Bug 428335

Summary: Widget shows unnecessary animations when first becoming visible on a thick vertical auto-hiding panel
Product: [Plasma] plasmashell Reporter: Franco Pellegrini <francogpellegrini>
Component: NotificationsAssignee: Kai Uwe Broulik <kde>
Status: RESOLVED FIXED    
Severity: minor CC: nate, plasma-bugs-null
Priority: NOR    
Version First Reported In: 5.20.2   
Target Milestone: 1.0   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Franco Pellegrini 2020-10-27 12:16:22 UTC 
SUMMARY
big panels with auto-hide (used with notifications, like windows 10 notification side-panel) display garbage when animating from top-down (panel placed on the top of the screen)

STEPS TO REPRODUCE
1. create a panel as big as half screen wide and half screen tall
2. place it on top of the screen
3. add notification widget
4. wait until several notifications accumulates
5. place mouse over the top screen section so the panel appear

OBSERVED RESULT
while the animation for unhide is displayed, lot of garbage is displayed on the panel.. very distracting

EXPECTED RESULT
show the notifications while animating the panel

SOFTWARE/OS VERSIONS
Operating System: KDE neon 5.20
KDE Plasma Version: 5.20.1
KDE Frameworks Version: 5.75.0
Qt Version: 5.15.0
Kernel Version: 5.4.0-52-generic
OS Type: 64-bit
Processors: 6 × Intel® Core™ i5-8400 CPU @ 2.80GHz
Memory: 22.9 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 630
Comment 1 Franco Pellegrini 2020-10-27 12:19:01 UTC 
note that the second time you un-hide the panel, the content seems "right", so it's a content refresh problem, you are waiting to finish the unroll animation to refresh the content
Comment 2 Franco Pellegrini 2020-10-28 09:30:02 UTC 
also the same panel start to flicker a lot at login
Comment 3 Nate Graham 2020-10-29 19:20:07 UTC 
Cannot reproduce with a thick auto-hide top panel in Plasma 5.20 or git master.
Comment 4 Franco Pellegrini 2020-10-30 02:03:07 UTC 
Tested at home with a compleatly different hardware, and can be reproduced as well

Operating System: KDE neon 5.20
KDE Plasma Version: 5.20.2
KDE Frameworks Version: 5.75.0
Qt Version: 5.15.0
Kernel Version: 5.4.0-52-generic
OS Type: 64-bit
Processors: 16 × AMD Ryzen 7 2700X Eight-Core Processor
Memory: 31.4 GiB of RAM
Graphics Processor: GeForce GTX 1080/PCIe/SSE2

1. Empty all notifications.
2. generate lots of notification with some program
3. place the mouse over the big hidden panel so it appear
4. The content (while animating) is usually garbage, transparent rectangle, or old notifications (typically buffer garbage).

I will try to record it next time
Comment 5 Franco Pellegrini 2020-10-30 02:15:28 UTC 
Here
https://youtu.be/Cf6G6YCm-1M

Look at the FIRST drop down. In this specific case, it show transparent content (it display the background) but other cases you can see garbage, or old notifications. Clearly a dirty buffer. 

You need to add lots of notifications compared to the last "panel unroll" to reproduce (the same content does not reproduce the problem as you can see in the video, only content changes trigger the issue).
Comment 6 Nate Graham 2020-10-30 15:08:41 UTC 
Weird. Seems like an issue with the notifications applet itself.
Comment 7 Nate Graham 2023-04-28 05:07:46 UTC 
The widget has gotten a number of changes that could have fixed this; any chance you can test again in Plasma 5.27 and confirm whether it's still happening? Thanks!
Comment 8 Franco Pellegrini 2023-04-28 10:01:19 UTC 
seems to be fixed
Comment 9 Nate Graham 2023-04-28 13:43:23 UTC 
Cool, let's call it fixed until it happens again. Thanks for following up!