adime_d_button_proc (3) - Linux Man Pages
DESCRIPTIONSimilar to Allegro's `d_button_proc()', but with 3d-ish style. It also has a slightly different behaviour: Unlike `d_button_proc()', the D_EXIT flag has no effect. Instead you need to set the `d1' field to one of the three constants:
The button behaves like a check box, i.e. when clicked it toggles between being in and being out.
The button exits the dialog when clicked.
If you provide a callback function in the dp2 field, then it will be called whenever the button is clicked. This callback should have the form `int my_callback(DIALOG *d)', and its return value will be passed back to the dialog manager.