Multimonitor: config option to display on multiple monitors

[felixfung]

Currently in a multi monitor setting, skippy displays only on a single monitor, the current active monitor as indicated by mouse position.

It is possible to display on all monitors, with each monitor displaying the expose/paging layout position of the windows originally from that monitor space.

For switch, probably the current behaviour should be preserved, or perhaps an additional config option could be introduced.

The implementation would be to change the MainWin position and size, and offsets. The complexity of implementation comes from the combinations of options: xinerama compilation, pseudoTrans, xrandr multimonitor setting, the multimonitor display options introduced in this task.

[felixfung]

A bit more thinking:

For switch, it is best to keep it single monitor.

For expose, it is best to have it multi-monitor, i.e. expose applied to the windows on their own monitor

For paging, it is hard to say... I think the current (single-monitor) implementation is pretty good, whereas for multi-monitor (each monitor displays an array of desktops on that monitor), the user has to visually link each desktop from different monitors.

So this feature proposal is bad for switch, great for expose, so-so for paging, and the implementation cost is high, and the risk of bug is high because of the high number of combinations of options...

So not sure about implementing this feature.