Bug 476816 - FormLayout flashes or flickers when initially loading, as if it starts in narrow mode and then immediately changes into wide mode
Summary: FormLayout flashes or flickers when initially loading, as if it starts in nar...
Status: RESOLVED DUPLICATE of bug 410352
Alias: None
Product: frameworks-kirigami
Classification: Frameworks and Libraries
Component: general (show other bugs)
Version: Master
Platform: Neon Linux
: NOR minor
Target Milestone: Not decided
Assignee: kdelibs bugs
URL:
Keywords: qt6
Depends on:
Blocks:
 
Reported: 2023-11-11 03:07 UTC by Vishwas Parpattegar
Modified: 2025-03-31 22:23 UTC (History)
9 users (show)

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Description Vishwas Parpattegar 2023-11-11 03:07:20 UTC 
SUMMARY
***
Energy Saving menu in system settings flashes and moves right when switching between power profiles using the new menu.
***


STEPS TO REPRODUCE
1.  Open System Settings
2. Navigate to Energy Saving Menu
3.  Switch between "On AC Power" / "On Battery" / "On Low Battery"

OBSERVED RESULT
the options below the header bar flash and move to the right when switching between options

EXPECTED RESULT
the options should switch between each other without flashing

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: KDE Neon Unstable Edition
KDE Plasma Version: 5.81.0
KDE Frameworks Version: 5.245
Qt Version: 6.6.0
Comment 1 Nate Graham 2023-11-15 19:28:58 UTC 
Can reproduce.
Comment 2 ratijas 2023-11-16 12:21:54 UTC 
That's because layout (specifically, FormLayout) is based on timers instead of polish lifecycle callbacks. I'm afraid it can't be entirely fixed without rewriting it to the native code, because we don't get enough level of control in QML code; an alternative to that would be to recalculate the whole layout of every geometry or children change of anything, which would be (1) quite expensive computationally-wise, (2) prone to binding loops and polish loops.
Comment 3 Nate Graham 2023-11-16 20:35:10 UTC 
Right, I can see it when I switch between applet config pages for the Task Manager. The FormLayout flickers in the same way as it loads.
Comment 4 Jakob Petsovits 2024-01-07 02:49:10 UTC 
Flicker in the Energy Saving module was fixed via https://invent.kde.org/plasma/powerdevil/-/merge_requests/302 by reusing one form for all power state profiles. Nate's reproduction in the "Configure Task Manager" dialog (and likely in several other spots) can still be observed.
Comment 5 Nate Graham 2025-03-19 22:32:31 UTC 
*** Bug 500572 has been marked as a duplicate of this bug. ***
Comment 6 Nate Graham 2025-03-28 22:52:07 UTC 
*** Bug 502100 has been marked as a duplicate of this bug. ***
Comment 7 David Edmundson 2025-03-31 22:23:04 UTC 
*** This bug has been marked as a duplicate of bug 410352 ***