//user U can take cursor on shape S <=> (U doesn't have other cursors && S is free)
public void HandleCursorRequest(LitePeer peer,
OperationRequest operationRequest,
SendParameters sendParameters)
{
var req = CursorRequest.Read(operationRequest.Parameters);
var changes = false;
if (req.doSet)
{
if (_doc.UserHasCursor(req.ownerId))
{
return; //already holds another cursor
}
var sh = _doc.TryGetShape(req.shapeId);
if (sh == null)
{
return; //no such shape
}
if (sh.GetCursor() != null)
{
return; // shape is busy
}
//ok, lock shape
_doc.LockShape(sh, req.ownerId);
changes = true;
}
else
{
//cursor remove operation is always ok
var sh = _doc.TryGetShape(req.shapeId);
if (sh == null)
{
return; //no such shape
}
_doc.UnlockShape(sh, req.ownerId);
changes = true;
}
if (changes)
{
_room.Broadcast(peer,
CursorEvent.Write(req.doSet, req.ownerId, req.shapeId, _topicId),
sendParameters,
(byte)DiscussionEventCode.CursorEvent,
BroadcastTo.RoomAll); //include self
}
}
