/// <summary>
/// Takes a <see cref="Common.Person">Person</see> and allows them
/// to join the chat room, if there is not already a chatter with
/// the same name
/// </summary>
/// <param name="person"><see cref="Common.Person">Person</see> joining</param>
/// <return
public bool Join(string name, ChatEventHandler chat_event_handler, out CommPointInfo[] person_list)
{
bool userAdded = false;
person_list = null;
CommPointInfo person = new CommPointInfo(name);
//carry out a critical section that checks to see if the new chatter
//name is already in use, if its not allow the new chatter to be
//added to the list of chatters, using the person as the key, and the
//ChatEventHandler delegate as the value, for later invocation
lock (syncObj)
{
if (!checkIfPersonExists(person.name) && person != null)
{
chatters.Add(person, chat_event_handler);
userAdded = true;
}
}
//if the new chatter could be successfully added, get a callback instance
//create a new message, and broadcast it to all other chatters, and then
//return the list of al chatters such that connected clients may show a
//list of all the chatters
if (userAdded)
{
ChatEventArgs e = new ChatEventArgs();
e.msgType = MessageType.UserEnter;
e.person = person.name;
BroadcastMessage(e);
//add this newly joined chatters ChatEventHandler delegate, to the global
//multicast delegate for invocation
ChatEvent += chat_event_handler;
//carry out a critical section that copy all chatters to a new list
lock (syncObj)
{
person_list = new CommPointInfo[chatters.Count];
chatters.Keys.CopyTo(person_list, 0);
}
// Tell the controller we have a new pilot that joined.
_controller_callback.Join(person.name);
}
return(userAdded);
}
/// <summary>
/// A request has been made by a client to leave the chat room,
/// so remove the <see cref="Common.Person">Person </see>from
/// the internal list of chatters, and unwire the chatters
/// delegate from the multicast delegate, so that it no longer
/// gets invokes by globally broadcasted methods
/// </summary>
public void Leave(string person)
{
if (person == null)
{
return;
}
bool userRemoved = false;
//get the chatters ChatEventHandler delegate
ChatEventHandler chatterToRemove = null;
//carry out a critical section, that removes the chatter from the
//internal list of chatters
lock (syncObj)
{
chatterToRemove = getPersonHandler(person);
if (chatterToRemove != null)
{
userRemoved = true; // Found the user that needs to be removed.
CommPointInfo comm_point = getPerson(person);
chatters.Remove(comm_point);
}
}
if (userRemoved)
{
//unwire the chatters delegate from the multicast delegate, so that
//it no longer gets invokes by globally broadcasted methods
ChatEvent -= chatterToRemove;
ChatEventArgs e = new ChatEventArgs();
e.msgType = MessageType.UserLeave;
e.person = person;
//broadcast this leave message to all other remaining connected
//chatters
BroadcastMessage(e);
// Tell the controller we have a pilot that left.
_controller_callback.Leave(person);
}
}
