Java GUI: Developing a Dartboard Applet and Smiley Tennis Ball Design

This assignment showcases Java code for creating a dartboard applet and a smiley tennis ball graphic using Java Swing. The dartboard applet allows customization of the diameter and number of lines, drawing concentric circles and radial lines. The smiley tennis ball graphic demonstrates drawing basic shapes like circles, ovals, and lines to create a simple face on the ball. The code provides examples of using Graphics class methods such as drawOval, drawLine, fillOval, and fill3DRect for GUI design in Java. Desklib offers this assignment as a resource for students, alongside a wide range of past papers and solved assignments.

Part 1
import java.awt.Graphics;
import javax.swing.JApplet;
public class Dartboard extends JApplet {
int Diameter;
int NumberPoints;
int inputlines;
double angle;
public void init() {
final int input = Integer.parseInt(getParameter("Width"));
final int Lines = Integer.parseInt(getParameter("Lines"));
Diameter = input;
inputlines = Lines;
}
// draw shapes on applet's background
public void paint(Graphics g) {
super.paint(g); // call paint method inherited from JApplet
g.drawOval(0, 0,
Diameter, Diameter);
g.drawOval(((Diameter / 2) / 3), ((Diameter / 2) / 3),
((Diameter / 3) * 2), ((Diameter / 3) * 2));
// done processing case
g.drawOval((((Diameter / 2) / 3) * 2), (((Diameter / 2) / 3) * 2),
(Diameter / 3), (Diameter / 3));
//check if the number of passed lines is within the bounds of the
requirements
if (inputlines < 2 || inputlines > 30) {
NumberPoints = 20;
} else {
NumberPoints = inputlines;
}
//find the angle that is to be used for the lines
angle = 360 / (double) NumberPoints;
int i; //for loop statement
int x; // X coordinate
int y; //y coordinate
for (i = 0; i < NumberPoints; i++) {
// find line angle in radians
double w = (angle * i) * Math.PI / 180;
x = (int) ((Diameter / 2) * Math.cos(w));

y = (int) ((Diameter / 2) * Math.sin(w));
g.drawLine(x + (Diameter / 2), y + (Diameter / 2), (Diameter /
2), (Diameter / 2));
}
}
}
Design
Smiley Tennis Ball at the Ireland v Georgia game.
Code:
import java.awt.*;
import java.awt.Event.*;
import javax.swing.*;
public class Flag extends JPanel {
public static void main(String[] args){
JFrame f = new JFrame("Flag");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Flag fl = new Flag();
fl.setBackground(Color.WHITE);
f.add(fl);
f.setSize(500, 270);
f.setVisible(true);
}
public void paintComponent(Graphics g){
super.paintComponent(g);
this.setBackground(Color.WHITE);

g.setColor(Color.GREEN);
g.fill3DRect(10, 10, 100, 50, true);
g.setColor(Color.WHITE);
g.fill3DRect(110, 10, 100, 50, true);
g.setColor(Color.ORANGE);
g.fill3DRect(210, 10, 100, 50, true);
g.setColor(Color.YELLOW);
g.fillOval(100,100,100,100);
g.setColor(Color.BLACK);
g.fillOval(120,125,20,20);
g.fillOval(160,125,20,20);
g.drawLine(150,165,150,150);
g.drawArc(110,106,80,90,-30,-120);
}
}
Screenshot