Converting from Timeline to Thread - multithreading

Question

I am trying to create a program that runs off of a thread instead of a timeline. Here is my modified program down below. I am not sure why it will not work. Any tips would be appreciated. The thread uses a task in order to start the animation. Thanks for your help.
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Arc;
import javafx.scene.shape.ArcType;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;
import javafx.util.Duration;
public class ch30 extends Application {
#Override // Override the start method in the Application class
public void start(Stage primaryStage) {
FanPane fan = new FanPane();
HBox hBox = new HBox(5);
Button btPause = new Button("Pause");
Button btResume = new Button("Resume");
Button btReverse = new Button("Reverse");
hBox.setAlignment(Pos.CENTER);
hBox.getChildren().addAll(btPause, btResume, btReverse);
BorderPane pane = new BorderPane();
pane.setCenter(fan);
pane.setBottom(hBox);
// Create a scene and place it in the stage
Scene scene = new Scene(pane, 200, 200);
primaryStage.setTitle("Exercise15_28"); // Set the stage title
primaryStage.setScene(scene); // Place the scene in the stage
primaryStage.show(); // Display the stage
Runnable first = new Begin();
Thread t1 = new Thread(first);
t1.start();
//Timeline animation = new Timeline(
//new KeyFrame(Duration.millis(100), e -> fan.move()));
//animation.setCycleCount(Timeline.INDEFINITE);
//animation.play(); // Start animation
scene.widthProperty().addListener(e -> fan.setW(fan.getWidth()));
scene.heightProperty().addListener(e -> fan.setH(fan.getHeight()));
//btPause.setOnAction(e -> first.wait());
btResume.setOnAction(e -> first.run());
btReverse.setOnAction(e -> fan.reverse());
}
/**
* The main method is only needed for the IDE with limited
* JavaFX support. Not needed for running from the command line.
*/
public static void main(String[] args) {
launch(args);
}
}
class FanPane extends Pane {
private double w = 200;
private double h = 200;
private double radius = Math.min(w, h) * 0.45;
private Arc arc[] = new Arc[4];
private double startAngle = 30;
private Circle circle = new Circle(w / 2, h / 2, radius);
public FanPane() {
circle.setStroke(Color.BLACK);
circle.setFill(Color.WHITE);
getChildren().add(circle);
for (int i = 0; i < 4; i++) {
arc[i] = new Arc(w / 2, h / 2, radius * 0.9, radius * 0.9, startAngle + i * 90, 35);
arc[i].setFill(Color.RED); // Set fill color
arc[i].setType(ArcType.ROUND);
getChildren().addAll(arc[i]);
}
}
private double increment = 5;
public void reverse() {
increment = -increment;
}
public void move() {
setStartAngle(startAngle + increment);
}
public void setStartAngle(double angle) {
startAngle = angle;
setValues();
}
public void setValues() {
radius = Math.min(w, h) * 0.45;
circle.setRadius(radius);
circle.setCenterX(w / 2);
circle.setCenterY(h / 2);
for (int i = 0; i < 4; i++) {
arc[i].setRadiusX(radius * 0.9);
arc[i].setRadiusY(radius * 0.9);
arc[i].setCenterX(w / 2);
arc[i].setCenterY(h / 2);
arc[i].setStartAngle(startAngle + i * 90);
}
}
public void setW(double w) {
this.w = w;
setValues();
}
public void setH(double h) {
this.h = h;
setValues();
}
}
class Begin implements Runnable {
private int times = 1000;
FanPane fan = new FanPane();
public Begin(){
// times = t;
}
#Override
public void run(){
//for (int i = 0; i < times; i++)
//{
fan.move();
}
}

Answer 1

Your thread needs a loop, that repeatedly pauses and then updates the UI. If you want to use an explicit thread instead of the more obvious Timeline, you need to write the code for that loop yourself.
The update of the UI cannot be called from the background thread you are creating: to update the UI on the FX Application thread you must wrap the call to the method(s) that update the UI in Platform.runLater(...).