Peter Hutterer authored Apr 13, 2021 and Simon Ser committed Sep 13, 2021

Hold gestures merely denote "there are fingers on the touchpad but they are
not moving". As touchpad touches are generally fully abstracted, a client
cannot currently know when a user is interacting with the touchpad without
moving - no motion events will be sent in this case.

The two use-cases here are:
- hold-to-interact: where a hold gesture is active for some time
  a menu could pop up, or some object is selected, etc.
- hold-to-cancel: where e.g. kinetic scrolling is currently active, the start
  of a hold gesture can be used to stop the scroll

Since hold gestures by definition do not have movement, there is no need for
an "update" stage in the gesture.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>