Seems like it would be useful to show on devices with a touch screen.

This is the presentation used by Index and I wouldn't be surprised if this idea is directly taken from it.

@cblack Thanks for mentioning that. No, it was not directly taken from it. In fact I never heard of index before and I just found it googling around, so linking a medium post for reference (guessing this is the one you meant): https://medium.com/@temisclopeolimac/index-overview-b2ddcb16534f. The images in that post show even some more interesting concepts for overlays, though.

I basically thought that because these options would only show up on selection of items that it might be interesting to have them floating indicating the non-permanent state of them. Inspiration might have come from overlays on Android (not sure about that, though) or the status overlays in Nautilus on GNOME as used in the third mockup.

I basically thought that because these options would only show up on selection of items that it might be interesting to have them floating indicating the non-permanent state of them.

Yes, that's a clear advantage. It avoids the potential of users feeling like the program morphs by itself below their fingertips. (Though I don't think this would be a big problem for my mockups either because stuff changing in the status bar is expected and it's more like a changing footnote if anything.)

One of the disadvantages I see is that overlays are generally used for things that require attention or should be explicitly dismissed. This is the case for many web pages but also for the overlay sheet seen in the window rules KCM. I think the chances are high that users will have to consciously parse the overlay and judge its use the first time they see it appearing. I would rather avoid this departure of the more common use of overlays.

Another disadvantage is that because the overlay is floating above the view, misclicking any of the actions just slightly means clicking the view and therefore potentially losing the selection.

Overall I still prefer my mockup but I wouldn't mind if this got implemented either.

I am not sure having the overlays use a contrasting style is necessary or even advantageous.

I guess it comes down to personal weighting of the different aspects, then. Also thanks for mentioning some downsides, as I have not thought about some of them.

Not sure, how to proceed from here as I'd also be fine with either approach. Maybe voting?

I don't think there is a point in voting because anyone can already voice their opinion here if they want to. The person implementing this will also spend more time on this than either of us did so they don't necessarily have to be confronted with final decisions anyway especially because sometimes new aspects or problems are discovered while working on it. I am fine with working on other things for now.

Alright! (I also was not entirely sure before whether you planned on implementing this)

(I kind of was but these plans always get postponed when I spot something I deem more important to work on. Right now it is in the "maybe eventually perhaps I might get to it" category. It would have been higher up if I had gotten more positive feedback but even then not within two month.)

I just had another look at index and I have to say their solution is probably the better orientation guide than my mockups, as it is much more mature with some nice UX solutions (like the x for "clear selection"):

https://invent.kde.org/maui/index-fm/-/raw/v1.2/screenshots/Screenshot_2.png