DELEGATION MODEL

11. Java Program to Create a List Box to Select Multiple Items and Display it in the Frame

            import java.awt.*;
            import java.awt.event.ActionEvent;
            import java.awt.event.ActionListener;
            
            public class MessageFrameApp extends Frame {
            
                public MessageFrameApp() {
                    // Set up the main frame
                    setTitle("Main Frame");
                    setSize(300, 200);
                    setLayout(new FlowLayout());
            
                    // Button to open the message frame
                    Button showMessageButton = new Button("Show Message");
                    showMessageButton.addActionListener(new ActionListener() {
                        
                        public void actionPerformed(ActionEvent e) {
                            openMessageFrame();
                        }
                    });
            
                    // Add button to the main frame
                    add(showMessageButton);
            
                    // Set up close operation
                    addWindowListener(new java.awt.event.WindowAdapter() {
                        
                        public void windowClosing(java.awt.event.WindowEvent windowEvent) {
                            System.exit(0);
                        }
                    });
                }
            
                private void openMessageFrame() {
                    // Create a new frame to display the message
                    Frame messageFrame = new Frame("Message Frame");
                    messageFrame.setSize(250, 150);
                    messageFrame.setLayout(new FlowLayout());
            
                    // Label to display the message
                    Label messageLabel = new Label("Hello, this is your message!");
                    messageFrame.add(messageLabel);
            
                    // Set up close operation for the message frame
                    messageFrame.addWindowListener(new java.awt.event.WindowAdapter() {
                        
                        public void windowClosing(java.awt.event.WindowEvent windowEvent) {
                            messageFrame.dispose();  // Close only the message frame
                        }
                    });
            
                    // Make the message frame visible
                    messageFrame.setVisible(true);
                }
            
                public static void main(String[] args) {
                    // Create and show the main frame
                    MessageFrameApp app = new MessageFrameApp();
                    app.setVisible(true);
                }
            }
        

OUTPUT