For my perl binding it is important that one can pass a data pointer to all callbacks, especially to "Format_Cbs" as in elm_slider_units_format_function_set(), elm_slider_indicator_format_function_set() of elm_progressbar_unit_format_function_set(). Another "problematic" function would be elm_calendar_format_function_set().
Enclosed you find a approach to solve this problem.
It would be wonderful, if the Efl-libraries could make data pointers also in format cbs possible...
Thanks in advance,