Bug 132442 - Page layout different from expect when scrolling down while pages are still loading/layouting (see comment 7)
Summary: Page layout different from expect when scrolling down while pages are still l...
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
Version:
(earliest affected)
Inherited From OOo
Hardware: All All
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: Page-View
  Show dependency treegraph
 
Reported: 2020-04-26 20:12 UTC by Telesto
Modified: 2020-09-06 20:28 UTC (History)
3 users (show)

See Also:
Crash report or crash signature:


Attachments
Example file (41.51 KB, application/vnd.oasis.opendocument.text)
2020-04-26 20:13 UTC, Telesto
Details
Example of wrong layout (403.12 KB, application/pdf)
2020-04-26 20:19 UTC, Telesto
Details
Possible good layout (403.00 KB, application/pdf)
2020-04-26 20:20 UTC, Telesto
Details

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Description Telesto 2020-04-26 20:12:51 UTC
Description:
Page layout different from expect when scrolling down while pages are still loading/layouting

Steps to Reproduce:
1. Open the attached file
2. Multi page 4 (3 or 4 pages on a row)
3. Scroll to bottom; take a look at the layout
4. File -> Reload followed by CTRL+END (fast) or scroll down left click & vertical scrollbar
5. Look at the endresult

Alternative
1. Open the attached file in single page view
2. File reload
3. Drag the scroll bar down with left mouse click immediately after opening -> Look at the layout... No issue when using navigator pag 70 or CTRL+END

Actual Results:
Layout is different depending on scrolling

Expected Results:
Shouldn't make a difference


Reproducible: Always


User Profile Reset: No



Additional Info:
Versie: 6.4.3.2 (x64)
Build ID: 747b5d0ebf89f41c860ec2a39efd7cb15b54f2d8
CPU-threads: 4; Besturingssysteem: Windows 6.3 Build 9600; UI-render: GL; VCL: win; 
Locale: nl-NL (nl_NL); UI-taal: nl-NL
Calc: CL
Comment 1 Telesto 2020-04-26 20:13:14 UTC
Created attachment 159970 [details]
Example file
Comment 2 Telesto 2020-04-26 20:19:12 UTC
Created attachment 159972 [details]
Example of wrong layout
Comment 3 Telesto 2020-04-26 20:20:37 UTC
Created attachment 159973 [details]
Possible good layout

[Note: PDF export is also affected]
Comment 4 Telesto 2020-04-26 20:23:09 UTC
Another way to reproduce
1. Scroll to the bottom
2. On the last page: CTRL+A
3. CTRL+X
4. CTRL+Z
5. Save & reload

or 
1. Scroll to the bottom
2. On the last page: CTRL+A
3. CTRL+X
4. CTRL+V
5. Save and reload
Comment 5 Telesto 2020-04-26 20:23:42 UTC
Also in 3.3.0
Comment 6 Buovjaga 2020-08-27 16:54:25 UTC
The file has 70 pages and I don't have time for puzzles - where is the difference?
Comment 7 Telesto 2020-08-27 17:42:24 UTC
(In reply to Buovjaga from comment #6)
> The file has 70 pages and I don't have time for puzzles - where is the
> difference?

Compare the last page..

Easier steps:
1. Open the attached file
2. Scroll to bottom & look at they layout
3. CTRL+A
4. CTRL+X
5. CTRL+Z -> Wait until rendering finishes.. different layout
Comment 8 Telesto 2020-08-27 17:43:31 UTC
Also in
Version: 6.0.6.0.0+
Build ID: c30963b8b4bbbe42a24b97aafa161eff9d7ccdd4
CPU threads: 4; OS: Windows 6.3; UI render: default; 
Locale: nl-NL (nl_NL); Calc: CL
Comment 9 Telesto 2020-08-27 17:47:28 UTC
@Michael,
Only for my understanding. Page rendering on file open is different from say select all undo? Or maybe should put it different, it possible to make file rendering on file open behave the same as CTRL+A/CTRL+Z. Would unify the layout (in this case)
Comment 10 Buovjaga 2020-08-28 06:07:30 UTC
(In reply to Telesto from comment #7)
> (In reply to Buovjaga from comment #6)
> > The file has 70 pages and I don't have time for puzzles - where is the
> > difference?
> 
> Compare the last page..
> 
> Easier steps:
> 1. Open the attached file
> 2. Scroll to bottom & look at they layout
> 3. CTRL+A
> 4. CTRL+X
> 5. CTRL+Z -> Wait until rendering finishes.. different layout

I see, content flows into the second column after step 5.

Arch Linux 64-bit
Version: 7.1.0.0.alpha0+
Build ID: e2fe4fde592564d35099ad1e2659ad682dfb77f5
CPU threads: 8; OS: Linux 5.8; UI render: default; VCL: kf5
Locale: fi-FI (fi_FI.UTF-8); UI: en-US
Calc: threaded
Built on 25 August 2020
Comment 11 Michael Stahl (allotropia) 2020-08-28 08:46:49 UTC
hmm guess it should look the same, but it's likely difficult to fix
Comment 12 Telesto 2020-08-28 08:56:14 UTC
(In reply to Michael Stahl (CIB) from comment #11)
> hmm guess it should look the same, but it's likely difficult to fix

I assume so; it's still surprises me that they layout is the same on file opening most of the time :-). With all those dynamics involved. I'm happy I didn't have to invent or maintain it; looks very hard to me. 

I predict it's related to layouting footnotes/tables. Somehow the rendering is off after the document is presented on screen. So if someone opens a document, shows up & starts scrolling immediately, there is a change the layout will be different on screen.

After save and reload they content can shift. However this holds only true for large documents. Especially including footnotes (and maybe also tables) and quite some layout (headings/columns or whatever)