How to settle an an image in Applet for tetris game

Question

I developing tetris game using applets. I have generated random shapes and making it move. But i don't know how to make it settle at the bottom. My shapes are vanishing once it reaches the end of the screen. Please help me on this regard. Here goes my code.

import java.applet.Applet;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.JFrame;
import javax.swing.JLabel;



public class TetrisGame
{
    public static void main (String argsp[])
    {
        JFrame frame = new JFrame("Tetris");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        final AppletClass applet = new AppletClass();
        frame.getContentPane().add(applet);
        applet.init();
        Thread t = new Thread(new Runnable()
        {

            @Override
            public void run() 
            {
                while(true)
                {
                    try 
                    {
                        Thread.sleep(1000);
                        applet.repaint();
                    }
                    catch (InterruptedException e) 
                    {
                        e.printStackTrace();
                    }               
                }
            }

        });
        t.start();

        frame.setBounds(10,10,410,610);
        frame.setVisible(true);
    }
}

class AppletClass extends Applet implements KeyListener
{

    private static final long serialVersionUID = 1L;
    static int xpos = 190;
    static int ypos =0;
    static int random1;
    static int reached_end=1;


    public void init()
    {
             System.out.println("aaa");
        setFocusable(true);
        requestFocus();
        addKeyListener(this);

    }
    public void paint (Graphics g)
    {

        generateRandomShapes(g);
    }

    public void generateRandomShapes (Graphics g)
    {

        int i=0;
        int x[] = new int[4];
        int y[] = new int[4];

        if(reached_end==1)
        {
            random1=(int)Math.floor(Math.random()*100);
            ypos=0;
        }

        x[0]=xpos;
        ypos =ypos+30;
        y[0]=ypos;

        if(ypos>420)
        {
            reached_end=1;
            ypos=0;
        }
        else
            reached_end=0;





        switch(random1%7)
        {
                case 0:
                    //straight line
                    for(i = 0;i<3;i++)
                    {
                        x[i+1]=x[i];
                        y[i+1]=y[i]+30;
                    }
                    break;
                case 1:
                    //L shape
                    for(i = 0;i<2;i++)
                    {
                        x[i+1]=x[i];
                        y[i+1]=y[i]+30;
                    }
                    x[i+1]=x[i]+30;
                    y[i+1]=y[i];
                    break;
                case 2:
                    //reverse L shape
                    for(i = 0;i<2;i++)
                    {
                        x[i+1]=x[i];
                        y[i+1]=y[i]+30;
                    }
                    x[i+1]=x[i]-30;
                    y[i+1]=y[i];
                    break;
                case 3:
                    //square shape
                    i=0;
                        x[i+1]=x[i];
                        y[i+1]=y[i]+30;
                    i++;
                        x[i+1]=x[i]+30;
                        y[i+1]=y[i];
                    i++;
                        x[i+1]=x[i];
                        y[i+1]=y[i]-30;
                    break;
                case 4:
                    //Inverse T shape
                    x[i+1]=x[i]-30;
                    y[i+1]=y[i]+30;
                    for(i = 1;i<3;i++)
                    {
                        x[i+1]=x[i]+30;
                        y[i+1]=y[i];
                    }
                    break;
                case 5:
                    //S shape
                    x[i+1]=x[i]-30;
                    y[i+1]=y[i]+30;
                    i++;
                    x[i+1]=x[i]+30;
                    y[i+1]=y[i];
                    i++;
                    x[i+1]=x[i]+30;
                    y[i+1]=y[i]-30;
                    break;
                case 6:
                    //Z shape
                    x[i+1]=x[i]+30;
                    y[i+1]=y[i];
                    i++;
                    x[i+1]=x[i];
                    y[i+1]=y[i]+30;
                    i++;
                    x[i+1]=x[i]+30;
                    y[i+1]=y[i];
                    break;

        }
        g.setColor(Color.BLACK);
        for(i=0;i<4;i++)
        {
            g.fillRect(x[i], y[i], 30, 30);
        }


    }

    public void keyReleased(KeyEvent e){;}
     public void keyTyped(KeyEvent e){;}

    public void keyPressed(KeyEvent e) 
    {
        System.out.println("Kkk "+e.getKeyCode());
        if(e.getKeyCode() == KeyEvent.VK_LEFT)
     {
        if(xpos>=30)
        {
            xpos=xpos-30;
        }
        System.out.println("xpos is :" + xpos);
     }
     if(e.getKeyCode() == KeyEvent.VK_RIGHT)
     { 
         xpos=xpos+30;
     }

     if(e.getKeyCode() == KeyEvent.VK_DOWN || e.getKeyCode() == KeyEvent.VK_SPACE)
     {
         ypos=420;
     }
 }
}

TIA

Roar

1) Thread.sleep(1000); Don't block the EDT (Event Dispatch Thread) - the GUI will 'freeze' when that happens. Instead of calling Thread.sleep(n) implement a Swing Timer for repeating tasks or a SwingWorker for long running tasks. See Concurrency in Swing for more details. 2) In this millennium, why AWT (Applet) rather than Swing (JApplet)? 3) For convenience and the best user experience, why not JFrame and JWS instead of JApplet or Applet? – Monotint

Answer 1

Your code only draws a single block. You must store the coordinates of all generated block and redraw them at every game frame.

Baskett