JavaFX: Is there a way to disable only one button of the Spinner?

Question

I want to disable just one arrow-button of the JavaFX Spinner component, so that they cannot assume illegal values: I have 2 components spinnerMin and spinnerMax with [2-6] as range of values, as in this picture; the behaviour I want is that when they get to the same value (e.g. Min: 3, Max: 3) the up arrow of Min becomes disabled, aswell as the down arrow of Max.

Anyone knows if this is possible or how can I achieve that in the smoothest way possible?

Edit: Thank jewelsea for the suggestion. I've added a listener to the valueProperty and set the valueFactory to change the range and it works as expected, even though it still doesn't disable and "gray out" the arrow, which is the behaviour I would like to achieve (but at this point I'm wondering if it is even possible).

spinnerMin.valueProperty().addListener((changed, oldval, newval) -> {
    spinnerMax.setValueFactory(new SpinnerValueFactory.IntegerSpinnerValueFactory(newval, 6, spinnerMax.getValue()));
});

spinnerMax.valueProperty().addListener((changed, oldval, newval) -> {
    spinnerMin.setValueFactory(new SpinnerValueFactory.IntegerSpinnerValueFactory(2, newval, spinnerMin.getValue()));
});

Answer 1

It is definitely possible to style the buttons as per the value in the spinner.

Below is one way you can accomplish the required behavior.

The general idea is to set some pseudo states to the Spinner when the min/max values are reached. And style the arrow buttons based on the pseudo states.

Below is the sample demo of the above approach.

import javafx.application.Application;
import javafx.css.PseudoClass;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Spinner;
import javafx.scene.control.SpinnerValueFactory;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
public class SpinnerDemo extends Application {
    @Override
    public void start(Stage stage) throws Exception {
        PseudoClass minPseudo = PseudoClass.getPseudoClass("minvalue");
        PseudoClass maxPseudo = PseudoClass.getPseudoClass("maxvalue");

        Spinner<Integer> spinner = new Spinner<>();
        spinner.getStyleClass().add(Spinner.STYLE_CLASS_SPLIT_ARROWS_VERTICAL);
        SpinnerValueFactory.IntegerSpinnerValueFactory valueFactory = new SpinnerValueFactory.IntegerSpinnerValueFactory(2, 5);
        spinner.valueProperty().addListener((obs, old, val) -> {
            spinner.pseudoClassStateChanged(minPseudo, val == valueFactory.getMin());
            spinner.pseudoClassStateChanged(maxPseudo, val == valueFactory.getMax());
        });
        spinner.setValueFactory(valueFactory);

        StackPane root = new StackPane(spinner);
        root.setPadding(new Insets(15));
        Scene sc = new Scene(root, 250, 200);
        sc.getStylesheets().add(getClass().getResource("spinner.css").toString());
        stage.setScene(sc);
        stage.setTitle("Spinner");
        stage.show();
    }
}

CSS code:

.spinner:maxvalue .increment-arrow-button {
    -fx-background-color: -fx-outer-border, #999999;
}
.spinner:minvalue .decrement-arrow-button {
     -fx-background-color: -fx-outer-border, #999999;
}

There may be other ways as well. But I think with this approach you have better control over the styling.