WebRTC Android Call

Class that represents a Call and handles all call related actions, including answering and ending a call.

In order to make a call invitation, you need to provide your callerName, callerNumber, the destinationNumber (or SIP credential), and your clientState (any String value).

   telnyxClient.call.newInvite(callerName, callerNumber, destinationNumber, clientState)

In order to be able to accept a call, we first need to listen for invitations. We do this by getting the Telnyx Socket Response as LiveData:

  fun getSocketResponse(): LiveData<SocketResponse<ReceivedMessageBody>>? =
        telnyxClient.getSocketResponse()

We can then use this method to create a listener that listens for an invitation - in this example we assume getSocketResponse is a method within a ViewModel.

 mainViewModel.getSocketResponse()
            ?.observe(this, object : SocketObserver<ReceivedMessageBody>() {
                override fun onConnectionEstablished() {
                    // Handle a succesfully established connection 
                }
                
                override fun onMessageReceived(data: ReceivedMessageBody?) {
                    when (data?.method) {
                        SocketMethod.CLIENT_READY.methodName -> {
                            // Fires once client has correctly been setup and logged into, you can now make calls. 
                        }

                        SocketMethod.LOGIN.methodName -> {
                           // Handle a successful login - Update UI or Navigate to new screen, etc.
                        }

                        SocketMethod.INVITE.methodName -> {
                           // Handle an invitation Update UI or Navigate to new screen, etc. 
                           // Then, through an answer button of some kind we can accept the call with:
                            val inviteResponse = data.result as InviteResponse
                            mainViewModel.acceptCall(inviteResponse.callId,  inviteResponse.callerIdNumber)
                        }

                        SocketMethod.ANSWER.methodName -> {
                            //Handle a received call answer - Update UI or Navigate to new screen, etc.
                        }

                        SocketMethod.BYE.methodName -> {
                           // Handle a call rejection or ending - Update UI or Navigate to new screen, etc.
                        }
                        SocketMethod.RINGING.methodName -> {
                            // Client Can simulate ringing state
                        }

                        SocketMethod.RINGING.methodName -> {
                            // Ringback tone is streamed to the caller
                            // early Media -  Client Can simulate ringing state
                        }
                    }
                }
                
                override fun onLoading() {
                    // Show loading dialog
                }

                override fun onError(message: String?) {
                   // Handle errors - Update UI or Navigate to new screen, etc.
                }

                override fun onSocketDisconnect() {
                    // Handle disconnect - Update UI or Navigate to login screen, etc.
                }

            })

When we receive a call we will receive an InviteResponse data class that contains the details we need to accept the call. We can then call the acceptCall method in TelnyxClient from our ViewModel:

The Telnyx WebRTC SDK allows for multiple calls to be handled at once. You can use the callId to differentiate the calls..

import java.util.UUID
// Retrieve all calls from the TelnyxClient
val calls: Map<UUID,Call> = telnyxClient.calls 

// Retrieve a specific call by callId
val currentCall: Call? = calls[callId]

With the current call object, you can perform actions such as:

1. Hold/UnHold currentCall.onHoldUnholdPressed(callId: UUID)
2. Mute/UnMute currentCall.onMuteUnmutePressed()
3. AcceptCall currentCall.acceptCall(...)
4. EndCall currentCall.endCall(callId: UUID)