Connectivity Monitor (Android)

ConnectivityMonitor.kt

interface ConnectivityMonitor {
    val isConnected: Boolean
    val networkType: NetworkType

    val isConnectedState: Flow<Boolean>
    val networkTypeState: Flow<NetworkType>
}

ConnectivityMonitorImpl.kt

import android.content.Context
import android.net.ConnectivityManager
import android.net.Network
import android.net.NetworkCapabilities

class ConnectivityMonitorImpl(appContext: Context) : ConnectivityMonitor {
    private val connectivityManager = appContext.getSystemService(ConnectivityManager::class.java)
    private val networkCallback = object : ConnectivityManager.NetworkCallback() {
        override fun onAvailable(network: Network) =
            connectivityManager.getNetworkCapabilities(network)?.let { networkCapabilities ->
                updateConnectionStatus(networkCapabilities = networkCapabilities)
                updateNetworkType(networkCapabilities = networkCapabilities)
            } ?: run {
                isConnectedState.value = true
            }

        override fun onLost(network: Network) {
            // Do not check for NetworkCapabilities here, as they might be wrong.
            // If we get this callback, we're certain that we've lost connection.
            isConnectedState.value = false
            networkTypeState.value = NetworkType.Unknown
        }

        override fun onCapabilitiesChanged(
            network: Network,
            networkCapabilities: NetworkCapabilities
        ) {
            updateConnectionStatus(networkCapabilities = networkCapabilities)
            updateNetworkType(networkCapabilities = networkCapabilities)
        }
    }

    override val isConnected: Boolean
        get() = isConnectedState.value
    override val networkType: NetworkType
        get() = networkTypeState.value

    override val isConnectedState: StateFlow<Boolean> = MutableStateFlow(init = false)
    override val networkTypeState: KmmState<NetworkType> = MutableStateFlow(init = NetworkType.Unknown)

    init {
        startMonitoring()
    }

    private fun startMonitoring() =
        connectivityManager.registerDefaultNetworkCallback(networkCallback)

    private fun updateConnectionStatus(networkCapabilities: NetworkCapabilities) {
        val isConnected =
            networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)

        isConnectedState.value = isConnected
    }

    private fun updateNetworkType(networkCapabilities: NetworkCapabilities) {
        val networkType = when {
            networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) -> NetworkType.WiFi
            networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) -> NetworkType.Cellular
            else -> NetworkType.Unknown
        }

        networkTypeState.value = networkType
    }
}

NetworkType.kt

enum class NetworkType { Unknown, Cellular, WiFi }