this is not really possible in the current design, as the contaiment is the primary thing that represent the activity (and since containments are not views is not possible to have the same applet in more than one)
other than feasability concerns, i'll keep it as a good feature request

there's a workaround, though: put it on a large windows-can-cover panel. :) that's what I do for the activitybar.

If you can not show it on all activities by design, then what about a function to at least populate a widget to all other activities? I.e. you add an applet on one activity and then it's copied to all others (creating new separate applets there).

Of course this would pose a problem when you repopulate an applet after a change. So the populated applets would somehow need a property that they are copies of each other and need to be replaced on repopulating.

I second the above.
Having to manually edit the appletrc file, duplicating the widget across the different activities, manually changing the the container and widget ID to avoid collision is anything but user-friendly.

- Gilboa

Hello!

This feature request was filed for KDE Plasma 4, which reached end-of-support status in August 2015. KDE Plasma 5's desktop shell has been almost completely rewritten for better performance and usability, so it is likely that this feature request is already implemented in Plasma 5, or is no longer applicable.

Accordingly, we hope you understand why we must close this feature request. If the requested feature is still desired but not implemented in KDE Plasma 5.12 or later, please feel free to open a new ticket in the "plasmashell" product after reading https://community.kde.org/Get_Involved/Bug_Reporting

If you would like to get involved in KDE's bug triaging effort so that future mass bug closes like this are less likely, please read https://community.kde.org/Get_Involved#Bug_Triaging

Thanks for your understanding!

Nate Graham