Develop Reference

Is there a better method than onMouseExited that detects when it exits no matter how fast it moves?

Can someone tell me how I can do so that an animation is made in a pane when the mouse is over said pane and make another when it is the opposite? I tried using the onMouseEntered and onMouseExited methods, with the first one there was no problem, however if we remove the mouse very quickly or abruptly, the program will not detect the exit of the mouse and therefore the animation will not be executed, can someone help me to solve this bug? please
first add 2 methods to an events from the scene builder for the pane, these are said methods
public void scale1 () {
double currentScaleX = pane1.getScaleX();
double currentScaleY = pane1.getScaleY();
if(currentScaleX ==1.0 && currentScaleY ==1.0) {
scale.setNode(pane1);
scale.setDuration(Duration.millis(100));
scale.setByX(0.75);
scale.setByY(0.75);
scale.play();
}
}
public void scale1Re () {
double currentScaleX = pane1.getScaleX();
double currentScaleY = pane1.getScaleY();
if(currentScaleX >1.0 && currentScaleY >1.0) {
scale.setNode(pane1);
scale.setDuration(Duration.millis(100));
scale.setByX(-0.75);
scale.setByY(-0.75);
scale.play();
}
}
However, when executed it works, but if we move the mouse very quickly, it will not detect the change and sometimes it will only execute the first methodIt is not seen in the screenshot, but my mouse is out of the pane
I even tried to make a mouselistener class in my controller class so that it detects when the mouse is out of the pane or something and automatically executes the second method, but I think I did it wrong
#Override
public void initialize(URL arg0, ResourceBundle arg1) {
pane1.setOnMouseExited(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent mouseEvent) {
Bounds bounds = principalPane.getBoundsInParent();
if (bounds.contains(mouseEvent.getSceneX(), mouseEvent.getSceneY())) {
scale1Re();
}
}
});
}

It's not the MouseExited that's being missed, it's the in progress transitions that cause the problem.
Two things need to be done. First, the ScaleTransition has be set to absolutes targets, so setToX() not setByX(). Second, change the play() to playFromStart(). Like so...
class MouseOverExample : Application() {
override fun start(stage: Stage) {
stage.scene = Scene(createContent())
stage.show()
}
private fun createContent(): Region = HBox(40.0).apply {
children += listOf(animatedPane(100.0), animatedPane(500.0), animatedPane(1200.0))
padding = Insets(40.0)
}
private fun animatedPane(transitionDuration: Double): Region = StackPane().apply {
children += Label("H").apply { style = "-fx-font-size: 40px;" }
style = "-fx-border-color: blue; -fx-border-width: 5px;"
padding = Insets(20.0)
val transition: ScaleTransition = ScaleTransition().also {
it.node = this
it.duration = Duration(transitionDuration)
}
onMouseEntered = EventHandler {
with(transition) {
toX = 1.5
toY = 1.5
playFromStart()
}
}
onMouseExited = EventHandler {
with(transition) {
toX = 1.0
toY = 1.0
playFromStart()
}
}
}
}
fun main() {
Application.launch(MouseOverExample::class.java)
}
This is Kotlin, but it should be easy enough to figure out.
This gives three Panes, each with a transition associated with it, and the durations are all different so that you can see how mouse speed has an impact.
At 100ms, a partial grow followed by a shrink looks just fine. At 1200ms, if the mouse exits and the grow transition stops after, say, 100ms then it will still take 1200ms to shrink back to the original size, which is kind of goofy. But in every case the Pane goes back to its original size no matter how fast you sweep the mouse through it.

JavaFX scroll started and ended

I have a very costly action to do on a mouse scroll on a pane. I currently use
pane.setOnScroll({myMethod()}).
The problem is that if you scroll a lot it computes everything many times. So what I want is to do my actions only when the scroll is finished. I hoped to use setOnScrollStarted, save the starting value and setOnScrollFinished to do my actions.
But I don't know why these two methods are never called. As a test I used
pane.setOnScroll({System.out.println("proof of action"});
and it was clearly never called.
Any idea on how to call my method only at the end of the scroll?
Thanks in advance, A

From the javadoc of ScrollEvent (emphasis mine):
When the scrolling is produced by a touch gesture (such as dragging a
finger over a touch screen), it is surrounded by the SCROLL_STARTED
and SCROLL_FINISHED events. Changing number of involved touch points
during the scrolling is considered a new gesture, so the pair of
SCROLL_FINISHED and SCROLL_STARTED notifications is delivered each
time the touchCount changes. When the scrolling is caused by a mouse
wheel rotation, only a one-time SCROLL event is delivered, without the
started/finished surroundings.
A possible workaround:
Increment a counter variable every time a scroll is detected. In the listener start a new thread that waits 1 second and performs the action that you want only if the counter equals to 1 (the last scrolling) then decrements the counter.
I created a Gist, but I copy here the code:
public class ScrollablePane extends Pane {
private Integer scrollCounter = 0;
private final ObjectProperty<EventHandler<? super ScrollEvent>> onScrollEnded = new SimpleObjectProperty<>();
public final ObjectProperty<EventHandler<? super ScrollEvent>> onScrollEndedProperty() {
return onScrollEnded;
}
public ScrollablePane() {
this.setOnScroll(e -> {
scrollCounter++;
Thread th = new Thread(() -> {
try {
Thread.sleep(1000);
if (scrollCounter == 1)
onScrollEnded.get().handle(e);
scrollCounter--;
} catch (Exception e1) {
e1.printStackTrace();
}
});
th.setDaemon(true);
th.start();
});
}
public void setOnScrollEnded(EventHandler<? super ScrollEvent> handler) {
onScrollEnded.setValue(handler);
}
}
To use it:
public class MyApplication extends Application {
#Override
public void start(Stage primaryStage) {
try {
BorderPane root = new BorderPane();
Scene scene = new Scene(root, 400, 400);
ScrollablePane pane = new ScrollablePane();
pane.setOnScrollEnded(e -> System.out.println("Scroll just has been ended"));
root.setCenter(pane);
primaryStage.setScene(scene);
primaryStage.show();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}

JavaFX. stop everything, except one process

public void close(){
KeyValue opacity = new KeyValue(canvas
.opacityProperty(), 0);
KeyFrame end = new KeyFrame(Duration.millis(500),
opacity);
Timeline t = new Timeline(end);
t.play();
t.setOnFinished(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
stage.close();
}
});
}
I have such a method, that changes opacity before quitting from app. It works fine, but during these 0.5 seconds Im still able to interact with UI. The question is how to stop everything except this Timeline execution before quitting?

Depends on how you set up your project. You could add a pane over the entire scene. Well, that doesn't prevent anyone from using the keyboard. So an alternative would be to consume all events like this:
root.addEventFilter(Event.ANY, e -> {
e.consume();
});

Call
stage.getScene().getRoot().setDisable(true);
before you start the timeline

Obtaining a de-focus event other than from Stage - JavaFX

I have a piece of code much like this:
package blah;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.control.TextInputControl;
import javafx.stage.Stage;
public class SimpleExample {
TextInputControl textFieldForWork;
LocalTextChangeListener localTextChangeListener;
public SimpleExample(TextInputControl textFieldForWork, Stage s) {
this.textFieldForWork = textFieldForWork;
localTextChangeListener = new LocalTextChangeListener();
System.out.println("Creating new focus listener for TextField component");
LocalFocusListener localFocusListener = new LocalFocusListener();
s.focusedProperty().addListener(new ChangeListener<Boolean>() {
#Override
public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
if (observable.getValue().toString().equals("false")) {
System.out.println("Removing TextField focus listener");
textFieldForWork.focusedProperty().removeListener(localFocusListener);
} else {
System.out.println("Adding TextField focus listener");
textFieldForWork.focusedProperty().addListener(localFocusListener);
}
}
});
}
private class LocalFocusListener implements ChangeListener {
#Override
public void changed(ObservableValue observable, Object oldValue, Object newValue) {
if (observable.getValue().toString().equals("true")) {
System.out.println("Adding text change listener");
textFieldForWork.textProperty().addListener(localTextChangeListener);
} else {
System.out.println("Removing text change listener");
textFieldForWork.textProperty().removeListener(localTextChangeListener);
}
}
}
private class LocalTextChangeListener implements ChangeListener {
#Override
public void changed(ObservableValue observable, Object oldValue, Object newValue) {
System.out.println("Textfield changed - do processing");
}
}}
The purpose of this code is to fire a listener each time the user types something in the textfield. The other necessary function of this code, is that upon dialog defocus, the textfield listeners should be removed.
Any help appreciated!

I'm not sure I really understand why you need to observe the focused property of the stage. Can't you just register the listener with the text field once and leave it there? It won't be invoked unless the text changes.
If you really need the functionality you describe, you can do it. Here's a description of what's going on:
The focusedProperty of the text field tracks whether or not the Node with focus within the current scene graph is the text field. It is "local to the scene graph", which means it is independent of whether or not the window is the active or focused window.
The focusedProperty of the window tracks whether or not the window has focus. This changes if you move the application to the background, etc.
Obviously, at the point where you create the text field, is hasn't been added to a scene or window, so just doing
textFieldForWork.getScene().getWindow().focusedProperty().addListener(...)
won't work, because getScene() will return null at this point. Even if the scene is non-null, it might not yet belong to a window, so you may have getScene() non-null but getScene().getWindow() null at some point.
So what you actually want to do is observe the sequence of properties. Start with textFieldForWork.sceneProperty() and observe it; if it changes and is non-null, then observe textFieldForInput.getScene().windowProperty(); when that changes and is non-null, observe textFieldForInput.getScene().getWindow().focusedProperty().
You could handle this yourself, creating listeners for each step in the chain and adding and removing them as necessary, but the EasyBind framework has API that manages exactly this use case. Using EasyBind you can do
MonadicObservableValue<Boolean> stageFocused =
EasyBind.monadic(textFieldForWork.sceneProperty())
.flatMap(Scene::windowProperty)
.flatMap(Window::focusedProperty)
.orElse(false);
stageFocused.addListener((obs, wasFocused, isNowFocused) -> {
if (isNowFocused) {
// stage now has focus...
} else {
// stage has lost focus...
}
});
If you want to check the condition that the text field has focus and the window containing it has focus, you can do
BooleanBinding stageAndTextFieldFocused = Bindings.createBooleanBinding(() ->
stageFocused.get() && tf.isFocused(),
stageFocused, tf.focusedProperty());
with stageFocused as above. Then just do
stageAndTextFieldFocused.addListener((obs, wasFocused, isNowFocused) ->
{ /* etc ... */ });

closed javafx window handler

I have to write a method that will do something when the user closes a window. So far I managed to write this code but it does not work (i placed it in my initialize method in my controller) :
Scene scene = myTable.getScene();
Window window = null;
if (scene != null)
{
window = scene.getWindow();
System.out.println("scene is not null");
window.addEventHandler(WindowEvent.WINDOW_HIDDEN, new EventHandler<WindowEvent>
()
{
#Override
public void handle(WindowEvent w)
{
System.out.println("do somethong here");
};
});
Unfortunately Even my message "scene is not null does not get displayed. Does anyone have a better idea on how to do it?

If you want to do something when the user closes the window you should use the setOnCloseRequest() method like this :
window.setOnCloseRequest(new EventHandler<WindowEvent>() {
#Override
public void handle(WindowEvent event) {
//do something
}
});
Now if scene is null then this code won't be executed and nothing will happen, maybe a little System.out.println(scene); before the test would help you debug this issue.

Add a change listener to the scene property of the table, and only add your event handler when the scene is changed to a non-null value.
As recommended by Marc, calling setOnCloseRequest or setOnHidden, is probably a better way to configure your EventHandler.