How to snap a placeable object on wall & move on to other walls of a room?

I want to place an object onto a wall and give control to the user to move it on the wall and then place it wherever he wants. When the user places on the wall, I want the object to move on to the sides of the wall. Example:- If we have 4 walls of a room, I want to object to jump from wall1 if the wall1 has ended, rotate itself and snap onto the wall 2 of the room.