Thank you for reporting the bug. Just to be sure: You're bug is about toolbars and not about the sidebar (Strg + F5), correct?
=> NEDINFO

(In reply to Dieter from comment #1)
> Thank you for reporting the bug. Just to be sure: You're bug is about
> toolbars and not about the sidebar (Strg + F5), correct?
> => NEDINFO

Dieter, I am speaking about both of them: the Sidebar (usually to the right of my screen, in general I show the Styles menu and the Navigator there) and the Toolbar-items which e.g. let me change the font or font size in a direct formatting manner.

Sorry for not referring to the thing on the right side of the screen as sidebar. But from my description it should have been almost clear.

Right now at the moment the thing is not flashing, I still have just checked it with the development version which I currently have. Normally I would install a later one these days. I do so almost every two weeks.

Ctl+F5 does not change anything on my screen. Sidebar: the thing which is activated by F11 or by Vorlagen>Formtvorlage verwenden.

I just went through the menues and I found that there was no checkmark at Ansicht>Seitenleiste (Strg+F5). 

However, Strg+F5 (the Ctl-keycap of a German keyboard has Strg on it) does not change anything with that checkmark.

For sure I checked the keyboard settings of my Xubuntu: Strg+F5 (alias Ctl+F5) has no assignment there.

(In reply to Adalbert Hanßen from comment #2)
> Sorry for not referring to the thing on the right side of the screen as
> sidebar. But from my description it should have been almost clear.

Thank you for clarification.

> Right now at the moment the thing is not flashing, I still have just checked
> it with the development version which I currently have. Normally I would
> install a later one these days. I do so almost every two weeks.
Did it happen again? => NEDINFO

I haven't noticed it. And if it is still present, it might be difficulet to reproduce

I just tried some examples in 

Version: 7.3.0.0.alpha0+ / LibreOffice Community
Build ID: 00a658ff104623d4e7fc984b5fc82d1a7e2607f2
CPU threads: 4; OS: Linux 5.4; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: de-DE
TinderBox: Linux-rpm_deb-x86_64@86-TDF, Branch:master, Time: 2021-06-26_23:58:36
Calc: threaded

The bug did not show up in those examples which I tried (probably one of them was the one which let me complain about it).

BTW excellent side finding: Now the Navigator adjusts itself to the proper headline associated to the current editing position. That's something which has long been missing!

(In reply to Adalbert Hanßen from comment #5)
> The bug did not show up in those examples which I tried (probably one of
> them was the one which let me complain about it).

So let's close it as WORKSFORME. Feel free to change it back to UNCONFIRMED, if it happens again and you're able to give some hints how to reproduce.

today it happened again with a large file in

Version: 7.4.0.0.alpha0+ / LibreOffice Community
Build ID: beb6c62e990599d91ac5d9183164c94d269027d3
CPU threads: 4; OS: Linux 5.4; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: en-US
Calc: threaded

I just updated away from this version the one of yesterday, but this one crashes too often: https://bugs.documentfoundation.org/show_bug.cgi?id=148075

I'll check for a newer development version in a few days.

Created attachment 179857 [details]
An example which shows the bug (the text in it describes another bug)

For sometime now I've noticed that large parts of my LibreOffice Writer window occasionally flicker. I first noticed this with very large files. However, I had also an example of a one page document (but then the flickering frequency seems to be less than with large files).

The flickering occurs when there is at least the Navigator or Style window open next to the actual text box. When flickering happens, it happens more often that keystrokes arrive out of sequence in the editor window. To avoid this, I have to type very slowly. 

I have indicators on the taskbar that constantly show me the CPU and memory usage. They show me that both are not the cause of the problem.

When composing an example for #148755 the flickering became extremely bad when I wrote the last example in it. After I inserted the last image into the table, it became catastrophic. I could hardly continue writing. Then after patiently adding more and more text, it got much better. But the flickering is still there.

The concurrency of the processes in LibreOffice might be insufficiently organized. Can this problem be improved by waiting to update the screen items for Styles, Navigator and the items in the Toolbox that control paragraph format, font size, and other formatting properties and the search box at the bottom until a writing pause of more than 1/10 of a second has passed? Could the contents of these screen areas just be calculated for now and not rolled out continuously? Another possibility would be to provide an order for updating the concurrent screen pieces: Always those of the categories first, then lower its priority behind that of the other pieces until those are finished. Of course, the text edit window should always be served immediately. I would even consider it acceptable if the areas other than the actual text edit window would update only during writing pauses, e.g. one or even two seconds after the last keystroke! The actual background work - e.g. searching, which position in the heading hierarchy is currently affected etc., can be done continuously in the background and discarded if necessary, if "dramatic changes" have happened in the editor window, like insert, PageUp, PageDown change of style sheet or at all more than a certain number of keystrokes since the last update of the concurrent screen areas. (For GUI programmers my explanations may sound a bit amateurish: In the second half of the 1980s I solved a similar problem in an 8086 controlled device this way – that one ran completely without operating system - ).

The bug is still present in today’s development version

Version: 7.4.0.0.alpha1+ / LibreOffice Community
Build ID: 66d8951df3c11ead0b9415eb292c3ae88689edf1
CPU threads: 4; OS: Linux 5.4; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: en-US
Calc: threaded

It looks that there is a relationship to the (very useful but not completely bugless) extension Alternative Searching version 1.4.2. The other strange thing is, that the flickering habit does not always show up but only sporadically (i.e. one of the more difficult to pin down bugs!).

When the bug shows up, keystrokes often arrive out off order leading to editing results like “tihs lin ehas smoe keysrtokes arrivingo ut off odrer”, which is very annoying.

The bug is still present in today's development Version: 7.4.0.0.alpha1+ / LibreOffice Community
Build ID: 66d8951df3c11ead0b9415eb292c3ae88689edf1
CPU threads: 4; OS: Linux 5.4; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: en-US
Calc: threaded

Flickering was with large parts of my LibreOffice Writer window. Fortunately it is not always present.

In the meantime I had the suspicion that it is related to the extension AltSearch . Today I encountered this bug un as very large file 

1. with Alt Ssarch deactivated (after leaving and starting LO Writer again).
2. with Alt Ssarch uninstalled (after leaving and starting LO Writer again).

So my preliminary conclusion is that my suspicion about a relation to AltSearch probaböly was wrong.

Strangely, after logging in with another user account on the same computer and opening the same file with this development version with AltSearch 1.4.2 installed for all users, flashing did not happen.

One more strange observation:

When logged in with the administrator account, where flickering happened, it also happened int the sample file attached to this bug report on 2022-04-30.


When logged in with my normal user account, flickering did not happen with both files, the one where I kept mu notes in experience with LibreOffice and also it did not happen with the mentioned sample file.

That's really strange!

Hi Adalbert,

(In reply to Adalbert Hanßen from comment #0)
> When writing a text and open toolbars for navigator and for styles or for
> styles alone (they are docked to the right margin of LO Writer’s window, I
> observer that the docked toolbars for styles and for navigator are flashing
> from tome to time. On the toolbar above the main editing area, the
> dropdown-selectors for the paragraph style and for the font and character
> size also flash. It looks like all these flashing elements flash
> simultaneously.
> Flashing only happens as long as at least one of Navigator and Styles
> toolbars is docked. It does not happen, if they are both free floating. But
> as soon as I dock them again, flashing comes back.
> Any Idea what is going wrong here?
No idea.
Haven't noticed as far either..

(In reply to Cor Nouws from comment #12)
> Hi Adalbert,
> 
> (In reply to Adalbert Hanßen from comment #0)
> > When writing a text and open toolbars for navigator and for styles or for
> > styles alone (they are docked to the right margin of LO Writer’s window, I
> > observer that the docked toolbars for styles and for navigator are flashing
> > from tome to time. On the toolbar above the main editing area, the
> > dropdown-selectors for the paragraph style and for the font and character
> > size also flash. It looks like all these flashing elements flash
> > simultaneously.

It is still there most of the times, even with 

Version: 7.5.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: 5b0a6621858b141022743dd8d500558895dedb1f
CPU threads: 4; OS: Linux 5.4; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: en-US
Calc: threaded

After I installed this version, my first oberservation was "the flashing syndrome is still present". Therefore I write "most of the times" because just now, when I wanted to verify if my second observation still holds:

> > Flashing only happens as long as at least one of Navigator and Styles
> > toolbars is docked. It does not happen, if they are both free floating. But
> > as soon as I dock them again, flashing comes back.
> > Any Idea what is going wrong here?

- Navigator and Styles are docked right now - but LO Writer is not flashing in the described way, although it checked it with the same file, which I used after I had installed this development version and put down the note on that!

I guess, it is something specific to Linux, because I have never observed this behavior under Windows 10. But I use Windows 10 at most 5% of all my computer time and when I do so, not more than 20% of the time LibreOffice is used. But I also use LibreOfficeWriter under Windows from time to time, especially to take notes on problems encountered there or to make odt-files by copy/paste from Abbyy Fine Reader after OCR from scanned documents. But the time of LibreOffice use there will be 20% or less.

> No idea.
> Haven't noticed as far either..

Then unfortunately you have little chance to kill this bug. I'll keep an eye on it!

Adalbert, can you please tell us what this returns in a terminal:

echo "$GTK_IM_MODULE"

If it returns "xim", please have a look at bug 144813 and see if changing that variable (possibly in the ~/.xinputrc file) solves the flickering issue.

(In reply to Stéphane Guillou (stragu) from comment #14)
> Adalbert, can you please tell us what this returns in a terminal:
> 
> echo "$GTK_IM_MODULE"
> 
> If it returns "xim", please have a look at bug 144813 and see if changing
> that variable (possibly in the ~/.xinputrc file) solves the flickering issue.

It returns nothing:

a@W:~$ echo "$GTK_IM_MODULE"

a@W:~$ 

After my last upgrade towards 

Version: 7.5.0.0.alpha1+ (X86_64) / LibreOffice Community
Build ID: da3dd48eaf9086f8ab28d6a6655f9a638e51433a
CPU threads: 4; OS: Linux 5.4; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: en-US
Calc: threaded

flickering was worse than ever before. It became less bad as soon as either the Navigator item or the Styles item ere not in the sidebar. It was gone when the sidebar was not shown.


But today it is not present (even with Styles and Navigator active on the sidebar). I suspect, it will be back in an hour or so!

I tried with your file, but there is no toolbar flashing. I suppose you still see this with the stable 7.5.1?

Does it make a difference, if you launch from the terminal with

SAL_USE_VCLPLUGIN=gen libreoffice

Version: 7.5.1.2 (X86_64) / LibreOffice Community
Build ID: 50(Build:2)
CPU threads: 8; OS: Linux 6.2; UI render: default; VCL: gtk3
Locale: fi-FI (fi_FI.UTF-8); UI: en-US
7.5.1-1
Calc: CL threaded

Currently I have 

Version: 7.6.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: a179f6c91692076e7e17babf4890638caa398384
CPU threads: 4; OS: Linux 5.4; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: en-US
Calc: threaded

After I had installed it on 2023-03-08, I noted that the flashing tool bar still persisted. But right now, as you are asking, I have a large document open in LO Writer and the toolbar is not flashing! Without your question this would have escaped my attention!

I have no more 7.5 version on my computer because of disk space.

I opened my old bug example from the running LO Writer session in parallel and I took notice of this: 

I had complained about the navigator switching the category from Headings to Tables as soon as the mouse cursor is placed in some table. During my test now it still showed me in the navigator the position of my selection among Tables  despite headings are selected (not expected). It continued to show "Headings" as selected category. As soon as I placed the selection to a place outside of any table, the Navigator behaved again as I expect it and showed me the position in the hierarchy of Headings (and the selection button kept dieplaying Headings, as expected)! 

I remember that it the Navigator once jumpte to Tables once I had placed the mouse cursor into any table, it kept showing only in the category of tables! If I remember right, I had actively to select Headings again. This seems to have made some progress and I am very happy with it. The Navigator also does not jump to the category sections if I click on something near the end of my bug sample file.

===

In the version information above I see the term VCL.

The environment variable you named is currently undefined on my computer.

Shall I repeat testing the example with my current development version after setting the environment variable as suggested by you?

(In reply to Adalbert Hanßen from comment #17)
> In the version information above I see the term VCL.
> 
> The environment variable you named is currently undefined on my computer.
> 
> Shall I repeat testing the example with my current development version after
> setting the environment variable as suggested by you?

You can just give the command literally in the terminal:

SAL_USE_VCLPLUGIN=gen libreoffice

Then it will set the variable only temporarily, for the process that is run.

(In reply to Buovjaga from comment #18)
> You can just give the command literally in the terminal:
> 
> SAL_USE_VCLPLUGIN=gen libreoffice
> 
> Then it will set the variable only temporarily, for the process that is run.

Adalvbert, have you tested it? Is the problem still present?
=> NEEDINFO

Currently I am on a journey and have my other computer with me. On this one, which has Version: 7.3.7.2 / LibreOffice Community
Build ID: 30(Build:2)
CPU threads: 4; OS: Linux 6.2; UI render: default; VCL: x11
Locale: de-DE (de_DE.UTF-8); UI: en-US
Ubuntu package version: 1:7.3.7-0ubuntu0.22.04.4
Calc: threaded

I started LibreOffice like this:

$ SAL_USE_VCLPLUGIN=gen libreoffice
Warning: failed to launch javaldx - java may not function correctly

(process:7539): dconf-WARNING **: 08:01:25.767: unable to open file '/etc/dconf/db/site': Datei »/etc/dconf/db/site« konnte nicht geöffnet werden: open() ist gescheitert: Datei oder Verzeichnis nicht gefunden; expect degraded performance


There I see this error message. In this case the problem persists: despite "Headings" is the category selected in the Navigator, the Navigator view shows the finding in the category "Tables" if I click on any of the words "HERE" which are in a table. It shows its findings correctly in the hierarchy of headings if I click somewhere else outside of tables.

Excuse me, I looked for the wrong error: The flashing toolbar does not happen in this installation (but the other bug of the Navigator not working as expected showed up again).

But I can tell one other finding: On the other computer (the one with the flashing navigator toolbar sickness currently not available here) the flashing toolbar did not show up at all user accounts, only at two of them. I tried to find out the differences but until now I was unable to find out what really makes the differences to cause the flashing toolbar quirk. Unfortunately I can't do any tests on that partial findings until in about 10 days.

Sorry, this post was wrong. 

The button "Navigate By" was pressed (correct) but the other button "ContentNavigation View" was not pressed.

It had been explained in https://bugs.documentfoundation.org/show_bug.cgi?id=148755#c5.

The operating principle here is not particularly logical or intuitive. But now it is at least as described in https://help.libreoffice.org/7.6/en-GB/text/swriter/01/02110000.html?&DbPAR=WRITER&System=WIN.

(In reply to Adalbert Hanßen from comment #20)
> In this case the problem persists: despite
> "Headings" is the category selected in the Navigator, the Navigator view
> shows the finding in the category "Tables" if I click on any of the words
> "HERE" which are in a table.
(In reply to Adalbert Hanßen from comment #21)
> Excuse me, I looked for the wrong error: The flashing toolbar does not
> happen in this installation (but the other bug of the Navigator not working
> as expected showed up again).
Yes, let's please stick to just the flickering here. The comments are already overwhelming in this report.

So can you confirm that the flickering does _not_ happen with gen VCL but it _does_ happen with gtk3?

Any chance you could record a video of the flickering issue when it happens?

(In reply to Adalbert Hanßen from comment #22)
> The button "Navigate By" was pressed (correct) but the other button
> "ContentNavigation View" was not pressed.
How do these relate to the bug? What settings need to be on or off to see the flickering?

(In reply to Stéphane Guillou (stragu) from comment #23)
> (In reply to Adalbert Hanßen from comment #20)
...
> 
> Any chance you could record a video of the flickering issue when it happens?
> 

How do I record what's happening on a part of the screen? I am on Linux, more precicely o Xunbuntu.

(In reply to Adalbert Hanßen from comment #25)
> How do I record what's happening on a part of the screen? I am on Linux,
> more precicely o Xunbuntu.

There are many screen recorders available. This is one of the easier ones, I think: https://github.com/vkohaupt/vokoscreenNG

You should be able to get it with:

sudo apt install vokoscreen-ng

Created attachment 197443 [details]
mkv-video of the flickering LO Writer window, additiona observation about mouse scroll wheel when mouse in Navigator part

With the help of the last comment I finally succeeded to take a footage of the flickering screen. Unfortunately it took me several trials to get it as an mkv-video and the aspect ratio of the footage is distorted. But one can clearly see the flickering.

Another thing which I shoe in it: scrolling by the mouse wheel behaves differently when the mouse cursor is in the main editing window or when it is in the Navigator window: When I scroll with the mouse over the Navigator, both the navigator and the main editing window scroll. I don't see a good reason, why the main editor window should scroll when I am scrolling in the navigator window without clicking there on some item.

This video was taken with 

Version: 25.2.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: d649e297fde11efab2c681605e27e513a183e314
CPU threads: 8; OS: Linux 6.8; UI render: default; VCL: gtk3
Locale: de-DE (de_DE.UTF-8); UI: de-DE
Calc: threaded.

(I hope it was with the right boundary conditions stragu was after. If not: lease tell me how to start LO Writer such that the right boundary conditions are met).

(In reply to Adalbert Hanßen from comment #28)
> Created attachment 197443 [details]
> mkv-video of the flickering LO Writer window, additiona observation about
> mouse scroll wheel when mouse in Navigator part

Is this in a Wayland or X11 session? You should be able to check it in a terminal with

echo $XDG_SESSION_TYPE