Bug 293687 - Task entries in Taskbar sometimes overlap
Summary: Task entries in Taskbar sometimes overlap
Status: RESOLVED DUPLICATE of bug 224447
Alias: None
Product: plasma4
Classification: Plasma
Component: widget-taskbar (show other bugs)
Version: 4.9.3
Platform: Gentoo Packages Linux
: NOR normal
Target Milestone: ---
Assignee: Plasma Bugs List
URL:
Keywords:
: 293805 297705 303016 309102 (view as bug list)
Depends on:
Blocks:
 
Reported: 2012-02-09 02:30 UTC by Jesse
Modified: 2013-09-14 19:25 UTC (History)
28 users (show)

See Also:
Latest Commit:
Version Fixed In:


Attachments
screenshot (65.45 KB, image/png)
2012-02-09 02:30 UTC, Jesse
Details
screenshot before moving item away - no overlap (23.91 KB, image/png)
2012-06-18 14:00 UTC, Martin Koller
Details
screenshot after moving item away - overlapped expanded group (23.10 KB, image/png)
2012-06-18 14:01 UTC, Martin Koller
Details
screenshot (18.06 KB, image/png)
2012-06-19 13:31 UTC, ZetaFunction
Details
task manager settings (47.96 KB, image/png)
2012-06-19 13:38 UTC, ZetaFunction
Details
screenshot showing the bug on kde 4.8.4 (240.34 KB, image/jpeg)
2012-08-20 12:19 UTC, Roberto Zanon
Details
Icons overlapping (36.29 KB, image/png)
2012-11-09 08:07 UTC, Mark Fraser
Details
Overlapping items in taskbar with KDE 4.11.1 (113.46 KB, image/png)
2013-09-14 19:25 UTC, blotto
Details

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Description Jesse 2012-02-09 02:30:05 UTC
Created attachment 68639 [details]
screenshot

Version:           unspecified (using KDE 4.8.0) 
OS:                Linux

The entries in the taskbar overlap sometimes when there's a change in the entries like on opening a new application or closing one.

I haven't been able to noticed any specific reason for this yet.

Attached is a screenshot depicting the issue.

Reproducible: Sometimes

Steps to Reproduce:
I would tell if I knew myself


Expected Results:  
Don't overlap

OS: Linux (x86_64) release 3.2.5-zen
Compiler: x86_64-pc-linux-gnu-gcc
Comment 1 Jesse 2012-02-09 02:32:52 UTC
In the screenshot, KWrite and Konsole's entries are overlapping. Apparently, these are the ones that mostly face the issue.
Comment 2 Thijs 2012-02-11 15:17:19 UTC
*** Bug 293805 has been marked as a duplicate of this bug. ***
Comment 3 Troy Cotter 2012-02-12 08:23:42 UTC
I can repeat the issue around 75% of the time if I open up firefox, and then konsole, and then close konsole the firefox task will move to the middle of the task bar.
Comment 4 Mahendra Tallur 2012-02-12 15:49:45 UTC
May I ask if that's Firefox related ? 

I also have issues with the new "Icon tasks" widget ; when I close Firefox, the widget doesn't realized FF is closed. I have to click it and wait for about 5 seconds for it to realize there's no instance running, then it works again.

So it seems to affect both the regular task bar and the new icon tasks widget.

[I'll probably file another bug report for that, once I make sure it's not already done]
Comment 5 Troy Cotter 2012-02-13 06:49:12 UTC
I don't think its firefox related, if anything I'd say Konsole is the issue. I can also reproduce by opening up some konsoles and then another program like dolphin and then if I close off certain konsoles dolphin will sometimes move to the middle of the task bar
Comment 6 Ingo Stierand 2012-03-08 12:45:37 UTC
The same here. This is a long standing bug and still remains in KDE 4.8.1.
I thought there was already a bug report about this issue but I cannot find it anymore.
Comment 7 ripper-tm 2012-04-20 15:13:40 UTC
https://bugs.kde.org/show_bug.cgi?id=297705
Seems to be the same bug. Steps to reproduce are listed there .
Comment 8 Ingo Stierand 2012-04-23 09:31:44 UTC
*** This bug has been confirmed by popular vote. ***
Comment 9 Ingo Stierand 2012-04-23 09:34:03 UTC
This bug seems to be related to bug #224447.
Comment 10 Mark 2012-05-04 19:12:04 UTC
*** Bug 297705 has been marked as a duplicate of this bug. ***
Comment 11 ZetaFunction 2012-06-12 12:50:20 UTC
it does not depend on the browser or konsole. Other icons on the panel of the tasks overlap аналогично. this was with mozilla, konsole, apper, kopete. So far this error can not fix.
Comment 12 Martin Bříza 2012-06-18 09:01:48 UTC
Also reported in the Red Hat Bugzilla for Fedora on https://bugzilla.redhat.com/show_bug.cgi?id=832753 .
Comment 13 Martin Koller 2012-06-18 13:57:43 UTC
I have it here currently reproducible, using KDE 4.9beta1.
I think it has to do with automatic grouping and de-grouping.
It happens here where I have 2 rows of entries in the taskbar, the bottom row in the left-most place holds the group of 2 kwrite windows.

Look at the screenshots:
The taskbar looks as in the first screenshot before it happens.
I move the "openSuse" taskbar entry window into a different virtual desktop and then the grouped kwrite windows get ungrouped and then I have the overlapping entries as seen in the second screenshot.

It probably has to do with the fact that the grouping is on the far left of the taskbar.
whenever I move a taskbar entry from the first row away, the ungrouping happens and also the most-right entry from the taskbar moves 1 position to the left and there it overlaps the previous group entry.

Again: the group is expanded. one entry from the group moves one row up and the second entry keeps its location but gets overlapped with the entry to the right of it which moves one position to the left.

Probably the algorithm does miscalculate the remaining number of entries when one entry is removed and also a group is expanding in the same step.
Comment 14 Martin Koller 2012-06-18 14:00:22 UTC
Created attachment 71911 [details]
screenshot before moving item away - no overlap
Comment 15 Martin Koller 2012-06-18 14:01:13 UTC
Created attachment 71912 [details]
screenshot after moving item away - overlapped expanded group
Comment 16 ZetaFunction 2012-06-19 13:31:37 UTC
Created attachment 71940 [details]
screenshot

This bug occurs when a grouping and sorting windows in the task bar
Comment 17 ZetaFunction 2012-06-19 13:38:06 UTC
Created attachment 71942 [details]
task manager settings

does not occur imposition of windows with these settings
Comment 18 John Fitzgibbon 2012-08-17 16:45:30 UTC
An observation that may help, (or not): This problem seems to be 64-bit-specific and less about the Linux/KDE version. I have a few 32-bit installs, (various Fedora/CentOS with whatever version of KDE is current for that linux), but have never seen the problem there. Happens quite a lot on my (main) 64-bit machine which has been through a few different revs of KDE.
Comment 19 Martin Koller 2012-08-17 19:17:58 UTC
Nope, it has nothing to do with the CPU type.
See my comment #13, #14 and #15.
With this description and the screenshots you can easily reproduce the problem
(which I did myself with different applications running. It has to do with the fact how a group is expanded and what is after it)
Comment 20 Roberto Zanon 2012-08-20 12:14:12 UTC
This bug is present also in kde 4.8.4 distributed within Kubuntu 12.04 (64 bit). I attached a screenshot too.
Comment 21 Roberto Zanon 2012-08-20 12:19:52 UTC
Created attachment 73319 [details]
screenshot showing the bug on kde 4.8.4
Comment 22 Jesse 2012-08-20 14:16:13 UTC
I haven't seen the bug in 4.9 yet.
Comment 23 Martin Koller 2012-08-20 14:21:50 UTC
But I have. See my comment #13
Comment 24 Jekyll Wu 2012-09-20 01:28:59 UTC
*** Bug 303016 has been marked as a duplicate of this bug. ***
Comment 25 tosiara 2012-10-13 14:59:57 UTC
Installed KDE 4.9.2 release 511 (opensuse update repo) - still same issue
Comment 26 DeMus 2012-10-25 15:06:09 UTC
Same problem here:
Hi, with a few recent installations I get 2 buttons on the task-manager located on the same spot, instead of next to each other. When I have 2 programs open, I see one button. When I click it, the other window is in front, indicating its name in the button. When I hover my mouse over the button I see the name of the hidden window.
Comment 27 Arjun Menon 2012-10-27 02:10:56 UTC
Just want to add, I've been experiencing this exact same problem. It's been happening quite often -- about once every two days, and I've been using Kubuntu for months now.
Comment 28 Mark Fraser 2012-11-09 08:07:58 UTC
Created attachment 75121 [details]
Icons overlapping

Saw this bug this morning in Kubuntu 12.10 with KDE 4.9.3.
Comment 29 Nick Elliott 2012-11-22 09:39:03 UTC
Ditto - I've been experiencing this behaviour for a long time, still happening in 4.9.3 (Kubuntu 12.10 64bit)
Comment 30 David Smith 2012-12-12 13:54:39 UTC
*** Bug 309102 has been marked as a duplicate of this bug. ***
Comment 31 David Smith 2012-12-12 13:59:02 UTC
Hello, also having this problem here in Debian testing (KDE 4.8.4) for the upcoming release of Debian Wheezy.

I made a video of it happening here:
http://v.youku.com/v_show/id_XNDg3NTAzMjY0.html

Any ideas or solutions?
Comment 32 David Smith 2012-12-12 14:30:28 UTC
I'd also like to say this is definitely not the fault of any of the applications..  It's clear that I can make this happen between any two applications..
So far I have done...
liferea + Icedove
Firefox + supertuxkart
dolphin + konsole
dia + gimp (that was especially confusing)

So it's definitely a bug in the KDE task widget.  It happens most often between any applications that you use the most, they just start misbehaving after a while like the taskbar forgets there is already an item at that taskbar location.
Comment 33 David Smith 2012-12-13 08:02:04 UTC
Made another video of how to reproduce, undo, and then reproduce again.
http://v.youku.com/v_show/id_XNDg3Nzk1NzQ0.html
Comment 34 hamelg 2013-01-06 00:08:23 UTC
When the bug occurs, unlocking then locking again widgets fixes the overlapping entries in the taskbar.
Comment 35 Arjun Menon 2013-01-06 12:50:02 UTC
I've also found that switching between activities can refresh the taskbar, and henceforth make the bug go away.

It's almost been an year since people have begun reporting the bug, and a question I have is, why do these bugs occur in the first place? I love KDE, but I've also used GNOME, and bugs of this (rather visibile) kind are not as common there. Is our smaller userbase partly to blame? Or perhaps is it the way that KDE is written? I know KDE's written in C++; and one thing about C++ (a language I like), is that you need some amount discipline to write it.

I've only been a KDE user so far, and perhaps it's time for me to get my feet wet with some KDE code. Anyone have suggestions on where to start?
Comment 36 Kevin Kofler 2013-01-06 13:01:08 UTC
Our userbase is not smaller than GNOME's.
Comment 37 Przemysław Węgrzyn 2013-01-06 14:07:31 UTC
(In reply to comment #35)

> I've only been a KDE user so far, and perhaps it's time for me to get my
> feet wet with some KDE code. Anyone have suggestions on where to start?

As the issue was irritating me as well, I've started digging through the code myself, too. 

Take a look at kde-workspace/plasma/desktop/applets/tasks/taskitemlayout.cpp
There's a method called 
 void TaskItemLayout::layoutItems() 

This method is called whenever a new item is added/removed from the task bar, and I believe this is a good place to start. Note, that TaskItemLayout class derives from QGraphicsGridLayout, so it might be that Qt is involved.

I don't have too much time to debug it, so if you find anything interesting - please share, so we can join our forces.

I don't want to start any ranting here (KDE is still a great environment for my day-2-day work), but I second to that issues like this one (obviously affecting usability) should have a higher priority assigned. Too much of KDE developer time goes into eye candy etc. (e.g. do you know anyone who really needs to rotate desktop widget  by arbitrary angle?).
Comment 38 Arjun Menon 2013-01-06 14:13:12 UTC
(In reply to comment #36)
> Our userbase is not smaller than GNOME's.

Ah, I didn't know. Most of the people I know use plain Ubuntu, atleast in the U.S. (I use Kubuntu.) I suppose KDE is used more widely in Europe,  South America, India and elsewhere?
Comment 39 Arjun Menon 2013-01-06 14:42:05 UTC
Thanks for the pointer.

(In reply to comment #37)
> (In reply to comment #35)
> 
> > I've only been a KDE user so far, and perhaps it's time for me to get my
> > feet wet with some KDE code. Anyone have suggestions on where to start?
> 
> As the issue was irritating me as well, I've started digging through the
> code myself, too. 
> 
> Take a look at kde-workspace/plasma/desktop/applets/tasks/taskitemlayout.cpp
> There's a method called 
>  void TaskItemLayout::layoutItems() 
> 
> This method is called whenever a new item is added/removed from the task
> bar, and I believe this is a good place to start. Note, that TaskItemLayout
> class derives from QGraphicsGridLayout, so it might be that Qt is involved.
> 
> I don't have too much time to debug it, so if you find anything interesting
> - please share, so we can join our forces.
> 
> I don't want to start any ranting here (KDE is still a great environment for
> my day-2-day work), but I second to that issues like this one (obviously
> affecting usability) should have a higher priority assigned. Too much of KDE
> developer time goes into eye candy etc. (e.g. do you know anyone who really
> needs to rotate desktop widget  by arbitrary angle?).
Comment 40 Kevin Kofler 2013-01-06 14:59:13 UTC
FYI, Ubuntu doesn't use GNOME anymore, Unity is a completely different beast (but this is getting off-topic).
Comment 41 Łukasz Żarnowiecki 2013-02-07 13:11:17 UTC
Confirmed on 4.9.5
Comment 42 hamelg 2013-02-10 15:05:10 UTC
still here on 4.10.00
Comment 43 Borden 2013-03-17 19:00:33 UTC
Is this a duplicate of Bug 224447?
Comment 44 John Doe 2013-04-06 10:54:35 UTC
This annoying bug is still present in the new version of OpenSUSE with KDE 4.10!

OS: OpenSUSE 12.3 x86_64
Kernel: 3.7.10-1.1
Qt: 4.8.4
KDE: 4.10.00 "release 1"
Comment 45 John Doe 2013-04-11 17:06:34 UTC
(In reply to comment #43)
> Is this a duplicate of Bug 224447?

Seems like it... How to mark something as duplicate?
Comment 46 Kevin Kofler 2013-04-11 21:46:03 UTC

*** This bug has been marked as a duplicate of bug 224447 ***
Comment 47 Dean 2013-05-27 21:00:29 UTC
I can confirm the same intermittent behaviour with KDE 4.10.3

The two applications I'm using most frequently in a work environment is Thunderbird and Firefox, so that's the situation I notice most.
Comment 48 blotto 2013-09-14 19:25:04 UTC
Created attachment 82322 [details]
Overlapping items in taskbar with KDE 4.11.1