Moved source into separate src directory due to popular request

[GpsPrune.git] / src / tim / prune / UpdateMessageBroker.java

diff --git a/src/tim/prune/UpdateMessageBroker.java b/src/tim/prune/UpdateMessageBroker.java
new file mode 100644 (file)
index 0000000..1659973
--- /dev/null
+++ b/src/tim/prune/UpdateMessageBroker.java
@@ -0,0 +1,104 @@
+package tim.prune;
+
+/**
+ * Class responsible for distributing update information
+ * to all registered listeners
+ */
+public abstract class UpdateMessageBroker
+{
+       private static final int MAXIMUM_NUMBER_SUBSCRIBERS = 8;
+       /** Array of all subscribers */
+       private static DataSubscriber[] _subscribers = new DataSubscriber[MAXIMUM_NUMBER_SUBSCRIBERS];
+       /** Index from which to start looking for an empty slot*/
+       private static int _searchStartIndex = 0;
+       /** Enable/disabled flag */
+       private static boolean _enabled = true;
+
+
+       /**
+        * Add a data subscriber to the list
+        * @param inSub DataSubscriber to add
+        */
+       public static void addSubscriber(DataSubscriber inSub)
+       {
+               // Loop looking for first null entry
+               for (int i=_searchStartIndex; i<MAXIMUM_NUMBER_SUBSCRIBERS; i++)
+               {
+                       if (_subscribers[i] == null)
+                       {
+                               _subscribers[i] = inSub;
+                               _searchStartIndex = i+1;
+                               break;
+                       }
+               }
+       }
+
+       /**
+        * Remove the given subscriber from the list
+        * @param inSub subscriber to remove
+        */
+       public static void removeSubscriber(DataSubscriber inSub)
+       {
+               for (int i=0; i<MAXIMUM_NUMBER_SUBSCRIBERS; i++)
+               {
+                       if (_subscribers[i] == inSub)
+                       {
+                               _subscribers[i] = null;
+                               // Could break out of the loop here but we want to make sure we remove all of them
+                       }
+               }
+               _searchStartIndex = 0; // for the next add, start from beginning to ensure all gaps are filled
+       }
+
+       /**
+        * Enable or disable the messaging (to allow temporary disabling for multiple operations)
+        * @param inEnabled false to disable, true to enable again
+        */
+       public static void enableMessaging(boolean inEnabled)
+       {
+               _enabled = inEnabled;
+       }
+
+       /**
+        * Send a message to all subscribers that
+        * the data has been updated
+        */
+       public static void informSubscribers()
+       {
+               informSubscribers(DataSubscriber.ALL);
+       }
+
+
+       /**
+        * Send message to all subscribers
+        * @param inChange Change that occurred
+        */
+       public static void informSubscribers(byte inChange)
+       {
+               // TODO: Launch separate thread so that whatever caused the inform can finish
+               if (!_enabled) return;
+               for (int i=0; i<_subscribers.length; i++)
+               {
+                       if (_subscribers[i] != null)
+                       {
+                               _subscribers[i].dataUpdated(inChange);
+                       }
+               }
+       }
+
+       /**
+        * Send message to all subscribers
+        * @param inMessage message to display informing of action completed
+        */
+       public static void informSubscribers(String inMessage)
+       {
+               if (!_enabled) return;
+               for (int i=0; i<_subscribers.length; i++)
+               {
+                       if (_subscribers[i] != null)
+                       {
+                               _subscribers[i].actionCompleted(inMessage);
+                       }
+               }
+       }
+}