Receiving data from endpoints via a callback

An endpoint can deliver data as it is received to one or more functions or class methods within your application.

Conceptually, this is the delivery mechanism that is probably most appropriate for datagram delivery such as UDP/IP.

To receive data from an endpoint via callback you need to:

1. Create the function or class method that will receive the data from the endpoint.
   • Your function or method must have one of the following signatures:
     1. void function_or_method_name (conexus::Data)
     2. void function_or_method_name (conexus::CData)
     • This means that the return type of the function or method must be void and the first parameter must be either conexus::Data or conexus::CData
     • If you want other parameters you must use sigc::bind , which is discussed in the Gtkmm tutorial and the sigc++ documentation.
2. Create the sigc++ slot that will receive the data from the endpoint.
   • Generally, sigc::mem_fun and sigc::ptr_fun will suffice
   • The required signature of the sigc::slot is either:
     1. sigc::slot<void, conexus::Data>
     2. sigc::slot<void, conexus::CData>
3. Connect the slot to the endpoint using either the connect_to_data() method if your function or method accepts conexus::Data as its first parameter or the connect_to_const_data() method if your function or method accepts conexus::CData as the first parameter.

The following image illustrates the sequence of operations in receiving data via callbacks.

Sequence of operations required to receive data via a callback mechanism.

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