点击并按住鼠标按钮，JavaFX微调器的更改很慢

Question

单击并按住向上/向下箭头按钮时，微调器更新的速度很慢。有没有办法提高更换速度？

当我用鼠标单击、单击、单击时，旋转器值的变化和我单击一样快。如果我每次按下键盘上的上/下箭头，或者如果我按住上/下箭头键，它也会快速变化。我希望当我单击并按住箭头按钮时，值能快速更改。

有人知道怎么做吗？

Answer 1

对费边的回答有一点改进。对鼠标进行以下修改将停止单击与微调器关联的文本字段时引起的NullPointerException。为费边干杯！

    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 2

我稍微修改了fabian的答案，以便在按住鼠标的同时降低旋转器的速度：

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;
}

停止计时器后，我们再次调整前一帧：

public void stop()
{
    previousFrame = currentFrame;

    [...]
}

Answer 3

SpinnerSkin的SpinnerBehavior每750毫秒触发一次更新。不幸的是，如果不使用反射访问private成员，就无法简单地设置/修改此行为。因此，在没有反射的情况下执行此操作的唯一方法是使用事件筛选器以更快的速度触发更新：

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();
}