Activity switcher problems [for Plasma and KWin teams]

[David Edmundson]

> 1) Make opening the activity switcher fast. That would need to throw away the
> lazy loading that we currently have. And I'm not sure that would be a
> sufficient improvement.

Note that a debug build of Qt makes a humongous difference to the
speed of all things QtQuick related, especially parsing. It might
appear a lot worse than it really is.

There's a few simple optimisations we can make in the current QML
before we have to start making hacks.

 - ActivityCreationDialog is created on load. twice.
This can and be in a Loader, and maybe we can make only one instance.

- ActivityItem should set a source size on the wallpaper image.

 - There's an add animation which due to the model being async means
the initial items get animated in. This will make things look slower
than they really are

>Advantages for this would be that kwin already has a global instance of
KActivities::Consumer class

The shell also has an instance of this class.