Bug 345545

Summary:	Application's icon flickers in Icon-only Task Manager when closing the application
Product:	[Plasma] plasmashell	Reporter:	Mika Allan Rauhala <mika.allan.rauhala>
Component:	Icons-only Task Manager	Assignee:	Eike Hein <hein>
Status:	RESOLVED FIXED
Severity:	normal	CC:	david.cortes.rivera, kde, plasma-bugs, rapiteanu.catalin, simonandric5
Priority:	NOR
Version:	master
Target Milestone:	1.0
Platform:	Compiled Sources
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Mika Allan Rauhala 2015-03-26 12:32:28 UTC

I have applications in Icon-only Task Manager that have "Show A Launcher When Not Running" enabled. When I quit such application, it's icon disappears in Icon-only Task Manager for < 0.5s. The place where the icon was becomes blank. After a very short duration, the icon comes back and works normally.

It seems that when a task changes state from running application to a launcher, the Task QML object for it gets recreated. Task QML component uses PlasmaCore.ItemItem for showing the icon. PlasmaCore.IconItem loads the icon asynchronously, causing the icon to be invisible for a while.

If I replace PlasmaCore.IconItem with a QIconItem in plasma-desktop/applets/taskmanager/package/contents/ui/Task.qml, the issues becomes fixed. This is not a proper fix since QIconItem lacks active hover effect.

Reproducible: Always

Steps to Reproduce:
1. Use Icon-only Task Manager as task manager
2. Open an application
3. Enable "Show A Launcher When Not Running"  for the application in Icon-only Task Manager
4. Quit the application

Actual Results:  
The application's icon disappears in Icon-only Task Manager for < 0.5s.

Expected Results:  
The application's icon stays same.

Comment 1 Eike Hein 2015-03-26 12:50:41 UTC

Good analysis; this is exactly the scope to which we're aware of the problem as well. We've got various things under way in the hopes of making IconItem more suitable for cases it's not doing well with right now.

Comment 2 Eike Hein 2016-06-16 23:25:26 UTC

This should be resolved with newer plasma-framework versions.

Comment 3 David 2018-06-20 15:32:43 UTC

I still experience this bug with some applications such as spyder in plasma 5.12.5.