Bug 418560 - After tiling and resizing there's a gap between window and the top bar when window is moved to the top
Summary: After tiling and resizing there's a gap between window and the top bar when w...
Status: RESOLVED NOT A BUG
Alias: None
Product: kwin
Classification: Plasma
Component: general (show other bugs)
Version: 5.18.3
Platform: Manjaro Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
: 418884 (view as bug list)
Depends on:
Blocks:
 
Reported: 2020-03-06 20:26 UTC by postix
Modified: 2021-06-16 17:38 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:
postix: Wayland+
postix: X11+

Attachments
Screen recording. (2.14 MB, video/mp4)
2020-03-06 20:26 UTC, postix 		Details
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Description postix 2020-03-06 20:26:06 UTC 
Created attachment 126639 [details]
Screen recording.

SUMMARY

When tiling a window by dragging it to the right edge and resizing it horizontally to the left, you end up having a weird effect:

When you try to place this window now under the top panel, you will see that it estimates the height of the top panel too big, i.e. it stays a few pixel under the top panel leaving a gap.

First if you go far more to the top with the mouse (dragging the window), it will jump over the gap and is placeable right under the top panel.


Badly explained? Please see the recording. :)


SOFTWARE/OS VERSIONS
Operating System: Manjaro Linux 
KDE Plasma Version: 5.17.5
KDE Frameworks Version: 5.68.0
Qt Version: 5.14.1
Kernel Version: 5.5.7-1-MANJARO


ADDITIONAL INFORMATION
Scaling: 1.5
Comment 1 Vlad Zahorodnii 2020-03-19 10:13:50 UTC 
X11 or Wayland?
Comment 2 Vlad Zahorodnii 2020-03-19 10:15:02 UTC 
*** Bug 418884 has been marked as a duplicate of this bug. ***
Comment 3 postix 2020-03-19 10:26:48 UTC 
(In reply to Vlad Zahorodnii from comment #1)
> X11 or Wayland?

I just tested it: Happens on both platforms.
Comment 4 postix 2020-03-19 10:28:28 UTC 
It does not happen if the window becomes quarter-tiled and resized. Only if after it was half-tiled and resized.
Comment 5 Vlad Zahorodnii 2020-03-19 10:30:07 UTC 
Do you set PLASMA_USE_QT_SCALING on X11?
Comment 6 postix 2020-03-19 10:47:52 UTC 
(In reply to Vlad Zahorodnii from comment #5)
> Do you set PLASMA_USE_QT_SCALING on X11?

Nope, here are the only relevant environment variables set on my system:

QT_SCREEN_SCALE_FACTORS=eDP1=1.5;DP1=1.5;DP2=1.5;HDMI1=1.5;VIRTUAL1=1.5;
GDK_DPI_SCALE=1.5
XDG_SESSION_TYPE=x11
KWIN_FORCE_LANCZOS=1
XDG_CURRENT_DESKTOP=KDE
QT_LINUX_ACCESSIBILITY_ALWAYS_ON=1
QT_AUTO_SCREEN_SCALE_FACTOR=0
GDK_SCALE=1.5
GTK_USE_PORTAL=1

I cannot reproduce this bug with GTK windows.
Comment 7 postix 2020-03-19 10:52:40 UTC 
Tested it with scaling 1.0 (rebooted), bug persists.
Comment 8 postix 2020-03-19 10:54:50 UTC 
@Comment 6: I can reproduce it with Thunderbird or Firefox as GTK apps. I could not reproduce it with Dino or Lutris however.
Comment 9 postix 2021-06-16 17:38:53 UTC 
Can no longer reproduce it.