JavaFX Spinner change is slow with click and hold of mouse button - javafx

Question

The speed of Spinner update is slow when I click and hold the up/down arrow buttons. Is there a way to increase the change speed?
When I click, click, click with the mouse, the spinner values change as fast as I click. It also changes fast if I use the up/down arrows on the keyboard for each key press or if I hold down the up/down arrow keys. I want the values to change that fast when I click and hold on the arrow buttons.
Anyone know a way to do that?

Answer 1

The SpinnerBehavior of the SpinnerSkin triggers updates every 750 ms. Unfortunately there is no way to simply set/modify this behavour without using reflection to access private members. Therefore the only way to do this without reflection is using event filters to trigger the updates at a faster rate:
private static final PseudoClass PRESSED = PseudoClass.getPseudoClass("pressed");
#Override
public void start(Stage primaryStage) {
Spinner<Integer> spinner = new Spinner(Integer.MIN_VALUE, Integer.MAX_VALUE, 0);
class IncrementHandler implements EventHandler<MouseEvent> {
private Spinner spinner;
private boolean increment;
private long startTimestamp;
private static final long DELAY = 1000l * 1000L * 750L; // 0.75 sec
private Node button;
private final AnimationTimer timer = new AnimationTimer() {
#Override
public void handle(long now) {
if (now - startTimestamp >= DELAY) {
// trigger updates every frame once the initial delay is over
if (increment) {
spinner.increment();
} else {
spinner.decrement();
}
}
}
};
#Override
public void handle(MouseEvent event) {
if (event.getButton() == MouseButton.PRIMARY) {
Spinner source = (Spinner) event.getSource();
Node node = event.getPickResult().getIntersectedNode();
Boolean increment = null;
// find which kind of button was pressed and if one was pressed
while (increment == null && node != source) {
if (node.getStyleClass().contains("increment-arrow-button")) {
increment = Boolean.TRUE;
} else if (node.getStyleClass().contains("decrement-arrow-button")) {
increment = Boolean.FALSE;
} else {
node = node.getParent();
}
}
if (increment != null) {
event.consume();
source.requestFocus();
spinner = source;
this.increment = increment;
// timestamp to calculate the delay
startTimestamp = System.nanoTime();
button = node;
// update for css styling
node.pseudoClassStateChanged(PRESSED, true);
// first value update
timer.handle(startTimestamp + DELAY);
// trigger timer for more updates later
timer.start();
}
}
}
public void stop() {
timer.stop();
button.pseudoClassStateChanged(PRESSED, false);
button = null;
spinner = null;
}
}
IncrementHandler handler = new IncrementHandler();
spinner.addEventFilter(MouseEvent.MOUSE_PRESSED, handler);
spinner.addEventFilter(MouseEvent.MOUSE_RELEASED, evt -> {
if (evt.getButton() == MouseButton.PRIMARY) {
handler.stop();
}
});
Scene scene = new Scene(spinner);
primaryStage.setScene(scene);
primaryStage.show();
}

Answer 2

I modified the answer of fabian a little bit to decrease the speed of the spinner while holding mouse down:
private int currentFrame = 0;
private int previousFrame = 0;
#Override
public void handle(long now)
{
if (now - startTimestamp >= initialDelay)
{
// Single or holded mouse click
if (currentFrame == previousFrame || currentFrame % 10 == 0)
{
if (increment)
{
spinner.increment();
}
else
{
spinner.decrement();
}
}
}
++currentFrame;
}
And after stopping the timer we adjust previousFrame again:
public void stop()
{
previousFrame = currentFrame;
[...]
}

Answer 3

A small improvement to Fabian's answer. Making the following mod to the MOUSE_RELEASED addEventerFilter will stop a NullPointerException caused when clicking the textfield associated with the spinner. Cheers Fabian!
spinner.addEventFilter(MouseEvent.MOUSE_RELEASED, evt -> {
Node node = evt.getPickResult().getIntersectedNode();
if (node.getStyleClass().contains("increment-arrow-button") ||
node.getStyleClass().contains("decrement-arrow-button")) {
if (evt.getButton() == MouseButton.PRIMARY) {
handler.stop();
}
}
});

Answer 4

An alternative to changing the update speed might in some cases be adjusting the amount by which the value increments/decrements per update.
SpinnerValueFactory.IntegerSpinnerValueFactory intFactory =
(SpinnerValueFactory.IntegerSpinnerValueFactory) spinner.getValueFactory();
intFactory.setAmountToStepBy(100);
Reference: http://news.kynosarges.org/2016/10/28/javafx-spinner-for-numbers/