Event model for multiple components

Question

Hi
For some time now I have been searching on the net for a proper way to do following:
I have a class that extends a JFrame. In it I instantiate and add two more classes ControlPanel and CanavasPanel which extend from JPanel...
All these are in SEPARATE files...My ControlPanel class has buttons that when clicked are supposed to draw different objects on the CanavasPanel...
How do I fire a method in my CanavasPanel class when a button is clicked in ControlPanel class??? These are all in separate files and I am looking for a solution that does not uses inner and anonymous classes..If I implement ActionListener in ControlPanel class I know a way of referencing CanavasPanel class so I can fire its methods...
Is it doable? And if so can someone explain to me what needs to be done.

Answer 1

Try out this way:
The below code is not complete code (where ever is ... it is fill in blanks):
public class MyFrame extends JFrame{
protected ControlPanel buttonPanel;
protected CanvasPanel canvasPanel;
public MyFrame(){  
// Initialize panels
canvasPanel = new CanvasPanel(...);
buttonPanel = new ButtonPanel(...);
// Set layout
this.getContentPane().setLayout(new BorderLayout())
/*----------- CHECK THIS --------*/
// Assuming Control Panel has some method used to add listener
// to draw button
// ex: setDrawButtonActionListener(ActionListener al){}
buttonPanel.setDrawButtonActionListener(new MyDrawActionListener());
// Now add panels
this.getContentPane().add(buttonPanel,BorderLayout.SOUTH);
this.getContentPane().add(canvasPanel,BorderLayout.CENTER);\
} // Constructor MyFrame
class MyDrawActionListener implements ActionListener{
public void actionPerformed(ActionEvent ae){
// Make sure that the canvas panel is initialized
if (canvasPanel != null){
canvasPanel.drawSomething();
}else{
// Your error message display here
} // Class MyDrawActionListener
} // Class MyFrame
Hope this helps.