rollingdisplayinfo.java

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package rollingdisplayinfo;

import java.awt.*;
import java.awt.event.*;
import java.applet.*;

/**
 * <p>Title: 滚动显示信息</p>
 * <p>Description: 从上至下滚动显示信息</p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: 北京师范大学计算机系</p>
 * @author 孙一林
 * @version 1.0
 */

public class RollingDisplayInfo extends MultiThreadApplet {
  boolean isStandalone = false;
  int info_num;         // 声明参数个数变量
  int y = 10;
  boolean pause = false; // 声明暂停标志变量

  //Get a parameter value
  public String getParameter(String key, String def) {
    return isStandalone ? System.getProperty(key, def) :
      (getParameter(key) != null ? getParameter(key) : def);
  }

  //Construct the applet
  public RollingDisplayInfo() {
  }
  //Initialize the applet
  public void init() {
    try {
      info_num = Integer.parseInt(this.getParameter("Info_num", "2"));
    }
    catch(Exception e) {
      showStatus("参数错误!"); // 在浏览器的状态栏目中显示错误信息
      e.printStackTrace();
      System.exit(-1);
    }
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  //Component initialization
  private void jbInit() throws Exception {
    this.setBackground(Color.white);    // 设置Applet的背景
    this.addMouseListener(new java.awt.event.MouseAdapter() {
      public void mouseEntered(MouseEvent e) {
        this_mouseEntered(e);
      }
      public void mouseExited(MouseEvent e) {
        this_mouseExited(e);
      }
    });
  }

  public void paint(Graphics g) {
    for(int i=1; i<=info_num; i++){
      g.drawString(this.getParameter("Info_"+String.valueOf(i),"1.今日要闻"),10,y+(i*14));
      // 获取并显示信息
    }
  }

  public void run(){		// 线程处理
    Thread current = Thread.currentThread();
    while (thisThread == current) {
      try {
        Thread.currentThread().sleep(100);
      }
      catch (InterruptedException e) {
      }
      repaint();
      if(!pause){
        y--;
      }
      if(y<0-info_num*14){
        y=getSize().height+14;
      }
    }
  }

  //Get Applet information
  public String getAppletInfo() {
    return "滚动显示信息";
  }
  //Get parameter info
  public String[][] getParameterInfo() {
    String[][] pinfo =
      {
      {"Info_num", "int", ""},
      };
    return pinfo;
  }

  void this_mouseEntered(MouseEvent e) {
    pause = true;       // 暂停滚动显示信息
  }

  void this_mouseExited(MouseEvent e) {
    pause = false;      // 恢复滚动显示信息
  }
}