support multiple callbacks

We support multiple callbacks for location so adding this to notifications to match. This is to ensure events are not missed for any reason.

Author: jkasten2

OneSignalSDK/onesignal/src/main/java/com/onesignal/NotificationPermissionController.kt

@@ -34,7 +34,8 @@ object NotificationPermissionController : PermissionsActivity.PermissionCallback
  private const val PERMISSION_TYPE = "NOTIFICATION"
  private const val ANDROID_PERMISSION_STRING = "android.permission.POST_NOTIFICATIONS"
 
- private var callback: OneSignal.PromptForPushNotificationPermissionResponseHandler? = null
+ private val callbacks:
+ MutableSet<OneSignal.PromptForPushNotificationPermissionResponseHandler> = HashSet()
 
  init {
  PermissionsActivity.registerAsCallback(PERMISSION_TYPE, this)
@@ -49,18 +50,18 @@ object NotificationPermissionController : PermissionsActivity.PermissionCallback
  fallbackToSettings: Boolean,
  callback: OneSignal.PromptForPushNotificationPermissionResponseHandler?,
  ) {
- if (callback != null) this.callback = callback
+ if (callback != null) callbacks.add(callback)
 
  if (notificationsEnabled()) {
- fireCallBack(true)
+ fireCallBacks(true)
  return
  }
 
  if (!supportsNativePrompt) {
  if (fallbackToSettings)
  showFallbackAlertDialog()
  else
- fireCallBack(false)
+ fireCallBacks(false)
  return
  }
 
@@ -74,7 +75,7 @@ object NotificationPermissionController : PermissionsActivity.PermissionCallback
 
  override fun onAccept() {
  OneSignal.refreshNotificationPermissionState()
- fireCallBack(true)
+ fireCallBacks(true)
  }
 
  override fun onReject(fallbackToSettings: Boolean) {
@@ -83,7 +84,7 @@ object NotificationPermissionController : PermissionsActivity.PermissionCallback
  showFallbackAlertDialog()
  else
  false
- if (!fallbackShown) fireCallBack(false)
+ if (!fallbackShown) fireCallBacks(false)
  }
 
  // Returns true if dialog was shown
@@ -98,21 +99,21 @@ object NotificationPermissionController : PermissionsActivity.PermissionCallback
  NavigateToAndroidSettingsForNotifications.show(activity)
  }
  override fun onDecline() {
- fireCallBack(false)
+ fireCallBacks(false)
  }
  }
  )
  return true
  }
 
- // Fires callback and clears it to ensure it is only called once.
- private fun fireCallBack(accepted: Boolean) {
- callback?.response(accepted)
- callback = null
+ // Fires callbacks and clears them to ensure each is only called once.
+ private fun fireCallBacks(accepted: Boolean) {
+ callbacks.forEach { it.response(accepted) }
+ callbacks.clear()
  }
 
  fun onAppForegrounded() {
- fireCallBack(notificationsEnabled())
+ fireCallBacks(notificationsEnabled())
  }
 
  private fun notificationsEnabled() = OSUtils.areNotificationsEnabled(OneSignal.appContext)