Switch (instantly) to the next/previous window of the panel

[pierrelegall]

Gnome Shell default window swich commands do not implement:

• a switch respecting the order of the windows in the panel (not by last used windows)
• an instantly window switch with one shortcut pressed (by default, the window is not switched till you don't release ctrl/alt/meta)

This proposal is to add this to Dash to Panel itself.

The idea behind this is to know before shortcut pressed wich window will be shown, using a consistent list of window, reorderable by the user in the panel.

To be more explicite:

Obviously, next AND previous window command is needed. This shortcut have to be customizable.

[undefiened]

Double this proposal: it would allow making it similar to tiling wm's where you can just switch between windows with win+h win+l in a logical linear manner. Imho the feature only makes sense as a part of the "Ungroup applications" option.

[undefiened]

I am trying to draft a simple solution to this, but I have a bit of a problem, so I was wondering if someone who understands the inner workings of this project can help me understand why it doesn't work? See #2214