How to implement Internet Connection listener for each Activity using JobScheduler and BroadcastReceiver

Question

I want to check if user has available connection to the internet and show Snackbar for him or other custom action.

App's minSdk is 23 (Android 6.0).

Since Android 7.0 there were some changes to BroadcastReceiver and receiving connection status. Now i have to use JobScheduler and Service to check connection status.

I've found tutorial here

But he is initializing JobScheduler inside NetworkConnectionActivity . I did this at the start of Application class where other services are initialized (like FirebaseMessagingService ).

What I want to achieve is to implement ConnectivityReceiverListener to multiple Activities in my App and override onNetworkConnectionChanged to get info when connection is changed. I will make custom reaction to this status depends on current Activity

Problem with this solution: As I implement that listener in my MainActivity it is not fired. But toast inside onNetworkConnectionChanged in NetworkSchedulerService was fired

Example Code:

    class MainActivity : AppCompatActivity(), ConnectivityReceiver.ConnectivityReceiverListener{


        var mConnectionSnackbar: Snackbar? = null
        override fun onNetworkConnectionChanged(isConnected: Boolean) {
            App.log("ConnectionChanged: $isConnected")
            app.isConnected = isConnected
            maybeShowConnectionSnackbar(isConnected)
        }

        fun maybeShowConnectionSnackbar(isConnected: Boolean){
            if (isConnected){
                mConnectionSnackbar?.dismiss()
            } else {
                if (mConnectionSnackbar == null){
                    mConnectionSnackbar = Snackbar.make(content, "Connection Lost", Snackbar.LENGTH_INDEFINITE)
                }
            }
        }
     **** onCreate and variable init ***
    }

Function in Application class:

private fun createConnectivityJobScheduler(){
        val myJob = JobInfo.Builder(0, ComponentName(this, NetworkSchedulerService::class.java))
                .setMinimumLatency(1000)
                .setOverrideDeadline(2000)
                .setRequiredNetworkType(JobInfo.NETWORK_TYPE_ANY)
                .setPersisted(true)
                .build()

        val jobScheduler = getSystemService(Context.JOB_SCHEDULER_SERVICE) as JobScheduler
        jobScheduler.schedule(myJob)
    }

Answer 1

try this

val serviceComponent = ComponentName(context, CallJob()::class.java)
val builder = JobInfo.Builder(0, serviceComponent)
builder.setMinimumLatency((30000).toLong())
builder.setOverrideDeadline((300000).toLong())
val jobScheduler = context.getSystemService(JobScheduler::class.java)

try {
    jobScheduler.schedule(builder.build())
} catch (e: Exception) {
    e.printStackTrace()
}

before that you need to check weather the scheduler was currently running or not..