How to fill QListWidget with custom widgets by using QStringList as data model

[Killian]

You might want to have a look at QItemDelegate.
Using a delegate enables you to completely customize the look of your items in a QListView (and other item containers as well).

[EneRevo]

This looks like the missing piece I wasn't aware of.

Thank you.

Edit:
Maybe I was a bit to fast.

The Delegate actually looks like what I wanted,
but I can't figure out how to use my designed QWidget with it or draw a QPushButton in the paint function (due to other forums and threads it isn't possible to draw a PushButton there, true?).