Bug 462113

SUMMARY

This is a small inconsistency I noticed. The Plasma Desktop offers the so-called Mouse Actions under "Desktop Context Menu >> Configure Desktop and Wallpaper...". By default, middle-click is assigned Paste as a Mouse Action, however, if you disable middle-click paste in "System Settings >> General Behavior" you'll still get that action listed under Mouse Actions, but it won't do anything.

To be honest, I doubt anyone disabling middle-click pasting in General Behavior would want to enable it specifically for the desktop and nothing else. People either want middle-click pasting or they don't. To reduce confusion and improve the user experience, I propose a more automatic solution to avoid controlling what is almost the same setting in two different places:

Unless the user sets another custom Mouse Action to the middle button, pasting on the desktop should be considered the default action and be controlled exclusively by the option in General Behavior.  For the sake of consistency, this concept could be expanded to the right-click too: eg. always open the context menu unless a mouse action overrides that behavior (this should also prevent the case of disabling the context menu action and being unable to go back to Mouse Actions to re-bind it).

For instance, if I assign the "Switch Desktop" mouse action to the middle button, it would do that, but if I do not set anything (by deleting the middle button action in Mouse Actions), by default, it should either paste or not paste on the desktop based on the option in General Behavior being enabled or not, without having to explicitly assign a mouse action to it.

This also means that by default the middle button and the right button (if this solution is also applied to it) should have no visible action bound to them on Mouse Actions (they shouldn't be listed there by default).

STEPS TO REPRODUCE
1. Disable "Middle Click: Paste selected text"  in System Settings >> General Behavior
2. Go to "Desktop Context Menu >> Configure Desktop and Wallpaper... >> Mouse Actions"
3. Make sure "Paste" is enabled as a middle button action
4. Copy some text
5. Middle-click to paste

OBSERVED RESULT

Nothing happens

EXPECTED RESULT

The options to paste shouldn't be controlled in two different places at the same time. That's too much granularity for too little benefit. Remove "Paste" as an option in Mouse Actions and make it either paste or not solely based on the global option to paste with the middle click being enabled or not (unless overridden by another kind of action).

Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.26.80
KDE Frameworks Version: 5.101.0
Qt Version: 5.15.7
Kernel Version: 5.15.0-53-generic (64-bit)
Graphics Platform: Wayland
Processors: 6 × Intel® Core™ i5-9400F CPU @ 2.90GHz
Memory: 7,7 GiB of RAM
Graphics Processor: AMD Radeon RX 570 Series

Additional Information:
Wayland session
This applies to the Folder View and Desktop View