flyword.java

一个利用java线程技术开发的飞字程序

/**
   @version 1.30 2001-05-06
   @author Cay Horstmann
*/

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;

/**
   Shows an animated bouncing ball running in a separate thread
*/
public class FlyWord
{
   public static void main(String[] args)
   {
      JFrame frame = new FlyFrame();
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.show();
   }
}

/**
   The frame with canvas and buttons.
*/
class FlyFrame extends JFrame
{
   /**
      Constructs the frame with the canvas for showing the
      bouncing ball and Start and Close buttons
   */
   public FlyFrame()
   {
      setSize(WIDTH, HEIGHT);
      setTitle("FlyThread");

      Container contentPane = getContentPane();
      canvas = new WordCanvas();//建立一个用于显示字体的面板
      contentPane.add(canvas, BorderLayout.CENTER);
      JPanel buttonPanel = new JPanel();//建立一个用于放置按钮的面板
      addButton(buttonPanel, "Start",
         new ActionListener()
            {
               public void actionPerformed(ActionEvent evt)
               {
                  addWord();
               }
            });//建立Start按钮，点击执行addWord()方法

      addButton(buttonPanel, "Close",
         new ActionListener()
            {
               public void actionPerformed(ActionEvent evt)
               {
                  System.exit(0);
               }
            });//建立Close按钮，点击执行System.exit(0)方法，退出程序
      contentPane.add(buttonPanel, BorderLayout.SOUTH);//把按钮面板添加入容器
   }

   /**
      Adds a button to a container.
      @param c the container
      @param title the button title
      @param listener the action listener for the button
   */
   public void addButton(Container c, String title,
      ActionListener listener)
   {
      JButton button = new JButton(title);
      c.add(button);
      button.addActionListener(listener);
   }//构建具体的按钮，并且添加事件监听器

   /**
      Adds a bouncing ball to the canvas and starts a thread
      to make it bounce
   */
   public void addWord()
   {
      y=y+size;
	  color=color+50;
      size=size+10;//这三行分别用于动态的改变字体的位置，颜色和大小
      Word b = new Word(canvas,x,y);
      b.setColor(color);
      b.setFontsize(size);
      canvas.add(b);

     WordThread thread = new WordThread(b);
      thread.start();//建立并且启动线程的运行
   }

   private WordCanvas canvas;
   public static final int WIDTH = 450;
   public static final int HEIGHT = 350;
    private static  int x=0,y=0,color=0,size=10;
}

/**
   A thread that animates a bouncing ball.
*/
class WordThread extends Thread
{
   /**
      Constructs the thread.
      @aBall the ball to bounce
   */
   public WordThread(Word aWord) { b = aWord; }

   public void run()
   {
      try
      {
         for (int i = 1; i <= 1000; i++)
         {
            b.move();
            sleep(5);
         }
      }
      catch (InterruptedException exception)
      {
      }
            //run()方法用于字体的水平移动   
   }

   private Word b;
}

/**
   The canvas that draws the balls.
*/
class WordCanvas extends JPanel
{
   /**
      Add a ball to the canvas.
      @param b the ball to add
   */
   public void add(Word b)
   {
      words.add(b);
   }

   public void paintComponent(Graphics g)
   {
       super.paintComponent(g);
       Graphics2D g2 = (Graphics2D)g;

     for (int i = 0; i < words.size(); i++)
       {
        Word b = (Word)words.get(i);
         b.draw(g2);
       }
   }



   private ArrayList words = new ArrayList();
}

/**
   A ball that moves and bounces off the edges of a
   component
*/
class Word
{
   /**
      Constructs a ball in the upper left corner
      @c the component in which the ball bounces
   */
   public Word(Component c,int aX,int aY) { canvas = c;x=aX;y=aY;}

   /**
      Draws the word at its current position
      @param g2 the graphics context
   */

   public  void draw(Graphics2D g2)
   {

       String string = "Hello,World!";
       g2.drawString(string,x,y);
       Font f=new Font("SansSerif",Font.BOLD,fontsize);
	   g2.setFont(f);
       g2.setPaint(new Color(colornumber));
       //用于具体的显示字体
   }

   /**
      Moves the ball to the next position, reversing direction
      if it hits one of the edges
   */
  public void setFontsize(int size)
   {fontsize=size;}

 public  void setColor(int c)
  {colornumber= c;}
  public void move()
   { x += dx;
    if (x >= canvas.getWidth())
      {
         x = 0;
      }


      canvas.repaint();//刷新面板
   }

   private Component canvas;
   private Color color;
   private static final int XSIZE = 15;
   private static final int YSIZE = 15;
   private int x ;
   private int y ;
   private int dx = 2;
   private int dy = 2;
   private int fontsize=0;
   private int colornumber=0;
}