Bug 433315

Summary:	Using the icon specified by the app's desktop file can cause a mismatch between the icon provided by the window itself which is visible in the Task Manager
Product:	[Plasma] plasmashell	Reporter:	Michal Kec (MiK) <KDE>
Component:	Task Manager and Icons-Only Task Manager widgets	Assignee:	Eike Hein <hein>
Status:	RESOLVED INTENTIONAL
Severity:	normal	CC:	nate, plasma-bugs-null
Priority:	NOR	Keywords:	usability
Version First Reported In:	5.21.0
Target Milestone:	1.0
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Application task bar: Three different windows, three identical icons Task switcher: Three different windows, three different (correct) icons

Description Michal Kec (MiK) 2021-02-20 11:10:21 UTC

Created attachment 135958 [details]
Application task bar: Three different windows, three identical icons

SUMMARY
While I use SeaMonkey (former Mozilla Application Suite <https://www.seamonkey-project.org/>), I have constantly open several windows: The browser, the mail reader, the mail composer and so on. Each type of window has distinguished application icon. Whereas I can see correct icons in task switcher (alt+tab) and window decorations (upper left corner), the icons on the task switching bar are wrong. All those different windows has just one icon - the main application logo. This is constantly confusing.

STEPS TO REPRODUCE
1. Run SeaMonkey
2. Open different windows: browser and mailer
3. Check the taskbar

OBSERVED RESULT
All icons are the same - an application logo.

EXPECTED RESULT
Icons on the taskbar should reflect the window icon, not the application logo.

SOFTWARE/OS VERSIONS
Operating System: KDE neon 5.21
KDE Plasma Version: 5.21.0
KDE Frameworks Version: 5.79.0
Qt Version: 5.15.2
Kernel Version: 5.11.0-051100-generic
OS Type: 64-bit
Graphics Platform: X11

ADDITIONAL INFORMATION
I've noticed the issue since I use Plasma 5 few years ago. This used to work earlier in KDE3/4. While it is just a minor issue (confusion) with icon+text task bar, it is a major usability issue for now-so-modern icon only task bar.

Not sure about another apps behavior, as only few apps today are "one process, multiple windows". LibreOffice for example has correct icons.

Comment 1 Michal Kec (MiK) 2021-02-20 11:11:17 UTC

Created attachment 135959 [details]
Task switcher: Three different windows, three different (correct) icons

Comment 2 Nate Graham 2021-02-22 22:47:49 UTC

The Task Manager uses the icon specified in the app's .desktop file.

The Task Switcher asks the window itself for what its icon should be.

Arguably, the non-Icons-Only Task Manager should be doing what the Task Switcher does, to prevent these kinds of mismatches, since both are displaying windows, not apps.

For the Icons-Only Task Manager, using the app icon makes more sense since it's designed to be listing apps, not windows.

Comment 3 Fushan Wen 2023-03-17 16:51:06 UTC

On Wayland it's not possible to assign an icon to a window without a desktop file, which means this bug will have to be closed as intentional.

Comment 4 Nate Graham 2023-03-27 19:05:13 UTC

I don't follow. How is that relevant, and why can't the non-icons-only Task Manager do the same thing that the Alt+Tab Task Switcher is already doing? If the Task Switcher can do it, surely the Task Manager can also do it, no?

Comment 5 Fushan Wen 2023-03-28 04:51:21 UTC

Because people who designed the wayland protocol had weird thoughts. That's it.

Comment 6 Nate Graham 2023-03-28 14:14:58 UTC

I don't understand what that means, sorry. Can you explain the technical details?