A small prototype for a switch-lights problem (four or more consecutive lights will be turned off) By Henry Chen https://henry416.wordpress.com

	import javafx.application.Application;
	import javafx.event.EventHandler;
	import javafx.scene.Group;
	import javafx.scene.Scene;
	import javafx.scene.input.MouseEvent;
	import javafx.scene.paint.Color;
	import javafx.scene.shape.Circle;
	import javafx.stage.Stage;
	public class LightSwitch extends Application {
	int[] array = new int[25];
	Circle[] light = new Circle[25];
	@Override
	public void start(Stage stage) {
	init(stage);
	stage.show();
	}
	public void init(Stage stage) {
	Group root = new Group();
	Scene scene = new Scene(root, 700, 500, Color.WHITE);
	for (int i = 0; i < 25; i++) {
	circleChange(i, root);
	}
	root.getChildren().addAll(light);
	stage.setTitle("Lights Problem");
	stage.setScene(scene);
	}
	public void circleChange(final int i, final Group root) {
	light[i] = new Circle(i * 25 + 25, 100, 10);
	light[i].setOnMouseClicked(new EventHandler<MouseEvent>() {
	public void handle(MouseEvent me) {
	if (array[i] == 1)
	array[i] = 0;
	else
	array[i] = 1;
	int counter = 0;
	int place = -1;
	boolean x = false;
	for (int a = 0; a < 25; a++) {
	if (array[a] == 1) {
	if (x == false) {
	place = a;
	x = true;
	}
	counter++;
	} else {
	if (counter >= 4 && x == true)
	a = 26;
	else {
	x = false;
	counter = 0;
	place = -1;
	}
	}
	}
	if (counter >= 4 && x == true)
	for (int b = 0; b < counter; b++)
	array[b + place] = 0;
	paint();
	me.consume();
	}
	});
	}
	public void paint() {
	for (int a = 0; a < 25; a++) {
	if (array[a] == 0)
	light[a].setFill(Color.BLACK);
	else
	light[a].setFill(Color.RED);
	}
	}
	public static void main(String args[]) {
	Application.launch(args);
	}
	}

view raw LightSwitch.java hosted with ❤ by GitHub

Draw a semi ring - JavaFX

	public class SemiDemo extends Application {
	@Override
	public void start(Stage primaryStage) {
	Group root = new Group();
	root.getChildren().add(drawSemiRing(120, 120, 100, 50, Color.LIGHTGREEN, Color.DARKGREEN));
	root.getChildren().add(drawSemiRing(350, 350, 200, 30, Color.LIGHTSKYBLUE, Color.DARKBLUE));
	Scene scene = new Scene(root, 300, 250);
	primaryStage.setScene(scene);
	primaryStage.show();
	}
	private Path drawSemiRing(double centerX, double centerY, double radius, double innerRadius, Color bgColor, Color strkColor) {
	Path path = new Path();
	path.setFill(bgColor);
	path.setStroke(strkColor);
	path.setFillRule(FillRule.EVEN_ODD);
	MoveTo moveTo = new MoveTo();
	moveTo.setX(centerX + innerRadius);
	moveTo.setY(centerY);
	ArcTo arcToInner = new ArcTo();
	arcToInner.setX(centerX - innerRadius);
	arcToInner.setY(centerY);
	arcToInner.setRadiusX(innerRadius);
	arcToInner.setRadiusY(innerRadius);
	MoveTo moveTo2 = new MoveTo();
	moveTo2.setX(centerX + innerRadius);
	moveTo2.setY(centerY);
	HLineTo hLineToRightLeg = new HLineTo();
	hLineToRightLeg.setX(centerX + radius);
	ArcTo arcTo = new ArcTo();
	arcTo.setX(centerX - radius);
	arcTo.setY(centerY);
	arcTo.setRadiusX(radius);
	arcTo.setRadiusY(radius);
	HLineTo hLineToLeftLeg = new HLineTo();
	hLineToLeftLeg.setX(centerX - innerRadius);
	path.getElements().add(moveTo);
	path.getElements().add(arcToInner);
	path.getElements().add(moveTo2);
	path.getElements().add(hLineToRightLeg);
	path.getElements().add(arcTo);
	path.getElements().add(hLineToLeftLeg);
	return path;
	}
	public static void main(String[] args) {
	launch(args);
	}
	}

view raw SemiDemo hosted with ❤ by GitHub