Bug 137841

Summary:	Sluggishness with 7.0 when a large picture in the document is visible
Product:	LibreOffice	Reporter:	ckoresko
Component:	Writer	Assignee:	Not Assigned <libreoffice-bugs>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	xiscofauli
Priority:	medium
Version:	7.0.2.2 release
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
Crash report or crash signature:		Regression By:
Attachments:	Screen capture demonstrating the issue Demo Writer .odt with a single large image and a line of text.

Description ckoresko 2020-10-28 23:41:56 UTC

Description:
On a new Fedora 33 with LO 7.0.2, I opened a 52000-word .odt document in Web View and noticed that I could easily out-type the new Writer.  Scrolling was also slow and chunky, especially when scrolling past graphics.  (The speed with a small document was normal.)  I tried the 6.4.7 version from libreoffice.org, and confirmed that it is much more responsive.  I also tried the 7.0.2 version from libreoffice.org and confirmed that it was slow (although perhaps not quite as slow as the Fedora 33 7.0.2).

It looks like something's wrong with Web View in LO7.

Steps to Reproduce:
1. Open a long (50000-word, with graphics) document in Writer
2. Jump to the end of the document
3. Type

Actual Results:
Characters appear with a noticeable delay, in clusters

Expected Results:
Characters appear without a noticeable delay, one per keystroke, as is the case with LO 6.4.7


Reproducible: Always


User Profile Reset: Yes


OpenGL enabled: Yes

Additional Info:
This was found on Fedora 33 running on VirtualBox 6.16 on a Windows 10 host.  I tried the Fedora 33 version of 7.0.2 with the switch to start in "safe mode", but it showed the same sluggish behavior.

I'm not sure if OpenGL was enabled.  "Use hardware acceleration" is checked, which I suspect means it was.

Comment 1 ckoresko 2020-11-04 12:29:51 UTC

After a little more testing, it's clear that the issue doesn't depend on the length of the document but rather on the presence of a largish image in it.

At a guess, Writer 7.0 is going back and recalculating something (the display layout?) between keystrokes whereas Writer 6.4 doesn't.  That might account for the long delay before a typed character is displayed.  On the other hand, scrolling gets slow and chunky in 7.0 as well, so maybe it's something else.

Even a long document can be edited smoothly in 7.0 if it contains no graphics.

Profiling might be useful to figure out what's going on.

Comment 2 ckoresko 2020-11-21 17:14:28 UTC

Created attachment 167453 [details]
Screen capture demonstrating the issue

Comment 3 Justin L 2020-12-24 12:45:02 UTC

Please attached a minimal example file that demonstrates the problem you have reported. If you can do it with a one paragraph/one picture document, that would be great.

Comment 4 Justin L 2020-12-24 15:20:44 UTC

Sounds like a duplicate of bug 138473, which might be a duplicate of bug 130768.

Comment 5 ckoresko 2020-12-24 15:31:48 UTC

Created attachment 168468 [details]
Demo Writer .odt with a single large image and a line of text.

Comment 6 ckoresko 2020-12-24 15:34:25 UTC

(In reply to Justin L from comment #4)
> Sounds like a duplicate of bug 138473, which might be a duplicate of bug
> 130768.

I think 138473 is a duplicate of this one, but 130768 looks like it refers to a performance issue painting the image itself (as opposed to displaying text typed into a file with a large image visible).

Comment 7 Xisco Faulí 2021-02-15 17:58:01 UTC

Hello bckoresko@atlanticbb.net,
I believe this issue might be fixed now after
https://git.libreoffice.org/core/commit/27a4aea50a9efa5c839b0ae2de1f9f14a7782f11.
Could you please try to reproduce it with a master build from
http://dev-builds.libreoffice.org/daily/master/ ?
You can install it alongside the standard version.
I have set the bug's status to 'NEEDINFO'. Please change it back to
'UNCONFIRMED' if the bug is still present in the master build

Comment 8 ckoresko 2021-02-16 03:59:13 UTC

Tested the master build on Fedora 33 and found that the behavior is much better.  I think the bug is indeed fixed.

Comment 9 Xisco Faulí 2021-02-16 08:29:43 UTC

(In reply to ckoresko from comment #8)
> Tested the master build on Fedora 33 and found that the behavior is much
> better.  I think the bug is indeed fixed.

Thanks for rechecking.
Closing as dupe of bug 138068

*** This bug has been marked as a duplicate of bug 138068 ***