why clicking on button does not show a new internalframe in this code?

[patil prashant]

My problem is that I am not able see a new Internal frame when I click the 'Show Frame 2' button in one internal frame.
The code for the files is as follows.Also the code for internal frames has to be in separate files.
What changes are needed to fix the problem?

  
//MainAppFrame.java

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

public class MainAppFrame extends JFrame{
	JDesktopPane jdp;
	JMenuBar mbar;
	JMenu menu;
	JMenuItem jmt;
	
	InFrame1 frame1=null;
	
    public MainAppFrame() {
    	jdp=new JDesktopPane();
    	mbar=new JMenuBar();
    	menu=new JMenu("Show");
    	mbar.add(menu);
    	jmt=new JMenuItem("New Frame");
    	menu.add(jmt);
    	jmt.addActionListener(new ShowFrame());
    	setJMenuBar(mbar);
    	setContentPane(jdp);
    }
    class ShowFrame implements ActionListener{
		public void actionPerformed(ActionEvent event){
			if((frame1==null)||(frame1.isClosed())){
				frame1=new InFrame1();
				jdp.add(frame1);
				frame1.setVisible(true);
				try {
    				frame1.setSelected(true);
				}catch (Exception ex) {
				
				}
			}
		}    	
    }
    public static void main(String[] args) {
       MainAppFrame mf=new MainAppFrame();
       mf.setSize(500,400);
       mf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       mf.setVisible(true); 
    }
}


//InFrame1.java

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

public class InFrame1 extends JInternalFrame {
	JPanel pan;
	JButton b1;
	InFrame2 frame2=null;
    public InFrame1() {
    	super("InFrame 1",true,true,true,true);
    	pan=new JPanel();
    	b1=new JButton("Show Frame 2");
    	b1.addActionListener(new ShowFrame2());
        //more code to create GUI   
    	pan.add(b1);
    	add(pan);
    	setSize(300,300);
    }
    
    class ShowFrame2 implements ActionListener{
    	public void actionPerformed(ActionEvent event){
    		if((frame2==null)||(frame2.isClosed())){
    			frame2=new InFrame2();
    			frame2.setVisible(true);
				try {
    				frame2.setSelected(true);
				}catch (Exception ex) {
				
				}
    		}
    	}
    }   
}


//Inframe2.java

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

public class InFrame2 extends JInternalFrame{
    public InFrame2() {
    	super("InFrame 2",true,true,true,true);
    	//code to create GUI
    	setSize(200,200);	
    }
}


 

[Rob Spoor]

You never add the new InFrame2 instance to any JDesktopPane. You'll need to give InFrame1 a field of type JDesktopPane, set in its constructor, that it then uses. A quick-and-dirty version (all classes are made non-public so they can fit in one file; look for lines with "// change here"):

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

class MainAppFrame extends JFrame
{
    JDesktopPane jdp;
    JMenuBar mbar;
    JMenu menu;
    JMenuItem jmt;

    InFrame1 frame1  =  null;

    public MainAppFrame()
    {
        jdp = new JDesktopPane();
        mbar = new JMenuBar();
        menu = new JMenu("Show");
        mbar.add(menu);
        jmt = new JMenuItem("New Frame");
        menu.add(jmt);
        jmt.addActionListener(new ShowFrame());
        setJMenuBar(mbar);
        setContentPane(jdp);
    }

    class ShowFrame implements ActionListener
    {
        public void actionPerformed(ActionEvent event)
        {
            if (frame1 == null || frame1.isClosed())
            {
                frame1 = new InFrame1(jdp); // change here
                jdp.add(frame1);
                frame1.setVisible(true);
                try
                {
                    frame1.setSelected(true);
                }
                catch (Exception ex)
                {
                    ex.printStackTrace();
                }
            }
        }
    }

    public static void main(String[] args)
    {
       MainAppFrame mf = new MainAppFrame();
       mf.setSize(500, 400);
       mf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       mf.setVisible(true);
    }
}

class InFrame1 extends JInternalFrame
{
    JPanel pan;
    JButton b1;
    InFrame2 frame2 = null;
    JDesktopPane jdp; // change here

    public InFrame1(JDesktopPane jdp) // change here
    {
        super("InFrame 1",true,true,true,true);
        this.jdp = jdp; // change here
        pan = new JPanel();
        b1 = new JButton("Show Frame 2");
        b1.addActionListener(new ShowFrame2());
        //more code to create GUI
        pan.add(b1);
        add(pan);
        setSize(300,300);
    }

    class ShowFrame2 implements ActionListener
    {
        public void actionPerformed(ActionEvent event)
        {
            if (frame2 == null || frame2.isClosed())
            {
                frame2 = new InFrame2();
                jdp.add(frame2); // change here
                frame2.setVisible(true);
                try
                {
                    frame2.setSelected(true);
                }
                catch (Exception ex)
                {
                    ex.printStackTrace();
                }
            }
        }
    }
}

class InFrame2 extends JInternalFrame
{
    public InFrame2()
    {
        super("InFrame 2",true,true,true,true);
        //code to create GUI
        setSize(200,200);
    }
}