Linking two class files?

Question

hello!
I have a class called paul.java and a class called trialgrid.java...
paul.java is a menu screen that simply has four buttons, one of the buttons is called btnOnePlayer, trialgrid.java is a battleships game that is one player!
my question is how do i get it so that when a user clicks on btnOnePlayer in paul.java it opens the trialgrid.java game of one player battleships??
any help would be amazing, thank you!!!!

Answer 1

this is a great question for this forum. Here is a code snippet that shows one way to use the ActionListener. You may also want to look into using Adapters. You could post another question about the Adapters and see what you get. Anyway, here is the code.
Paul.java
import javax.swing.* ;
import javax.swing.event.* ;
import java.awt.* ;
import java.awt.event.* ;
public class Paul implements ActionListener {
public Paul () {
   //do nothing in constructor since it happens in main
   //if this were part of bigger code, then constructor
   //may need to put GUI together
private static void createAndShowGUI (Paul paul) {
   JFrame frame = new JFrame ("Battle Ship") ;
   Container pane = frame.getContentPane() ;
   pane.setLayout (new BorderLayout()) ;
   JButton onePlayerButton = new JButton ("One Player") ;
   //here is the action connection. The Paul class (which is "this")
   //implements the Actionistener interface. See the method below
   //call actionPerformed. This comes from the implementation of
   //ActionListener. When the button is clicked the code in the
   // actionPerformed method is exectuted.
   onePlayerButton.addActionListener (paul) ;
   pane.add (onePlayerButton, BorderLayout.CENTER) ;
   frame.pack() ;
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) ;
   frame.setVisible(true) ;
public void actionPerformed (ActionEvent ae) {
   //since I know that the only way into the method is
   //from the onePalyerButton, I do not have to check
   //how I got here. I just do the work.
   TrialGrid grid = new TrialGrid () ;
   grid.showGrid () ;
public static void main (String[] args) {
     javax.swing.SwingUtilities.invokeLater(new Runnable() {
       public void run() {
           Paul paul = new Paul() ;
           createAndShowGUI(paul);
Here is the TrialGrid.java that pops up with the button
import javax.swing.* ;
public class TrialGrid extends JFrame {
public TrialGrid () {
public void showGrid () {
   this.getContentPane().add (new JLabel ("ONE PLAYER")) ;
   this.setSize (500,500) ;
   this.setVisible (true) ;
}