some updates on screen locking related things

[Marco Martin]

On Wednesday 23 January 2013, Aaron J. Seigo wrote:
> hi ...
> 
> as promised, i collected the ideas for screen locking in Plasma Workspaces
> 2 on the wiki:
> 
> 	http://community.kde.org/Plasma/screenlocker
> 
> further comments, ideas, etc. are welcome and I expect that those points
> will refine considerably over time.
> 
> also, in the aseigo/qmlkrunner branch of kde-workspace i pushed some
> changes yesterday that add a switchUser dbus API to ksmserver. now when
> switch user is called, the screen first locks and then shows the
> switchUser UI.
> 
> this brings a few subtle changes:
> 
> * it relies on the theme to have a switch user UI. if it doesn't ... the
> screen just locks. there is currently no way for external components (e.g.
> kickoff or other launchers) to know that this is the case and to therefore
> hide the user switching feature if the locker doesn't provide it. right
> now that is a hypothetical situation only, but will need addressing at
> some point.

a couple of alternatives may be:

* if the root item of the lock screen doesn't have some property to say that 
supports locking (or even its metadata.desktop) load another qml file instead 
that is purely used as fallback

* fit the user switching ui in the ksmserver logout dialog instead of 
lockscreen (that is qml anyways) the switch user ui in the lockscreen would 
use the same file as default, so the dialogs would look exactly the same

> * the screen locks. :) previously, one would pick an existing session or
> approve starting a new one and then it would go through the whole process.
> now the screen locks first ... even if you change your mind and hit
> 'cancel', you have to enter your password to get back to the desktop. i'm
> still debating whether or not this is actually a problem or not.
> 
> it's still a work in progress, so input is welcome.

loading the ui with the logout window would solve this "hard to cancel" 
problem (mostly an issue just on passwordless login systems where one would 
like to never be confronted with a password)

on the other hand simplifies the process a lot, since when the session is 
switched it has to lock the screen eventually as well, to me is the thing that 
may make this approach "win" ;)

Cheers,
Marco Martin