问用Java绘制connect 4电路板

EN

import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import javax.swing.*;

public class CompositeBoardTest extends JFrame {
    private static int size = 400;
    private static int offset = 10;
    private static int ovalSize = size/4 - offset*2;
    private static int pos = offset/2;
    private static int incr = size/4;

    public static void main( String[] args ) throws Exception {
        SwingUtilities.invokeLater( new Runnable() {
            public void run() { new CompositeBoardTest(); }
        } );
    }

    public CompositeBoardTest() {
        super( "CompositeBoardTest" );
        setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );

        Board board = new Board();
        getContentPane().add( board );
        setSize( size, size+34 );
        setVisible( true );
    }

    static class Board extends JPanel implements ActionListener {
        private int[][] pieces = new int[4][4];
        private Piece addingPiece = null;
        private Timer pieceDropped = null;

        public Board() {
            setPreferredSize( new Dimension( size, size ) );
            setBounds( 0, 0, size, size );
            pieceDropped = new Timer( 50, this );
            addMouseListener( new MouseAdapter() {
                public void mousePressed( MouseEvent e ) {
                    int column = ( e.getPoint().x-pos )/incr;
                    addPiece( column );
                }
            });
        }

        protected void paintComponent( Graphics g ) {
            super.paintComponent( g );

            Graphics2D g2d = (Graphics2D) g;
            Composite comp = g2d.getComposite();

            Dimension d = getSize();
            int w = d.width;
            int h = d.height;

            BufferedImage buffImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
            Graphics2D gbi = buffImg.createGraphics();

            // Clear area
            g2d.setColor( Color.WHITE );
            g2d.fillRect( 0, 0, w, h );

            // Draw screen
//          gbi.setColor( Color.YELLOW );
            gbi.setColor( Color.BLUE );
            gbi.fillRect( 0, 0, w, h );

            // Draw pieces or holes
            gbi.setColor( Color.RED );
            for ( int row = 0 ; row < 4 ; row++ ) {
                for ( int column = 0 ; column < 4 ; column++ ) {
                    if ( pieces[row][column] == 1 ) {
                        gbi.setComposite( AlphaComposite.getInstance( AlphaComposite.SRC_OVER, .1f ) );
                    } else {
                        gbi.setComposite( AlphaComposite.getInstance( AlphaComposite.CLEAR, 0.5f ) );
                    }
                    gbi.fillOval( incr*column+pos, incr*row+pos, ovalSize, ovalSize );
                }
            }

            // Draw adding piece if we have it
            if ( addingPiece != null ) {
                gbi.setComposite( AlphaComposite.getInstance( AlphaComposite.DST_OVER, 1.0f ) );
                gbi.fillOval( addingPiece.x, addingPiece.y, ovalSize, ovalSize );
            }

            // Draws the buffered image.
            g2d.drawImage(buffImg, null, 0, 0);

//          g2d.setComposite( comp );
        }

        public void addPiece( int column ) {
            if ( addingPiece == null ) {
                if ( pieces[0][column] == 0 ) {
                    addingPiece = new Piece();
                    addingPiece.row = 0;
                    addingPiece.column = column;
                    addingPiece.x = incr*column+pos;
                    addingPiece.y = 0;
                    pieceDropped.start();
                } else {
                    getToolkit().beep();
                }
            }
        }

        public void actionPerformed( ActionEvent e ) {
            if ( addingPiece != null ) {
                addingPiece.y += 5;
                int row = ( addingPiece.y - pos )/incr + 1;
                if ( row > 3 || pieces[row][addingPiece.column] == 1 ) {
                    pieces[row-1][addingPiece.column] = 1;
                    addingPiece = null;
                    pieceDropped.stop();
                }
            }
            repaint();
        }
    }
 
    private static class Piece {
        public int row, column, x, y;
    }
}