What I tried so far: SWTBot and WindowTester.
My problem with SWTBot is that I can click into an edit field, but I can't type into it. I looked up this issue in google and it looks like that SWTBot does not have this feature implemented.
With WindowTester I had other problems: SWTWidgetLocator is working with texts so if I have a button with no text just image, I can not click it.
Thus on the whole I'm looking for either a workaround to the problems I mentioned above or a tool which does not have these shortcomings.
I'm working in an Eclipse RCP enviroment.