Spinner

In JavaFX, a Spinner is a control that allows users to select a value from a sequence of values. It usually has up and down arrows to increment or decrement the value. You can use it for numbers, dates, or even custom lists.

Example: Numeric Spinner

FXML (hello-view.fxml)

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Label?>
<?import javafx.scene.control.Spinner?>
<?import javafx.scene.layout.VBox?>

<VBox spacing="15" alignment="CENTER"
      xmlns="http://javafx.com/javafx/17"
      xmlns:fx="http://javafx.com/fxml/1">

    <Label text="Select Quantity"/>
    <Spinner fx:id="quantitySpinner"
             prefWidth="100"/>
</VBox>

Controller (HelloController.java)

package org.example.demo;

import javafx.fxml.FXML;
import javafx.scene.control.Spinner;
import javafx.scene.control.SpinnerValueFactory;

public class HelloController {

    @FXML
    private Spinner<Integer> quantitySpinner;

    @FXML
    public void initialize() {
        // Set numeric values from 0 to 10, starting at 1, step 1
        SpinnerValueFactory<Integer> valueFactory =
                new SpinnerValueFactory.IntegerSpinnerValueFactory(0, 10, 1, 1);
        quantitySpinner.setValueFactory(valueFactory);
    }
}

Key Features of Spinner:

1. ValueFactory: Determines what kind of values the spinner will hold. Examples:

   • IntegerSpinnerValueFactory → numeric integers
   • DoubleSpinnerValueFactory → decimal numbers
   • ListSpinnerValueFactory → custom lists (e.g., ["Red", "Green", "Blue"])

2. Editable: You can allow users to type values manually using spinner.setEditable(true).

3. Increment/Decrement: Controlled by arrows or keyboard.

4. Range and Step: Configured in the SpinnerValueFactory.