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 abstract class UpdateMessageBroker
   8 {
   9         private static final int MAXIMUM_NUMBER_SUBSCRIBERS = 7;
  10         /** Array of all subscribers */
  11         private static DataSubscriber[] _subscribers = new DataSubscriber[MAXIMUM_NUMBER_SUBSCRIBERS];
  12         /** Counter of the number of subscribers added so far */
  13         private static int _subscriberNum = 0;
  14         /** Enable/disabled flag */
  15         private static boolean _enabled = true;
  16
  17
  18         /**
  19          * Add a data subscriber to the list
  20          * @param inSub DataSubscriber to add
  21          */
  22         public static void addSubscriber(DataSubscriber inSub)
  23         {
  24                 _subscribers[_subscriberNum] = inSub;
  25                 _subscriberNum++;
  26         }
  27
  28         /**
  29          * Enable or disable the messaging (to allow temporary disabling for multiple operations)
  30          * @param inEnabled false to disable, true to enable again
  31          */
  32         public static void enableMessaging(boolean inEnabled)
  33         {
  34                 _enabled = inEnabled;
  35         }
  36
  37         /**
  38          * Send a message to all subscribers that
  39          * the data has been updated
  40          */
  41         public static void informSubscribers()
  42         {
  43                 informSubscribers(DataSubscriber.ALL);
  44         }
  45
  46
  47         /**
  48          * Send message to all subscribers
  49          * @param inChange Change that occurred
  50          */
  51         public static void informSubscribers(byte inChange)
  52         {
  53                 // TODO: Launch separate thread so that whatever caused the inform can finish
  54                 if (!_enabled) return;
  55                 for (int i=0; i<_subscribers.length; i++)
  56                 {
  57                         if (_subscribers[i] != null)
  58                         {
  59                                 _subscribers[i].dataUpdated(inChange);
  60                         }
  61                 }
  62         }
  63
  64         /**
  65          * Send message to all subscribers
  66          * @param inMessage message to display informing of action completed
  67          */
  68         public static void informSubscribers(String inMessage)
  69         {
  70                 if (!_enabled) return;
  71                 for (int i=0; i<_subscribers.length; i++)
  72                 {
  73                         if (_subscribers[i] != null)
  74                         {
  75                                 _subscribers[i].actionCompleted(inMessage);
  76                         }
  77                 }
  78         }
  79 }