Need help in a game design.Cirles,lines intersections

Question

Hello,
Im trying to create a board game (the go game) but i have problems with the design. Till now i have design a 19 * 19 table and what i want is when i click with the mouse on this table to display circles, but i want them exactly on the intersection. With my program i get circles everywhere i click and not on the intersection of the line.
So if anyone can help me,i would like to tell me, how can i place the circle exactly on the intersection? Also i would like to eliminate the clicks just on the table and not outside of it.
Please help if anyone knows, im not that expert in java
My code is this till now.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class goGame extends JFrame {
private int x1Value , y1Value ;
boolean isWhitesTurn = true,first = true;
public goGame()
super( "Go game" );
Color redbrown = new Color (75,17,17);
setBackground(redbrown);
addMouseListener(
// anonymous inner class
new MouseAdapter() {
// store drag coordinates and repaint
public void mouseClicked( MouseEvent event )
x1Value = event.getX();
y1Value = event.getY();
repaint();
} // end anonymous inner class
); // end call to addMouseMotionListener
setSize( 700,550 );
setVisible(true);
public void paint( Graphics g )
Graphics2D graphics2D = (Graphics2D ) g;
Color redbrown = new Color (75,17,17);
g.setColor(redbrown);
Color lightbrown = new Color (192,148,119);
g.setColor(lightbrown);
if (first) {
//paint yellow the big rectangle
graphics2D.setPaint(new GradientPaint (600,100, Color.yellow,100, 10,Color.red,true));
graphics2D.fillRect(60,60,450,450);
graphics2D.setPaint(Color.black);
graphics2D.setStroke(new BasicStroke(3.0f));
//draw rows
int y=60;
for (int n=0; n<=18 ; n++)
g.drawLine(60,y,510,y );
y= y + 25;
//draw columns
int x = 60;
for (int n=0; n<=18 ; n++)
g.drawLine(x,510,x,60);
x = x + 25;
g.setColor(Color.green) ;
//draw the 1st 3 vertical dots
int z = 133;
for (int n=0; n<=2; n++)
g.fillOval(133,z,5,5);
z = z + 150;
//draw the 2 vertical dots of the 1st row-dot , the 1 already exists
int w = 283;
for (int n =0; n<=1; n++)
g.fillOval(w,133,5,5);
w = w + 150;
//draw the 2 vertical dots of the 2nd row-dot
int t = 283;
for (int n=0; n<=2; n++)
g.fillOval(283,t,5,5);
t = t + 150;
//draw the last dots
g.fillOval(433,283,5,5);
g.fillOval(433,433,5,5);
first = false;
if (isWhitesTurn) g.setColor(Color.white);
else g.setColor(Color.black);
g.fillOval( x1Value, y1Value,20,20 );
isWhitesTurn = !isWhitesTurn ;
// execute application
public static void main( String args[] )
goGame application = new goGame();
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

Answer 1

This will capture vertical and horizontal
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class GoGame extends JFrame
public GoGame()
     getContentPane().setLayout(null);
     setBounds(10,10,510,520);
     getContentPane().add(new TheTable());
     setVisible(true);
public class TheTable extends JPanel
     int[][]points  = new int[19][19];
     boolean black  = true;
public TheTable()
     setBounds(20,20,453,453);
     addMouseListener(new MouseAdapter()
          public void mouseReleased(MouseEvent m)
               Point p = clickOnIntersection(m.getPoint());
               if (p != null && points[p.x/25][p.y/25] == 0)
                    int x = p.x/25;
                    int y = p.y/25;
                    if (black)
                         points[x][y] = 1;
                         black = false;
                    else
                         points[x][y] = 2;
                         black = true;
                    capture(x,y);
                    repaint();
private Point clickOnIntersection(Point p)
     Rectangle rh = new Rectangle(0,0,getWidth(),4);
     Rectangle rv = new Rectangle(0,0,4,getHeight());
     for (int h=0; h < 19; h++)
          rh.setLocation(0,h*25-1);
          if (rh.contains(p))
               for (int v=0; v < 19; v++)
                    rv.setLocation(v*25-1,0);
                    if (rv.contains(p)) return(new Point(v*25+1,h*25+1));
     return(null);
private void capture(int x, int y)
     onTheY(x,y,points[x][y]);
     onTheX(x,y,points[x][y]);
private void onTheY(int x, int y, int col)
     for (int j=x-1; j > -1; j--)
          if (points[j][y] == 0) break;
          if (points[j][y] == col)
               outOnY(j,x,y);
               break;
     for (int j=x+1; j < 19; j++)
          if (points[j][y] == 0) break;
          if (points[j][y] == col)
               outOnY(x,j,y);
               break;
private void onTheX(int x, int y, int col)
     for (int j=y-1; j > -1; j--)
          if (points[x][j] == 0) break;
          if (points[x][j] == col)
               outOnX(j,y,x);
               break;
     for (int j=y+1; j < 19; j++)
          if (points[x][j] == 0) break;
          if (points[x][j] == col)
               outOnX(y,j,x);
                break;
private void outOnY(int f, int t, int y)
     for (f=f+1; f < t; f++) points[f][y] = 0;
private void outOnX(int f, int t, int x)
     for (f=f+1; f < t; f++) points[x][f] = 0;
public void paintComponent(Graphics g)
     super.paintComponent(g);
     Graphics2D g2 = (Graphics2D)g;
     g2.setPaint(new GradientPaint(getWidth(),getHeight(),Color.yellow,0,0,Color.red,true));
     g2.fillRect(0,0,getWidth(),getHeight());
     g2.setColor(Color.black);
     for (int n=0; n < 19; n++)
          g2.fillRect(0,n*25,getWidth(),3);
          g2.fillRect(n*25,0,3,getHeight());
     g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);          
     g2.setColor(Color.green) ;
     for (int n=0; n < 3; n++)
          g2.fillOval(25*3-1,n*150+74,5,5);
          g2.fillOval(25*9-1,n*150+74,5,5);
          g2.fillOval(25*15-1,n*150+74,5,5);
     for (int x=0; x < 19; x++)
          for (int y=0; y < 19; y++)
               if (points[x][y] != 0)
                    if (points[x][y] == 1) g.setColor(Color.black);     
                    if (points[x][y] == 2) g.setColor(Color.white);     
                    g2.fillOval(x*25-9,y*25-9,20,20);
public static void main(String[] args)
     GoGame game = new GoGame();
     game.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}Noah