Won't paint to canvas

Question

Hi,
I know this is a bit of a chunk of code but it is all beginner stuff. I posted earlier on this. It won't paint with the to the canvas.
Any help very much appreciated.
Warby
package Stejava;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
/** An example class used to demonstrate the basics of
* creating components such as panels, arranging
* components using layout objects, and nesting
* components inside each other.
public class Assignment_2 extends JFrame
     JMenuBar menuBar;
     JMenu menu;
     JMenuItem menuItem;
     public JPanel grid, gridBag, flow, outputScreen, optionsBox, message, baseButtons,
          another, centreOne, centreTwo, centreThree, lower, style, size, colours, shapes,
          menuPane;
     JRadioButtonMenuItem rbMenuItem1, rbMenuItem2;
     public JTextField text;
     public JButton black, red, green;
     public JCheckBox checkStyle;
     /** Class constructor method
          * @param titleText Window's title bar text
     public Assignment_2( String titleText ) // constructor
          super( titleText );
          // listener for close event
          addWindowListener( new WindowAdapter() {
          /** End the program when the user
* closes the window
public void
windowClosing( WindowEvent e )
Assignment_2.this.dispose();
System.exit( 0 );
               }// end windowclosing()
          }// end WindowAdaptor()
          // end parameter listing of addWindowListener(). No code it seems.
          // menu bar
          menuBar = new JMenuBar();
setJMenuBar(menuBar);
          //Build the first menu.
menu = new JMenu("A Menu");
menuBar.add(menu);
          //a group of JMenuItems
menuItem = new JMenuItem("none" );
          menu.add(menuItem);
menuItem = new JMenuItem("Point" );
          menu.add(menuItem);
          menuItem = new JMenuItem("Line" );
          menu.add(menuItem);
          menuItem = new JMenuItem("Triangle" );
          menu.add(menuItem);
          menuItem = new JMenuItem("Square" );
          menu.add(menuItem);
          menuItem = new JMenuItem("Circle" );
          menu.add(menuItem);
          menuItem = new JMenuItem("Oval" );
          menu.add(menuItem);
          menuItem = new JMenuItem("Text" );
          menu.add(menuItem);
          outputScreen = new JPanel();
          outputScreen.setSize(300,240);
          outputScreen.setMinimumSize(new Dimension(300, 200) );
          outputScreen.setPreferredSize( new Dimension(300, 200 ));
          outputScreen.setBorder(BorderFactory.createTitledBorder( "Output" ) );
          outputScreen.setLayout( new BorderLayout() );
          style = new JPanel();
          style.setBorder(BorderFactory.createTitledBorder( "Style" ) );
          style.setLayout( new GridLayout( 0, 1 ) );
          style.add( new JCheckBox( "Bold" ) );
          style.add( new JCheckBox( "Italics" ) );
          size = new JPanel();
          size.setBorder(BorderFactory.createTitledBorder( "Size" ) );
          size.setLayout( new BoxLayout( size, BoxLayout.Y_AXIS));
          size.setMinimumSize(new Dimension(100, 100) );
          size.setPreferredSize( new Dimension(100, 100 ));
          menuPane = new JPanel();
          menuPane.setBorder(BorderFactory.createTitledBorder( "" ) );
          menuPane.setMinimumSize( new Dimension(250, 400));
          menuPane.setLayout( new BorderLayout() );
          menuPane.add( menuBar );
          centreOne = new JPanel();
          centreOne.setBorder(BorderFactory.createTitledBorder( "Text Options" ) );
          centreOne.setLayout( new GridLayout( 0, 1 ) );
          centreOne.setMinimumSize(new Dimension(100, 220) );
          centreOne.setPreferredSize( new Dimension(100, 220 ));
          centreOne.add( style );
          centreOne.add( size );
          centreTwo = new JPanel();
          centreTwo.setBorder(BorderFactory.createTitledBorder( "Colours" ) );
          centreTwo.setLayout( new GridLayout( 0, 1 ) );
          centreTwo.setMinimumSize(new Dimension(100, 220) );
          centreTwo.setPreferredSize( new Dimension(100, 220 ));
          //centreTwo.add ( colours );
          centreThree = new JPanel();
          centreThree.setBorder(BorderFactory.createTitledBorder( "Shapes" ) );
          centreThree.setLayout( new BorderLayout() );
          centreThree.setPreferredSize( new Dimension(100, 220 ));
          centreThree.setMinimumSize( new Dimension(100, 220));
          centreThree.add ( menuPane );
          optionsBox = new JPanel();
     //optionsBox.setLayout( new BorderLayout() );
          optionsBox.setPreferredSize( new Dimension(300, 220 ));
          optionsBox.setMinimumSize( new Dimension(300, 220));
          optionsBox.setSize ( 300, 220 );
          optionsBox.add ( centreOne );
          optionsBox.add ( centreTwo );
          optionsBox.add ( centreThree );
          lower = new JPanel();
          lower.setBorder(BorderFactory.createTitledBorder( "" ) );
          lower.setMinimumSize( new Dimension(250, 400));
          lower.setLayout( new GridLayout( 0, 1 ) );
          message = new JPanel();
          message.setBorder(BorderFactory.createTitledBorder("Message" ) );
          message.setLayout( new BorderLayout() );
          text = new JTextField( "hhhh" );
          message.add( text, BorderLayout.CENTER );
          //button bar and buttons
          baseButtons = new JPanel();
          baseButtons.setBorder( BorderFactory.createTitledBorder( "" ) );
          baseButtons.setLayout( new FlowLayout( FlowLayout.CENTER ) );
          black = new JButton( "About" );
          black.addActionListener( new ButtonListener( Color.black ) );
          baseButtons.add( black );
          red = new JButton( "Draw" );
          red.addActionListener( new ButtonListener( Color.red ) );
          baseButtons.add( red );
          green = new JButton( "Exit" );
          green.addActionListener(new ButtonListener( Color.green ) );
          baseButtons.add( green );
          // radio buttons for text size
          menu.addSeparator();
ButtonGroup group1 = new ButtonGroup();
          size.setLayout( new GridLayout( 0, 1 ) );
          rbMenuItem1 = new JRadioButtonMenuItem("Small");
group1.add(rbMenuItem1);
size.add(rbMenuItem1);
rbMenuItem1 = new JRadioButtonMenuItem("Medium");
group1.add(rbMenuItem1);
size.add(rbMenuItem1);
          rbMenuItem1 = new JRadioButtonMenuItem("Large");
group1.add(rbMenuItem1);
size.add(rbMenuItem1);
          // radio buttons
          menu.addSeparator();
ButtonGroup group2 = new ButtonGroup();
          //size.setLayout( new FlowLayout( FlowLayout.CENTER ) );
          rbMenuItem2 = new JRadioButtonMenuItem("Black");
group2.add(rbMenuItem2);
centreTwo.add(rbMenuItem2);
rbMenuItem2 = new JRadioButtonMenuItem("Red");
group2.add(rbMenuItem2);
centreTwo.add(rbMenuItem2);
          rbMenuItem2 = new JRadioButtonMenuItem("Orange");
group2.add(rbMenuItem2);
centreTwo.add(rbMenuItem2);
          rbMenuItem2 = new JRadioButtonMenuItem("Yellow");
group2.add(rbMenuItem2);
centreTwo.add(rbMenuItem2);
rbMenuItem2 = new JRadioButtonMenuItem("Green");
group2.add(rbMenuItem2);
centreTwo.add(rbMenuItem2);
          rbMenuItem2 = new JRadioButtonMenuItem("Blue");
group2.add(rbMenuItem2);
centreTwo.add(rbMenuItem2);
          //aCanvas.repaint();
          //aCanvas.setSize( 100, 100 );
          //aCanvas.setVisible( true );
          //aCanvas.setLayout( new GridLayout( 0, 1 ) );
          //aCanvas.setMinimumSize(new Dimension(100, 100) );
          //aCanvas.setPreferredSize( new Dimension(100, 100 ));
          // container     
          Container cp = getContentPane();
          cp.setLayout( new BorderLayout() );
          cp.add( outputScreen, BorderLayout.NORTH );
          cp.add( optionsBox, BorderLayout.CENTER );
          cp.add( lower, BorderLayout.SOUTH );
          lower.add( message );
          lower.add( baseButtons );
          pack();
          setSize (350, 580);
          setResizable( false );
          setVisible( true );
          outputScreen.add( new myCanvas() );
     }// ends what ??? Constructor???
                    //inner class for painting
     class myCanvas extends Canvas
          /** Class constructor
               public myCanvas()
                    repaint();
                    setBackground( Color.white );
                    //setBorder( BorderFactory.createTitledBorder( "Sample output from drawing methods:" ) );
               }// end paint constructor
          public void paint(Graphics g)
               super.paint(g); // clears background
               g.drawLine( 50, 50, 100, 200 );
               g.setColor( Color.blue );
               g.drawRoundRect( 150, 300, 100, 125, 15, 15 );
               g.setColor( Color.red );
               g.fillOval( 400, 200, 50, 180 );
          }// end method paint()     
     } // end myClass;
          //myCanvas aCanvas = new myCanvas();
/** The class representing the button event
* listeners
class ButtonListener implements ActionListener
     public Color c;
/** Class constructor
* @param c the color for this button
public ButtonListener( Color c )
this.c = c;
/** Respond to the action events
* @param e The click event
public void actionPerformed( ActionEvent e )
text.setForeground( c );
          outputScreen.repaint(7);
          //outputScreen.aCanvas.paint();
}// end class ButtonListener()
/** The class representing the colored icons on
* the buttons
class ColorIcon implements Icon
public Color c;
public static final int DIAMETER = 10;
/** Class constructor
* @param c the color for this button
public ColorIcon( Color c )
this.c = c;
/** Paint the color icon with a black border
* @param cp the component holding the icon
* @param g the graphics context for the icon
* @param x the x draw start position
* @param y the y draw start position
public void paintIcon( Component cp, Graphics g, int x, int y )
g.setColor( c );
g.fillOval( x, y, DIAMETER, DIAMETER );
g.setColor( Color.black );
g.drawOval( x, y, DIAMETER, DIAMETER );
/** Get the icon's height
* @return the height of the icon
public int getIconHeight()
return DIAMETER;
/** Get the icon's width
* @return the width of the icon
public int getIconWidth()
return DIAMETER;
}// end class colorIcon
}// end colorIcon
/** The test method for the class
* @param args not used
public static void main( String[] args )
new Assignment_2( "Assignment_2" );
}// end class Assignment_2

Answer 1

No, does not look correct.
Canvas is a "heavyweight" awt component.
It is generally a bad idea to mix these with the "lightweight" swing JComponents.
Forget that and let's move on
Paint directly on the JPanel
example(strech and maximize to see what happens):import javax.swing.*;
import java.awt.*;
public class Test extends JFrame
   public Test()
      setDefaultCloseOperation(EXIT_ON_CLOSE);
      setSize(100,100);
      OutputScreen oScr = new OutputScreen();
      getContentPane().add(oScr, BorderLayout.CENTER);
      oScr.setToolTipText("<html>Test<br>Patern</html>");
   public static void main(String[] args)
          new Test().setVisible(true);
class OutputScreen extends JPanel
   public void paint(Graphics g)
      Rectangle r = getBounds();
      g.setColor(Color.white);
      g.clearRect(r.x, r.y, r.width, r.height);
      g.setColor(Color.red);
      g.fillOval(r.x, r.y, r.width, r.height);
}