I have a concurrent task that can be in two states – active (working) and paused (via Thread.sleep(xxxx)). When task is working indeterminate ProgressIndicator should be visible to show user that there is a running Task. When task is paused then ProgressIndicator shouldn’t be shown.

This is my solution:

public class JavaFxTest7 extends Application {

    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage stage) {
        var indicator = new ProgressIndicator();
        indicator.setProgress(ProgressIndicator.INDETERMINATE_PROGRESS);
        var vBox = new VBox(indicator);
        var scene = new Scene(vBox, 300, 200);
        stage.setScene(scene);
        stage.show();

        Task<Boolean> task = new Task<Boolean>() {
            @Override
            protected Boolean call() throws Exception {
                while(!isCancelled()) {
                    this.updateValue(true);
                    for (long l = 1; l < 150000L; l++) {
                        System.out.println("Working");
                    }
                    System.out.println("Pause");
                    this.updateValue(false);
                    Thread.sleep(2500);
                }
                return null;
            }
        };
        indicator.visibleProperty().bind(task.valueProperty());
        new Thread(task).start();
    }

}

This code works as expected and does everything I need. However, I don’t like this solution because it is not logical. I use task value to control visibility of the indicator and it is not good. I wanted to add listener to Task state property but as I understand I can’t control state.

Is there a better solution for such problem? Maybe I should use Service instead of Task?