Make a label update while dragging a slider - slider

Question

I'm using a Slider in my javaFX project and I have a Label that updates when I move the slider.
I want the Label to update whilst I'm dragging the Slider and not only when the drag is dropped.
This is my code:
betSlider.valueChangingProperty().addListener(new ChangeListener<Boolean>() {
#Override
public void changed(ObservableValue<? extends Boolean> source, Boolean oldValue, Boolean newValue) {
betLabel.textProperty().setValue(String.valueOf((int)betSlider.getValue()));
} });

Answer 1

You just need to change the valueChangingProperty() to valueProperty() and TADA, it works as you want !
A small sample is attached here :
import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.Slider;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class Demo extends Application {
#Override
public void start(Stage primaryStage) {
// Add a scene
VBox root = new VBox();
Scene scene = new Scene(root, 500, 200);
final Label betLabel = new Label("sdsd");
final Slider betSlider = new Slider();
betSlider.valueProperty().addListener(new ChangeListener<Number>() {
#Override
public void changed(
ObservableValue<? extends Number> observableValue,
Number oldValue,
Number newValue) {
betLabel.textProperty().setValue(
String.valueOf(newValue.intValue());
}
}
});
root.getChildren().addAll(betSlider, betLabel);
betLabel.textProperty().setValue("abc");
// show the stage
primaryStage.setTitle("Demo");
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}

Answer 2

Bind the label's textProperty to the slider's valueProperty.
A format conversion is required in the binding to make it work.
Either Itachi's valueProperty() ChangeListener or a binding will work.
import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class Slide extends Application {
#Override public void start(Stage stage) {
Label label = new Label();
Slider slider = new Slider(1, 11, 5);
label.textProperty().bind(
Bindings.format(
"%.2f",
slider.valueProperty()
)
);
VBox layout = new VBox(10, label, slider);
layout.setStyle("-fx-padding: 10px; -fx-alignment: baseline-right");
stage.setScene(new Scene(layout));
stage.setTitle("Goes to");
stage.show();
}
public static void main(String[] args) { launch(args); }
}

Answer 3

And if you want to do completely in in FXML, you can do this:
<TextField prefWidth="50" text="${speedSlider.value}"/>
<Slider fx:id="speedSlider" orientation="HORIZONTAL" prefWidth="300"
min="60" max="100000" blockIncrement="100"/>

Answer 4

Adding an alternative that seems simpler and easier to me:
Given a slider named slMySlider and a label named lblMySlider
Add a MouseEvent.MOUSE_DRAGGED event handler to the slider and have it call a helper method:
slMySlider.addEventHandler(MouseEvent.MOUSE_DRAGGED, this::changeLabelHandler);
Have the helper method change the label's text:
private void changeLabelHandler(MouseEvent e) {
lblMySlider.setText("Value: " + String.format("%1.2f", slMySlider.getValue()));
}

Answer 5

slider.valueProperty().addListener((observable, oldValue, newValue) ->
label.setText("sliderNameLabel: " + newValue));

Answer 6

If you have a slider in JavaFX 8, you could do this:
slider().addListener(e -> {
// Your code here could be anything.
});