X-Git-Url: http://gitweb.fperrin.net/?p=GpsPrune.git;a=blobdiff_plain;f=src%2Ftim%2Fprune%2FUpdateMessageBroker.java;fp=src%2Ftim%2Fprune%2FUpdateMessageBroker.java;h=16599735a80fc831ede28f72241f1310f42a3bb7;hp=0000000000000000000000000000000000000000;hb=ce6f2161b8596f7018d6a76bff79bc9e571f35fd;hpb=2d8cb72e84d5cc1089ce77baf1e34ea3ea2f8465

diff --git a/src/tim/prune/UpdateMessageBroker.java b/src/tim/prune/UpdateMessageBroker.java
new file mode 100644
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);
+			}
+		}
+	}
+}