UserHandler

User event handler.

Listens for user-related event notifications, including:

• Subscriptions: subscribed user status changes, subscription sync completion, and subscription changes on other devices

• Friends: friend additions, deletions, application status changes, friend list clearing (server-initiated only), and friend info multi-device sync

Register via NCEngine.addUserHandler. All callback methods have default empty implementations; override only the callbacks you need.

NCEngine.addUserHandler("USER_ID", object : UserHandler {
    override fun onSubscriptionChanged(event: SubscriptionChangedEvent) {
        event.events.forEach { info ->
            println("User ${info.userId} status changed")
        }
    }

    override fun onFriendAdd(event: FriendAddEvent) {
        println("Friend added: ${event.userId}")
    }

    override fun onFriendDelete(event: FriendDeleteEvent) {
        println("Friends deleted: ${event.userIds}")
    }
})