Clean and optimize menu drawers flows

Author: LunarX

app/src/main/java/com/infomaniak/mail/data/cache/mailboxContent/FolderController.kt

@@ -36,7 +36,6 @@ import io.realm.kotlin.query.RealmQuery
 import io.realm.kotlin.query.RealmResults
 import io.realm.kotlin.query.RealmSingleQuery
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.mapNotNull
 import javax.inject.Inject
 
@@ -50,13 +49,12 @@ class FolderController @Inject constructor(
         return getFoldersQuery(mailboxContentRealm(), withoutChildren = true).asFlow()
     }
 
-    fun getMenuDrawerFolders(): Flow<Pair<ResultsChange<Folder>, ResultsChange<Folder>>> {
-        val defaultFoldersFlow = getDefaultFoldersQuery(mailboxContentRealm()).asFlow()
-        val customFoldersFlow = getCustomFoldersQuery(mailboxContentRealm()).asFlow()
-        return defaultFoldersFlow.combine(
-            flow = customFoldersFlow,
-            transform = { defaultFolders, customFolders -> defaultFolders to customFolders }
-        )
+    fun getMenuDrawerDefaultFolders(): Flow<ResultsChange<Folder>> {
+        return getDefaultFoldersQuery(mailboxContentRealm()).asFlow()
+    }
+
+    fun getMenuDrawerCustomFolders(): Flow<ResultsChange<Folder>> {
+        return getCustomFoldersQuery(mailboxContentRealm()).asFlow()
     }
 
     fun getMoveFolders(): RealmResults<Folder> {

app/src/main/java/com/infomaniak/mail/ui/MainViewModel.kt

@@ -83,7 +83,9 @@ import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.emptyFlow
+import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.mapLatest
@@ -156,17 +158,16 @@ class MainViewModel @Inject constructor(
         it?.let(mailboxController::getMailbox)
     }.asLiveData(ioCoroutineContext)
 
-    val currentFoldersLive = _currentMailboxObjectId.flatMapLatest { objectId ->
-        objectId
-            ?.let {
-                folderController.getMenuDrawerFolders().map { (defaultFolders, customFolders) ->
-                    Pair(
-                        defaultFolders.list.flattenFolderChildren(dismissHiddenChildren = true),
-                        customFolders.list.flattenFolderChildren(dismissHiddenChildren = true),
-                    )
-                }
-            }
-            ?: emptyFlow()
+    private val currentDefaultFoldersLive = _currentMailboxObjectId.filterNotNull().flatMapLatest {
+        folderController.getMenuDrawerDefaultFolders().map { it.list.flattenFolderChildren(dismissHiddenChildren = true) }
+    }
+
+    private val currentCustomFoldersLive = _currentMailboxObjectId.filterNotNull().flatMapLatest {
+        folderController.getMenuDrawerCustomFolders().map { it.list.flattenFolderChildren(dismissHiddenChildren = true) }
+    }
+
+    val currentFoldersLive = currentDefaultFoldersLive.combine(currentCustomFoldersLive) { defaultFolders, customFolders ->
+        defaultFolders to customFolders
     }.asLiveData(ioCoroutineContext)
 
     val currentQuotasLive = _currentMailboxObjectId.flatMapLatest {