Thread: Chess Game

Hello,

I am working on my project with my partner for my school and we faced some problems, since we can move the x's and the 0'x across but we can't move the X's or the 0'x down. Also, when I exit the program, won't work with getSource() but works with getActionCommand.

Any help or feedback will be helpful.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
 
public class Breakthrough extends JFrame implements ActionListener
{
   private JButton[][] gridUnits; // array holding grid square buttons
   private int x = 0;
   private int y = 0;
   private int y2 = 7;
   private boolean found = false;
 
 
   public Breakthrough()
   {
 
      //JMenuBar objects
      JMenuBar jmb = new JMenuBar(); 
      JMenu jmFile = new JMenu("File");
      JMenu jmHelp = new JMenu("Help");
      JMenuItem jmiExit = new JMenuItem("Exit");
      JMenuItem jmiAbout = new JMenuItem("About");
 
      //adding JMenuBar objects to the JFrame, gui
      jmFile.add(jmiExit); 
      jmHelp.add(jmiAbout); 
      jmb.add(jmFile); 
      jmb.add(jmHelp); 
      setJMenuBar(jmb);
 
      //Mnemonic objects
      jmFile.setMnemonic(KeyEvent.VK_F);
      jmHelp.setMnemonic(KeyEvent.VK_H);
      jmiExit.setMnemonic(KeyEvent.VK_X);
      jmiAbout.setMnemonic(KeyEvent.VK_A);
 
      //Adding ActionListener
      jmiExit.addActionListener(this); 
      jmiAbout.addActionListener(this);
 
 
      //creates grid
      JPanel grid = new JPanel();
      grid.setLayout(new GridLayout(8,8));
      grid.setSize(700,700);
 
      //creates grid squares
 
      gridUnits = new JButton[8][8];
 
      //creates 64 grid square buttons
      for(int rows = 0; rows< gridUnits.length;rows++)
      {
         for(int cols = 0; cols< gridUnits.length; cols++)
         { 
            gridUnits[rows][cols] = new JButton();
         }
 
      } 
 
      //adds 64 buttons to the grid
 
      for (int rows = 0; rows < gridUnits.length; rows++)
      {
 
         for(int cols = 0; cols < gridUnits.length; cols++)
         {
            grid.add(gridUnits[rows][cols]);
 
         }
 
      }
 
 
      //sets text for 16 buttons to the letter "X"
      for( int rows = 0; rows< gridUnits.length; rows++)
      {
 
         for(int cols = 0;cols <2; cols++)
         {
            gridUnits[rows][cols].setText("X");
         }
      }
 
 
      //sets text for 16 buttons to the letter "O"
 
      for(int rows = 0; rows< gridUnits.length; rows++)
      {
 
         for(int cols = 6;cols <8; cols++)
         {
            gridUnits[rows][cols].setText("O");
         }
 
      }      
 
      add(grid);
 
      for (int rows = 0; rows < gridUnits.length; rows++)
      {
 
         for(int cols = 0; cols < gridUnits.length; cols++)
         {
            gridUnits[rows][cols].addActionListener(this);
 
         }
 
      }
 
 
 
   }
 
   public void actionPerformed(ActionEvent ae)
   {
      Object choice = ae.getSource();
      //Object choice = ae.getActionCommand();
 
      if(choice == "Exit")
      {
         System.exit(0);
      }
      else if (choice == "About")
      {
         JOptionPane.showMessageDialog(null,"121 MiniPrject: Chess" +
				"\nFebruary 19, 2014" + "\nDeveloped By Hassan Ndow & Kevin Whetstone", "Chess", JOptionPane.INFORMATION_MESSAGE);
      }
 
      try
      { 
         for (int rows = 0; rows < gridUnits.length; rows++)
         {
 
            for(int cols = 0; cols < gridUnits.length; cols++)
            {
 
 
               if(choice == gridUnits[rows][cols] && (gridUnits[rows][cols].getText().equals("X")) &&(x == 0 && y == 0))
               {
                  x = rows;
                  y = cols;
 
               }
 
 
               if(choice == gridUnits[x][y+1] && (gridUnits[x][y].getText().equals("X")) && (gridUnits[x][y+1].getText().equals("")))
               {
                  gridUnits[x][y].setText("");
                  gridUnits[x][y+1].setText("X");
 
               }
 
 
               if(choice == gridUnits[rows][cols] && (gridUnits[rows][cols].getText().equals("X")))
               {
                  x = rows;
                  y = cols;
 
               }
 
 
               if(choice == gridUnits[rows][cols] && (gridUnits[rows][cols].getText().equals("O")) &&(x == 0 && y2 == 7))
               {
                  x = rows;
                  y2 = cols;
 
               }
 
 
               if(choice == gridUnits[x][y2-1] && (gridUnits[x][y2].getText().equals("O")) && (gridUnits[x][y2-1].getText().equals("")))
               {
                  gridUnits[x][y2].setText("");
                  gridUnits[x][y2-1].setText("O");
 
               }
 
 
               if(choice == gridUnits[rows][cols] && (gridUnits[rows][cols].getText().equals("O")))
               {
                  x = rows;
                  y2 = cols;
 
               }
 
            }
 
         }//end of outer for loop
      }
 
      catch(NullPointerException npe)
      {
         npe.printStackTrace();
      }
      catch(ArrayIndexOutOfBoundsException aio)
      {
         aio.printStackTrace();
      }
 
      System.out.println(x);
      System.out.println(y);
 
 
 
   }//end of actionPerformed
 
 
 
 
   public static void main (String[] args)
   {
 
      //creates a Breakthrough object
      Breakthrough bt = new Breakthrough();
      bt.setTitle("Breakthrough");
      bt.setSize(700,700);
      bt.setLocationRelativeTo(null);
      bt.setVisible(true);
      bt.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   }
}

getSource() returns an object and you are trying to compare said object to "Exit", but you don't have any "Exit" objects. However, you do have a bmiExit object, but the scope of that variable wouldn't allow it to be referenced in the actionPerformed method. So change the scope of the object(s) you want to check via getSource() and then test the result against the object itself instead of a literal string. As for the x's and o's movement, I am too tired to be of much help there.

Thank you for your help on the getSource method, and for the x's and 0'x movement, no problem.

Thanks again,

Kevin

You and your partner should learn to comment your code, especially if you want to show it to someone else to get their help. Please don't tell me "We do it after the code is done." That's pointless on so many levels.

Please give your variables better names. What's a gridUnit? Why not chessPiece? Even better, whitePawn, blackPawn, whiteKing, blackQueen, etc. Using piece-specific names will lead you to creating a ChessPiece class - a good thing - in which the piece's name, original location, current location, move rules, possible moves, move history, etc. could be stored.

You have a very busy actionPerformed() method without a clue given about what it's doing. Comments would be nice. A single actionPerformed() method for every possible user action may not be the best approach. Perhaps one for the menu items and another for the "chess" pieces might be simpler. If you expand the ability of the game to keep track of pieces as I suggested above, then a separate action listener for pieces will be appreciated.

Comment your code so that you and we can see what it's supposed to be doing, and then come back and post it, IF you still need help.

Originally Posted by GregBrannon

You and your partner should learn to comment your code, especially if you want to show it to someone else to get their help. Please don't tell me "We do it after the code is done." That's pointless on so many levels.

Please give your variables better names. What's a gridUnit? Why not chessPiece? Even better, whitePawn, blackPawn, whiteKing, blackQueen, etc. Using piece-specific names will lead you to creating a ChessPiece class - a good thing - in which the piece's name, original location, current location, move rules, possible moves, move history, etc. could be stored.

You have a very busy actionPerformed() method without a clue given about what it's doing. Comments would be nice. A single actionPerformed() method for every possible user action may not be the best approach. Perhaps one for the menu items and another for the "chess" pieces might be simpler. If you expand the ability of the game to keep track of pieces as I suggested above, then a separate action listener for pieces will be appreciated.

Comment your code so that you and we can see what it's supposed to be doing, and then come back and post it, IF you still need help.

Thank you for your patience. I understand the frustration and I will bring that issue when I talk with my partner about that.

Thanks again,

Kevin