tim/prune/UpdateMessageBroker.java

   1 package tim.prune;
   2
   3 /**
   4  * Class responsible for distributing update information
   5  * to all registered listeners
   6  */
   7 public class UpdateMessageBroker
   8 {
   9         private DataSubscriber[] _subscribers;
  10         private int _subscriberNum = 0;
  11         private static final int MAXIMUM_NUMBER_SUBSCRIBERS = 4;
  12
  13
  14         /**
  15          * Constructor
  16          * @param inTrack Track object
  17          */
  18         public UpdateMessageBroker()
  19         {
  20                 _subscribers = new DataSubscriber[MAXIMUM_NUMBER_SUBSCRIBERS];
  21         }
  22
  23
  24         /**
  25          * Add a data subscriber to the list
  26          * @param inSub DataSubscriber to add
  27          */
  28         public void addSubscriber(DataSubscriber inSub)
  29         {
  30                 _subscribers[_subscriberNum] = inSub;
  31                 _subscriberNum++;
  32         }
  33
  34
  35         /**
  36          * Send a message to all subscribers that
  37          * the data has been updated
  38          */
  39         public void informSubscribers()
  40         {
  41                 for (int i=0; i<_subscribers.length; i++)
  42                 {
  43                         if (_subscribers[i] != null)
  44                         {
  45                                 _subscribers[i].dataUpdated();
  46                         }
  47                 }
  48         }
  49 }