Access to the X and Y expressions in TreeViewer


I need your help about Treeviewer. I am using ROOT 5.32/04 on windows XP.

I’m currently writing a short program to draw, in the same canvas, a 2D histogram and its projections. Attached is a running example (code.c). I would like to use this code via TreeViewer: i.e. use drag and drop expressions (the “X expression” and “Y expression”) before loading my program. Therefore I would get not only the 2D histogram but also its projection automatically drawn.

Basically, I would like to use “leaves drag and drop” in the X box and Y box of the Treeviewer without opening and modifying my program. I would like to use it the following way: the user drags and drops leaves in the X and Y fields, loads “code.c” (in the command field) in order histograms will be automatically drawn. Is it possible?
I have many different graphs to draw, it’s the reason why I want to automate my program.

I look for the solution here : But I don’t identify where informations of the X and Y boxes are located.

Do you have any constructive advice ?

Thank you in advance for your help,
code.c (2.33 KB)