java获取在控件的类定义中添加自定义控件的场景大小
我有一个涟漪按钮，一旦点击，就会播放涟漪效果动画。
在按钮的皮肤内部，有一个Circle，在程序开始执行时，它的不透明度被设置为0，单击按钮后，不透明度被设置为1，按钮的半径变大
有一种DoubleBinding结合，其定义如下：
DoubleBinding circleRippleRadius = new DoubleBinding() {
{
bind(heightProperty(), widthProperty()); // Sets the parameters of the bind method.
}
@Override // Overrides the computeValue method, which computes the value of the binding.
protected double computeValue() {
return Math.max(heightProperty().get(), widthProperty().get()); // Return the greatest of both numbers
}
};
我希望使用添加按钮的场景的高度和宽度，而不是使用按钮的heightProperty和widthProperty属性，因为我希望按钮单击后出现的圆圈填充整个屏幕
我怎样才能做到这一点
更新：以下是定义动画组件值和动画本身的代码：
private void createRippleEffect(Circle circleRipple) {
circleRipple.setOpacity(1.0); // Sets the opacity of the circleRipple to 0, since it must not be showed yet.
/*Fade Transition*/
FadeTransition fadeTransition = new FadeTransition(RIPPLE_DURATION, circleRipple);
fadeTransition.setInterpolator(Interpolator.EASE_OUT);
fadeTransition.setFromValue(1.0); // Sets the opacity to %100
fadeTransition.setToValue(1.0); // The opacity doesn't change.
/*Scale Transition*/
Timeline scaleRippleTimeline = new Timeline();
NumberBinding circleRippleRadius =
Bindings.max(Bindings.selectDouble(sceneProperty(), "width"),
Bindings.selectDouble(sceneProperty(), "height"));
circleRippleRadius.addListener((ObservableValue<? extends Number> observable, Number oldValue, Number newValue) -> { // Each time it changes
KeyValue scaleValue = new KeyValue(circleRipple.radiusProperty(), newValue, Interpolator.EASE_OUT);
KeyFrame scaleFrame = new KeyFrame(RIPPLE_DURATION, scaleValue);
scaleRippleTimeline.getKeyFrames().add(scaleFrame);
});
private void createRippleEffect(Circle circleRipple) {
circleRipple.setOpacity(1.0); // Sets the opacity of the circleRipple to 0, since it must not be showed yet.
/*Fade Transition*/
FadeTransition fadeTransition = new FadeTransition(RIPPLE_DURATION, circleRipple);
fadeTransition.setInterpolator(Interpolator.EASE_OUT);
fadeTransition.setFromValue(1.0); // Sets the opacity to %100
fadeTransition.setToValue(1.0); // The opacity doesn't change.
/*Scale Transition*/
Timeline scaleRippleTimeline = new Timeline();
NumberBinding circleRippleRadius =
Bindings.max(Bindings.selectDouble(sceneProperty(), "width"),
Bindings.selectDouble(sceneProperty(), "height"));
circleRippleRadius.addListener((ObservableValue<? extends Number> observable, Number oldValue, Number newValue) -> { // Each time it changes
KeyValue scaleValue = new KeyValue(circleRipple.radiusProperty(), newValue, Interpolator.EASE_OUT);
KeyFrame scaleFrame = new KeyFrame(RIPPLE_DURATION, scaleValue);
scaleRippleTimeline.getKeyFrames().add(scaleFrame);
});
SequentialTransition rippleTransition = new SequentialTransition(); // The circle must change its opacity and scale at the same time
rippleTransition.getChildren().addAll(
scaleRippleTimeline,
fadeTransition
);
ParallelTransition parallelTransition = new ParallelTransition();
getStyleClass().addListener((ListChangeListener.Change<? extends String> c) -> { // Don't pay attention to this. The style changes if
// the CSS file has "toggle" or "flat" inside its list,
// but these are never added so it doesn't matter.
if (c.getList().indexOf("flat") == -1 && c.getList().indexOf("toggle") == -1) {
setMinWidth(88);
setEffect(new DropShadow(BlurType.GAUSSIAN, Color.rgb(0, 0, 0, 0.30), 5, 0.10, 0, 2));
parallelTransition.getChildren().addAll(rippleTransition); // parallelTransition is basically the same as rippleTransition, since
// "toggle" and "flat" are never added to the CSS's list.
} else {
parallelTransition.getChildren().addAll(rippleTransition);
setMinWidth(USE_COMPUTED_SIZE);
setEffect(null);
}
});
this.addEventHandler(MouseEvent.MOUSE_PRESSED, event -> {
parallelTransition.stop(); // In case that the parallelTransition is already running, stop it.
circleRipple.setOpacity(0.0); // Sets the opacity of the circle to 0, since the animation must play from he beginning.
circleRipple.setRadius(0.1); // Sets the radius to 0.1 for the same reason as the circle's opacity.
circleRipple.setCenterX(event.getX()); // The center of the circle is the location in which the mouse was clicked.
circleRipple.setCenterY(event.getY()); // The center of the circle is the location in which the mouse was clicked.
parallelTransition.playFromStart(); // Plays the animation.
});
}
这就是定义按钮外观的方法：
@Override
public Skin<?> createDefaultSkin() {
ButtonSkin buttonSkin = getButtonSkin();
if (buttonSkin == null) {
buttonSkin = new ButtonSkin(this);
Circle circleRipple = new Circle(0.1, RIPPLE_COLOR);
buttonSkin.getChildren().add(0, circleRipple);
setSkin(buttonSkin);
createRippleEffect(circleRipple);
getStyleClass().add("ripple-button"); // What the CSS does is changing the button's color and text size, nothing important.
}
return buttonSkin;
}
提前谢谢
解决方案：
问题是circleRippleRadius的值比舞台的值短，这可能是因为舞台的大小与场景的大小不同。我不知道，现在我知道了
为了让按钮的圆圈填满整个屏幕，我所要做的就是将stage的widthProperty和heightProperty属性作为参数传递给按钮的构造函数
在button的类中，我为宽度和高度创建了两个ReadOnlyDoubleProperty属性，它们在创建按钮之前是空的；在这种情况下，定义的ReadOnlyDoubleProperty属性的值将被作为参数传递的widthProperty和heightProperty属性的值覆盖
这样做之后，我所要做的就是为每个属性添加一个侦听器，并在其中一个属性每次更改时将circleRippleRadius的值更改为更大的属性值
# 1 楼答案
您不应该扩展双重绑定。相反，您应该从现有的工厂方法创建绑定：
要绑定到场景属性，需要使用Bindings.selectDouble，它可以处理按钮最初为空的场景属性：