Exercise30_02.java

package ch_30;

import javafx.application.Application;
import javafx.application.Platform;
import javafx.scene.Scene;
import javafx.scene.input.KeyCode;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Polygon;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;

import java.util.*;
import java.util.stream.Collectors;

/**
 * 30.2 (Racing cars) Rewrite {@linkplain ch_15.Exercise15_29} using a thread to control
 * car racing. Compare the program with Programming Exercise 15.29 by setting
 * the delay time to 10 in both programs. Which one runs the animation faster?
 */
public class Exercise30_02 extends Application {
    @Override
    public void start(Stage primaryStage) {
        CarPane car = new CarPane();

        Scene scene = new Scene(car, 200, 200);
        primaryStage.setTitle(getClass().getName());
        primaryStage.setScene(scene);
        primaryStage.show();

        scene.widthProperty().addListener(e -> car.setW(car.getWidth()));
        scene.heightProperty().addListener(e -> car.setH(car.getHeight()));

        car.setOnMousePressed(e -> car.suspend());
        car.setOnMouseReleased(e -> car.resume());

        car.requestFocus();
        car.setOnKeyPressed(e -> {
            if (e.getCode() == KeyCode.UP) {
                car.faster();
            } else if (e.getCode() == KeyCode.DOWN) {
                car.slower();
            }
        });
    }

}

class CarPane extends Pane {
    private double w = 200;
    private double h = 200;
    private double baseX = 0;
    private double baseY = h;
    private Circle c1 = new Circle(baseX + 10 + 5, baseY - 10 + 5, 5);
    private Circle c2 = new Circle(baseX + 30 + 5, baseY - 10 + 5, 5);

    private Rectangle carBody = new Rectangle(baseX, baseY - 20, 50, 10);
    private Polygon carTop = new Polygon(baseX + 10, baseY - 20,
            baseX + 20, baseY - 30, baseX + 30, baseY - 30,
            baseX + 40, baseY - 20);
    private int sleepTime = 50;

    private Thread thread = new Thread(() -> {
        try {
            while (true) {
                Platform.runLater(() -> move());
                Thread.sleep(sleepTime);
            }
        } catch (InterruptedException ex) {
        }
    });

    public CarPane() {
        carBody.setFill(Color.GREEN);
        carTop.setFill(Color.RED);
        this.getChildren().addAll(c1, c2, carBody, carTop);

        thread.start();
    }

    public void suspend() {
        thread.suspend();
    }

    public void resume() {
        thread.resume();
    }

    public void faster() {
        if (sleepTime > 1)
            sleepTime--;
    }

    public void slower() {
        sleepTime++;
    }

    public void move() {
        if (baseX > w)
            baseX = -20;
        else
            baseX += 1;

        setValues();
    }

    public void setValues() {
        c1.setCenterX(baseX + 10 + 5);
        c1.setCenterY(baseY - 10 + 5);
        c2.setCenterX(baseX + 30 + 5);
        c2.setCenterY(baseY - 10 + 5);

        carBody.setX(baseX);
        carBody.setY(baseY - 20);

        carTop.getPoints().clear();
        carTop.getPoints().addAll(baseX + 10, baseY - 20,
                baseX + 20, baseY - 30, baseX + 30, baseY - 30,
                baseX + 40, baseY - 20);
    }

    public void setW(double w) {
        this.w = w;
        setValues();
    }

    public void setH(double h) {
        this.h = h;
        baseY = h;
        setValues();
    }
}