repaint not working

[S Connor]

Hi, I'm trying to make a simple program that will feature some graphics. It will have a JCombobox that the user selects to draw various shapes. I can't get the repaint function to work however. Please help!

package selectingshapes;
import java.awt.Graphics;

import java.awt.Color;
import javax.swing.JPanel;
import java.awt.Graphics2D;
/**
 *
 * @author Sean
 */
public class ColorJPanel extends JPanel{
    private int drawShape = 3;
    /** Creates a new instance of ColorJPanel */
    public ColorJPanel() {
        
    }
    
    public void paintComponent ( Graphics g )
     {
               
        super.paintComponent( g );
       
        
        this.setBackground( Color.WHITE );
        
        Color color = Color.MAGENTA;
        g.setColor( color );
        switch( drawShape ) {
            case 0:
                g.fillRect(15, 100, 100, 20);
            case 1:
                g.fillRect(15, 50, 50, 20);
            case 2:
                g.fillOval(15, 200, 200, 20);
            case 3:
                g.fillRect(15, 80, 80, 20);
        }
    }
   
    
    public void setDrawShape( int i )
    {
        drawShape = i;
        repaint();
        System.out.println("Repainting");
    }
   
}

package selectingshapes;
import java.awt.Graphics;
import java.awt.Color;
import javax.swing.JPanel;
import java.awt.Graphics2D;
import java.awt.FlowLayout;
import java.awt.event.ItemEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JComboBox;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import java.awt.*;
import java.awt.event.ItemListener;
/**
 *
 * @author Sean
 */


public class ComboBoxFrame extends JFrame{
    
    /** Creates a new instance of ComboBoxFrame */
    
    
    private JComboBox shapesJComboBox;      //combobox to hold names of icons
    private JLabel label;                   //label to display selected icon
    private String names[] = {"Rectangle", "Square", "Elipse", "Triangle"};
    private ColorJPanel colorJPanel = new ColorJPanel();
    
    public ComboBoxFrame( ) {
        super ("Testing JComboBox");
        setLayout( new FlowLayout());
        shapesJComboBox = new JComboBox( names );
        shapesJComboBox.setMaximumRowCount(4);
        
        shapesJComboBox.addItemListener(
            new ItemListener()
        {
            public void itemStateChanged( ItemEvent event )
            {
                if ( event.getStateChange() == ItemEvent.SELECTED )
                { 
                    //Do something to the added panel
                    //Needs to communicate with drawing of ColorJPanel
                   
                  colorJPanel.setDrawShape(shapesJComboBox.getSelectedIndex());
                  System.out.printf("%d", shapesJComboBox.getSelectedIndex());
                }
            }
        }
                );
        
        add( shapesJComboBox );
        
    }
    
}

import javax.swing.JFrame;
import java.awt.*;
import java.awt.Graphics;
/**
 *
 * @author Sean
 */
public class Main {
    
    /** Creates a new instance of Main */
    public Main() {
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        ComboBoxFrame frame = new ComboBoxFrame( );
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        ColorJPanel colorJPanel = new ColorJPanel();
        frame.setLayout(new GridLayout(2, 2));
        
        frame.setSize( 400, 180 );
        frame.setVisible( true );
        frame.add(colorJPanel);
    }
    
}

Many thanks for any sggestions

[Carey Brown]

First off your case statements need a 'break' after them.

[Carey Brown]

You are creating two ColorJPanels only one of which you are setting the shape number on, the other is always shape '3'. Your frame size is too small, you'll see the rectangle if you stretch the window out.

[Carey Brown]

You are setting the layout in two places; should only be in one. Suggest using BorderLayout and putting the ComboBox in NORTH and the panel in CENTER.

[S Connor]

Thanks. Could you explain how I get my JComboBox class to modify the behaviour of an instance of another class (in this case the ColorJPanel class)?
When I delete the second ColorJPanel class, there is no way for the JComboBox to access the Panel it needs to communicate with.
EDIT: have resolved issues, thank you for the help