Refactor: Restrict sliders to new 'Slider' key kind

Setting 'slider="true"' on a key is no longer enough to make a slider,
the key must also be of kind 'Slider'.

Only the KeyValue that started sliding is now considered, they can be
generated with negative values. This allows keys that don't have the
complementary cursor movement key on the opposite direction.

This will help implement other kind of sliders as well as up/down
sliders.

0 files changed, 0 insertions, 0 deletions