button press events of TextCtrlAndButton class, can be handled here.
Also, if custom handling for regular events is desired, then that can
also be done (for example, wxSystemColourProperty custom handles
- wxEVT_COMMAND_CHOICE_SELECTED to display colour picker dialog when
+ wxEVT_CHOICE to display colour picker dialog when
'custom' selection is made).
If the event causes value to be changed, SetValueInEvent()