It's off topic now and i don't want to harvest this thread could you may put it in an extra one? Also to ask others what they think about it.
Actually a GadgetExtra()/SetGadgetExtra() should have been there from the start (like for listitems), because now we have the problem with backward compatibility. My suggestion would be to take a new field for the SetGadgetFilter and a function pair as you suggested to set/get the context field. As skid approved that we can use it, probably a lot have it in use in their programs and changing only the filter for the TextField and the TextArea is much easier and would not hurt anybody. If you could implement it now with MaxGuiEx that would really be fine, because than there is an official way we can go.
Actually a GadgetExtra()/SetGadgetExtra() should have been there from the start (like for listitems), because now we have the problem with backward compatibility. My suggestion would be to take a new field for the SetGadgetFilter and a function pair as you suggested to set/get the context field. As skid approved that we can use it, probably a lot have it in use in their programs and changing only the filter for the TextField and the TextArea is much easier and would not hurt anybody. If you could implement it now with MaxGuiEx that would really be fine, because than there is an official way we can go.