Weird behaviour of AppImages in panel (task bar)

[ralfheinz]

Hi all,

half of the AppImages I use cannot be started from the panel (task bar). Clicking the icon leads to 'chdir: No such file or directory'. (Kubuntu 22.04, Plasma 5.27.11) All AppImages were integrated into the system with AppImageLauncher and can be launched via start menu, KRunner or by double-clicking the AppImage itself without an exception. The problem therefore only affects the icon area of the panel.

Bringing an AppImage to the panel couldn't be easier: I select 'Stick to panel' in the context menu of the running app’s icon, that’s it. Unfortunately it doesn’t work with some AppImages and I can’t detect any difference to the ones that work. In detail:

- balenaEtcher - no, not working
- Darktable - no
- Digikam - yes, working
- FontBase - yes
- Inkscape - no
- qDslrDashboard - yes
- Scribus - yes
- XNViewMP - no

It’s not a real problem, I could live very well without panel icons at all, since I prefer to use KRunner anyway. I would just like to understand why it works with some AppImages and not with others, even though I treat them all the same. Can I influence the behaviour at all or should I just ignore it?

[jlittle]

Does it work if you drag it to the panel from dolphin?

[claydoh]

(Kubuntu 20.04, Plasma 5.27.11)

I assume you mean Kubuntu 22.04?

How did you install Appimagelauncher? The PPA is quite old now, and the "daily" is only a bit fresher. but is more current than the current continuous build on their github
I don't see any very similar bugs on a quick browse of their tracker, though one is sort of similar. It sounds like the tool is not parsing things correctly, or the appimage itself has some sort of issue that confuses the tool.
If *all* appimages didn't work, I would think ity is is Plasma issue, but since some do, I suspect something odd in the .desktop files appimagelauncher is creating.

[ralfheinz]

jlittle Thanks for your feedback. I’ve tried to drag the .desktop files from Dolphin and now – surprise! – the AppImages start when their icon gets clicked. It would be a good solution or at least a workaround, but there appears a second instance of the same icon after the app has started. Any chance to get rid of those useless duplicates?

claydoh Thanks to you too. You were right, my Kubuntu is of course 22.04, I corrected it in my post. I installed AppImageLauncher with a .deb file from GitHub, version number is 2.2.0. The exact same version is running on another machine with Lunix Mint 21.3. To see if Plasma is somehow involved, I tried Darktablr and Inkscape there (same versions as in Kubuntu) and both of them can be launched from the panel without problems. Of course this doesn’t prove Plasmas responsibility but it might be a hint. The .desktop files seem to be okay as far as I can see. At least they don’t significantly differ from those of the working apps.

[jlittle]

jlittle ... there appears a second instance of the same icon after the app has started. Any chance to get rid of those useless duplicates?

Right-click the panel at the bottom left (some other places work too, but not all), choose "Enter edit mode", hover the mouse over the icon you don't want, click "Remove", close edit mode, either the close button at the right, or the exit edit mode button at the top of the screen (or wherever the panel is not, it moves about).

[claydoh]

I'd suggest trying the more current version, the "continuous" build from 2023 from my link. That's the version I had the least issues with when used it regularly.

I can see the tool using incorrect icon naming, sizing or locations, based on a few of the bug reports involving missing icons.

Dragging the desktop file to the panel creates a launcher widget, not a pinned Task Manager entry, so you might not be able to get rid of the duplicate, since you have a widget plus a taskbar item when it is is running.

[ralfheinz]

jlittle Hovering over no matter what part of the panel in edit mode doesn’t offer the option to do something with an icon. All options seem to affect the icon bar in total. Maybe I got something wrong.

claydoh I’ve installed the continous version as you suggested and there is a small difference now: Clicking the Darktable icon (representing the group of weird ones) doesn’t throw an error anymore. Instead a second generic icon appears, showing an blue circular loading animation around itself for 5 to 7 seconds, then the animation stops and the generic icon disappears again. Overall this perfomance is slightly more entertaining than the somewhat harsh error messages, but the result is sadly the same as the app won’t open.

I tend to ignore this whole icon area of the panel from now on. I really like KDE Plasma and the panel itself but consider the icon plasmoid as pretty odd. The AppImage issue isn’t the first fiddling I had with it and I gradually start to lose patience with its stubbornness. (As I do my daily work on MacOS machines with a 'dock' that can be managed by 4 year old children without any problem, it’s very hard to take this icon bar serious.)

Anyway: Many thanks to both of you for your help and patience. Maybe a future update will do any better.

[claydoh]

The panel is a place that holds widgets. Like your system tray, launcher menu, and the task manager. These all can be moved around on the panel, and other widgets can be added. Heck, you can delete the panel and place these same widgets directly on the desktop (almist) wherever you wish.

The Task Manager has multiple variations, both official and third party. The default is the one you normally pin apps to, if desired.

Dragging an item from the menus to somewhere outside the task manager actually creates a separate launcher widget independent from the taskbar section of the panel. A bit awkward to do since the Task Manager widget auto-expands to fill space on a panel. It slides out of the way when the drop target is between widgets. Not obvious, for sure, without understanding the general modularity of things.

Adding app as launcher widgets instead of being pinned to the taskbar is mainly useful for those using the old school task manager that uses the rectangular blocks for running apps instead of marking the icon. A lot of people still like this space waster

But you didn't have any launher icon widgets - that would have been noticeable while hovering over things in edit mode.

After that long winded reply (for me), back to topic:

The ultimate issue is likely from third party tools as well as an app package format that still can have rough edges before you even get to how a creator makes then. All on top of any potential issues on Plamsa's menu system and caching, despite being normally xdg compliant.

I have been unable to reproduce this myself. This doesn't mean anything, since it is obvious that you are. But it may indicate it being difficult to discover what the root cause is.

[ralfheinz]

claydoh thank you for the clear explanation of the panel and widget concept. I already understood the basics, but obviously hadn't quite internalized the details yet. The official name of my problem widget is therefore 'Icons only Task Manager', but luckily, as I said, it's the only widget that's behaving strange, everything else works as expected. So no reason for sleepless nights. And I agree that it's really hard sometimes to detect what is happening exactly under the hood.