1 files changed, 73 insertions, 0 deletions
diff --git a/mavigator-uav/src/main/scala/mavigator/uav/Connection.scala b/mavigator-uav/src/main/scala/mavigator/uav/Connection.scala
new file mode 100644
index 0000000..7399657
--- /dev/null
+++ b/mavigator-uav/src/main/scala/mavigator/uav/Connection.scala
@@ -0,0 +1,73 @@
+package mavigator.uav
+
+import akka.actor.ActorLogging
+import scala.collection.mutable.ArrayBuffer
+
+import akka.actor.Actor
+import akka.actor.ActorRef
+import akka.actor.Terminated
+import akka.actor.actorRef2Scala
+import akka.util.ByteString
+
+/** Protocol definition. */
+object Connection {
+
+  /** Any messages received and transmitted by actors implementing this protocol. */
+  sealed trait Message
+
+  /** Messages emitted by actors implementing this protocol. */
+  trait Event extends Message
+
+  /** Received data from the uav (or any other systems on the link) */
+  case class Received(bstr: ByteString) extends Event
+
+  /** The connection closed or could not be opened */
+  case class Closed(message: String) extends Event
+
+  /** Messages that can be received by actors implementing this protocol. */
+  trait Command extends Message
+
+  /** Register the sender to be notified on events */
+  case object Register extends Command
+
+  case class Unregister(client: ActorRef) extends Command
+
+  /** Send given bytes out to the uav (or any other systems on the link) */
+  case class Send(bstr: ByteString) extends Command
+
+}
+
+/** Common behavior of connection actors. */
+trait Connection { myself: Actor with ActorLogging =>
+
+  private val _clients = new ArrayBuffer[ActorRef]
+
+  /** Current clients that should be notified on incoming messages. */
+  def clients = _clients.toSeq
+
+  /** Adds a client to the client list and acquires a deathwatch. */
+  protected def register(client: ActorRef): Unit = {
+    _clients += client
+    myself.context.watch(client)
+    myself.log.info("Client registered {}", client)
+  }
+
+  /** Remove client and release deathwatch. */
+  protected def unregister(client: ActorRef): Unit = if (clients contains client) {
+    _clients -= client
+    myself.context.unwatch(client)
+    myself.log.info("Client unregistered {}", client)
+  }
+
+  /** Sends a message to all registered clients. */
+  protected def sendAll(msg: Any): Unit = clients foreach (_ ! msg)
+
+  /** Common registration behavior. Manages the messages `Register` and `Terminated` by
+    * registering and unregistering clients. */
+  protected def handleRegistration: Receive = {
+    case Connection.Register => register(sender)
+    case Terminated(client) => unregister(client)
+    case other => myself.log.warning("Unknown message: {}", other)
+  }
+
+}