let add_key_binding key callback (evbox: GBin.event_box) =
ignore (evbox#event#connect#key_press (function
| key' when GdkEvent.Key.keyval key' = key ->
let add_key_binding key callback (evbox: GBin.event_box) =
ignore (evbox#event#connect#key_press (function
| key' when GdkEvent.Key.keyval key' = key ->