EXtend functionality of QListWidget by making a plugin and use it in designer?

[wysota]

But on thing i am wondering about is it really necessary to include the QCoreApplication. Cause it seems as if it was needed in my program but it is not clear from the documentation that it is needed in cases like this.

QCoreApplication is responsible for initialising plugins.

BUT then again i dont find the documentation to be very good it leaves a lot of guessing to be done.

That's your opinion According to me it just doesn't try to be smarter than the reader as some docs do.