quake: add a new option onlyone.

[exzombie]

This option allows using a single instance of the app with multiple
screens instead of having a separate app for each screen. It works
better if there is only one instance of the quake object, i.e.

local quake = lain.util.quake({onlyone=true})

and

awful.key({ modkey, }, "z", function () quake:toggle() end),

[lcpz]

@liquiddandruff reported here that the option seems not working with his setup.

Since I'm not a multiscreen user, and you introduced the PR, I'd like to have your help, @exzombie.

---

@liquiddandruff when you spawn quake on the other screen, is the previous instance visible?

[exzombie]

@liquiddandruff, do you construct your quake object inside connect_for_each_screen or globally? Option onlyone only makes sense when having a global quake object. If you make one for each screen, it can have no effect. In fact, I intended to update the wiki when this PR was merged, but forgot.

@copycat-killer, I thought that the default behaviour of spawning a new terminal for each screen was a bit strange, now I know why :) . I decided to introduce a new parameter in order not to change behaviour for existing configurations. But since using onlyone also requires moving quake to global context, would it make sense to remove the onlyone parameter and just always scan all screens? One can then choose whether to have a global or per-screen quake object, a simple documentation change.

[lcpz]

You're right, my head is elsewhere these days.

I'll remove the option and change documentation.

[liquiddandruff]

When I spawn quake on the other screen, the previous instance is still visible, yes. And I did construct the quake object for each screen instead of globally. It seems the problem has been identified; am eager for the next revision, and thanks to you both!

[exzombie]

I took the liberty of updating the wiki as keybinding has to be done differently. I also removed onlyone from the table. But you still need to fix the code: on line 36, you iterate over self.screen; use nil instead. I'm glad this will be solved without a superfluous parameter :) .