How to make C++ code draw on Java components

Question

We are designing physics app, and we would like to have it written in Java, and also we want to use root (root is writen in C++). Root has some nice graphical features -- it is able to draw very nice 3D charts, and I'm thinking whether it's possible to embedd those charts in Java app.

Is there any way to make C++ code draw on for example JPanel?

Is there a way to pass back mouse/keyboard events? - we would like to have some interactivity, like rotating a 3d chart.

I asked similar question about embedding a lot of C++ code (that is not related to drawing anything) in Java app (also about root) it's here.

Answer 1

Since SWT is built to be a fairly thin wrapper around native widgets, it may be easier to work with than Swing/AWT for your particular task. I realize this particular link is a bit old, but it does show how to quickly wrap a native widget.

Answer 2

The JNI comment on the question itself seems to be the best way forward - I don't think you want to draw with root as-is; you'll want to write some interface code in between which is called from Java via JNI, which asks 'root' to redraw its image at a given size (the appropriate size for the image being something only the java component would know). Pass it back to the java component from the JNI call as just 32-bit image data, for instance.

I would not assume you can draw into a java component even in AWT; as it's basically java wrappers around native components - where the drawing is usually done in the native component itself (by the operating system, not by the java code).