More idiomatic kotlin

app/src/main/java/chat/rocket/android/chatrooms/infrastructure/ChatRoomsRepository.kt

@@ -25,3 +25,6 @@ class ChatRoomsRepository @Inject constructor(val dao: ChatRoomDao){
         GROUPED_NAME,
     }
 }
+
+fun ChatRoomsRepository.Order.isGrouped(): Boolean = this == ChatRoomsRepository.Order.GROUPED_ACTIVITY
+        || this == ChatRoomsRepository.Order.GROUPED_NAME
\ No newline at end of file

app/src/main/java/chat/rocket/android/chatrooms/viewmodel/ChatRoomsViewModel.kt

@@ -8,12 +8,15 @@ import chat.rocket.android.chatrooms.adapter.ItemHolder
 import chat.rocket.android.chatrooms.adapter.RoomMapper
 import chat.rocket.android.chatrooms.domain.FetchChatRoomsInteractor
 import chat.rocket.android.chatrooms.infrastructure.ChatRoomsRepository
+import chat.rocket.android.chatrooms.infrastructure.isGrouped
 import chat.rocket.android.server.infraestructure.ConnectionManager
 import chat.rocket.android.util.livedata.TransformedLiveData
+import chat.rocket.android.util.livedata.transform
 import chat.rocket.core.internal.realtime.socket.model.State
 import kotlinx.coroutines.experimental.launch
 import kotlinx.coroutines.experimental.newSingleThreadContext
 import me.henrytao.livedataktx.distinct
+import me.henrytao.livedataktx.map
 import me.henrytao.livedataktx.nonNull
 import timber.log.Timber
 
@@ -33,25 +36,25 @@ class ChatRoomsViewModel(
     fun getChatRooms(): LiveData<List<ItemHolder<*>>> {
         return Transformations.switchMap(ordering) { order ->
             Timber.d("Querying rooms for order: $order")
-            val grouped = order == ChatRoomsRepository.Order.GROUPED_ACTIVITY
-                    || order == ChatRoomsRepository.Order.GROUPED_NAME
-            val roomData = repository.getChatRooms(order).nonNull().distinct()
-            TransformedLiveData(runContext, roomData) { rooms ->
+            repository.getChatRooms(order)
+                    .nonNull()
+                    .distinct()
+                    .transform(runContext) { rooms ->
                         rooms?.let {
-                    mapper.map(rooms, grouped)
+                            mapper.map(rooms, order.isGrouped())
+                        }
                     }
-            }.nonNull()
         }
     }
 
     fun getStatus(): MutableLiveData<State> {
-        return Transformations.map(connectionManager.statusLiveData.nonNull().distinct()) { state ->
+        return connectionManager.statusLiveData.nonNull().distinct().map { state ->
             if (state is State.Connected) {
                 // TODO - add a loading status...
                 fetchRooms()
             }
             state
-        }.nonNull()
+        }
     }
 
     private fun fetchRooms() {

app/src/main/java/chat/rocket/android/push/GroupedPush.kt

@@ -6,7 +6,7 @@ import javax.inject.Singleton
 typealias TupleGroupIdMessageCount = Pair<Int, AtomicInteger>
 
 class GroupedPush {
-    // Notifications received from the same server are grouped in a single bundled notification.
+    // Notifications received from the same server are isGrouped in a single bundled notification.
     // This map associates a host to a group id.
     val groupMap = HashMap<String, TupleGroupIdMessageCount>()
 

app/src/main/java/chat/rocket/android/push/PushManager.kt

@@ -273,7 +273,7 @@ class PushManager @Inject constructor(
     private fun getContentIntent(context: Context, notificationId: Int, pushMessage: PushMessage, grouped: Boolean = false): PendingIntent {
         val notificationIntent = context.changeServerIntent(pushMessage.info.host)
         // TODO - add support to go directly to the chatroom
-        /*if (!grouped) {
+        /*if (!isGrouped) {
             notificationIntent.putExtra(EXTRA_ROOM_ID, pushMessage.info.roomId)
         }*/
         return PendingIntent.getActivity(context, randomizer.nextInt(), notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT)

app/src/main/java/chat/rocket/android/util/livedata/TransformedLiveData.kt

@@ -7,7 +7,6 @@ import kotlinx.coroutines.experimental.Job
 import kotlinx.coroutines.experimental.android.UI
 import kotlinx.coroutines.experimental.launch
 import kotlinx.coroutines.experimental.withContext
-import timber.log.Timber
 import kotlin.coroutines.experimental.CoroutineContext
 
 
@@ -22,6 +21,8 @@ class TransformedLiveData<Source, Output>(
         job?.cancel()
         job = launch(runContext) {
             transformation(source)?.let { transformed ->
+                // Could have used postValue instead, but using the UI context I can guarantee that
+                // a canceled job will never emit values.
                 withContext(UI) {
                     value = transformed
                 }
@@ -30,13 +31,15 @@ class TransformedLiveData<Source, Output>(
     }
 
     override fun onActive() {
-        Timber.d("Attaching observer")
         source.observeForever(observer)
     }
 
     override fun onInactive() {
-        Timber.d("Detaching observer")
         job?.cancel()
         source.removeObserver(observer)
     }
 }
+
+fun <Source, Output> LiveData<Source>.transform(
+    runContext: CoroutineContext = CommonPool,
+    transformation: (Source?) -> Output?) = TransformedLiveData(runContext, this, transformation)
\ No newline at end of file