Question

I’m trying to make a button class (abstract) so I can set what function is that button going to trigger when clicked dynamically when my program load.

I want to construct all my buttons by reading XML files, this is to avoid code replication so having only 1 “generic” button class is really useful for me.

I was wondering if you could dynamically pass the necessary information about a method, like a pointer to the method’s owner and method in question name, or even better the direct pointer to the method, for a button to call that function/method when clicked ?

Answer 1

Since pointer to function is a runtime artifact you cannot store that in the offline configuration. I see two solutions that might fit what you describe:

1. put your functions into a dynamic library and load them by name – that way your configuration would map a button to library path/function name pair,
2. build a “registry” of named function pointers at startup, probably some hash table, so the configuration would map a button to the hash key.

From experience though I would say that building such facilities are usually overkill, and the configuration quickly becomes heavier then the app itself.

Some additional pointers: Boost.Signals, QT Signals, Command and Chain of Responsibility design patterns.