Bug 362910

Summary:	No panel after removing laptop from docking station, two panels after adding one
Product:	[Plasma] plasmashell	Reporter:	Jens Müller <blog>
Component:	generic-multiscreen	Assignee:	Aleix Pol <aleixpol>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	bugs.kde.org, kde, plasma-bugs
Priority:	NOR
Version:	5.5.5
Target Milestone:	1.0
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Jens Müller 2016-05-10 21:57:54 UTC

I am using KDE on Ubuntu 16.04 (plasma-desktop has Version: 4:5.5.5-0ubuntu1).

My machine is a laptop which I am using either in a docking station with two external screens, or undocked with just the internal screen. I somehow managed to disable the internal screen when undocked, and this setting seems to get remembered. Before (on Ubuntu 15.10), I used to have very weird problems when undocking the laptop -- these seem to be gone now.

But I still have a minor problem: When I undock the laptop, all windows are shown on the internal screen. So far, so good. But unfortunately, no panel is shown. I usually solve this by minimizing all windows so that the desktop is shown, then right-clicking and choosing New Panel > Default. However, I then have _two_ panels, on at the bottom and one at the top of the screen. I can then right-click on the one I don't want and remove it, and afterwards everything is fine. Still, this is a wee bit annoying ...

Reproducible: Always

Steps to Reproduce:
1. Laptop is in docking station, with two external screens.
2. Remove laptop from docking station, open lid.
 
3. Minimize windows so that desktop is visible.
4. Right-click, add default panel

Actual Results:  
After step 2: No panel is visible.

After step 4: Two panels are visible (at the top and at the bottom)

Expected Results:  
After step 2: One panel should be visible.

After step 4: Only one panel should be added, not two.

Comment 1 Piotr Dobrogost 2016-07-16 10:04:53 UTC

> After step 4: Only one panel should be added, not two.
I guess only one panel is really added and the other one is the one moved from – now disconnected – external screen.

I think this could be marked as a duplicate of bug #356225.

Comment 2 Jens Müller 2016-07-16 11:06:03 UTC

Hi Piotr,

yes, the first part definitely is.

But do you also have a possible explanation for the second part, that when adding a panel on the screen where it is missing, there suddenly are two panels on that screen (at the bottom and additionally at the top of the screen)?

Comment 3 David Edmundson 2016-07-16 18:16:25 UTC

it's a bit odd, but clearly related to this code needing a properly thought through rewrite.

In any case can you attach your  ~/.config/plasma-org.kde.plasma.desktop-appletsrc
to the linked bug.

(it shouldn't any personal data in, but you might want to check it first)

*** This bug has been marked as a duplicate of bug 356225 ***

Comment 4 Piotr Dobrogost 2016-07-17 11:54:13 UTC

(In reply to Jens Müller from comment #0)
> 
> I somehow
> managed to disable the internal screen when undocked, and this setting seems
> to get remembered.

So you have no screen at all when undocked. :) I guess it was supposed to be "when docked" instead, yes?

(In reply to Jens Müller from comment #2)
> 
> yes, the first part definitely is.

Not sure what you mean by "the first part".
 
> But do you also have a possible explanation for the second part, that when
> adding a panel on the screen where it is missing, there suddenly are two
> panels on that screen (at the bottom and additionally at the top of the
> screen)?

I can only guess that adding a new panel somehow reinitializes all existing ones and due to another bug the already existing panel is moved to the top of the screen, where you added a new panel.

One thing to note is that you want to run the latest KDE as there were some changes to multi-monitor management in 5.7.0 (see link to blog in bug #356225 for details). However it seems these changes did not resolve multiple problems in this area.