Dunst: Flicker with --replace

[CyberShadow]

In a bash shell, run:

r=0; while true ; do r=$(dunstify --replace=$r --printid "Hi $r - $RANDOM") ; sleep 1 ; done

Very often there is a visible flicker when the notification is replaced.

Would it be possible to eliminate it?

[WhyNotHugo]

Absolutely no flicker here. What WM are you using?

[CyberShadow]

i3-gaps. Can still see the flicker both on my desktop and laptop, with or without compositing (Compton).

[bebehei]

I can verify this. Using i3 with compton.

[gangelop]

Same here, i3, different kind of flickering with or without compton. It happens with the volume notification from clementine, if you scroll the volume up/down fast enough. The flickering is slightly different with and without compton (I think..)
. With compton, sometimes the notification completely disappears until I move it to my other monitor. I never bothered reporting it because I have no idea where to start investigating this. :S

EDIT: just to clarify, for me it is also reproducible with @CyberShadow's dunstify reproducer (again both with and without compton).

[gregf]

I can reproduce the flicker with the above script. i3-gaps no compton.

[WhyNotHugo]

Odd, I can't reproduce this on i3wm, neither with nvidia nor intel (just in case video card made any difference).

Can you quickly try with i3wm just to narrow down if it's i3-gaps-specific or not?

[gregf]

I have an amd video card using the opensource drivers.

[tsipinakis]

I can confirm that it also happens on i3wm with compton enabled, strangely enough it happens much less frequently if at all without compton.

[reuseman]

I have bspwm with compton enabled and the graphic card is intel, and I got the flicker too

[ghost]

The notifications of the rhythmbox music player flicker as well ( i also use i3 gaps with compton).
After running dunst with -print i noticed that rhythmbox tries to print its notification multiple times for some reason, so i guess dunst flickers on i3/compton when it refreshes an already existing notification.

[josduj]

Setting glx-use-copysubbuffermesa to true fixed the compton flicker for me (only flickers slightly if I spam it like a maniac).

[reuseman]

@josduj Thank you for the solution, but there are still two problems.

1. If someone use the xrender backend
2. If someone use dunst to display a notification everytime the volume, brightness, etc., is increased or decreased. Or just something that needs high refresh, an that means spam like a maniac

[g-suraj]

Have the same issue, i3-gaps with compton.

[bebehei]

I guess, I've got the issue:

1. notification.c:431
   
   
   
   • The previous notification will get closed
   
   
2. notification.c:574
   
   
   
   • It will get removed from the displayed queue
   
   
3. notification.c:596
   
   
   
   • wake_up() will get called
   
   
4. dunst.c:239
   
   
   
   • wich triggers the x window to hide
   
   
5. notification.c:519
   
   
   
   • bu until this point the notification queue is empty
   
   

So there is a full x_win_show and x_win_hide call in between replacing the notification. I'm not that experienced with X, but I'd guess this is the problem.

[bebehei]

If some of you could verify, that the fix proposed in #391 works, would be great.

[CyberShadow]

@bebehei Yes, it works for me! Can't speak about the patch but it does completely remove the flicker, both in the repro command above and my real use-case (showing current volume when adjusting it).