Create a window to insert editable geometric drawings

[Manuel Pulido]

Hi everyone, I need some help. I'm building a racks configurator that sizes the vertical and horizontal racks based on the weight of the pallets. One of the features, once I've given the dimensions of a single rack and a rectangular space, is to provide a plan view of the racks layout. Is there a library or module I can use to draw these objects, which also allows me to graphically modify the dimensions and then export the drawing to AutoCAD? I'm currently creating an SCR file that I'll then import into AutoCAD, but I can't show the user the drawing before exporting it to AutoCAD. I've attached a photo of the type of drawing I need to make, which is essentially a set of rectangles. 

Thanks for your help.