Kotlin

Fetch conversation events

Add getConversationEvents(conversation); call inside onSuccess callback inside getConversationEvents() method:

private fun getConversation() {
    client.getConversation(CONVERSATION_ID, object : NexmoRequestListener<NexmoConversation?> {
        override fun onSuccess(conversation: NexmoConversation?) {
            this@MainActivity.conversation = conversation

            conversation?.let {
                getConversationEvents(it)
            }
        }

        override fun onError(apiError: NexmoApiError) {
            conversation = null
            Toast.makeText(this@MainActivity, "Error: Unable to load conversation", Toast.LENGTH_SHORT)
        }
    })
}

Add conversationEvents method to store conversation events:

private val conversationEvents = mutableListOf<NexmoEvent>()

Add getConversationEvents method to retrieve conversation events:

private fun getConversationEvents(conversation: NexmoConversation) {
    conversation.getEvents(100, NexmoPageOrder.NexmoMPageOrderAsc, null,
        object : NexmoRequestListener<NexmoEventsPage?> {
            override fun onSuccess(nexmoEventsPage: NexmoEventsPage?) {
                nexmoEventsPage?.pageResponse?.data?.let { conversationEvents.addAll(it) }
                updateConversationView()

                runOnUiThread {
                    chatContainer.visibility = View.VISIBLE
                    loginContainer.visibility = View.GONE
                }
            }

            override fun onError(apiError: NexmoApiError) {
                Toast.makeText(this@MainActivity, "Error: Unable to load conversation events", Toast.LENGTH_SHORT)
            }
        })
}

Above method adds events to conversationEvents collection and updates the view. Now add the missing updateConversationView method:

private fun updateConversationView() {
    val lines = ArrayList<String>()

    for (event in conversationEvents) {
        var line = when (event) {
            is NexmoMemberEvent -> {
                val userName = ""
                if (event.embeddedInfo != null) {
                    val userName = event.embeddedInfo.user.name
                }

                when (event.state) {
                    NexmoMemberState.JOINED -> "$userName joined"
                    NexmoMemberState.INVITED -> "$userName invited"
                    NexmoMemberState.LEFT -> "$userName left"
                    NexmoMemberState.UNKNOWN -> "Error: Unknown member event state"
                }
            }
            is NexmoMessageEvent -> {
                "${event.embeddedInfo.user.name} said: ${event.message.text}"
            } else -> {
                "Unsupported event ${event.eventType}"
            }
        }
        lines.add(line)
    }

    // Production application should utilise RecyclerView to provide better UX
    conversationTextView.text = if (lines.isNullOrEmpty()) {
        "Conversation has No messages"
    } else {
        lines.joinToString(separator = "\n")
    }
}

Events are stored in the conversationEvents property. You should remove these events after the logout. Update the body of the setConnectionListener and call conversationEvents.clear:

client.setConnectionListener((connectionStatus, connectionStatusReason) -> {
    if (connectionStatus == NexmoConnectionListener.ConnectionStatus.CONNECTED) {
        //...
    } else if (connectionStatus == NexmoConnectionListener.ConnectionStatus.DISCONNECTED) {
        //...

        conversationEvents.clear();
    }
});

NOTE: In this tutorial, we are only handling member-related events NexmoMemberEvent and NexmoMessageEvent. Other kinds of events are being ignored in the above when expression (else -> null).