Develop Reference

JavaFX mouse drag events not firing

I tried almost everything, but the mouse drag events are not firing, like explained here:
https://openjfx.io/javadoc/11/javafx.graphics/javafx/scene/input/MouseDragEvent.html
Here is a minimal example, so you can try it out (I am using Java 11 with JavaFX 11.0.2):
import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.*;
import javafx.stage.Stage;
public class Main extends Application {
private double mouseClickPositionX, mouseClickPositionY, currentRelativePositionX, currentRelativePositionY;
#Override
public void start(Stage primaryStage) throws Exception{
primaryStage.setTitle("Hello World");
BorderPane mainBorderPane = new BorderPane();
BorderPane centerBorderPane = new BorderPane();
FlowPane flowPane = new FlowPane();
GridPane gridPane = new GridPane();
Button button1 = new Button("button1");
gridPane.add(button1, 0, 0);
flowPane.getChildren().add(gridPane);
centerBorderPane.setCenter(flowPane);
HBox hbox = new HBox();
TilePane tilePane = new TilePane();
Button button2 = new Button("button2");
tilePane.getChildren().add(button2);
hbox.getChildren().add(tilePane);
mainBorderPane.setCenter(centerBorderPane);
centerBorderPane.setBottom(hbox);
// button2 event handlers
button2.setOnMousePressed(event -> {
mouseClickPositionX = event.getSceneX();
mouseClickPositionY = event.getSceneY();
currentRelativePositionX = button2.getTranslateX();
currentRelativePositionY = button2.getTranslateY();
button2.setMouseTransparent(true);
});
button2.setOnMouseDragged(event -> {
button2.setTranslateX(currentRelativePositionX + (event.getSceneX() - mouseClickPositionX));
button2.setTranslateY(currentRelativePositionY + (event.getSceneY() - mouseClickPositionY));
});
button2.setOnDragDetected(event -> {
button2.startFullDrag();
});
button2.setOnMouseReleased((event) -> {
button2.setMouseTransparent(false);
});
// button1 event handlers
button1.setOnMouseDragReleased((event) -> {
System.out.println("it works in button1");
});
// gridPane event handlers
gridPane.setOnMouseDragReleased((event) -> {
System.out.println("it works in gridPane");
});
primaryStage.setScene(new Scene(mainBorderPane, 300, 275));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
I want to get the reference of button2 either in button1 or in gridPane via setOnMouseDragReleased. There are many nested panes etc. because I wanted to maintain the original project layout structure. I did this because I am not sure if this also can be a reason for the non functioning.
Thanks in advance.

I've ended up manually triggering the events from centerBorderPane to gridPane, using node.fireEvent(event). Also implemented a helper function, which returns the right child node:
private Optional<Node> findNode(Pane pane, double x, double y) {
return pane.getChildren().stream().filter(n -> {
Point2D point = n.sceneToLocal(x, y);
return n.contains(point.getX(), point.getY());
}).findAny();
}
Don't forget to consume the events, so you won't get into an infinite loop.

MOUSE_DRAG_RELEASED fires when a drag ends on this node. For example
centerBorderPane.setOnMouseDragReleased((event) -> {
System.out.println("centerBorderPane drag released");
});
should fire when you drag button2 and the drag ends on centerBorderPane.
To fire an event when the mouse is dragged over button1 use button1.setOnMouseDragged
If you want to propagate a mouse event from parent to its children see this

How to reverse animation after it has finished?

I have a list of animations and I want to be able to play them by clicking on a "next" button and playing them back by clicking a "previous" button. So I can play the first animation, then play the 2nd animation, then play the 2nd animation backwards and reach the position like after playing the first animation only.
My problem is that I can't reverse the animation after it's finished. I know that I can set autoReverse but then each animation will reverse immediately.
Here is an example for one animation:
import javafx.animation.TranslateTransition;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
import javafx.util.Duration;
public class AnimTest extends Application {
#Override
public void start(Stage stage) throws Exception {
Circle c = new Circle(5, Color.RED);
TranslateTransition move = new TranslateTransition(Duration.seconds(2), c);
move.setByX(10);
move.setByY(10);
Button next = new Button("Next");
Button previous = new Button("Previous");
next.setOnAction(e -> {
move.setRate(1);
move.play();
});
previous.setOnAction(e -> {
move.setRate(-1);
move.play();
});
Pane p = new Pane(c);
p.setPrefSize(50, 50);
HBox buttons = new HBox(next, previous);
VBox root = new VBox(p, buttons);
stage.setScene(new Scene(root));
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
After pressing "next" I want "previous" to move the ball back to its original position (so effectively x by -10 and y by -10) and not playing the "following" animation in reverse.
In practice, my animations animate different objects in the scenegraph and they can be parallel/sequential transitions. For the list I keep a current location index i and doing:
next.setOnAction(e -> {
Animation move = list.get(i);
move.setRate(1);
move.play();
i++;
});
previous.setOnAction(e -> {
i--;
Animation move = list.get(i);
move.setRate(-1);
move.play();
});
in an attempt to reverse the previous animation.
How can I do this?
To clarify, my list is of Animation. The TranslateTransition was just an example.

The issue here is using "relative" movement instead of absolute movement.
If you set byX = 10 the animation moves the node 10 to the right when played forward which means the proper way of reversing the animation would be to place the node at the end position immediately and then moving the node back to the original location before starting the animation.
Since you don't want to use the same animation over and over again finding the correct way to invert different animations could be difficult for animations using "relative" values. If you instead use absolute ones this shouldn't simply playing the animations backwards shouldn't cause any issues.
Example
#Override
public void start(Stage stage) {
Circle c = new Circle(5, Color.RED);
// create alternating right/down movement animations with absolute movement
List<Animation> animations = new ArrayList<>(10);
for (int i = 0; i < 10; i++) {
TranslateTransition move = new TranslateTransition(Duration.seconds(1), c);
animations.add(move);
int step = i >> 1;
if ((i & 1) == 0) {
move.setFromX(step * 10);
move.setToX((step + 1) * 10);
} else {
move.setFromY(step * 10);
move.setToY((step + 1) * 10);
}
}
final ListIterator<Animation> iterator = animations.listIterator();
Button next = new Button("Next");
Button previous = new Button("Previous");
previous.setDisable(true);
next.setOnAction(e -> {
Animation move = iterator.next();
next.setDisable(!iterator.hasNext());
previous.setDisable(false);
move.setRate(1);
move.play();
});
previous.setOnAction(e -> {
Animation move = iterator.previous();
next.setDisable(false);
previous.setDisable(!iterator.hasPrevious());
move.setRate(-1);
move.play();
});
Pane p = new Pane(c);
p.setPrefSize(100, 100);
HBox buttons = new HBox(next, previous);
VBox root = new VBox(p, buttons);
stage.setScene(new Scene(root));
stage.show();
}

I managed to trick my way into "storing" the reverse cycle for later use using a PauseTransition that pauses the animation after the forward cycle. Then the animation can be played from the second cycle and it will reverse. Not the pretiest solution but it works (except for when you press the buttons too quickly. I tried to solve it with the comment code but it didn't quite get there so if anyone has a solution please tell)
import java.util.ArrayList;
import java.util.List;
import javafx.animation.Animation;
import javafx.animation.ParallelTransition;
import javafx.animation.PauseTransition;
import javafx.animation.TranslateTransition;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
import javafx.util.Duration;
public class AnimTest extends Application {
int current = 0;
final int size = 5;
#Override
public void start(Stage stage) throws Exception {
Circle c = new Circle(10, Color.RED);
List<Animation> animations = new ArrayList<>(size);
for (int i = 0; i < size; i++) {
TranslateTransition move = new TranslateTransition(Duration.seconds(1), c);
move.setByX(20);
move.setByY(20);
PauseTransition pauser = new PauseTransition(move.getCycleDuration());
ParallelTransition parallel = new ParallelTransition(move, pauser);
pauser.setOnFinished(e -> parallel.pause());
parallel.setCycleCount(2);
parallel.setAutoReverse(true);
animations.add(parallel);
}
Button next = new Button("Next");
Button previous = new Button("Previous");
previous.setDisable(true);
Label l = new Label(current + "");
next.setOnAction(e -> {
next.setDisable(current == size - 1);
previous.setDisable(false);
/* if (current > 0) {
Animation last = animations.get(current - 1);
last.jumpTo(last.getCycleDuration());
}*/
Animation cur = animations.get(current);
cur.playFromStart();
current++;
l.setText(current + "");
});
previous.setOnAction(e -> {
current--;
l.setText(current + "");
next.setDisable(false);
previous.setDisable(current == 0);
/* if (current < size - 1) {
Animation last = animations.get(current + 1);
last.stop();
}*/
Animation cur = animations.get(current);
cur.play();
});
Pane p = new Pane(c);
p.setPrefSize(200, 200);
HBox buttons = new HBox(5, next, previous, l);
VBox root = new VBox(p, buttons);
stage.setScene(new Scene(root));
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
I used the disable/enable buttons code from fabian (+1).

I found the quickest solution is to add a listener to the currentRateProperty, listen for it to change to -1 and pause the transition (after the first cycle completes).
There is no cycleCompleted listener or any similar listener, but listening for the cycle to complete can be achieved that way.
Note that the cycleCount must be set to 2, and autoReverse must be set to true.
Node node = ...;
double byX = ...;
TranslateTransition transition = new TranslateTransition();
transition.setNode(node);
transition.setCycleCount(2);
transition.setAutoReverse(true);
transition.setByX(byX);
transition.currentRateProperty().addListener((obs, old, now) -> {
if (now.intValue() == -1) {
transition.pause();
}
});
Button play = new Button("Play");
play.setOnAction(event -> transition.play());
Note that both the forward and backward translation are triggered by the same method call transition.play(), hence there is only one button for both motions, but this of course can be changed. But personally, i like it that way.
In your case, it would look like this:
public class AnimTest extends Application {
#Override
public void start(Stage stage) throws Exception {
Circle c = new Circle(5, Color.RED);
TranslateTransition move = new TranslateTransition(Duration.seconds(2), c);
move.setAutoReverse(true);
move.setCycleCount(2);
move.setByX(10);
move.setByY(10);
move.currentRateProperty().addListener((obs, old, now) -> {
if (now.intValue() == -1) {
move.pause();
}
});
Button next = new Button("Next/Previous");
next.setOnAction(e -> {
move.play();
});
Pane p = new Pane(c);
p.setPrefSize(50, 50);
HBox buttons = new HBox(next);
VBox root = new VBox(p, buttons);
stage.setScene(new Scene(root));
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}

To reverse an animation in java, first you have to set the animation's autoReverse property to true and also set the cycleCount to 2.
Below is a simple code snippet i wrote earlier that makes use of the things stated above.
ScaleTransition scaleTransition = new ScaleTransition(duration, btn);
scaleTransition.setByX(1.2);
scaleTransition.setByY(1.2);
scaleTransition.setAutoReverse(true);
scaleTransition.setCycleCount(2);
scaleTransition.play();

Sidescrolling over image in JavaFX

I've wrapped my brain around a challenge for 2 days now. I am all empty for ideas, so I hope someone out there know how to do this.
I got inspired by Angela Caicedo's city app, from the website https://blogs.oracle.com/acaicedo/entry/managing_multiple_screens_in_javafx, and trying to make a similar app-gui to show available rooms and lecture halls at my University.
I am using Java FX to build the gui, and I get the whole GUI printed out, which is a java fx pane with a image on it. What I want, however, is to just see a small part of the gui (the backgroundimage I am using is w:1500px h:500, so each part will be w:500px h:500px), then be able to push a button or a arrow (or similar) to move the window to the next step. On top of the image there is 3 panes with w:500px h:500px snapped to each other. Maybe this is a bad solution, considering all the pane-types Java FX has available.
So, what I need is a constrained viewer of sorts.
I've also used FMXL to build the GUI, having one FMXL document, one Controller and a css-file to handle the design.
I'm sure I've been everywhere on the internet by now, so I really hope someone has done this before in Java FX :)
Ok, here is some code example. The first sample works nice, but I want to implement the second example instead. I am reading on the TranslateTransition of JavaFX, but my efforts of trying to switch the code is hopeless..
1'st example (working, and is fading in and out of the fxml screen):
public boolean setScreen(final String name){
if (screens.get(name) != null) { //screen loaded
final DoubleProperty opacity = opacityProperty();
if (!getChildren().isEmpty()) { //if there is more than one screen
Timeline fade = new Timeline(
new KeyFrame(Duration.ZERO, new KeyValue(opacity, 1.0)),
new KeyFrame(new Duration(2000), new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent t) {
getChildren().remove(0); //remove the displayed screen
getChildren().add(0, screens.get(name)); //add the screen
Timeline fadeIn = new Timeline(
new KeyFrame(Duration.ZERO, new KeyValue(opacity, 0.0)),
new KeyFrame(new Duration(2000), new KeyValue(opacity, 1.0)));
fadeIn.play();
}
}, new KeyValue(opacity, 0.0)));
fade.play();
} else {
setOpacity(0.0);
getChildren().add(screens.get(name)); //no one else been displayed, then just show
Timeline fadeIn = new Timeline(
new KeyFrame(Duration.ZERO, new KeyValue(opacity, 0.0)),
new KeyFrame(new Duration(1000), new KeyValue(opacity, 1.0)));
fadeIn.play();
}
return true;
} else {
System.out.println("screen hasn't been loaded!!! \n");
return false;
}
}
Second example, the TranslateTransition I want to implement instead:
private final double IMG_WIDTH = 500;
private final double IMG_HEIGHT = 500;
private final int NUM_OF_IMGS = 3;
private final int SLIDE_FREQ = 4; // in secs
#Override
public void start(Stage stage) throws Exception {
stage.initStyle(StageStyle.UNDECORATED);
StackPane root = new StackPane();
Pane clipPane = new Pane();
// To center the slide show incase maximized
clipPane.setMaxSize(IMG_WIDTH, IMG_HEIGHT);
clipPane.setClip(new Rectangle(IMG_WIDTH, IMG_HEIGHT));
HBox imgContainer = new HBox();
ImageView imgGreen = new ImageView(new Image(getClass().getResourceAsStream("uib_01.jpg")));
ImageView imgBlue = new ImageView(new Image(getClass().getResourceAsStream("uib_02.jpg")));
ImageView imgRose = new ImageView(new Image(getClass().getResourceAsStream("uib_03.jpg")));
imgContainer.getChildren().addAll(imgGreen, imgBlue, imgRose);
clipPane.getChildren().add(imgContainer);
root.getChildren().add(clipPane);
Scene scene = new Scene(root, IMG_WIDTH, IMG_HEIGHT);
stage.setTitle("Image Slider");
stage.setScene(scene);
startAnimation(imgContainer);
stage.show();
}
private void startAnimation(final HBox hbox) {
EventHandler<ActionEvent> slideAction = (ActionEvent t) -> {
TranslateTransition trans = new TranslateTransition(Duration.seconds(1.5), hbox);
trans.setByX(-IMG_WIDTH);
trans.setInterpolator(Interpolator.EASE_BOTH);
trans.play();
};
EventHandler<ActionEvent> resetAction = (ActionEvent t) -> {
TranslateTransition trans = new TranslateTransition(Duration.seconds(1), hbox);
trans.setByX((NUM_OF_IMGS - 1) * IMG_WIDTH);
trans.setInterpolator(Interpolator.EASE_BOTH);
trans.play();
};
List<KeyFrame> keyFrames = new ArrayList<>();
for (int i = 1; i <= NUM_OF_IMGS; i++) {
if (i == NUM_OF_IMGS) {
keyFrames.add(new KeyFrame(Duration.seconds(i * SLIDE_FREQ), resetAction));
} else {
keyFrames.add(new KeyFrame(Duration.seconds(i * SLIDE_FREQ), slideAction));
}
}
Timeline anim = new Timeline(keyFrames.toArray(new KeyFrame[NUM_OF_IMGS]));
anim.setCycleCount(Timeline.INDEFINITE);
anim.playFromStart();
}
The screen should change on button click. I have this in a separate controller class:
import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.image.ImageView;
import javafx.scene.input.MouseEvent;
public class roomAppController implements Initializable, ScreenController {
private ScreenPane myScreenPane;
#FXML
public ImageView bldArw_1;
public ImageView rmArw_1;
#FXML
private void handleExitButtonEvent(MouseEvent e) {
System.out.println("Button is clicked");
System.exit(0);
}
#FXML
private void handleNextPageEvent(MouseEvent e) {
if((ImageView)e.getSource() == bldArw_1) {
myScreenPane.setScreen("buildingScreen");
}
if((ImageView)e.getSource() == rmArw_1) {
myScreenPane.setScreen("roomScreen");
}
System.out.println("Clicked");
}
#Override
public void initialize(URL location, ResourceBundle resources) {
}
#Override
public void setScreenPane(ScreenPane screenPage) {
myScreenPane = screenPage;
}
}

JavaFx Transparent window - yes please. Mouse transparent - no thanks

I would like to create a simple JavaFx class that shows the user a translucent rectangle (say an arbitrary 50% transparency) covering the users screen. It should simply allow me to get the Point of a mouse click event. This sounds trivial, but when I create transparent windows they always seem to be transparent to mouse events rather than just my requirement of semi-transparent visibility. The mouse event is never triggered.
I've used setMouseTransparent(false) on the rectangle and the root pane, but this makes no difference. I'd be really grateful if somebody could indicate any errors/misconceptions.
Here's the trivial test class I have created:
public class ClickScreen implements MouseListener {
private ClickScreenListener listener;
private Stage window;
private Point point;
public ClickScreen(ClickScreenListener listener) {
// Get screen size
Rectangle2D r = Screen.getPrimary().getBounds();
// Something to put stuff in
StackPane root = new StackPane();
// Translucent rectangle on the pane
Rectangle rectangle = new Rectangle(r.getWidth(), r.getHeight());
rectangle.setFill(Color.rgb(183, 183, 183, 0.5));
root.getChildren().add(rectangle);
Scene scene = new Scene(root, r.getWidth(), r.getHeight());
scene.setFill(null);
window = new Stage();
window.initStyle(StageStyle.TRANSPARENT);
window.setTitle("Click drop location");
window.setScene(scene);
this.listener = listener;
}
public Point getLocation(){
return point;
}
#Override
public void mouseClicked(MouseEvent e) {
point = e.getLocationOnScreen();
listener.screenClicked(point);
}
}
Edit:
A simpler example of the transparency issue I am experiencing is from this Hello World! example. When I mouse over the button, it's about 50:50 chance of clicking the button or just clicking "through" and giving focus to the underlying window (which is usually eclipse in my case). Would love you thoughts on this.
public class HelloWorld extends Application {
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) {
primaryStage.setTitle("Hello World!");
Button btn = new Button();
btn.setText("Say 'Hello World'");
btn.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
System.out.println("Hello World!");
}
});
StackPane root = new StackPane();
root.getChildren().add(btn);
Scene scene = new Scene(root, 300, 250);
scene.setFill(null);
primaryStage.setScene(scene);
primaryStage.initStyle(StageStyle.TRANSPARENT);
primaryStage.show();
}
}

Check your Imports
You are using some kind of weird setup where you are mixing AWT/Swing classes and JavaFX classes, which really isn't advised (and doesn't work at all in the combination and manner you have used). Just be careful in your JavaFX programs not to import any java.awt.* or javax.swing.* classes unless you really know what you are doing in mixing code for two different toolkits.
Sample Solution
Here is a sample solution which imports only JavaFX classes and utilizes JavaFX events, but otherwise tries to stick to the coding/callback style of the sample code in your question. (The sample could be further simplified through use of Java 8 lambdas).
import javafx.application.Application;
import javafx.event.*;
import javafx.geometry.*;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.*;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.*;
public class ClickListenerSample
extends Application
implements ClickScreenListener {
private Label clickFeedbackLabel = new Label("");
#Override public void start(Stage stage) {
Button listen = new Button("listen");
listen.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
new ClickScreen(ClickListenerSample.this);
}
});
VBox layout = new VBox(10);
layout.getChildren().setAll(
listen,
clickFeedbackLabel
);
layout.setPadding(new Insets(10));
stage.setScene(new Scene(layout, 100, 80));
stage.show();
}
public static void main(String[] args) {
launch(args);
}
#Override public void screenClicked(Point2D point) {
clickFeedbackLabel.setText(point.getX() + ", " + point.getY());
}
}
interface ClickScreenListener {
void screenClicked(Point2D point);
}
class ClickScreen {
private ClickScreenListener listener;
private Stage window;
private Point2D point;
public ClickScreen(ClickScreenListener listener) {
// Get screen size
Rectangle2D r = Screen.getPrimary().getBounds();
// Something to put stuff in
StackPane root = new StackPane();
root.setStyle("-fx-background-color: null;");
// Translucent rectangle on the pane
Rectangle rectangle = new Rectangle(r.getWidth(), r.getHeight());
rectangle.setFill(Color.rgb(183, 183, 183, 0.5));
root.getChildren().add(rectangle);
Scene scene = new Scene(root, r.getWidth(), r.getHeight());
scene.setFill(null);
window = new Stage();
window.initStyle(StageStyle.TRANSPARENT);
window.setTitle("Click drop location");
window.setScene(scene);
scene.setOnMouseClicked(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent event) {
point = new Point2D(event.getScreenX(), event.getScreenY());
listener.screenClicked(point);
window.hide();
}
});
window.show();
this.listener = listener;
}
public Point2D getLocation(){
return point;
}
}

JavaFX effect on background

I'm using this to make a iOS-themed JavaFX2 (Java7) application with a frosted glass effect. The problem is that this code uses its effect on an ImageView. I'd like it to use its effect on whatever's behind the window, like this:
Is there anyway to do that? I'd also like that small drop-shadow effect you see around the above image.
To be clear, I don't want that slider or anything, just the effect of being able to see through the window and having that slight shadow around the edges. I want to use this iOS7-ish effect instead of aero, though.
This might be important: I'm using a modified version of Undecorator.

import javafx.animation.*;
import javafx.application.*;
import javafx.beans.property.*;
import javafx.embed.swing.SwingFXUtils;
import javafx.geometry.Insets;
import javafx.scene.*;
import javafx.scene.control.Label;
import javafx.scene.effect.*;
import javafx.scene.Cursor;
import javafx.scene.Node;
import javafx.scene.image.*;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
import javafx.stage.StageStyle;
import javafx.util.Duration;
public class FrostyTech extends Application {
private static final double BLUR_AMOUNT = 10;
private static final Effect frostEffect =
new BoxBlur(BLUR_AMOUNT, BLUR_AMOUNT, 3);
private static final ImageView background = new ImageView();
private static final StackPane layout = new StackPane();
#Override public void start(Stage stage) {
layout.getChildren().setAll(background, createContent());
layout.setStyle("-fx-background-color: null");
Scene scene = new Scene(
layout,
200, 300,
Color.TRANSPARENT
);
Platform.setImplicitExit(false);
scene.setOnMouseClicked(event -> {
if (event.getClickCount() == 2) Platform.exit();
});
makeSmoke(stage);
stage.initStyle(StageStyle.TRANSPARENT);
stage.setScene(scene);
stage.show();
background.setImage(copyBackground(stage));
background.setEffect(frostEffect);
makeDraggable(stage, layout);
}
// copy a background node to be frozen over.
private Image copyBackground(Stage stage) {
final int X = (int) stage.getX();
final int Y = (int) stage.getY();
final int W = (int) stage.getWidth();
final int H = (int) stage.getHeight();
try {
java.awt.Robot robot = new java.awt.Robot();
java.awt.image.BufferedImage image = robot.createScreenCapture(new java.awt.Rectangle(X, Y, W, H));
return SwingFXUtils.toFXImage(image, null);
} catch (java.awt.AWTException e) {
System.out.println("The robot of doom strikes!");
e.printStackTrace();
return null;
}
}
// create some content to be displayed on top of the frozen glass panel.
private Label createContent() {
Label label = new Label("Create a new question for drop shadow effects.\n\nDrag to move\n\nDouble click to close");
label.setPadding(new Insets(10));
label.setStyle("-fx-font-size: 15px; -fx-text-fill: green;");
label.setMaxWidth(250);
label.setWrapText(true);
return label;
}
// makes a stage draggable using a given node.
public void makeDraggable(final Stage stage, final Node byNode) {
final Delta dragDelta = new Delta();
byNode.setOnMousePressed(mouseEvent -> {
// record a delta distance for the drag and drop operation.
dragDelta.x = stage.getX() - mouseEvent.getScreenX();
dragDelta.y = stage.getY() - mouseEvent.getScreenY();
byNode.setCursor(Cursor.MOVE);
});
final BooleanProperty inDrag = new SimpleBooleanProperty(false);
byNode.setOnMouseReleased(mouseEvent -> {
byNode.setCursor(Cursor.HAND);
if (inDrag.get()) {
stage.hide();
Timeline pause = new Timeline(new KeyFrame(Duration.millis(50), event -> {
background.setImage(copyBackground(stage));
layout.getChildren().set(
0,
background
);
stage.show();
}));
pause.play();
}
inDrag.set(false);
});
byNode.setOnMouseDragged(mouseEvent -> {
stage.setX(mouseEvent.getScreenX() + dragDelta.x);
stage.setY(mouseEvent.getScreenY() + dragDelta.y);
layout.getChildren().set(
0,
makeSmoke(stage)
);
inDrag.set(true);
});
byNode.setOnMouseEntered(mouseEvent -> {
if (!mouseEvent.isPrimaryButtonDown()) {
byNode.setCursor(Cursor.HAND);
}
});
byNode.setOnMouseExited(mouseEvent -> {
if (!mouseEvent.isPrimaryButtonDown()) {
byNode.setCursor(Cursor.DEFAULT);
}
});
}
private javafx.scene.shape.Rectangle makeSmoke(Stage stage) {
return new javafx.scene.shape.Rectangle(
stage.getWidth(),
stage.getHeight(),
Color.WHITESMOKE.deriveColor(
0, 1, 1, 0.08
)
);
}
/** records relative x and y co-ordinates. */
private static class Delta {
double x, y;
}
public static void main(String[] args) {
launch(args);
}
}
Related Questions
Frosted Glass Effect in JavaFX?
How do I create a JavaFX transparent stage with shadows on only the border?

The visual effect that you want for OS dependent window decoration, can only be achieved through the APIs that OS provides. And thus was eliminated by StageStyle.TRANSPARENT below.
For JavaFX content itself, you can control the visuals of the stage > scene > root pane hierarchy. Stage and scene do not (and not aimed to) support advanced stylings so were eliminated by setting as transparent below.
#Override
public void start(Stage primaryStage) {
StackPane root = new StackPane();
root.setStyle("-fx-background-color: null;");
root.setPadding(new Insets(10));
DoubleProperty doubleProperty = new SimpleDoubleProperty(0);
Region region = new Region();
region.styleProperty().bind(Bindings
.concat("-fx-background-radius:20; -fx-background-color: rgba(56, 176, 209, ")
.concat(doubleProperty)
.concat(");"));
region.setEffect(new DropShadow(10, Color.GREY));
Slider slider = new Slider(0, 1, .3);
doubleProperty.bind(slider.valueProperty());
root.getChildren().addAll(region, slider);
primaryStage.initStyle(StageStyle.TRANSPARENT);
Scene scene = new Scene(root, 300, 250);
scene.setFill(Color.TRANSPARENT);
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
However the drop shadow effect does not play well with alpha value of the background color. You can observe it by changing the shadow's color to another contrast one.
Output:

To expand on Jewlsea's answer .. And using the above example with JavaFX ONLY ..
While the classes are not public API, it does avoid the AWT stack completely.
Here is a non public example :
// copy a background node to be frozen over.
private Image copyBackground(Stage stage) {
final int X = (int) stage.getX();
final int Y = (int) stage.getY();
final int W = (int) stage.getWidth();
final int H = (int) stage.getHeight();
final Screen screen = Screen.getPrimary();
try {
Robot rbt = com.sun.glass.ui.Application.GetApplication().createRobot();
Pixels p = rbt.getScreenCapture(
(int)screen.getBounds().getMinX(),
(int)screen.getBounds().getMinY(),
(int)screen.getBounds().getWidth(),
(int)screen.getBounds().getHeight(),
true
);
WritableImage dskTop = new WritableImage((int)screen.getBounds().getWidth(), (int)screen.getBounds().getHeight());
dskTop.getPixelWriter().setPixels(
(int)screen.getBounds().getMinX(),
(int)screen.getBounds().getMinY(),
(int)screen.getBounds().getWidth(),
(int)screen.getBounds().getHeight(),
PixelFormat.getByteBgraPreInstance(),
p.asByteBuffer(),
(int)(screen.getBounds().getWidth() * 4)
);
WritableImage image = new WritableImage(W,H);
image.getPixelWriter().setPixels(0, 0, W, H, dskTop.getPixelReader(), X, Y);
return image;
} catch (Exception e) {
System.out.println("The robot of doom strikes!");
e.printStackTrace();
return null;
}
}
Results with a small dropshadow added:
DropShadow shdw = new DropShadow();
shdw.setBlurType(BlurType.GAUSSIAN);
shdw.setColor(Color.GAINSBORO);
shdw.setRadius(10);
shdw.setSpread(0.12);
shdw.setHeight(10);
shdw.setWidth(10);
layout.setEffect(shdw);

The opacity is a property of Node, which is the parent class in JavaFX for things that show up on the screen. http://docs.oracle.com/javafx/2/api/javafx/scene/Node.html#opacityProperty
So you can just set the opacity on the object that you want to have fade away. You then have to add some sort of way to change the opacity on the desired object. Using the slider from your image is one way, but there are others.
Drop shadows can be done using the DropShadow effect... http://docs.oracle.com/javafx/2/api/javafx/scene/effect/DropShadow.html. I have never used it. This is a little high level but if there are follow up questions in the comments I can help answer them.