It may not be quite what you're looking for, but the NetBeans Platform provides a framework for doing this sort of thing. You might like to have a look at the paint program that is one of the supplied code samples.
You could program it from scratch using the standard
Java Platform, but it wouldn't be "simple"... it would be long and complicated, and there's no need to re-invent the wheel.
I'm not sure but I think Eclipse has something similar, based around SWT (an alternative to Swing that uses native widgets).