gtk3.22 makes gedit & pluma screen flash for short text only

[Wei Tsui]

Environment: Ubuntu 18.04 development branch;
GTK-3 version: 3.22;

For almost all gtk3-based text editor, such as gedit, pluma, mousepad. There is textview flashing issue when the textview doesn't have its side-scrollbar. Typically, short text in textview can make this condition satisified.

1) Editor textview flashing problem only happens in OS physical hosts, and doesn't happen when editors run inside Virtualbox.

2) Editor textview flashing problem doesn't happen in Ubuntu 16.04 which is of lower gtk3 version;

3) If text document is long to generate either side of scrollbar for the editor textview, then the textview is no longer flashing.

More to see: https://github.com/mate-desktop/pluma/issues/282
Still, I just ensure that it is not a pluma issue but happens in all gtk3-based text editor including gedit.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: libgtk-3-0 3.22.28-1ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-10.11-generic 4.15.3
Uname: Linux 4.15.0-10-generic x86_64
ApportVersion: 2.20.8-0ubuntu10
Architecture: amd64
CurrentDesktop: MATE
Date: Sat Feb 24 14:32:35 2018
SourcePackage: gtk+3.0
UpgradeStatus: No upgrade log present (probably fresh install)

[dino99 (9d9)]

Just checked on my ubuntu gnome-shell session, with gedit & a short text file: does not see 'flashing' issue with a non scrollbar little text.
My system has 'proposed' archive enabled and use intel builtin video.

[Wei Tsui (ghostplant)]

Yes, for all GPU-accelerated window manager such as mutter, metacity-composite, marco-composite, these is no screen flashing. However, disable GPU-accelerate will make it sharply flash, typically using metacity-nocomposite and marco-nocomposite.

However, even if using to metacity-nocomposite/marco-nocomposite to disable GPU-accelerate, all gtk2.0-based textview such as leafpad is still good and doesn't flash at all, but all gtk3.0 textview will heavily flash that makes eyes unconfortable.

Especially for black-background + white-foreground textview => maximum the text editor => fill full text in editor while ensuring no boundary overflow to prevent producing the side scrollbar => dynamic selecting multi-line text by mouse => extrodinary high-contrast flashing nearly makes eyes blind.

[Wei Tsui (ghostplant)]

Besides, Ubuntu 16.04 gtk3 editor (gedit/pluma) doesn't flash on disabling GPU-accelerate.

[dino99 (9d9)]

Is this still an issue ?

[Launchpad Janitor (janitor)]

[Expired for gtk+3.0 (Ubuntu) because there has been no activity for 60 days.]

[rendier (the-wandering-god)]

I am having text flashing issues in several text editors. Loading a large file causing the scrollbar to appear stops the issue. Linux Mint 19, i see it in gedit and xed. I'm on a MS Surface Pro-4 with the jakeday kernel installed.