JMenuItems Disappear After repaint()

[D. Brown]

I have written a dice roller program with "File" and "Help" menus. The File menu has "New Game" and "Exit" menu items. When the program first starts, I can click on "File" and see the "New Game" and "Exit" menu items, but after the first dice roll, I can't see the "Exit" menu item any more. I'm guessing that the repaint() call has done something to cover it up. The accelerator keys still work.

Does this problem sound familiar? I can't find any obvious refernce to it when I Google or search this site. I can post code if necessary.

I have tried this with same result with:

Eclipse Juno, Linux Iced Tea 1.6
Eclipse Helios, Linux Iced Tea 1.6
Eclipse Juno Windows 32 (Vista), Java 1.7

Thanks for any advice.

[D. Brown]

Ok, this takes care of it:

menuBar.updateUI();

Is that the best solution?

[Darryl Burke]

No. the updateUI() method should only be needed after changing the Look-and-Feel.

To get better help sooner, post a SSCCE (Short, Self Contained, Correct (Compilable), Example) that demonstrates the problem.

edit
1. Does your code respect Swing's single threaded rule?
2. does your GUI mix AWT and Swing components?

[D. Brown]

I did my best to trim the code down and do the SSCCE thing. Below are the DiceRoller (main) class and the Roll Dice class. I have also attached one graphic image of a die. I guess you can copy it 5 times and name the new files "two.jpg" etc.

There are still two calls to update(), but they're commented out.

While trimming the code down and making sure it would still compile, I ran into something interesting. When I removed the scroll area from the center region, the problem went away. When I put the scroll area back in, the problem re-appeared. Why would that happen??

The teacher for the class I'm taking compiled the program on his computer, and he did not see the problem. I think he's using a Mac.

When I first start the program, I can get to File | Exit ok. After the first dice roll, I can get to File, but Exit is gone.

All insight is appreciated.

I tried to attach the source as files. But I got a scolding from the forum program, first saying that I couldn't attach files with extension .java, and then that I couldn't attach files with an extension .txt. I couldn't find anything about this in a FAQ, but I concluded that source should be posted in the message. So it's below.

Dave

==============DiceRoller.java==============

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

public class DiceRoller implements ActionListener {
    
// window frame
    
        private JFrame frame;
        private JPanel panelE, panelW, smallPanelS;
        private JButton rollButton;
        private JTextArea textArea;
        private JPanel contentPane;
	private RollDice dieA, dieB;
	private JScrollPane scrollArea;
	private int number;
	private JMenuBar menuBar;
    
  
    public static void main (String []  args) {
        DiceRoller gui = new DiceRoller();
        gui.start();
    }    
    
    public void start()
    {
        frame = new JFrame("Dice Roller");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        makeMenus();
        makeContent();
        frame.pack();
        frame.setVisible(true);
    }
    
    private void makeMenus()
    {
        //JMenuBar menuBar;
        menuBar = new JMenuBar();
        frame.setJMenuBar(menuBar);
        
        // set up menus
        menuBar.add(makeFileMenu());
        
    }
    
    private JMenu makeFileMenu()
    {
        JMenu menu;
        JMenuItem menuItem;        // set up the File menu
        menu = new JMenu("File");
              
        // add New menu item
        menuItem = new JMenuItem("New Game");
        menuItem.addActionListener(new NewListener());
        menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N, Event.CTRL_MASK));
        menu.add(menuItem);
          
        menu.addSeparator();

        menuItem = new JMenuItem("Exit");
        menuItem.addActionListener(new ExitListener());
        menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_E, Event.CTRL_MASK));
        menu.add(menuItem);
        return menu;
    }    
    
    private void makeContent() {
        contentPane = (JPanel)frame.getContentPane();
        contentPane.setLayout(new BorderLayout(16,16));
        makeWestRegion();
        makeCenterRegion();
        makeEastRegion();
        makeSouthRegion();
    
    }
    
    private void makeSouthRegion() {
        
    	JPanel panelS = new JPanel();
       	panelS.setBorder(BorderFactory.createTitledBorder("Roll here:"));           
        contentPane.add(panelS, BorderLayout.SOUTH);
        smallPanelS = new JPanel();
        panelS.add(smallPanelS);
        rollButton = new JButton ("Roll the Dice");
        rollButton.addActionListener(this);
        smallPanelS.add(rollButton);
        }
    
    private void makeWestRegion() {
        
        panelW = new JPanel();
        panelW.setBorder(BorderFactory.createTitledBorder("Die 1"));        
        panelW.setPreferredSize(new Dimension(300,350));       
        contentPane.add(panelW, BorderLayout.WEST);
        dieA = new RollDice();
        dieA.roll();
        panelW.add(dieA);
        }
    
    private void makeEastRegion()
    {
        
        panelE = new JPanel();
        panelE.setBorder(BorderFactory.createTitledBorder("Die 2"));
        panelE.setPreferredSize(new Dimension(300,350));        
        contentPane.add(panelE, BorderLayout.EAST);
        dieB = new RollDice();
        dieB.roll();
        panelE.add(dieB);
    }
    
    private void makeCenterRegion() {
    	    	
    	 textArea = new JTextArea(20,25);
         textArea.setEditable(false);
         textArea.setLineWrap(true);
         textArea.setWrapStyleWord(true);
         textArea.setFont(new Font("Serif", Font.BOLD, 14));
         scrollArea = new JScrollPane(textArea);
         scrollArea.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
         scrollArea.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
         textArea.append("Hi, and welcome to the dice game. Click to roll.\n\n");
         textArea.setCaretPosition(textArea.getText().length());

         JPanel panelC = new JPanel();
         panelC.setBorder(BorderFactory.createTitledBorder("Status of the Game"));
         panelC.add(scrollArea);
         contentPane.add(panelC, BorderLayout.CENTER);        
    }
    
    private class AboutListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            JOptionPane.showMessageDialog(frame,
                    "Dice Game\n\nVersion 1.0\n\nBy Dave",
                    "About Seattle Trip Planner",
                    JOptionPane.INFORMATION_MESSAGE);
           // menuBar.updateUI();
        }
    }
    
    private class ExitListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            System.exit(0);
        }
    }
    
    private class NewListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e) {
        
        	textArea.setText("You can roll to start a new game.\n\n");      
        	
        }
    }

	@Override
	public void actionPerformed(ActionEvent e) {
		
    		if (e.getSource() == rollButton)
    			
    		dieA.roll();
            panelW.add(dieA);
            number = dieA.rand + 1;
            textArea.append("Die one was " + number);
            
            dieB.roll();
            panelE.add(dieB);
            number = dieB.rand +1;
            textArea.append(", die two was " + number + ".\n");
            
            // menuBar.updateUI();
                        
	}
    
}
 
========================RollDice.java=============================

import java.util.Random;
import java.awt.Graphics;
import java.awt.Canvas;
import javax.swing.*;

class RollDice extends Canvas {

	Random r = new Random();
	int rand;	
	ImageIcon dice1, dice2, dice3, dice4, dice5, dice6;
	
	public RollDice() {
		
		setSize(300, 300);
		
		dice1 = new ImageIcon(getClass().getResource("one.jpg"));
		dice2 = new ImageIcon(getClass().getResource("two.jpg"));
		dice3 = new ImageIcon(getClass().getResource("three.jpg"));
		dice4 = new ImageIcon(getClass().getResource("four.jpg"));
		dice5 = new ImageIcon(getClass().getResource("five.jpg"));
		dice6 = new ImageIcon(getClass().getResource("six.jpg"));
		
	}
	
	public int roll() {
		
		rand = r.nextInt(6);
		repaint();
		return rand;
			
	}
	
	public void paint (Graphics g) {
		
		if (rand == 0) dice1.paintIcon(this, g, 50, 20);
		if (rand == 1) dice2.paintIcon(this, g, 50, 20);
		if (rand == 2) dice3.paintIcon(this, g, 50, 20);
		if (rand == 3) dice4.paintIcon(this, g, 50, 20);
		if (rand == 4) dice5.paintIcon(this, g, 50, 20);
		if (rand == 5) dice6.paintIcon(this, g, 50, 20);
		
	}

}

[D. Brown]

That should be, call to updateUI(), not call to update().

[Michael Dunn]

as Darryl hinted/suggested, the problem is this line

class RollDice extends Canvas {

read how to do your drawing/painting here
http://docs.oracle.com/javase/tutorial/uiswing/painting/index.html

[m Korbel]

1. there no reason to use AWT Canvas (excluding for Multimedia, OpenGL/CL, or there are a few good 3rd party libraries based on AWT)

2. AWT Canvas is heavyweight Component, then is basically always on top of lightweight JMenu & JMenuItem, have to change lightweight status for Swing JComponents (I'd not suggest)

3. put Icon /ImageIcon to the JLabel , for dices could be JButton the best of ways (layed by GridLayout)

4. in the case that you want to use painting then to change Canvas to the JPanel or JComponent, have to override PreferredSize for resizable contents

[D. Brown]

That was interesting reading. I'm still digesting it. I think I get the heavyweight/lightweight business now, and how it's causing the problem.