alcsnow.java

Java Applet网页特效 .觉得还不错.

// Decompiled by Jad v1.5.7g. Copyright 2000 Pavel Kouznetsov.
// Jad home page: http://www.geocities.com/SiliconValley/Bridge/8617/jad.html
// Decompiler options: packimports(3) fieldsfirst ansi 
// Source File Name:   alcsnow.java

import java.applet.Applet;
import java.awt.*;
import java.util.Random;

public class alcsnow extends Applet
    implements Runnable
{

    Thread mainThread;
    Image offScrn;
    Graphics offGrph;
    Random rand;
    int stopFlag;
    long stopTime;
    int snowX[];
    int snowY[];
    int snows;
    int wind;
    int threadSleep;
    Dimension dim;
    Image gAlc[];
    MediaTracker mt;

    public void init()
    {
        rand = new Random();
        dim = size();
        offScrn = createImage(dim.width, dim.height);
        offGrph = offScrn.getGraphics();
        String s = getParameter("snows");
        if(s == null)
            snows = 100;
        else
            snows = Integer.valueOf(s).intValue();
        if(snows > 500)
            snows = 500;
        s = getParameter("threadsleep");
        if(s == null)
            threadSleep = 80;
        else
            threadSleep = Integer.valueOf(s).intValue();
        if(threadSleep < 10)
            threadSleep = 10;
        else
        if(threadSleep > 1000)
            threadSleep = 1000;
        snowX = new int[snows];
        snowY = new int[snows];
        for(int i = 0; i < snows; i++)
        {
            snowX[i] = rand.nextInt() % (dim.width / 2) + dim.width / 2;
            snowY[i] = rand.nextInt() % (dim.height / 2) + dim.height / 2;
        }

        s = getParameter("graphic");
        if(s == null)
        {
            s = getParameter("graph");
            if(s == null)
            {
                s = getParameter("grph");
                if(s == null)
                    s = "tento1.gif";
            }
        }
        mt = new MediaTracker(this);
        gAlc = new Image[1];
        gAlc[0] = getImage(getDocumentBase(), s);
        mt.addImage(gAlc[0], 0);
        try
        {
            mt.waitForID(0);
        }
        catch(InterruptedException _ex)
        {
            return;
        }
        stopFlag = 0;
    }

    public void start()
    {
        if(mainThread == null)
        {
            mainThread = new Thread(this);
            mainThread.start();
        }
    }

    public void stop()
    {
        mainThread = null;
    }

    public void run()
    {
        while(mainThread != null) 
        {
            try
            {
                Thread.sleep(threadSleep);
            }
            catch(InterruptedException _ex)
            {
                return;
            }
            repaint();
        }
    }

    public void paint(Graphics g)
    {
        offGrph.setColor(Color.black);
        offGrph.fillRect(0, 0, dim.width, dim.height);
        offGrph.drawImage(gAlc[0], 0, 0, this);
        drawBackSnow();
        g.drawImage(offScrn, 0, 0, null);
    }

    public void update(Graphics g)
    {
        paint(g);
    }

    public void drawBackSnow()
    {
        offGrph.setColor(Color.white);
        for(int i = 0; i < snows; i++)
        {
            offGrph.fillRect(snowX[i], snowY[i], 1, 1);
            snowX[i] += rand.nextInt() % 2 + wind;
            snowY[i] += (rand.nextInt() % 6 + 5) / 5 + 1;
            if(snowX[i] >= dim.width)
                snowX[i] = 0;
            if(snowX[i] < 0)
                snowX[i] = dim.width - 1;
            if(snowY[i] >= dim.height || snowY[i] < 0)
            {
                snowX[i] = Math.abs(rand.nextInt() % dim.width);
                snowY[i] = 0;
            }
        }

        switch(rand.nextInt() % 100)
        {
        case -2: 
            wind = -2;
            return;

        case -1: 
            wind = -1;
            return;

        case 0: // '\0'
            wind = 0;
            return;

        case 1: // '\001'
            wind = 1;
            return;

        case 2: // '\002'
            wind = 2;
            return;
        }
    }

    public alcsnow()
    {
    }
}