Notes

1.shape

import java.awt.Graphics;
import javax.swing.JPanel;

public class Shapes extends JPanel {

private final int choice; // user's choice of which shape to draw

// constructor sets the user's choice
public Shapes(int userChoice) {
choice = userChoice;
}

// draws a cascade of shapes starting from the top-left corner
public void paintComponent(Graphics g) {
super.paintComponent(g);

for (int i = 0; i < 10; i++) {
// pick the shape based on the user's choice
switch (choice) {
case 1 -> // draw rectangles
g.drawRect(10 + i * 10, 10 + i * 10,
50 + i * 10, 50 + i * 10);
case 2 -> // draw ovals
g.drawOval(10 + i * 10, 10 + i * 10,
50 + i * 10, 50 + i * 10);
}
}
}
}
1.2.shape test
import javax.swing.JFrame; // handle the display
import javax.swing.JOptionPane;

public class ShapesTest
{
public static void main(String[] args)
{
// obtain user's choice
String input = JOptionPane.showInputDialog(
"Enter 1 to draw rectanglesn" +
"Enter 2 to draw ovals");

int choice = Integer.parseInt(input); // convert input to int

// create the panel with the user's input
Shapes panel = new Shapes(choice);

JFrame application = new JFrame(); // creates a new JFrame

application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
application.add(panel);
application.setSize(300, 300);
application.setVisible(true);
}
}

2.draw panel
import java.awt.Graphics;
import javax.swing.JPanel;

public class DrawPanel1 extends JPanel {

public void paintComponent(Graphics g) {
super.paintComponent(g);
int width = getWidth();
int height = getHeight();
g.drawLine(0, 0, width, height);

g.drawLine(0, height, width, 0);
}
}


2.1. draw panel test
import javax.swing.JFrame;

public class DrawPanel1Test {

public static void main(String[] args) {
DrawPanel1 panel = new DrawPanel1();

JFrame application = new JFrame();
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
application.add(panel);
application.setSize(500, 500);
application.setVisible(true);
}
}
3.draw smiely
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;

public class DrawSmiley extends JPanel {

public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.fillOval(10, 10, 200, 200);
g.setColor(Color.BLACK);
g.fillOval(55, 65, 30, 30);
g.fillOval(135, 65, 30, 30);
g.fillOval(50, 110, 120, 60);
g.setColor(Color.BLACK);
g.fillRect(50, 110, 120, 30);
g.fillOval(50, 120, 120, 40);
}
}

3.1- smiely test
import javax.swing.JFrame;

public class DrawSmileyTest
{
public static void main(String[] args)
{
DrawSmiley panel = new DrawSmiley();
JFrame application = new JFrame();

application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
application.add(panel);
application.setSize(300 ,300);
application.setVisible(true);
}
}

4.dialoge
import javax.swing.JOptionPane;

public class Dialog {

public static void main(String[] args) {
JOptionPane.showMessageDialog(null, "Welcome to Java");
}
}
5.