way this worked in 2.4x wasn't really clean, with events going all over the place and using dubious variables such as G.but->lockpoin or G.sima->menunr. It works as follows now, for example: xco= uiDefIDPoinButs(block, CTX_data_main(C), NULL, (ID**)&sima->image, ID_IM, &sima->pin, xco, yco, sima_idpoin_handle, UI_ID_BROWSE|UI_ID_RENAME|UI_ID_ADD_NEW|UI_ID_OPEN|UI_ID_DELETE|UI_ID_ALONE|UI_ID_PIN); The last two parameters are a callback function, and a list of events or functionalities that are supported. The callback function will then get the ID pointer + event to handle.