Question

I have to create a vertical menu using clutter in C. Can anyone help me how to implement focus shift using the navigation keys for the menu where i want to highlight the focused menu option.

Answer 1

the easiest way is to mark the actor that contains all the menu items as reactive, assign to it the key focus using clutter_actor_grab_key_focus() and connect to the key-press-event signal. then you can use clutter_event_get_key_symbol() on the ClutterEvent passed to the signal and match it agains key symbols like CLUTTER_KEY_Down or CLUTTER_KEY_Up.

then there’s even the possibility to use ClutterBindingPool to handle tuples of (key symbol, modifier) and assign them to a specific callback function.

for more information, see the API reference:

http://developer.gnome.org/clutter/stable/ClutterActor.html#clutter-actor-grab-key-focus
http://developer.gnome.org/clutter/stable/ClutterActor.html#ClutterActor-key-press-event
http://developer.gnome.org/clutter/stable/clutter-Events.html#clutter-event-get-key-symbol
http://developer.gnome.org/clutter/stable/clutter-Key-Bindings.html

the list of key symbols in in the clutter-keysyms.h header:

http://git.gnome.org/browse/clutter/tree/clutter/clutter-keysyms.h

there are various recipes in the Cookbook as well:

https://developer.gnome.org/clutter-cookbook/stable/events-handling-key-events.html