[Ayatana-dev] Home lens status update

[Mikkel Kamstrup Erlandsen <mikkel.kamstrup@xxxxxxxxxxxxx>]

Hey all,

Been hacking frantically to get the HomeLens class in UnityCore working 
smoothly, and I think I am just about there. I'll just add a few more 
tests and it's ready for mp. If you wanna peek you need all the branches 
from: https://bugs.launchpad.net/ubuntu/+source/unity/+bug/885738 (where 
you can also find a screenshot 
https://launchpadlibrarian.net/90419671/Screenshot_Unity_HomeLens.png)

NOTE: Currently I implemented in a way that require an ABI break in 
libunity-core (but not API break).

The way it is going to work is to allow lenses to put up arbitrary 
categories in the global results. Before this lenses were shoehorned 
into one category. Then we (we=mhr3 and me) will make sure the default 
lenses behave as they should.

Under the hood HomeLens is a smart Lens subclass in libunity-core 
(shared by u3d and u2d) that merges all global results and categories on 
the fly and expose it as one bog standard Lens instance. I am telling 
you that this is a *lot* more complicated than it sounds :-). But rest 
assured that it's easy to consume in Unity3/2d.

To make sure we get a sane layout I've implemented a way to control the 
overall sorting on the home screen in a gsettings key. After we've 
landed the home-lenses branch I'll look into sorting the dash lens-bar 
icons by the same rules (they are currently rather arbitrarily sorted 
alphabetically, without possibility for user overrides).

I am pretty excited about all of this because a) it empowers users and 
lens authors to customize the home screen, yet keeping it slick and 
unity-styled, and b) it allows OEMs or thin clients providers to do the 
same.

But basically everything is working nicely. Except for the first item 
below I am about ready to merge-propose. Todo:

- Add a few more tests cases to the rather complex HomeLens class

- Music lens to collate results into one category (wip by mhr3)

- Recent Apps doesn't filter out running apps that are not favorites 
(wip by mhr3, blocking on bamf merge queue)

- Unity2d enablement (should be easy, by design of the HomeLens class). 
I can do this unless someone beats me to it

Good weekend all!

Cheers,
Mikkel