = 0;
if (timer == null) {
timer = new Timer(interval, this);
} else {
timer.setDelay(interval);
}
if (ADJUSTTIMER) {
timer.setRepeats(false);
timer.setCoalesce(false);
}
timer.start();
}
/** Reacts to the timer's action events. */
public void actionPerformed(ActionEvent e) {
if (ADJUSTTIMER) {
long time = System.currentTimeMillis();
if (lastCall > 0) { // adjust nextDelay
// XXX maybe should cache this after a while
// actual = time - lastCall
// difference = actual - interval
// nextDelay = previousDelay - difference
// = previousDelay - (time - lastCall - interval)
int nextDelay = (int) (previousDelay - time + lastCall + getRepaintInterval());
if (nextDelay < MINIMUM_DELAY) {
nextDelay = MINIMUM_DELAY;
}
timer.setInitialDelay(nextDelay);
previousDelay = nextDelay;
}
timer.start();
lastCall = time;
}
incrementAnimationIndex(); // paint next frame
}