Unit-5: GUI Programming, Building Applets and Introduction to Annotations

Required packages,

1. The java.awt package contains the core AWT graphics classes:
   • GUI Component classes (such as Button, TextField, and Label),
   • GUI Container classes (such as Frame, Panel, Dialog and ScrollPane),
   • Layout managers (such as FlowLayout, BorderLayout and GridLayout),
   • Custom graphics classes (such as Graphics, Color and Font).
2. The java.awt.event package supports event handling:
• Event classes (such as ActionEvent, MouseEvent, KeyEvent and WindowEvent),
• Event Listener Interfaces (such as ActionListener, MouseListener, KeyListener and WindowListener),
• Event Listener Adapter classes (such as MouseAdapter, KeyAdapter, and WindowAdapter).

Simple java application

import javax.swing.JOptionPane;

public class HelloWorldGUI1 {
   
   public static void main(String[] args) {
      JOptionPane.showMessageDialog( null, "Hello World!" );
   }

}

another simple source code for the java gui.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class HelloWorldGUI2 {
   
   private static class HelloWorldDisplay extends JPanel {
      public void paintComponent(Graphics g) {
         super.paintComponent(g);
         g.drawString( "Hello World!", 20, 30 );
      }
   }
   
   private static class ButtonHandler implements ActionListener {
      public void actionPerformed(ActionEvent e) {
         System.exit(0);
      }
   }
   
   public static void main(String[] args) {
      
      HelloWorldDisplay displayPanel = new HelloWorldDisplay();
      JButton okButton = new JButton("OK");
      ButtonHandler listener = new ButtonHandler();
      okButton.addActionListener(listener);

      JPanel content = new JPanel();
      content.setLayout(new BorderLayout());
      content.add(displayPanel, BorderLayout.CENTER);
      content.add(okButton, BorderLayout.SOUTH);

      JFrame window = new JFrame("GUI Test");
      window.setContentPane(content);
      window.setSize(250,100);
      window.setLocation(100,100);
      window.setVisible(true);

   }
   
}

 JFrame is window frame

JFrame window = new JFrame("GUI Test");

to see the window set this configuration

window.setContentPane(content);
window.setSize(250,100);
window.setLocation(100,100);

other option is

• Panel: a rectangular box under a higher-level container, used to layout a set of related GUI components in pattern such as grid or flow.
• ScrollPane: provides automatic horizontal and/or vertical scrolling for a single child component.

others.

asd