[Ayatana] Unity autohide slide angle

[Paul Sladen <ubuntu@xxxxxxxxxxxxxxx>]

(Personal) Reflections on Unity Launcher autohide; see video at bottom
for a possible interaction improvement by tweaking the slide angle.

Currently the Unity Launcher autohides by moving westwards off the
edge of the screen ...if the user intuitively tries "chasing" the
Launcher by moving the pointer westwards, it will not bring it back.

The Launcher is effectively hiding in the north-west of the screen
currently---the vendor logo being the target where the user must
move the pointer to in order to fetch it back.

I've been wondering whether, if the hiding transition direction were
to be changed to be a 30-degree or 45-degree diagonal (rather than the
present horizontal), it might be more intuitive to the user---so I
implemented this as a test:

  http://www.paul.sladen.org/ubuntu/unity/launcher-autohide-north-west.mp4 (639 kB)

It could do with some amount of tweaking, and it's subtle enough
that eight out of ten cats probably wouldn't notice the difference (if 
asked upfront), even though their sub-conscious will likely notice.

	-Paul

PS. I've also now tried 21 degrees, which corresponds to the ratio of
the box of the vendor logo; this is even more subtle but seems to
still convey the hint of where the Launcher might have gone and
perhaps looks a tad slicker/smoother.