Default touch screen edge gestures

[Martin Gräßlin]

Hi Plasmates,

now that we have touch screen edge swipe gesture support both on X11 and 
Wayland we could define which actions to put on each edge.

My suggestion would be to put a sensible action on each of the four 
actions.

Personal proposal:

*Left Edge:*
Window Switching as the default alt+tab theme is on the left side. Also 
on Windows 10 this happens on the left edge.

*Top Edge:*
Present Windows as 4 finger swipe downwards on touchpad triggers present 
windows.

*Bottom Edge:*
Desktop Grid as 4 finger swipe upwards on touchpad triggers desktop 
grid.

*Right Edge:*
Application launcher


What I dislike about the proposal is: Present Windows and Alt+Tab are 
kind of redundant. Given that a better default edge would be nice for 
top edge. KRunner would be a nice fit as it's also on top, but it's 
rather useless on touch.

The application launcher is rather disconnected in the default setup if 
we swipe in from left screen. What I personally would prefer if we could 
trigger the application dashboard. Of course we still don't have working 
touch support in the application launchers, so if we go for that we need 
fixing (same applies for alt+tab btw.).

So please comment and propose your own ideas.

Cheers
Martin