scale textures using scrollbars that show/enable when texture is clicked on

I'm creating a basic face editor for class and can't figure out how to get the scrollbar's centered on the default rec/shape variable.

I want to increase the textures: width and Height.

And move it: left, right, up or down.

So if I have a nose on a face. I click on the nose, then 4 scroll bars pop up and using them I can adjust the X,Y and W, H.

Here is what I have so far

https://db.tt/KxE1tQDZ