What is internal frame? Write a program that displays an internal frame within some parent frame.

Internal frame is a frame that is inside another frame. The JInternalFrame class is used to display a JFrame-like window within another window. Usually, we add internal frames to a desktop pane. The desktop pane, in turn, might be used as the content pane of a JFrame. The desktop pane is an instance of JDesktopPane, which is a subclass of JLayeredPane that has added API for managing multiple overlapping internal frames.

In the program below, we are just displaying five frames inside another frame.

//MyInternalFrame.java

import javax.swing.*;

public class MyInternalFrame extends JFrame {

public MyInternalFrame() {

for(int i=0; i<5; i++) {

JInternalFrame frame = new JInternalFrame("Internal Frame" + i);

frame.setLocation(i*50+10, i*50+10);

frame.setSize(200, 150);

this.add(frame);

frame.setVisible(true);

}

setVisible(true);

setSize(800, 600);

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public static void main(String[] args) {

new MyInternalFrame();

}

}