Getting something on a canvas

Question

Hi,
I'm still battling with this canvas. This code puts the text: "test from the canvas" on the screen on a grey background, OK, but I can't get it to do anything when I push a button. I know the button works. Any help? (ps this is not an applet)
          myCanvas aCanvas = new myCanvas();
          // 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 );
          outputScreen.add( aCanvas, BorderLayout.CENTER );
          pack();
          setSize (350, 580);
          setResizable( false );
          setVisible( true );
          outputScreen.repaint();
     }// ends class constructor
        public class myCanvas extends Canvas
          public Graphics g;
          public myCanvas()
          super();
          //setBackground(Color.yellow);
          setForeground(Color.blue);
          public void paint(Graphics g)
               super.paint(g);
               g.setColor(Color.yellow);
               g.drawString( "test from the canvas", 10, 10 ) ;
          }// end method paint()     
     } // end 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 )
           myCanvas theCanvas = new myCanvas();
          theCanvas.setBackground( Color.white );
          theCanvas.setForeground( Color.white );
   }// end class ButtonListener()
 

Answer 1

Try this:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CanTest extends JFrame implements ActionListener
     myCanvas aCanvas = new myCanvas();
     JButton  jb1     = new JButton("Red");
     JButton  jb2     = new JButton("green");
public CanTest ()
     super();
     setBounds(6,6,550,400);     
     addWindowListener(new WindowAdapter()
    {     public void windowClosing(WindowEvent ev)
               dispose();     
               System.exit(0);
     JPanel sot = new JPanel();
     sot.add(jb1);
     jb1.setForeground(Color.red);
     jb1.addActionListener(this);
     sot.add(jb2);
     jb2.setForeground(Color.green);
     jb2.addActionListener(this);
     getContentPane().add("Center",aCanvas );
     getContentPane().add("South",sot);
     setVisible(true);
public void actionPerformed(ActionEvent a)
     Component co = (Component)a.getSource();
     aCanvas.setForeground(co.getForeground());
     aCanvas.repaint();
public class myCanvas extends Canvas
public myCanvas()
     super();
     setForeground(Color.blue);
     setBackground(Color.pink);
public void paint(Graphics g)     
     super.paint(g);          
     g.setColor(getForeground());     
     g.drawString( "test from the canvas", 20, 20 ) ;     
public void update(Graphics g)     
     paint(g);
public static void main (String[] args)
     new CanTest ();  
}       Noah