Progress Indicator

ProgressIndicator in JavaFX is similar to ProgressBar, but it shows progress circularly instead of horizontally. It also ranges from 0.0 (0%) to 1.0 (100%) and can be indeterminate (spinning) when progress isn’t known.

Example: Simple Circular Progress Indicator

FXML (hello-view.fxml)

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

<?import javafx.scene.control.ProgressIndicator?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.VBox?>

<VBox spacing="10" alignment="CENTER"
      xmlns="http://javafx.com/javafx/17"
      xmlns:fx="http://javafx.com/fxml/1"
      fx:controller="org.example.demo.HelloController">

    <ProgressIndicator fx:id="progressIndicator" prefWidth="100" prefHeight="100"/>
    <Button text="Start Task" onAction="#startTask"/>
</VBox>

Controller (HelloController.java)

package org.example.demo;

import javafx.fxml.FXML;
import javafx.scene.control.ProgressIndicator;
import javafx.concurrent.Task;

public class HelloController {

    @FXML
    private ProgressIndicator progressIndicator;

    @FXML
    private void startTask() {
        Task<Void> task = new Task<>() {
            @Override
            protected Void call() throws Exception {
                for (int i = 1; i <= 100; i++) {
                    Thread.sleep(50); // simulate work
                    updateProgress(i, 100); // update progress
                }
                return null;
            }
        };

        progressIndicator.progressProperty().bind(task.progressProperty());

        new Thread(task).start();
    }
}

Key Notes:

1. Progress Value

   • 0.0 → 0%
   • 1.0 → 100%
   • -1 → indeterminate (spinning animation)

2. Binding

   • progressIndicator.progressProperty().bind(task.progressProperty()); keeps the circular indicator synced with the task.

3. Indeterminate Mode Example

progressIndicator.setProgress(-1); // starts spinning

💡 Tip: ProgressIndicator is often used for loading dialogs or tasks where a circular spinner looks cleaner than a horizontal bar.