How to detect material change event completed

I am updating material dynamically from blueprint (changing texture/diffuse). I have created widget blueprint which contains the menu to choose the textures/material and when player clicks on the button/menu it changes the material. However for the first time it takes a bit while to apply the texture which is confusing because they don’t see any change. So I want to add some effect (probably a loading/wait animation) till the material is applied. Is there way I can capture the event? So I can start animation till I get notification?