mate-screenshot: captured area includes fading-off selection overlay

[mhanor]

Expected behaviour

Select area to grab only captures relevant area, not overlays drawn by mate-screenshot

Actual behaviour

When mate-screenshot is used with the option Select area to grab (when using Shift+Print Screen), the screenshot includes the overlay drawn when selecting the area. This is perfectly visible when using marco window manager with picom as compositor (any variety: GLX, Hybrid, Xrender), where the selection overlay in current version of mate-tweak (Installed: 22.04.4-1) is greenish. I'm opening the bug on mate-utils because I think mate-screenshot should handle this situation better. I don't think mate-tweak should do anything different - the overlay looks nice as it currently is.

The screenshot captures the fading overlay. After investigating the code, it seems the problem is caused by a fixed delayed callback at https://github.com/mate-desktop/mate-utils/blob/master/mate-screenshot/src/screenshot-utils.c#L446

Increasing the delay from 200 to 500ms seems to fix the issue in my case, but this requires recompilation. As a workaround, maybe the delay should be configurable. There is a delay parameter configurable as integer under org.mate.screenshot, but it's only used in certain scenarios.

Steps to reproduce the behaviour

1. Run mate-screenshot -a
   Or press Shift+Print Screen and select Select area to grab
2. Drag to select the area to capture
3. Check the result

MATE general version

1.26.0

Package version

1.26.0-1

Linux Distribution

Debian bookworm x64 (branch Testing)

Link to bugreport of your Distribution (requirement)

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1008224

[iaon]

The workaround from here
https://gitlab.gnome.org/GNOME/gnome-screenshot/-/issues/56#note_1409450

In my case it was fixed by creating

~/.config/marco-picom.conf

fade-exclude = [
    "class_g = 'mate-screenshot'"
];

Configuration file path was taken from this file
/usr/bin/marco-picom

[mhanor]

The work around doesn't seem to work for me, applied in another way.
I use mate-tweak to select for window manager the picom glx config which runs /usr/bin/marco-glx in my case. I've added --fade-exclude "class_g = 'mate-screenshot'" \ in the parameter list by editing marco-glx file, but the fade exclude doesn't seem to work.
If I create the marco-picom.conf file as shown above, in ~/.config path, it replaces the configuration entirely, replacing the run parameters what marco-glx script uses to start picom with. Picom has to have a proper conf file in order to use glx, which is what I want in the first place, to get rid of the screen artifacting when scrolling or watching movies.