Boolean - True when the connection is open, or data exists in the Indy buffer.

Connected is an overridden Boolean function used to indicate that connection for the IOHandler has been established, and that the internal buffer is assigned or contains existing data. 

Connected calls the protected ReadFromSource method with a request of 0 (zero) bytes to check the availability of the data source for the IOHandler. 

Connected calls the inherited method to retrieve the return value for the function. The return value for the function is True when the InputBuffer contains exisiting data, or when ClosedGracefully is False and the InputBuffer is assigned.

CheckForDataOnSource 

CheckForDisconnect 

ClosedGracefully