ClutterInputFocus is an abstract object to be subclassed by UI actors and
the wayland interface and represents the user of an input method. It
represents the current focus of the input method, so all emitted signals
and public API hooks are expected to be called when the input method is
currently interfacing with the input focus.
ClutterInputMethod is an abstract class (to be implemented in the upper
layers) that represents the input method itself. Besides focus management
itself, all public API calls that would be called by the subclasses are
delivered through the current input focus.
Use a set of bitwise enum flags to set different keyboard accessibility
features and the necessary vfunc hooks in clutter input device so that
keyboard preferences can be passed to different input device
implementations.
The idea is to be able to configure either the clutter own
implementation of keyboard accessibility for evdev, or eventually
configure AccessX from the X11 clutter input device using the same
mechanism.
https://bugzilla.gnome.org/show_bug.cgi?id=788564
This function call only applies to tablets, and thus will error
out unless it's called with CLUTTER_TABLET_DEVICEs. This will
allow setting absolute/relative mapping on those on the fly, as
this is optional.
Those map closely what we get from libinput. Button events have
been made its own separate struct, its semantics fall somewhere
in between of ClutterButtonEvent and ClutterKeyEvent, so is better
emitted as its own set.
