Beginners Questions about Multiple JPanels in JFrame and event handling

Question

I am a newbie with SWING, and even a newerbie in Event Handling. So here goes.
I am writing a maze program. I am placing a maze JPanel (MazePanel) at the center of a JFrame, and a JPanel of buttons (ButtonPanel) on the SOUTH pane. I want the buttons to be able to re-randomize the maze, solve the maze, and also ouput statistics (for percolation theory purposes). I have the backbone all done already, I am just creating the GUI now. I am just figuring out EventHandlers and such through the tutorials, but I have a question. I am adding an ActionListener to the buttons which are on the ButtonPanel which are on JFrame (SOUTH) Panel. But who do I make the ActionListener--Basically the one doing the work when the button is pressed. Do I make the JFrame the ActionListener or the MazePanel the ActionListener. I need something which has access to the maze data (the backbone), and which can call the Maze.randomize() function. I'm trying to make a good design and not just slop too.
Also I was wondering if I do this
JButton.addActionListener(MazePanel), and lets say public MazePanel implments ActionListenerdoesn't adding this whole big object to another object (namely the button actionlistener) seem really inefficient? And how does something that is nested in a JPanel on JFrame x get information from something nested in another JPanel on a JFrame x.
Basically how is the Buttons going to talk to the maze when the maze is so far away?

Answer 1

I'm not an expert, but here's what I'd do....
You already have your business logic (the Maze classes), you said. I'm assuming you have some kind of public interface to this business logic. I would create a new class like "MazeGui" that extends JFrame, and then create the GUI using this class. Add buttons and panels as needed to get it to look the way you want. Then for each button that does a specific thing, add an anonymous ActionListener class to it and put whatever code you need inside the ActionListener that accesses the business logic classes and does what it needs to.
This is the idea, though my code is totally unchecked and won't compile:
import deadseasquirrels.mazestuff.*;
public class MazeGui extends JFrame {
  JPanel buttonPanel = new JPanel();
  JPanel mazePanel = new JPanel();
  JButton randomizeB = new JButton();
  JButton solveB = new JButton();
  JButton statsB = new JButton();
  // create instanc(es) of your Maze business logic class(es)
  myMaze = new MazeClass();
  // add the components to the MazeGui content pane
  Component cp = getContentPane();
  cp.add(); // this doesn't do anything, but in your code you'd add
            // all of your components to the MazeGui's contentpane
  randomizeB.addActionListener(new ActionListener {
    void actionPerformed() {
      Maze newMaze = myMaze.getRandomMazeLayout();
      mazePanel.setContents(newMaze); // this is not a real method!
                                      // it's just to give you the idea
                                      // of how to manipulate the JPanel
                                      // representing your Maze diagram,
                                      // you will probably be changing a
                                      // subcomponent of the JPanel
  solveB.addActionListener(new ActionListener {
    void actionPerformed() {
      Solution mySolution = myMaze.getSolution();
      mazePanel.setContents(mySolution); // again, this is not a real
                                         // method but it shows you how
                                         // the ActionListener can
                                         // access your GUI
  // repeat with any other buttons you need
  public static void main(String[] args) {
    MazeGui mg = new MazeGui();
    mg.setVisible(true);
    // etc...
}