timescroll.java

本程序实现了日历与时间功能

import java.applet.*;
import java.awt.*;
import java.net.*;
import java.util.*;
import java.io.*;

 
class TimeAndDateFormatter {

    String formattedDate;

    String  daysOfWeek[]   = { "星期日","星期一","星期二","星期三","星期四","星期五","星期六" };

    String  monthsOfYear[] = { "一月","二月","三月","四月","五月","六月",
                               "七月","八月","九月","十月","十一月","十二月"  };

    TimeAndDateFormatter( Date date, String title ) {

        int h = date.getHours();
        int m = date.getMinutes();
        int s = date.getSeconds();

        int dy = date.getDay();
        int dt = date.getDate();
        int mn = date.getMonth();
        int yr = date.getYear();

        String hours, minutes, seconds, am_pm;
        String day, numericalDate, month, year;

        if( h == 0 ) {
            hours = new String( "12"  );
            am_pm = new String( "AM" );
        } else if( h > 12 ) {
            hours = new String( "" + (h-12) );
            am_pm = new String( "PM"     );
        } else if( h == 12 ) {
            hours = new String( "12" );
            am_pm = new String( "PM"  );
         } else {
            hours = new String( "" + h );
            am_pm = new String( "AM"  );
        }

        if( m < 10 ) {
            minutes = new String( "0" + m );
        } else {
            minutes = new String( ""  + m );
        }

        if( s < 10 ) {
            seconds = new String( "0" + s );
        } else {
            seconds = new String( ""  + s );
        }

        day = daysOfWeek[ dy ];
        
        numericalDate = new String( "" + dt );

        month = monthsOfYear[ mn ];

        year  = new String( "" + (1900 + yr) );

        formattedDate = new String( day + ", " +
                                    month + " " +
                                    numericalDate + "日 , " +                                    
                                    year + " 年 " + title + "  " +
                                    hours   + ":" +
                                    minutes + ":" +
                                    seconds + " " + am_pm
                                    );
    }

    public String toString() {
        return formattedDate;
    }
}



public class TIMESCROLL extends Applet implements Runnable 
  {

    private Thread clock;
    private String font_name, title, datestring;			
    private int height, width, font_size;		
    private Font wordFont;
    private FontMetrics wordMetrics;
    private int textcolor, backcolor, bordercolor;
    private int stringx, stringy;
    private int delay, s_width;
    TimeAndDateFormatter formattedTimeAndDate;
    private Image offI;
    private Graphics offG;
        
 public void init() 
    {
      String temp;


      height = size().height;	
      width = size().width;
      offI = createImage(width,height);
      offG = offI.getGraphics();
 
     delay = 30;
     temp=getParameter("title");
     title = (temp==null) ? " " : temp;
     temp=getParameter("font");
     font_name= (temp==null) ? "TimesRoman" : temp;
     temp = getParameter("fontsize");
     font_size= (temp==null) ? 12 : Integer.parseInt( temp );

     						
     wordFont = new Font(font_name, Font.BOLD, font_size);
     if (wordFont == null)
       wordFont = getFont();
     wordMetrics = getFontMetrics (wordFont);

    temp = getParameter("Fore");
    textcolor = (temp==null) ? 0x000000 : Integer.parseInt(temp, 16);
    temp = getParameter("backcolor");
    backcolor= (temp==null) ? 0xffffff : Integer.parseInt(temp, 16);
    temp = getParameter("Back");
    bordercolor = (temp==null) ? backcolor : Integer.parseInt(temp, 16);

 }


  public void start() 
     {
       clock = new Thread(this); 	
       clock.start();	
     }
	
  public void stop() 
    {
      clock.stop();
    }


    public void run() 
      {
       Thread.currentThread().setPriority(Thread.MIN_PRIORITY);	
       int x=width;
      while(true) 
       {
         Date date = new Date();

          formattedTimeAndDate =
            new TimeAndDateFormatter( date, title );

          datestring = formattedTimeAndDate.toString();
          

          offG.setFont(wordFont);			
          offG.setColor(new Color(backcolor));		
          offG.fillRect(0,0,width,height);
          offG.setColor(new Color(textcolor));
          s_width = wordMetrics.stringWidth(datestring);
          stringy = (height - (wordMetrics.getHeight()-wordMetrics.getLeading()))/2 + (wordMetrics.getHeight()-wordMetrics.getLeading()-wordMetrics.getDescent());		 
          stringx = (width - s_width)/2;

          offG.drawString (datestring, x, stringy);
          offG.setColor(new Color(bordercolor));
          offG.drawRect(0, 0, width-1, height-1);	
          
          repaint();
          x--;
          if(x == stringx)
          {
             try 
             {
                Thread.sleep(5000);
             } 
             catch( InterruptedException ex ){} 
          }
          
          if(x <-width)
          {
            x = width;
          }
          try {
                Thread.sleep(delay);
              } 
          catch( InterruptedException e ) 
            {}
        }    
    }


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

  public synchronized void paint(Graphics g) 
    {
       g.drawImage(offI,0,0,this);

    }
	
	
  public void paintApplet(Graphics g) 
    {				
	}


}