void requestAllSyncData() throws IOException;
+ /**
+ * Add a handler to receive new messages.
+ * Will start receiving messages from server, if not already started.
+ */
+ void addReceiveHandler(ReceiveMessageHandler handler);
+
+ /**
+ * Remove a handler to receive new messages.
+ * Will stop receiving messages from server, if this was the last registered receiver.
+ */
+ void removeReceiveHandler(ReceiveMessageHandler handler);
+
+ boolean isReceiving();
+
/**
* Receive new messages from server, returns if no new message arrive in a timespan of timeout.
*/