Thread: Adding a Panel from a different class

I'm having this problem figuring out how to add a Panel that has been set up in a different class into another class that has a Frame. Basically when the program starts the use just sees a Frame, they then select "new game" from the menu and what I want is a panel to show up with the Polygon Kanji game I've set up. When I make a new object of the class my panel is in, it pops up but in a seperate frame (not sized because I didn't set that up) that I had to put in because it was showing an error for doing repaint() which is needed for the polygons, so I know that I'm probably doing this wrong.
I tried experimenting abit but I'm not getting anywhere, however I've never seen let alone done something like this and google is giving me programs that although similar are not what I want. Can please someone help me?

This is my full code:

import javax.swing.*;
import java.awt.* ;
import java.awt.event.* ;
import java.util.* ;
 
 
public class KanjiGame {
		public static void main(String args[]) {
 
		   new KanjiInterface ();
 
		}
 
 
}

import javax.swing.* ;
import java.awt.* ;
import java.awt.event.* ;
import java.util.* ;
 
public class KanjiInterface extends JFrame implements ActionListener {
 
	JMenuBar menuBar ;
	JMenu menuSession ;
	JMenuItem subNewGame, subLoadGame ;
	KanjiRoku roku ;
 
 
	KanjiInterface(){
		//Creates the window
		super("Kanji Game") ;
		setLocation( new Point(100, 100) ) ;
		//this.getContentPane().setBackground( Color.white ) ;
		setSize( 600, 600 ) ;
		setResizable( false ) ;
 
		//Creates the Menu Bar along with sub-menus
		menuBar = new JMenuBar() ;
		menuSession = new JMenu("Session") ;
		subNewGame = new JMenuItem("New Session") ;
		subNewGame.addActionListener(this) ;
		subLoadGame = new JMenuItem("Load Session") ;
		menuBar.add(menuSession) ;
		menuSession.add( subNewGame ) ;
		menuSession.add( subLoadGame ) ;
		this.setJMenuBar(menuBar) ;
		/*
		//Create Panel for graphics
		graphArea = new MyComponent() ;
		graphArea.setBackground(Color.WHITE) ;
	 	add(graphArea, BorderLayout.CENTER) ;
	 	*/
	 	setVisible( true ) ; 	
	 	addWindowListener( new WindowCatcher() ) ;
	}	
 
	public void actionPerformed( ActionEvent evt ){
		if ( evt.getSource() == subNewGame ){
			roku = new KanjiRoku() ;
			//add(roku.graphArea, BorderLayout.CENTER) ;
		}
	}
 
	class WindowCatcher extends WindowAdapter{
		public void windowClosing( WindowEvent evt ){
			evt.getWindow().dispose();
			System.exit(0) ;
		}
	}
 
 
	}

import javax.swing.* ;
 
import java.awt.* ;
import java.awt.event.* ;
import java.util.* ;
 
public class KanjiRoku extends JFrame{
	MyComponent graphArea ;
	Color one = Color.blue ;
	Color two = Color.blue ;
	Color three = Color.blue ;
	Color four = Color.blue ;
	int firstx[]={275,325,325,275} ;
	int firsty[]={100,100,175,175} ;
	int secondx[]={150,450,450,150} ;
	int secondy[]={180,180,230,230} ;
	int thirdx[]={255,292,180,143} ;
	int thirdy[]={263,300,412,375} ;
	int fourthx[]={345,308,420,457} ;
	int fourthy[]={263,300,412,375} ;
	Polygon firstStroke = new Polygon(firstx,firsty,4) ;
	Polygon secondStroke = new Polygon(secondx,secondy,4) ;
	Polygon thirdStroke = new Polygon(thirdx,thirdy,4) ;
	Polygon fourthStroke = new Polygon(fourthx,fourthy,4) ;
	ArrayList<Integer> strokes = new ArrayList<Integer>() ;
	int roku[]={1,2,3,4} ;
	int taker ;
	int result = 0 ;
	Boolean complete = false ;
 
	KanjiRoku(){	
		//Create Panel for graphics
		graphArea = new MyComponent() ;
		graphArea.setBackground(Color.WHITE) ;
	 	add(graphArea, BorderLayout.CENTER) ;
	 	setVisible( true ) ;
 
 
	 	//Adding listener
	 	graphArea.addMouseListener(new MouseCatcher ()) ;
 
 
	}
 
	class MyComponent extends JPanel{
	public void paintComponent(Graphics g){
		super.paintComponent(g) ;
	    g.setColor(one) ;
	    g.fillPolygon(firstStroke) ;
	    g.setColor(two) ;
	    g.fillPolygon(secondStroke) ;	
	    g.setColor(three) ;
	    g.fillPolygon(thirdStroke) ;	
	    g.setColor(four) ;
	    g.fillPolygon(fourthStroke) ;	
 
	}
	}
 
	public class MouseCatcher extends MouseAdapter {
 
		public void mouseClicked(MouseEvent e)
		{
 
    		int xpos = e.getX();
			int ypos = e.getY();
			if(firstStroke.contains(xpos,ypos)){
			    one = Color.red ;
			    strokes.add(1) ;
			   // StrokeChecker() ;
			    taker++ ;
			}
			if(secondStroke.contains(xpos,ypos)){
			    two = Color.red ;
			    strokes.add(2) ;
			   // StrokeChecker() ;
			    taker++ ;
			}
			if(thirdStroke.contains(xpos,ypos)){
			    three = Color.red ;
			    strokes.add(3) ;
			  //  StrokeChecker() ;
			    taker++ ;
			}
			if(fourthStroke.contains(xpos,ypos)){
			    four = Color.red ;
			    strokes.add(4) ;
			  //  StrokeChecker() ;
			    taker++ ;
			}
		    repaint() ;
		    if(taker == 4){
		    	StrokeChecker() ;
		    }
		    }
		}
 
 
 
	public void StrokeChecker(){
	 int firstCom1 = strokes.get(0) ;
	 int firstCom2 = roku[0] ;
	 int secondCom1 = strokes.get(1) ;
	 int secondCom2 = roku[1] ;
	 int thirdCom1 = strokes.get(2) ;
	 int thirdCom2 = roku[2] ;
	 int fourthCom1 = strokes.get(3) ;
	 int fourthCom2 = roku[3] ;
	 if(firstCom1 == firstCom2){
		 result += 1 ;
	 }
	 if(secondCom1 == secondCom2){
		 result += 1 ;
	 }
	 if(thirdCom1 == thirdCom2){
		 result += 1 ;
	 }
	 if(fourthCom1 == fourthCom2){
		 result += 1 ;
	 }
	 switch(result) {
	 case 0:
		 JOptionPane.showMessageDialog( null, "Not even one right...", "Result", JOptionPane.PLAIN_MESSAGE ) ;
		 break ;
	 case 1:
		 JOptionPane.showMessageDialog( null, "You need more practice", "Result", JOptionPane.PLAIN_MESSAGE ) ;
		 break ;
	 case 2:
		 JOptionPane.showMessageDialog( null, "Good try", "Result", JOptionPane.PLAIN_MESSAGE ) ;
		 break ;
	 case 3:
		 JOptionPane.showMessageDialog( null, "Nearly! Try again!", "Result", JOptionPane.PLAIN_MESSAGE ) ;
		 break ;
	 case 4:
		 JOptionPane.showMessageDialog( null, "You did it!", "Result", JOptionPane.PLAIN_MESSAGE ) ;
		 break ;
 
	 }
	 }
 
}

I want to know is there is a way I can put the panel I have created in my KanjiRoku class into the frame that is in KanjiInterface? I could try the CardLayout but I want to see if its possible to try it this way first which would make things easier for me in the long run.

Really? Is it that easy? I'll try it out, thank you very much!

Oh, my intention had nothing to do with CardLayout, my original idea was that there would be a called to the JPanel via a constructor when the user clicks on "New Session" via JMenu, however that idea didn't work and I was wondering how it could be done. If I have to use CardLayout then can I still use JMenu to get the Panel?

Thank you for your advice but I've decided to try something a bit more simpler, seems to be working alright.