Lockscreen multiscreen behavior

[David Kahles]

On 06/17/2015 05:07 PM, Martin Gräßlin wrote:
> Am 2015-06-17 14:39, schrieb David Kahles:
>> On 06/17/2015 05:30 AM, Martin Gräßlin wrote:
>>> Am 2015-06-16 16:58, schrieb David Kahles:
>>>> Hello,
>>>> I want to hear some opinions about the multiscreen behavior of the 
>>>> lockscreen.
>>>>
>>>> Currently the lockscreen is displayed on all connected monitors. I
>>>> would prefer if the
>>>> lockscreen is displayed only on the primary monitor, as it's done at
>>>> the loginscreen,
>>>> because there is no need for multiple instances.
>>>> I think this also matches the behavior of other operating
>>>> systems/desktop environments.
>>>>
>>>> What do you think?
>>>
>>> When we redid the lockscreen to be in QML with the lock always shown 
>>> we did it that way on purpose. The main problem is that we don't 
>>> know which screen the user is expecting it to be on. Even more we 
>>> don't know whether the primary screen is actually the user's primary 
>>> screen. We cannot expect users to configure it as they use it.
>>>
>>> Easy example: notebook, external screen connected, internal screen 
>>> is obviously the primary screen as it's a notebook. Now user closes 
>>> the lid, screen stays configured to be on and locks the screen: at 
>>> that point user has a broken system because lock screen is not shown 
>>> any more. User might even try to hard turn off the system at that 
>>> point, because user doesn't even think of the idea the closed 
>>> notebook screen could have the locker.
>>>
>>> So overall: if we want to be sure that users always can lock in 
>>> again, we need to show on all screens.
>> That makes sense, it could save much trouble.
>> Out of curiosity: why should the monitor in the closed lid be
>> configured to stay on? The only reason that
>> comes to my mind is, when the lid-closed sensor is broken.
>
> in an ideal world: not needed. In the world we live in (X11) it might 
> be needed. Consider the case that I plug in an external TV to my 
> notebook to watch a movie and close the lid. If it would disable the 
> output, I would get about 1-2 min of freezes, becuase XRandR/Intel is 
> freezing. In addition Plasma would start to shuffle everything around, 
> KWin would shuffle everything around for things I don't need. I'm 
> happy with all my open windows to stay on the notebook screen even if 
> they are not visible to me as in that usecase the only thing that 
> matters is the vlc on the big screen.
Thanks for your reply, this makes sense. Then it sounds like a good idea 
to have the lockscreen on all screens.

David