$1.$ Create a new Eclipse Java project named TicTacToe GUI Game.

$2.$ Copy the games.board package from the Lesson $3$ project named BoardGameTester to your new project:

Right$-$click $($or Control$-$click$)$ on the games.board entry in the src folder of the Lesson $3$ project.

Choose Copy from the dropdown menu.

Right$-$click $($or Control$-$click$)$ on the src folder name in your new project.

Choose Paste from the dropdown menu.

$3.$ In the Cell.java file, have the Cell class extend the JButton class. This will ensure that each cell on the board has the look and feel of a standard Java button.

$4.$ Override the paintComponent$()$ method in JButton by adding this method to the Cell class as follows:

@Override

public void paintComponent$($Graphics g$)\{$

$//$paint the basic button first

super.paintComponent$($g$)$;

int offset $=5$;

Graphics$2$D g$2=($Graphics$2$D$)$ g;

g$2.$setStroke$($new BasicStroke$(5))$;

$//$ now paint $0$ or X if required

switch$($content$)\{$

case NOUGHT:

$//$Draw O

g$2.$setColor$($Color$.$RED$)$;

g$2.$drawOval$($offset$,$offset,

this.getWidth$()-$ offset $*2,$

this.getHeight$()-$ offset $*2)$;

break;

case CROSS:

$//$Draw X

g$2.$setColor$($Color$.$BLACK$)$;

g$2.$drawLine$($offset$,$ offset,

this.getWidth$()-$ offset $,$

this.getHeight$()-$ offset $)$;

g$2.$drawLine$($this$.$getWidth$()-$ offset,

offset, offset,

this.getHeight$()-$ offset$)$;

break;

$\}$

$\}$

If your code has errors, make sure you use the necessary import statements!

This code uses the enhanced Graphics$2$D class, a subclass of Graphics provided with Java$2$D$,$ to set the stroke thickness to more than one pixel.

$5.$ In the Board.java file, have the Board class extend the JPanel class. This will ensure that the board can lay out each cell and process its UI events.

$6.$ Replace the Board constructor with the following code:

public Board$($int rows, int columns, ActionListener ah$)\{$

cells $=$ new Cell$[$rows$][$columns$]$;

this.setLayout$($new GridLayout$(3,3))$;

for$($ int r $=0$; r $<$ cells.length; r$++)\{$

for $($int c $=0$; c $<$ cells$[$r$].$length; c$++)\{$

cells$[$r$][$c$]=$ new Cell$($r$,$c$)$;

this.add$($cells$[$r$][$c$])$;

cells$[$r$][$c$].$addActionListener$($ah$)$;

$\}$

$\}$

$\}$

This will add each cell to the UI and assign an ActionListener object to each cell. Remember to use the necessary imports.

$7.$ In the BoardGameTester.java file, have the BoardGameTester class extend JFrame. This will ensure that the game is hosted in a Java window. Again, check that you have the necessary import statements.

$8.$ Replace the content of the main$()$ method with the following code:

SwingUtilities.invokeLater$($ new Runnable $()\{$

public void run$()\{$ new BoardGameTester$()$; $\}$

$\})$;

$9.$ Declare the following instance variables in the BoardGameTester class $($not inside main$()!)$:

private Board gb;

private int turn;

$10.$ Add the following method to the class:

private void takeTurn$($Cell c$)\{$

Mark curMark $=($turn$++\%2==0)?$

Mark.NOUGHT: Mark.CROSS;

gb$.$setCell$($curMark$,$c$.$getRow$(),$c$.$getColumn$())$;

$\}$

$11.$ Define the following constructor to create the board, provide the event listener, and display the board in the window:

private BoardGameTester$()\{$

gb $=$ new Board$(3,3,$ new ActionListener$()\{$

public void actionPerformed$($ActionEvent ae$)\{$

Cell c $=($Cell$)$ ae$.$getSource$()$;

takeTurn$($c$)$;

$\}$

$\})$;

this.add$($gb$)$;

this.setDefaultCloseOperation$($EXIT$\_$ON$\_$CLOSE$)$;

this.setTitle$("$TIC$-$TAC$-$TOE"$)$;

this.setSize$(300,300)$;

this.setVisible$($true$)$;

$\}$

$12.$ Rewrite the setCell method in the Board class to use a try$-$catch block so the program will display a message $($in the console$)$ and continue if the player clicks on an occupied cell.