// On the server disconnecting
private static void Disconnected(Connection Sender, DisconnectMessage Message)
{
// Unhook handlers
Server.MessageReceived -= MessageReceived;
Server.Disconnect -= Disconnected;
// Reset the signals
InitialisedEvent.Dispose();
InitialisedEvent = null;
UserEvent.Dispose();
UserEvent = null;
}
// Handler for when the server receives a message
private static void MessageReceived(Connection Sender, Message Msg)
{
bool Locked = true;
Monitor.Enter(Lock);
// Don't echo changes back to the server - changes made in this
// function have been sent to us by the server
ReportModelChanges = false;
if (Msg is InitialiseMessage)
{
// Initialisation of the client - load in the data
LoadSnapshot((Msg as InitialiseMessage).Snapshot, false);
// Signal that we've received the initial data
InitialisedEvent.Set();
}
else if (Msg is UserInformationMessage)
{
// Information on the User and their Room
UserInformationMessage m = (Msg as UserInformationMessage);
User User = m.User;
Room Room = m.Room;
if (User == null)
{
throw new ArgumentNullException("Received a null user.");
}
if (Room == null)
{
throw new ArgumentNullException("Received a null room.");
}
// Acquire references to the actual user/room
DataSnapshot Frame = TakeSnapshot(false);
CurrentUser = Frame.Users.SingleOrDefault(u => u.Id == User.Id);
CurrentRoom = Frame.Rooms.SingleOrDefault(r => r.Id == Room.Id);
// Signal that we've received the user data
UserEvent.Set();
}
else if (Msg is DataMessage)
{
DataMessage Data = (DataMessage)Msg;
// Get references to linked objects
using (DataRepository Repo = new DataRepository(false))
Data.Item.Expand(Repo);
// If we're not deleting it, set references to this item
if (!Data.Delete)
{
Data.Item.Attach();
}
else // Otherwise remove references
{
Data.Item.Detach();
}
// Store the type of the received data
Type t = Data.Item.GetType();
// Get the right table from the dictionary (match received type to key)
IList Table = Tables.Single(p => t == p.Key || t.IsSubclassOf(p.Key)).Value;
// Find the index of the item in the table
int Index = -1;
for (int x = 0; x < Table.Count; x++)
{
if (((DataModel)Table[x]).Id == Data.Item.Id)
{
Index = x;
break;
}
}
if (!Data.Delete)
{
if (Index < 0) // Doesn't already exist, add it
{
Table.Add(Data.Item);
}
else // Already exists, update it
{
((DataModel)Table[Index]).Update(Data.Item);
}
}
else // Delete it
{
Table.RemoveAt(Index);
}
// Release the lock
Monitor.Exit(Lock);
// Note that we've already released it
Locked = false;
// Fire the change of data handler
DataChanged(Data.Item.GetType());
}
ReportModelChanges = true; // Continue reporting changes
if (Locked) // Release the lock if we haven't already
{
Monitor.Exit(Lock);
}
}
// Initialise the database model from the server
public static Tuple <User, Room> Initialise(Connection Server, ConnectMessage Msg)
{
try
{
// Thread safe
Monitor.Enter(Lock);
// Reset the signal that's set when the data's received
if (InitialisedEvent == null)
{
InitialisedEvent = new ManualResetEvent(false);
}
InitialisedEvent.Reset();
// Reset the signal that's set when the user information's received
if (UserEvent == null)
{
UserEvent = new ManualResetEvent(false);
}
UserEvent.Reset();
// Set the current server
DataRepository.Server = Server;
// Hook up network events
Server.MessageReceived += MessageReceived;
Server.Disconnect += Disconnected;
// Hook up data changed events
_Bookings.CollectionChanged += Data_CollectionChanged;
_Departments.CollectionChanged += Data_CollectionChanged;
_Rooms.CollectionChanged += Data_CollectionChanged;
_Users.CollectionChanged += Data_CollectionChanged;
_Subjects.CollectionChanged += Data_CollectionChanged;
_Periods.CollectionChanged += Data_CollectionChanged;
_Classes.CollectionChanged += Data_CollectionChanged;
// Send the connection message
Server.Send(Msg);
}
catch
{
return(null);
}
finally
{
// Release the lock
Monitor.Exit(Lock);
}
try
{
// Wait for both signals to fire, signalling completion
InitialisedEvent.WaitOne();
UserEvent.WaitOne();
}
catch
{
// Disconnected during initialise
return(null);
}
// Return the User and their Room (grouped together for easy return value)
return(new Tuple <User, Room>(CurrentUser, CurrentRoom));
}
