Choice removeAll will make its newly added content unvisible.

JDK: 1.2.2 D
OS: Solaris 2.6
Locale: C, zh_CN

In this build, when using CHoice's removeAll method to remove its content, then
add new item in it, the newly added items will not be visible.
Following is a program to reproduce it.

===========================CheckChoice.java===================================
import java.awt.*;
import java.awt.event.*;
import java.io.*;

public class CheckChoice extends Thread {
   
   Choice choice1;
   Choice choice2;
   Choice choice3;
   int itemCount = 0;
   static CheckChoice choiceThread;

   public static void main(String args[]) {
       choiceThread = new CheckChoice();
       choiceThread.start();
   }

   public CheckChoice() {
       Frame f = new Frame("Check Choice");
       f.setLayout(new BorderLayout());
       choice1 = new Choice();
       choice2 = new Choice();
       choice3 = new Choice();
       f.add(choice1, BorderLayout.NORTH);
       f.add(choice3, BorderLayout.CENTER);
       f.add(choice2, BorderLayout.SOUTH);
       f.pack();
       f.show();
   }

   public void run() {
       while (true) {
       if (choice1 != null && itemCount < 40) {
           choice1.add("I am Choice, yes I am : " + itemCount * itemCount);
           choice2.add("I am the same, yes I am : "+ itemCount * itemCount);
           choice3.add("I am the same, yes I am : "+ itemCount * itemCount);
           itemCount ++;
       }
       if (itemCount >= 20 && choice1 != null && choice1.getItemCount() > 0) {
           choice1.removeAll();
           choice2.removeAll();
           choice3.removeAll();
           itemCount = 0;
       }
       //System.out.println("iiiiiiiii " + itemCount);
       try {
           Thread.sleep(1000);
       } catch (Exception ex) {
       }
       }
    }
}
===============================================================================

run this program, wait several minutes to see its performance.


jim.hu@prc 1999-01-25