Okay, first things first: I suck at interpreting what can be found in qdbus-viewer.

Anyway, when I used SC 4.5.x, I used xbindkeys to bind the two thumb-keys on my mouse to switch between virtual desktops. That worked great (thanks Hans!).

Now, however, I've ditched the virtual desktops and only use activities. I find it rather confusing to use both to be honest.

The command(s) in question I used in 4.5.x was

"qdbus org.kde.kwin /KWin org.kde.KWin.nextDesktop"

and

"qdbus org.kde.kwin /KWin org.kde.KWin.previousDesktop"

Now, the question is: what would be a good equivalent to switch between activities instead?

I found a "SetCurrentActivity" method under org.kde.kactivitymanagerd /ActivityManager org.kde.ActivityManager, but I don't know how to switch to the next activity (there is also one method to get the current activity).

What I would do instead is to use xte to simulate the keyboard shortcuts to switch activities (Super+Tab and Super+Shift+Tab by default), which is also described in the guide.

Okay, now I feel really stupid. Why didn't I think of that...especially since I use that method for the "present windows" effect.

Now I only need to figure out why it doesn't work as it should. It works when I use the keypresses itself, but when mapped to the mouse it triggers other shortcuts at what seems to be random. I.e. it sometimes brings up krunner, and at other times it de-iconifies amarok.

Okay, update 2: after having re-assigned which hotkey is responsible for switching activity (and editing .xbindkeysrc accordingly) it works. No idea why that was necessary but at least now it works as I want it to!