I found this :
SNew(SUniformGridPanel).Visibility(this, &SFriendItemImpl::PendingActionVisibility, EFriendActionType::RemoveFriend)
in the developper folder / FriendsAndChat module on the engine.
While I think I understand that we are settings a delagate to alter the visibility of the SUniformGridPanel, I clearly don’t understand where it’s define.
The only visibility delagate I found is on UMG Widget, nothing in Slate part.
I look are the arguments of SUniformGridPanel, there is no slate marco in the ARGS section defining this, nor in the Construct.
I hope someone will be able to help me to understand where this is declare/done because I can be very interested in having such mechanism, but I need to be sure on how it works before using it.