同时按下JavaFX检测多个键盘键

Question

正如标题所说,我想检测同时(同时)按下并同时按下(同时)一段时间的多个键盘按键.我试图添加多个事件处理程序,Scene但它不起作用:

EventHandler<KeyEvent> handler1 = key -> {
     //logic1 here
}

EventHandler<KeyEvent> handler2 = key -> {
     //logic1 here
}

getScene().addEventHandler(KeyEvent.KEY_PRESSED, handler1);
getScene().addEventHandler(KeyEvent.KEY_PRESSED, handler2);

为什么我要这样做:

我有一些代码,我想根据用户的keyboard keys按下调整矩形的大小.例如,如果用户按下RIGHT ARROW矩形,则从右侧增加,如果用户按下,UP ARROW则矩形从顶部增加.

问题:

但是当用户同时按下[ RIGHT ARROW]和[ UP ARROW]并按住它们时,上面的两个动作必须一起发生,而不仅仅是其中一个动作.

Answer 1

只需操作一些布尔属性:

private BooleanProperty upPressed = new SimpleBooleanProperty();
private BooleanProperty rightPressed = new SimpleBooleanProperty();

private BooleanBinding anyPressed = upPressed.or(rightPressed);

// ...

getScene().setOnKeyPressed(e -> {
    if (e.getCode() == KeyCode.UP) {
        upPressed.set(true);
    }
    if (e.getCode() == KeyCode.RIGHT) {
        rightPressed.set(true);
    }
});

getScene().setOnKeyReleased(e -> {
    if (e.getCode() == KeyCode.UP) {
        upPressed.set(false);
    }
    if (e.getCode() == KeyCode.RIGHT) {
        rightPressed.set(false);
    }
});

如果同时按下两个键,则两个属性都为true,因此您可以使用布尔属性注册侦听器,或者AnimationTimer根据需要选中它们,例如:

double delta = .. ;

AnimationTimer timer = new AnimationTimer() {
    @Override
    public void handle(long timestamp) {
        if (upPressed.get()) {
            rect.setY(rect.getY()-delta);
            rect.setHeight(rect.getHeight() + delta);
        }
        if (rightPressed.get()) {
            rect.setWidth(rect.getWidth() + delta);
        }
    }
};

anyPressed.addListener((obs, wasPressed, isNowPressed) -> {
    if (isNowPressed) {
        timer.start();
    } else {
        timer.stop();
    }
});