Hi Pavel, first of all thanks for your efforts!
- It is necessary to make the widget display only real disk devices (not virtual, not loop or ram) by default.
I tried to fix this once but unfortunately the systemactivity dataengine uses ksysguard which then probes kernel interfaces directly through some C code. It doesn't use Solid, where filtering out those interfaces would be easy. I'm not knowledgable enough in that codebase to comment on how that could be achieved there.
- I need to make sure that after disabling all settings the widget is empty.
I guess the sources is stored as a StringList and the widget assumes that when the list is empty, it uses the default set of all sources. Perhaps you can store a pseudo "EMPTY!" entry in the list to denote nothing is checked. However, I don't see why you would want to place a widget that then does not show anything?
Cheers Kai Uwe
