The moment you start giving other food than breastmilk, you've begun weaning your baby. However a baby who is not 1 is not ready to wean, but like you say more interested in "doing" than bfing. He still needs to nurse you might just have to change how you do it. Perhaps in a quiet, darker room. Maybe the tops ups are all he needs, as babies get far more effient at get the milk they need out and a few minutes maybe enough. Just don't take this as a sign that your baby wants to quit bfing.