Kotlin examples for my post

Callbacks.kt

//DataRepository.kt, which handles all db handling, where I have passed 3 callbacks, finished, error or maximum tabs reached
public fun addTab(tabModelToInsert: TabModel, 
                  onFinished: (tabModel: TabModel) -> Unit = {}, 
                  onError: (tabModel: TabModel, message: String) -> Unit = { tabModel, message -> }, 
                  onMaxTabReached: (tabModel: TabModel) -> Unit = {}) {
  if (canAddMoreTabs()) {
    val currentMaxId = getCurrentMaxId() ?: 0
      try {
        realm.executeTransaction {
          addTabModelToRealm()
          onFinished(tabModel)
        }
      } catch(e: Exception) {
        onError(tabModelToInsert, e.toString())
        v("Error in inserting tab")
      }
  } else {
     onMaxTabReached(tabModelToInsert)
  }
}

//In Main activity view model
dataRepository?.addTab(tabModel, onFinished = {
                            pageAdapter?.addTab(it)
                        }, onError = { tabModel, error ->
                            FirebaseCrash.log(error)
                        }, onMaxTabReached = {
                            FirebaseAnalytics.getInstance(activity).logEvent("AddingTabsMaxEventReached", null)
                            showSnackbar(view)
                        })

KotlinDialogSamples.kt

//Part of Functions.kt, this and below 3 functions helps to create dialog.
public fun Context.showDialog(cancelable: Boolean = false, cancelableTouchOutside: Boolean = false, builderFunction: AlertDialog.Builder.() -> Any) {
    val builder = AlertDialog.Builder(this)
    builder.builderFunction()
    val dialog = builder.create();

    dialog.setCancelable(cancelable)
    dialog.setCanceledOnTouchOutside(cancelableTouchOutside)
    dialog.show()
}


public fun AlertDialog.Builder.positiveButton(text: String = "OK", handleClick: (i: Int) -> Unit = {}) {
    this.setPositiveButton(text, { dialogInterface, i -> handleClick(i) })
}

public fun AlertDialog.Builder.negativeButton(text: String = "CANCEL", handleClick: (i: Int) -> Unit = {}) {
    this.setNegativeButton(text, { dialogInterface, i -> handleClick(i) })
}

public fun AlertDialog.Builder.neutralButton(text: String, handleClick: (i: Int) -> Unit = {}) {
    this.setNeutralButton(text, { dialogInterface, i -> handleClick(i) })
}


//Sample of this code in MainActivityViewModel
activity.showDialog {
    setTitle("Pick Path")
    positiveButton("Pick Files", { pickPathToRead() })
    negativeButton()
}

KotlinExamples.kt

//Functions.kt
public fun Context.setNotification(id: Int = 0, builderMethod: NotificationCompat.Builder.() -> Any) {
    val builder = NotificationCompat.Builder(this)
    builder.apply {
        builderMethod()
    }
    notificationManager().notify(id, builder.build())
}
//FCM Service.kt
this@MyFCMService.setNotification(2488, {
                    setContentTitle(it.title)
                    setContentText(it.body)
                    setColor(R.color.colorPrimary)
                    setSmallIcon(R.drawable.ic_notification_icon)

                    setAutoCancel(true)
                    val bigTextStyle = NotificationCompat.BigTextStyle(this)
                    bigTextStyle.setBigContentTitle(it.title)
                    bigTextStyle.bigText(it.body)
                    bigTextStyle.setSummaryText(it.body)

                    setStyle(bigTextStyle)
    
                    val intent = Intent(this@MyFCMService, MainActivity::class.java)
                    intent.putExtras(remoteMessage.data.extractBundle())
                    val stackBuilder: TaskStackBuilder = TaskStackBuilder.create(this@MyFCMService)
                    stackBuilder.addNextIntent(intent)
                    val pendingIntent = stackBuilder.getPendingIntent(2488, PendingIntent.FLAG_UPDATE_CURRENT)
                    setContentIntent(pendingIntent)
})