Re: how to delete a JList element

On Jun 21, 5:08 pm, Roedy Green <see_webs...@mindprod.com.invalid>
wrote:
[...]


[...]

Right, in my GUI:

guestJList.setModel(BedAndBreakfast.getInstance().listModel);
//BedAndBreakfast is the "database"

and then in BedAndBreakfast:

   /*@see GUI
    *this method makes the DefaultListModel match the
    *HashMap which stores the data.
    *ideally, this method shouldn't be required.
    *I'm not quite sure why, but without it
    *nothing synchronizes with the JList.setModel
    *in the GUI*/
   public void sync()
   {
      listModel.clear();
      Collection<?> foos = getGuests();
      for (Object obj : foos)
      {listModel.addElement(obj);}
   }

to try to "sync" up the Map with the ListModel because every example I
see imbeds the data in with the JList, which is what I think I'm going
to do.

Sending an Array or Vector from the "database" (BedAndBreakfast) just
has no effect on syncing with the JList.

For what it's work, here's the "database":

package a00720398.data;

import java.util.*;
import javax.swing.*;
import a00720398.util.*;

public class BedAndBreakfast
{

   private static final BedAndBreakfast INSTANCE = new
BedAndBreakfast();

   private HashMap guests = new LinkedHashMap<Integer, Guest>();
   public DefaultListModel listModel = new DefaultListModel();

   private BedAndBreakfast()
   {sync();}

   public static BedAndBreakfast getInstance()
   {return INSTANCE;}

   /*@see GUI
    *this method makes the DefaultListModel match the
    *HashMap which stores the data.
    *ideally, this method shouldn't be required.
    *I'm not quite sure why, but without it
    *nothing synchronizes with the JList.setModel
    *in the GUI*/
   public void sync()
   {
      listModel.clear();
      Collection<?> foos = getGuests();
      for (Object obj : foos)
      {listModel.addElement(obj);}
   }

   public Collection<?> getGuests()
   {
      return guests.values();
   }

   public void removeGuest(int i)
   {
      System.out.println("index: " + i);
      guests.remove(i);
      sync();
   }

   @SuppressWarnings( "unchecked" )
   public void addGuest(Guest guest)
   {
      sync();
      if (guest.getID() == 0)
      { //if ID is default value
     int i = getGuests().size() + 1;
     guest.setID(i); //kludge to append to the "end" of the Map
      }

      guests.put(guest.getID(), guest); //hopefully no duplicates
      sync();
      //System.out.println("\n************\n" + getGuests());
   }
}

When I have the JList.setModel method convert the Map to Array it
simply fails to sync :(

thanks,

Thufir