use XkbKeycodeToKeysym instead of XKeycodeToKeysym (deprecation)

[Antoine Martin]

We get these warnings:

/usr/include/gtk-2.0/gtk/gtkitemfactory.h:47:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
bindings.c: In function '__pyx_f_8wimpiggy_8lowlevel_8bindings_KeysymToKeycodes':
bindings.c:10353:7: warning: 'XKeycodeToKeysym' is deprecated (declared at /usr/include/X11/Xlib.h:1695) [-Wdeprecated-declarations]
bindings.c: In function '__pyx_f_8wimpiggy_8lowlevel_8bindings__get_modifier_mappings':
bindings.c:11494:9: warning: 'XKeycodeToKeysym' is deprecated (declared at /usr/include/X11/Xlib.h:1695) [-Wdeprecated-declarations]
bindings.c: In function '__pyx_pf_8wimpiggy_8lowlevel_8bindings_68get_keycodes_down':
bindings.c:12712:5: warning: 'XKeycodeToKeysym' is deprecated (declared at /usr/include/X11/Xlib.h:1695) [-Wdeprecated-declarations]

See ​freedesktop.org bug 5349 and ​freedesktop.org bug 25732

Together with the fix in ​108#comment:12, this should fix most keyboard related issues?

[Antoine Martin]

We may have to use more than just XkbKeycodeToKeysym... there's a whole new API to use in Xkb, with very little in terms of "howto" documentation.

Maybe we can get away with just figuring out "group" and "level"?

This ought to allow us to fix the following bugs:

• #108: the only remaining issue that I perceived was with right Alt (ISO_Level_3 shift) + "ß" (right of top row "0") which should produce a "\", but continues to produce a "ß".
• #109: dvorak-fr

And maybe also:

• #91: control key with custom xmodmap changes... (should work)
• #86: 2 keyboards on a client, each with a different layout

[Antoine Martin]

done in r1772