Bug 511415

Summary:	Thumbnails are slow to view and fail to appear sometimes
Product:	[Frameworks and Libraries] frameworks-kio	Reporter:	medin <med.medin.2014>
Component:	Open/save dialogs	Assignee:	KIO Bugs <kio-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	kdelibs-bugs-null
Priority:	NOR
Version First Reported In:	6.19.0
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description medin 2025-10-31 09:48:43 UTC

Steps:

1. Prepare a folder with more than 300 files containing quality images (>6mb) and some videos.
2. Try to open open/save dialog from Firefox then check that Show Preview is enabled.
3. Navigate to that folder containing images and videos and let it generate all thumbnails.
4. Close open/save dialog then reopen it again and navigate again to that folder.

Expected result:
Thumbnails show appears instantly.

Observed result:
Thumbnails are slow to appear like they are recreated each time you use open/save dialog. And sometimes when you scroll fast some images and videos never show their thumbnails.

NB: This behavior is not present when you browse such folder using Dolphin, thumbnails appears fast without any problem the second time you visit such folder.