You may have heard already that the Xtext team is currently porting Xtext and Xtend to IntelliJ IDEA. To get acquainted with the new APIs I decided to spend a few hours of my spare time to port FXDiagram as well. Here is a screencast of the first shot with a class diagram for Java code:
As the core of FXDiagram is independent of Eclipse, this was easier than expected. IDEA is a Swing (!) application, and the JFXPanel allows to embed JavaFX controls within Swing. The hardest part was actually to use Java as Xtend is not yet available on IDEA ;-) FXDiagram's configurable model access made it easy to integrate with IDEA's PSI model and its transactions.
I must admit that the overall experience is a bit snappier in IDEA than in Eclipse. I assume this is because the Oracle team has spent more effort on the JFXPanel than on the FXCanvas. Unfortunately, multi-touch gestures don't work yet, but I had to port them to the the FXCanvas myself as well.