Question

1. Design and implement an application that displays an animation of a car (side view) moving across the screen from left to right. Create a Car class that represents the car. (Hint: Use timer class as in the Rebound class and here are the list of Graphics methods you can use to draw different shapes: 2. Design and implement an application that draws a traffic light and uses a push button to change the state of the light. Derive the drawing surface from the JPanel class and use another panel to organize the drawing surface and the button.

Answer 1

import java.awt.*;

public class Car {

private int x, y;

private java.awt.Color color;

private boolean isFilled;

/* Creates a new instance of Car /

public Car () {

x = 0;

y = 50;

color = Color.RED;

isFilled = true;

}

public Car (int x, int y, Color color, boolean isFilled ){

this.x = x > 0 ? x: 0;

this.y = y > 40 ? y : 40;

this.color = color;

this.isFilled = isFilled;

}

public void draw (Graphics g){

g.setColor (color);

int xs[] = {x*2, x*2+15, x*2+65, x*2+100};

int ys[] = {y, y-20, y-20, y};

g.fillPolygon (xs, ys, 4);

g.fillRoundRect (x*2, y, 105, 20, 5,5);

g.setColor (Color.black);

g.fillOval (10 + x*2, y+20, 18, 18);

g.fillOval (70 + x*2, y+20, 18, 18);

}

public void move (Graphics g){

x++;

draw (g);

}

}

// Test.java

import java.awt.Color;

import java.awt.Graphics;

import javax.swing.*;

public class Test extends JApplet {

private Car c, c2;

public Test (){

c = new Car ();

c2 = new Car (0,180,Color.ORANGE,true);

}

public void run () {

while(true){

try{

repaint ();

Thread.sleep (20);

} catch (InterruptedException e) {

}

}

}

public void paint (Graphics g) {

super.paint (g);

c.move (g);

c2.move (g);

}

public static void main (String[] args) {

JFrame frame = new JFrame ();

Test t = new Test ();

frame.setTitle ("Moving Car");

frame.getContentPane ().add (t);

frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);

frame.setSize (1024, 400);

frame.setVisible (true);

t.run ();

}

}