JavaFX Transition - Darken button on hover - button

Question

I'm a beginner in JavaFX. I'm trying to create my own Button subclass that would have its on animations for mouse enter and mouse exit. The animation I'm trying to achieve is a simple "darken" or "dim" transition that would darken the color of the button background when user hovers over the button , and would animate back to normal state when the mouse exits the button.
First I thought I can achieve this with FillTransition, but for that I would need the specific darker color of the button, that depends on the button color.
So now I'm trying to basically fade in and fade out a low-opacity black rectangle on top of the button, but the rectangle doesn't seem to appear at all.
Here's the code of my button:
public class FlatButton extends Button {
private Rectangle dimRectangle;
private Duration dimDuration = Duration.millis(250);
private Color dimColor = new Color(0,0,0,0.11);
public FlatButton(String text) {
super(text);
getStyleClass().addAll("flat-button-style");
createEffect();
}
private void createEffect()
{
dimRectangle = new Rectangle(this.getWidth(), this.getHeight(), dimColor);
dimRectangle.setOpacity(1.0);
dimRectangle.setX(this.get);
FadeTransition enterTransition = new FadeTransition(dimDuration, this);
enterTransition.setInterpolator(Interpolator.EASE_OUT);
enterTransition.setFromValue(0.0);
enterTransition.setToValue(1.0);
FadeTransition exitTransition = new FadeTransition(dimDuration, this);
exitTransition.setInterpolator(Interpolator.EASE_OUT);
exitTransition.setFromValue(1.0);
exitTransition.setToValue(0.0);
this.setOnMouseEntered(new EventHandler<MouseEvent>(){
public void handle(MouseEvent mouseEvent){
enterTransition.play();
}
});
this.setOnMouseExited(new EventHandler<MouseEvent>(){
public void handle(MouseEvent mouseEvent){
exitTransition.play();
}
});
}
}
EDIT: The part in the code "new FadeTransition(dimDuration, this);" should be "new FadeTransition(dimDuration, dimRectangle);". It's just something I was testing.
EDIT2: I figured that "dimRectangle = new Rectangle(this.getWidth(), this.getHeight(), dimColor);" is not really working , but I havent found a way yet how to make the rectangle fill the button dimensions.

Answer 1

You could use a ColorAdjust effect and change it's brightness property using a Timeline.
public class ButtonFadeDemo extends Application {
#Override
public void start(Stage primaryStage) {
try {
Pane root = new Pane();
Button button = new Button("Click me!");
ColorAdjust colorAdjust = new ColorAdjust();
colorAdjust.setBrightness(0.0);
button.setEffect(colorAdjust);
button.setOnMouseEntered(e -> {
Timeline fadeInTimeline = new Timeline(
new KeyFrame(Duration.seconds(0),
new KeyValue(colorAdjust.brightnessProperty(), colorAdjust.brightnessProperty().getValue(), Interpolator.LINEAR)),
new KeyFrame(Duration.seconds(1), new KeyValue(colorAdjust.brightnessProperty(), -1, Interpolator.LINEAR)
));
fadeInTimeline.setCycleCount(1);
fadeInTimeline.setAutoReverse(false);
fadeInTimeline.play();
});
button.setOnMouseExited(e -> {
Timeline fadeOutTimeline = new Timeline(
new KeyFrame(Duration.seconds(0),
new KeyValue(colorAdjust.brightnessProperty(), colorAdjust.brightnessProperty().getValue(), Interpolator.LINEAR)),
new KeyFrame(Duration.seconds(1), new KeyValue(colorAdjust.brightnessProperty(), 0, Interpolator.LINEAR)
));
fadeOutTimeline.setCycleCount(1);
fadeOutTimeline.setAutoReverse(false);
fadeOutTimeline.play();
});
root.getChildren().addAll(button);
Scene scene = new Scene(root, 800, 400);
primaryStage.setScene(scene);
primaryStage.show();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}