lyx scrolling jumps up the cpu and sluggish

[baytuni]

Binary package hint: lyx

When scrolling down in a document with tables and figures (images not shown on the document) scrolling makes X server use a high amount of cpu and the output of scroll on the screen is slow and sluggish.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: lyx 2.0.0~rc1-1
ProcVersionSignature: Ubuntu 2.6.38-8.41-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
Architecture: amd64
Date: Sun Apr 10 18:35:21 2011
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: lyx
UpgradeStatus: Upgraded to natty on 2011-04-07 (3 days ago)

[baytuni (oytun-peksel)]

Before scrolling

[baytuni (oytun-peksel)]

While scrolling

[humanplayer2 (humanplayer2)]

Same problem.

I would like to point out that cpu usage rises even when not scrolling vertically, but also when one moves the cursor horizontally through text -- in particular math and spell-check environments.

[rawphi (raphael-ist)]

http://comments.gmane.org/gmane.editors.lyx.general/70264 talks about this being a regression in the QT libraries.

As a workaround, you can add the line:

\force_paint_single_char false

into the lyx preferences file (~/.lyx/preferences) & restart lyx

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Dan Lea (danlea)]

I have this problem intermittently with a small document (it comes and goes fairly inexplicably) and the '\force_paint_single_char false' workaround doesn't seem to help.