+val connect_button: GButton.button -> (unit -> unit) -> unit
+
+ (** connect a unit -> unit callback to a particular key press event. Event can
+ * be specified using its keysym and a list of modifiers which must be in
+ * effect for the callback to be executed. Further signal processing of other
+ * key press events remains unchanged; further signal processing of the
+ * specified key press depends on the stop parameter *)
+val connect_key:
+ GObj.event_ops ->
+ ?modifiers:Gdk.Tags.modifier list ->
+ ?stop:bool -> (* stop signal handling when the given key has been pressed?
+ * Defaults to false *)
+ Gdk.keysym -> (* (= int) the key, see GdkKeysyms.ml *)
+ (unit -> unit) -> (* callback *)
+ unit
+