I'm wondering whether it might make sense to set up either a thread, or a wiki page where one can enter his common workflow as a basis to discuss how buttons etc. should behave...
...then again, being an xmonad user on my computers, I get the impression that it probably will be difficult to accomodate everyone's workflow with a generic configuration.
...Maybe it would make sense to define
[Events] (short/long action on every key event)
and
[Actions] (pan n pixels/flip page/...)
and allow for user defined configurations there?
I'm not sure what will be less of a hassle for the developers :P
I personally will work most in hide-margins or column-mode (when it becomes available) to read, using panning to hide/show margins next to the visible area.
I'd expect the left buttons to switch screens in these modes and I'd need some convenient way to switch between scribbling and erasing.
Colour selection would come best via bottom bar, but menu is acceptable.
Long presses of 'back' button would go to main directory, and long pressing of 'home' buton would be a user configurable action (e.g. abovementioned scribble switch).
Cheers!
P.S.: PF4Mobile: I agree that it is not useful to have the same functionality twice when input events are scarce
(I would make the panning result dependent on the zoom mode. In my favoured zoom modes mentioned above, I have given the implicit contextual information that I'm mostly not interested in margins, but may be for annotation reasons - that's why I'd prefer the joystick to act as hide/show margin functionality there. If an arbitrary zoom level is chosen, your 'line' or an 'n pixel' panning makes a lot more sense.)