Creating a custom editor window with a grid

I'm not actually sure if what I'm asking is possible, I've seen a few examples that seem to do it but have been unable to figure out how or replicate.

What I want to do is create a custom editor window with a grid panel in it, similar to the animator screen. I want to be able to place buttons or icons in this grid and move them around, as well as draw shapes over it. The screenshot below shows what I'm talking about with the animator.

I'd like my editor window to look almost exactly like this, with the panel on the side for certain fields to describe some of the objects placed in the grid, and then the objects movable and placable in the grid.

Does anyone know if I can do this and how?