Develop Reference

How to make a method call wait for an animation to finish

I want to make a notification window with animated text. A notification would be sent by a button click and the animation would start playing. My problem is that when I click the button again before the previous animation is done, two animations get executed at once. How do I make each method call of "sendMessage()" wait for the other to finish? If it has any significance there are multiple nodes that call the sendMessage() method in my program unlike in my MRE, so I want some kind of Queue with messages. Here is my MRE:
public class AnimationTest extends Application {
private final Label messageLabel = new Label();
#Override
public void start(Stage stage) throws IOException {
VBox vBox = new VBox();
vBox.setAlignment(Pos.CENTER);
Scene scene = new Scene(vBox, 320, 240);
vBox.getChildren().add(messageLabel);
Button button = new Button();
button.setOnAction(event -> sendMessage("Some animated text."));
vBox.getChildren().add(button);
stage.setScene(scene);
stage.show();
}
private void sendMessage(String message) {
final IntegerProperty i = new SimpleIntegerProperty(0);
Timeline timeline = new Timeline();
KeyFrame keyFrame = new KeyFrame(
Duration.millis(40),
event -> {
if (i.get() > message.length()) {
timeline.stop();
} else {
messageLabel.setText(message.substring(0, i.get()));
i.set(i.get() + 1);
}
});
timeline.getKeyFrames().add(keyFrame);
timeline.setCycleCount(Animation.INDEFINITE);
timeline.play();
}
public static void main(String[] args) {
launch();
}
}

For the specific example you posted, the easiest approach is to disable the button immediately prior to starting the animation, and enable it again when the animation stops. Here is one way to do this:
public class AnimationTest extends Application {
private final Label messageLabel = new Label();
#Override
public void start(Stage stage) {
VBox vBox = new VBox();
vBox.setAlignment(Pos.CENTER);
Scene scene = new Scene(vBox, 320, 240);
vBox.getChildren().add(messageLabel);
Button button = new Button();
button.setOnAction(event -> {
Animation animation = sendMessage("Some animated text.");
button.disableProperty().bind(Bindings.equal(animation.statusProperty(), Animation.Status.RUNNING));
});
vBox.getChildren().add(button);
stage.setScene(scene);
stage.show();
}
private Animation sendMessage(String message) {
final IntegerProperty i = new SimpleIntegerProperty(0);
Timeline timeline = new Timeline();
KeyFrame keyFrame = new KeyFrame(
Duration.millis(40),
event -> {
if (i.get() > message.length()) {
timeline.stop();
} else {
messageLabel.setText(message.substring(0, i.get()));
i.set(i.get() + 1);
}
});
timeline.getKeyFrames().add(keyFrame);
timeline.setCycleCount(Animation.INDEFINITE);
timeline.play();
return timeline ;
}
public static void main(String[] args) {
launch();
}
}
If you want to allow these messages to accumulate in a queue, and a new animation to start when the old one finishes, you need to keep a queue of the messages and a reference to a current animation that's running (if there is one). You can poll the queue from an AnimationTimer and start a new animation when a new message appears, if there is no current animation running.
I'd recommend thinking about whether this is the approach you want to take; there's no guarantee here that your messages will not appear more quickly than they can be animated, in which case the queue will grow indefinitely. However, this is an implementation if you can otherwise assure that this is not the case:
public class AnimationTest extends Application {
private final Label messageLabel = new Label();
private final Queue<String> messages = new LinkedList<>();
private Animation currentAnimation = null ;
#Override
public void start(Stage stage) {
VBox vBox = new VBox();
vBox.setAlignment(Pos.CENTER);
Scene scene = new Scene(vBox, 320, 240);
vBox.getChildren().add(messageLabel);
Button button = new Button();
button.setOnAction(event -> messages.add("Some animated text."));
AnimationTimer timer = new AnimationTimer() {
#Override
public void handle(long l) {
if (currentAnimation == null || currentAnimation.getStatus() == Animation.Status.STOPPED) {
String message = messages.poll();
if (message != null) {
currentAnimation = sendMessage(message);
currentAnimation.play();
}
}
}
};
timer.start();
vBox.getChildren().add(button);
stage.setScene(scene);
stage.show();
}
private Animation sendMessage(String message) {
final IntegerProperty i = new SimpleIntegerProperty(0);
Timeline timeline = new Timeline();
KeyFrame keyFrame = new KeyFrame(
Duration.millis(40),
event -> {
if (i.get() > message.length()) {
timeline.stop();
} else {
messageLabel.setText(message.substring(0, i.get()));
i.set(i.get() + 1);
}
});
timeline.getKeyFrames().add(keyFrame);
timeline.setCycleCount(Animation.INDEFINITE);
return timeline ;
}
public static void main(String[] args) {
launch();
}
}
Note there are no threading considerations here. The handle() method is invoked on the FX Application Thread, so the only requirement is that the messages are placed in the queue on the same thread. This happens in this example because the button's event handler is invoked on that thread. If your messages are coming from a background thread, you should ensure they are added to the queue on the FX Application Thread, either by using Platform.runLater(...) or (preferably) by using the JavaFX Concurrency API (i.e. by retrieving the messages in a Task or Service and adding them to the queue in an onSucceeded handler).

Set a boolean (best do it atomic, because multithreading and stuff...) at animation start & end.
Disable the Button when boolean is in animation phase.

How to check is mouse cursor is on the button in Java FX?

I'm new to Java and I'm wondering if it is possible to check if mouse cursor is for example on the button? I mean not getting clicking events but just moving cursor on the button.
I had working code getting click and then printing something, but I want to change it a little and I can't find out why it doesn't work.
public class Main extends Application implements EventHandler<MouseEvent> {
Button button;
Stage window;
Scene scene;
#Override
public void start(Stage primaryStage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
primaryStage.setTitle("Where's the button?");
button.setText("Click me!");
button.setOnMouseMoved(this);
StackPane layout = new StackPane();
layout.getChildren().add(button);
Scene scene = new Scene(layout, 300,350);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
#Override
public void handle(MouseEvent actionEvent) {
System.out.println("You clicked the button!");
}
}

I have made small code for you. Take a look. It prints in the console "Ho-Ho-Ho-Hovereed!" once you hover over your button.
#Override
public void start(Stage primaryStage) {
Button btn = new Button();
btn.setText("Hover over me.'");
btn.hoverProperty().addListener((event)->System.out.println("Ho-Ho-Ho-Hovereeed!"));
StackPane root = new StackPane();
root.getChildren().add(btn);
Scene scene = new Scene(root, 300, 250);
primaryStage.setTitle("Mouse manpulation example in JavaFX!");
primaryStage.setScene(scene);
primaryStage.show();
}

i guess you can do that with event handler or css, like...
button.setOnMouseEntered(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent mouseEvent) {
System.out.println("Cursor Over Button");
}
});
or/with styles (css)
.button:hover{
-fx-background-color: red;
}

Each Node provides a hover property to track whether the mouse cursor is hovering over it or not. By using a simple listener, you can detect when the mouse starts and stops hovering:
button.hoverProperty().addListener((observable, oldValue, newValue) -> {
if (newValue) {
System.out.println("Hovering...");
} else {
System.out.println("Retreating...");
}
});
With this listener, newValue will always be true if the mouse is currently hovering over the button and change to false when the mouse leaves the area.

There is also a useful check on a Node - isHover() You can use it on MouseEvents to check if the mouse is hovering over the needed node. Such a tip ;)

button.setOnMouseEntered( (event ) -> {
button.setTranslateX(button.getTranslateX() + 20);
button.setTranslateY(button.getTranslateY() + 20);
});`
Replace button.setOnMouseMoved(this); with my code. This will do!

displaying a tooltip in javafx brings its stage into the foreground

I am trying to work around this bug in the jdk: http://bugs.java.com/bugdatabase/view_bug.do?bug_id=8088624
public class Blubb extends Application {
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception {
Button btn = new Button("Click");
btn.setTooltip(new Tooltip("Blubb"));
Scene scene = new Scene(new BorderPane(btn), 320, 240);
primaryStage.setScene(scene);
primaryStage.show();
Stage secondStage = new Stage();
secondStage.setScene(new Scene(new BorderPane(new Button("Click")), 320, 240));
//secondStage.initOwner(primaryStage);
secondStage.show();
}
}
If the button on the primary stage is hovered, it will come in front of the second stage. I found that calling initOwner() on a Stage will eliminate this behavior.
Now my problem is following: I have multiple "popups" that have a common owner (the primary stage). Hovering over controls on the primary stage doesn't cause any unexpected behavior after the initOwner() workaround. If you however hover over controls in a popup while another popup was in focus, the hovered popup will steal focus.
Is there a way I can work around this bug for not only the primary stage but also the popups?
UPDATE: turns out my workaround has undesired side-effects. Javadocs for Stage state following:
A stage will always be on top of its parent window.
So additionally, what would be a workaround that makes the popup not "always on top" and minimizable?

There is a way to get around it by overlaying StackPanes. Create your Scene with a StackPane so that you can add another StackPane when the stage has lost its focus. The overlayed pane will prevent Tooltips or anything else happening on mouse-over while the pane is not in focus. You may also minimize any of your stages and they won't be always-on-top.
public class Blubb extends Application {
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception {
Button button_1 = new Button("Button #1");
button_1.setTooltip(new Tooltip("Blubb #1"));
StackPane primary = new StackPane(new BorderPane(button_1));
primaryStage.setScene(new Scene(primary, 320, 240));
addStageFocusListener(primaryStage, primary);
primaryStage.show();
Button button_2 = new Button("Button #2");
button_2.setTooltip(new Tooltip("Blubb #2"));
StackPane second = new StackPane(new BorderPane(button_2));
Stage secondStage = new Stage();
addStageFocusListener(secondStage, second);
secondStage.setScene(new Scene(second, 320, 240));
secondStage.show();
}
public void addStageFocusListener(Stage stage, StackPane stackPane) {
stage.focusedProperty().addListener(new ChangeListener<Boolean>(){
public final StackPane preventTooltip = new StackPane();
public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
if(stage.isFocused()) {
if(stackPane.getChildren().contains(preventTooltip)) {
stackPane.getChildren().remove(preventTooltip);
}
} else {
stackPane.getChildren().add(preventTooltip);
}
}
});
}
}

You can try this:
public static final disableMouseEventOnUnfocus(final Stage stage)
{
if (stage == null
|| stage.getScene() == null
|| stage.getScene().getRoot() == null)
return;
else
{
stage.getScene().getRoot().mouseTransparentProperty().bind(stage.focusedProperty().not());
}
}
I didn't try it though, but if it works, this should be a good alternative. There is no need to restructure your layout, and you can leave all your layout in FXML, without specifying fx:id for the tooltips.

I've come up with this alternative solution, as I've found it easier in my case to subclass Tooltip and apply a fix there. I just overload the show() method to only show if the owning window is focused. It's working like a charm for me...
public class FixedTooltip extends Tooltip {
public FixedTooltip(String string) {
super(string);
}
#Override
protected void show() {
Window owner = getOwnerWindow();
if (owner.isFocused())
super.show();
}
}

You could try to unset the tooltip whenever the node's window loses focus. Such as below:
public class Blubb extends Application {
public static void main(String[] args) {
launch(args);
}
public static void installTooltip(Node n, Tooltip tp)
{
Window w = n.getScene().getWindow();
w.focusedProperty().addListener((val, before, after) -> {
if (after)
Tooltip.install(n, tp);
else
Tooltip.uninstall(n, tp);
});
if (w.isFocused())
Tooltip.install(n, tp);
else
Tooltip.uninstall(n, tp);
}
#Override
public void start(Stage primaryStage) throws Exception {
Tooltip tp = new Tooltip("Blubb");
Button btn = new Button("Click");
Scene scene = new Scene(new BorderPane(btn), 320, 240);
primaryStage.setScene(scene);
//primaryStage.show();
Stage secondStage = new Stage();
secondStage.setScene(new Scene(new BorderPane(new Button("Click")), 320, 240));
//secondStage.initOwner(primaryStage);
secondStage.show();
primaryStage.show();
installTooltip(btn, tp);
}
}
Of course, you would have to call installTooltip after the node is added to the component.

Javafx: how to fill a TilePane with circles and add an event handler to each one

I tryed with this code but it is not working:
public class Scacchiera extends Application {
TilePane root;
#Override
public void start(Stage primaryStage) {
root = new TilePane();
root.setPrefColumns(4);
root.setPrefRows(4);
for (int i = 0; i < 16; i++) {
Circle c = new Circle(i);
c.addEventHandler(ActionEvent.ACTION, new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
System.out.println("Circle clicked");
}
});
root.getChildren().add(c);
}
Scene scene = new Scene(root, 300, 250);
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Why? Can you help me? I am not sure what is the problem but may be my events handler dies with the for cicle..

Circles are just shapes, they don't have actions like controls.
What you want to do is is handle an onMouseClicked event to your circle:
// java 8
circle.setOnMouseClicked(mouseEvent -> System.out.println("Mouse Clicked!"));

New Stage in Javafx is coming to center

We are using more than one stage(window) in JavaFX for a desktop standalone application. So when we drag or move any of the stage(window) form one point to another and clicking a certain button to navigate to the other page means the new stage is coming to center again(default position). Is there any methods to set the future stage(future windows) also in the previous stage location or point(previous windows). Please help.

You can control stage location before showing it. Just remember last stage coordinates and create new one in the same point:
public class FXStages extends Application {
private int counter = 0;
#Override
public void start(final Stage stage) {
Button btn = new Button();
btn.setText("Reopen");
btn.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
stage.close();
Stage newStage = new Stage();
newStage.setX(stage.getX());
newStage.setY(stage.getY());
start(newStage);
}
});
StackPane root = new StackPane();
root.getChildren().add(btn);
Scene scene = new Scene(root, 300, 250);
stage.setTitle("Stage " + counter++);
stage.setScene(scene);
stage.show();
}
}