Tic-Tac-Toe game using java

You will create a very basic but functional Tic-Tac-Toe game. The first move must draw an X, the next must draw an O, and so on. You must not be able to overwrite a position that is already filled on the board. You do not need to check for game completion, the game simply ends when the board is full. I have provided a documented example which you should use as your starting point. See the comments for implementation hints and details. When a button is pressed down, the X or O should be drawn in the appropriate position, but it must not be committed until the mouse is finally released. That is, a player should be able to drag the mouse inside of the grid and the X or O should follow their cursor.

Answer:

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
public class TicTacToe1 extends JFrame {
	private int turns = 1;
	private char[][] board = new char[3][3];

	private int xTable[] = {46, 79, 113};   // xTable[i] gives the displacement for rowNumber i
	private int yTable[] = {113, 146, 180};

	private boolean moveInProgress = false;
	private boolean moveSuccessful;
	private int potentialRow;
	private int potentialCol;
	

	public TicTacToe1(){
		super("Tictactoe Board");
		setSize(300, 300);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		// Clear board
		for(int r = 0; r < 3; r++) {
			for(int c = 0; c < 3; c++) {
				board[r][c] = '\0';
			}
		}

		addMouseListener(new MouseListener() {
			@Override
			public void mouseClicked(MouseEvent e) { }

			@Override
			public void mousePressed(MouseEvent e) {
				potentialRow = getMouseRow(e);
				potentialCol = getMouseCol(e);
				moveInProgress = true;

				moveSuccessful = addMove(potentialRow, potentialCol);

				repaint();
			}

			@Override
			public void mouseReleased(MouseEvent e) {
				if(moveInProgress) {
					moveInProgress = false;
					if(moveSuccessful) {
						turns++;
					}
					repaint();
				}
			}

			@Override
			public void mouseEntered(MouseEvent e) { }

			@Override
			public void mouseExited(MouseEvent e) {	}
		});

		addMouseMotionListener(new MouseMotionListener() {
			@Override
			public void mouseDragged(MouseEvent e) {
				if(moveInProgress) {
					int mouseRow = getMouseRow(e);
					int mouseCol = getMouseCol(e);

					if( !(mouseRow == potentialRow && mouseCol == potentialCol) ) {
						if(moveSuccessful) {
							deleteMove(potentialRow, potentialCol);
						}
						moveSuccessful = addMove(mouseRow, mouseCol);
						potentialRow = mouseRow;
						potentialCol = mouseCol;
					}

					repaint();
				}
			}

			@Override
			public void mouseMoved(MouseEvent e) { }
		});

		setVisible(true);
	}

	public void paint(Graphics g){
		int red = 255, green = 0, blue = 0;
		Font my_font;
		my_font = new Font( "Serif", Font.BOLD, 18 );
		super.paint(g); // Note use of super!!
		g.setColor(new Color(red, green, blue)); // One way to set color
		g.drawLine(40, 140, 140, 140);
		g.drawLine(40, 173, 140, 173);
		g.drawLine(73, 107, 73, 207);
		g.drawLine(107, 107, 107, 207);
		g.setColor(new Color(0, 0, 0));
		g.fillRect(20, 87, 140, 5);
		g.fillRect(20, 87, 5, 140);
		g.fillRect(20, 222, 140, 5);
		g.fillRect(155, 87, 5, 140);
		g.setColor(Color.blue);       // Another way to set color
		g.setFont(my_font);
		g.drawString("My Tic Tac Toe Board", 20, 280);
		displayMoves(g);	
	}

	private boolean deleteMove(int row, int col) {
		if(board[row][col] == '\0') {
			return false;
		} else {
			board[row][col] = '\0';
			return true;
		}
	}

	private boolean addMove(int row, int col) {
		if(board[row][col] == '\0') {
			board[row][col] = (turns % 2 == 1) ? 'X' : 'O';
			return true;
		} else {
			return false;
		}
	}

	private int getMouseCol(MouseEvent e) {
		if(e.getX() <= 73) {
			return 0;
		} else if(e.getX() <= 107) {
			return 1;
		} else {
			return 2;
		}
	}

	private int getMouseRow(MouseEvent e) {
		if(e.getY() <= 140) {
			return 0;
		} else if(e.getY() <= 173) {
			return 1;
		} else {
			return 2;
		}
	}

	private void displayMoves(Graphics g){
		for(int r = 0; r < 3; r++) {
			for(int c = 0; c < 3; c++) {
				switch(board[r][c]) {
					case 'X':
						drawX(g, r, c);
						break;
					case 'O':
						drawCircle(g, r, c);
						break;
				}
			}
		}
	}

	private void drawX(Graphics g, int rowNo, int columnNo){

		g.drawLine(xTable[columnNo], yTable[rowNo],
				xTable[columnNo] + 10, yTable[rowNo] + 20);
		g.drawLine(xTable[columnNo], yTable[rowNo] + 20,
				xTable[columnNo] + 10, yTable[rowNo]);
	}

	private void drawCircle(Graphics g, int rowNo, int columnNo){
		g.drawOval(xTable[columnNo], yTable[rowNo], 20, 20);
	}


	public static void main(String args[]){
		new TicTacToe1();
	}
}