combine download schedule progress and result into LoadingState

app/src/main/java/be/digitalia/fosdem/activities/MainActivity.kt

@@ -37,6 +37,7 @@ import be.digitalia.fosdem.api.FosdemUrls
 import be.digitalia.fosdem.db.AppDatabase
 import be.digitalia.fosdem.fragments.*
 import be.digitalia.fosdem.model.DownloadScheduleResult
+import be.digitalia.fosdem.model.LoadingState
 import be.digitalia.fosdem.utils.*
 import be.digitalia.fosdem.widgets.FadeOutViewMediator
 import com.google.android.material.navigation.NavigationView
@@ -95,50 +96,52 @@ class MainActivity : AppCompatActivity(R.layout.main), CreateNfcAppDataCallback
         // Progress bar setup
         val progressBar: ProgressBar = findViewById(R.id.progress)
         val progressBarMediator = FadeOutViewMediator(progressBar)
-        FosdemApi.downloadScheduleProgress.observe(this) { progressValue ->
-            if (progressValue != 100) {
-                // Visible
-                progressBarMediator.isVisible = true
-                with(progressBar) {
-                    if (progressValue == -1) {
-                        isIndeterminate = true
-                    } else {
-                        isIndeterminate = false
-                        progress = progressValue
-                    }
-                }
-            } else {
-                // Invisible
-                progressBarMediator.isVisible = false
-                with(progressBar) {
-                    isIndeterminate = false
-                    progress = 100
-                }
-            }
-        }
 
-        // Monitor the schedule download result
-        FosdemApi.downloadScheduleResult.observe(this) { singleEvent ->
-            val result = singleEvent.consume() ?: return@observe
-            val snackbar = when (result) {
-                is DownloadScheduleResult.Error -> {
-                    Snackbar.make(contentView, R.string.schedule_loading_error, ERROR_MESSAGE_DISPLAY_DURATION)
-                            .setAction(R.string.schedule_loading_retry_action) { FosdemApi.downloadSchedule(this) }
-                }
-                is DownloadScheduleResult.UpToDate -> {
-                    Snackbar.make(contentView, R.string.events_download_up_to_date, Snackbar.LENGTH_LONG)
-                }
-                is DownloadScheduleResult.Success -> {
-                    val eventsCount = result.eventsCount
-                    val message = if (eventsCount == 0) {
-                        getString(R.string.events_download_empty)
-                    } else {
-                        resources.getQuantityString(R.plurals.events_download_completed, eventsCount, eventsCount)
+        // Monitor the schedule download
+        FosdemApi.downloadScheduleState.observe(this) { state ->
+            when (state) {
+                is LoadingState.Loading -> {
+                    progressBarMediator.isVisible = true
+                    with(progressBar) {
+                        val progressValue = state.progress
+                        if (progressValue == -1) {
+                            isIndeterminate = true
+                        } else {
+                            isIndeterminate = false
+                            progress = progressValue
+                        }
+                    }
+                }
+                is LoadingState.Idle -> {
+                    progressBarMediator.isVisible = false
+                    with(progressBar) {
+                        isIndeterminate = false
+                        progress = 100
+                    }
+
+                    state.result.consume()?.let { result ->
+                        val snackbar = when (result) {
+                            is DownloadScheduleResult.Error -> {
+                                Snackbar.make(contentView, R.string.schedule_loading_error, ERROR_MESSAGE_DISPLAY_DURATION)
+                                        .setAction(R.string.schedule_loading_retry_action) { FosdemApi.downloadSchedule(this) }
+                            }
+                            is DownloadScheduleResult.UpToDate -> {
+                                Snackbar.make(contentView, R.string.events_download_up_to_date, Snackbar.LENGTH_LONG)
+                            }
+                            is DownloadScheduleResult.Success -> {
+                                val eventsCount = result.eventsCount
+                                val message = if (eventsCount == 0) {
+                                    getString(R.string.events_download_empty)
+                                } else {
+                                    resources.getQuantityString(R.plurals.events_download_completed, eventsCount, eventsCount)
+                                }
+                                Snackbar.make(contentView, message, Snackbar.LENGTH_LONG)
+                            }
+                        }
+                        snackbar.show()
                     }
-                    Snackbar.make(contentView, message, Snackbar.LENGTH_LONG)
                 }
             }
-            snackbar.show()
         }
 
         // Setup drawer layout

app/src/main/java/be/digitalia/fosdem/api/FosdemApi.kt

@@ -13,6 +13,7 @@ import be.digitalia.fosdem.db.AppDatabase
 import be.digitalia.fosdem.livedata.LiveDataFactory.scheduler
 import be.digitalia.fosdem.livedata.SingleEvent
 import be.digitalia.fosdem.model.DownloadScheduleResult
+import be.digitalia.fosdem.model.LoadingState
 import be.digitalia.fosdem.model.RoomStatus
 import be.digitalia.fosdem.parsers.EventsParser
 import be.digitalia.fosdem.parsers.RoomStatusesParser
@@ -42,8 +43,7 @@ object FosdemApi {
     private const val ROOM_STATUS_EXPIRATION_DELAY = 6L * DateUtils.MINUTE_IN_MILLIS
 
     private var downloadJob: Job? = null
-    private val _downloadScheduleProgress = MutableLiveData<Int>()
-    private val _downloadScheduleResult = MutableLiveData<SingleEvent<DownloadScheduleResult>>()
+    private val _downloadScheduleState = MutableLiveData<LoadingState<DownloadScheduleResult>>()
     private var roomStatuses: LiveData<Map<String, RoomStatus>>? = null
 
     /**
@@ -67,7 +67,7 @@ object FosdemApi {
 
     @MainThread
     private suspend fun downloadScheduleInternal(context: Context) {
-        _downloadScheduleProgress.value = -1
+        _downloadScheduleState.value = LoadingState.Loading()
         val res = try {
             val scheduleDao = AppDatabase.getInstance(context).scheduleDao
             val response = HttpUtils.get(FosdemUrls.schedule, scheduleDao.lastModifiedTag) { body, rawResponse ->
@@ -77,7 +77,7 @@ object FosdemApi {
                     ByteCountSource(body.source(), length / 10L) { byteCount ->
                         // Cap percent to 100
                         val percent = (byteCount * 100L / length).toInt().coerceAtMost(100)
-                        _downloadScheduleProgress.postValue(percent)
+                        _downloadScheduleState.postValue(LoadingState.Loading(percent))
                     }.buffer()
                 } else {
                     body.source()
@@ -87,31 +87,20 @@ object FosdemApi {
                 scheduleDao.storeSchedule(events, rawResponse.lastModified)
             }
             when (response) {
-                is HttpUtils.Response.NotModified -> DownloadScheduleResult.UpToDate    // Nothing to parse, the result is up-to-date
-                is HttpUtils.Response.Success -> DownloadScheduleResult.Success(response.body)
+                is HttpUtils.Response.NotModified -> DownloadScheduleResult.UpToDate    // Nothing parsed, the result is up-to-date
+                is HttpUtils.Response.Success -> {
+                    FosdemAlarmManager.onScheduleRefreshed()
+                    DownloadScheduleResult.Success(response.body)
+                }
             }
         } catch (e: Exception) {
             DownloadScheduleResult.Error
         }
-        _downloadScheduleProgress.value = 100
-
-        if (res is DownloadScheduleResult.Success) {
-            FosdemAlarmManager.onScheduleRefreshed()
-        }
-        _downloadScheduleResult.value = SingleEvent(res)
+        _downloadScheduleState.value = LoadingState.Idle(SingleEvent(res))
     }
 
-    /**
-     * @return The current schedule download progress:
-     * -1   : in progress, indeterminate
-     * 0..99: progress value
-     * 100  : download complete or inactive
-     */
-    val downloadScheduleProgress: LiveData<Int>
-        get() = _downloadScheduleProgress
-
-    val downloadScheduleResult: LiveData<SingleEvent<DownloadScheduleResult>>
-        get() = _downloadScheduleResult
+    val downloadScheduleState: LiveData<LoadingState<DownloadScheduleResult>>
+        get() = _downloadScheduleState
 
     @MainThread
     fun getRoomStatuses(context: Context): LiveData<Map<String, RoomStatus>> {

app/src/main/java/be/digitalia/fosdem/model/LoadingState.kt

@@ -0,0 +1,13 @@
+package be.digitalia.fosdem.model
+
+import be.digitalia.fosdem.livedata.SingleEvent
+
+sealed class LoadingState<out T : Any> {
+    /**
+     * The current download progress:
+     * -1   : in progress, indeterminate
+     * 0..99: progress value in percents
+     */
+    class Loading(val progress: Int = -1) : LoadingState<Nothing>()
+    class Idle<T : Any>(val result: SingleEvent<T>) : LoadingState<T>()
+}