Use coroutines in TaskListViewModel

app/build.gradle.kts

@@ -150,7 +150,8 @@ dependencies {
     implementation("androidx.hilt:hilt-work:${Versions.hilt_androidx}")
     implementation("androidx.hilt:hilt-lifecycle-viewmodel:${Versions.hilt_androidx}")
 
-    implementation("androidx.room:room-runtime:${Versions.room}")
+    implementation("androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0")
+    implementation("androidx.room:room-ktx:${Versions.room}")
     kapt("androidx.room:room-compiler:${Versions.room}")
     implementation("androidx.lifecycle:lifecycle-extensions:2.2.0")
     implementation("io.reactivex.rxjava2:rxandroid:2.1.1")

app/licenses.yml

@@ -549,12 +549,6 @@
   license: The Apache Software License, Version 2.0
   licenseUrl: http://www.apache.org/licenses/LICENSE-2.0.txt
   url: https://developer.android.com/topic/libraries/architecture/index.html
-- artifact: org.jetbrains.kotlinx:kotlinx-coroutines-core-common:+
-  name: kotlinx-coroutines-core-common
-  copyrightHolder: JetBrains s.r.o.
-  license: The Apache Software License, Version 2.0
-  licenseUrl: http://www.apache.org/licenses/LICENSE-2.0.txt
-  url: https://github.com/Kotlin/kotlinx.coroutines
 - artifact: org.conscrypt:conscrypt-android:+
   name: org.conscrypt:conscrypt-android
   copyrightHolder: Android Open Source Project
@@ -726,3 +720,9 @@
   license: COMMON DEVELOPMENT AND DISTRIBUTION LICENSE (CDDL) Version 1.0
   licenseUrl: https://glassfish.dev.java.net/public/CDDLv1.0.html
   url: http://jcp.org/aboutJava/communityprocess/final/jsr250/index.html
+- artifact: androidx.room:room-ktx:+
+  name: room-ktx
+  copyrightHolder: Android Open Source Project
+  license: The Apache Software License, Version 2.0
+  licenseUrl: http://www.apache.org/licenses/LICENSE-2.0.txt
+  url: https://developer.android.com/topic/libraries/architecture/index.html

app/src/main/assets/licenses.json

@@ -1298,20 +1298,6 @@
       "url": "https://developer.android.com/topic/libraries/architecture/index.html",
       "libraryName": "Android Paging-Common"
     },
-    {
-      "artifactId": {
-        "name": "kotlinx-coroutines-core-common",
-        "group": "org.jetbrains.kotlinx",
-        "version": "+"
-      },
-      "copyrightHolder": "JetBrains s.r.o.",
-      "copyrightStatement": "Copyright © JetBrains s.r.o. All rights reserved.",
-      "license": "The Apache Software License, Version 2.0",
-      "licenseUrl": "http://www.apache.org/licenses/LICENSE-2.0.txt",
-      "normalizedLicense": "apache2",
-      "url": "https://github.com/Kotlin/kotlinx.coroutines",
-      "libraryName": "kotlinx-coroutines-core-common"
-    },
     {
       "artifactId": {
         "name": "conscrypt-android",
@@ -1730,6 +1716,20 @@
       "normalizedLicense": "cddl1",
       "url": "http://jcp.org/aboutJava/communityprocess/final/jsr250/index.html",
       "libraryName": "jsr250-api"
+    },
+    {
+      "artifactId": {
+        "name": "room-ktx",
+        "group": "androidx.room",
+        "version": "+"
+      },
+      "copyrightHolder": "Android Open Source Project",
+      "copyrightStatement": "Copyright © Android Open Source Project. All rights reserved.",
+      "license": "The Apache Software License, Version 2.0",
+      "licenseUrl": "http://www.apache.org/licenses/LICENSE-2.0.txt",
+      "normalizedLicense": "apache2",
+      "url": "https://developer.android.com/topic/libraries/architecture/index.html",
+      "libraryName": "room-ktx"
     }
   ]
 }

app/src/main/java/com/todoroo/astrid/dao/TaskDao.kt

@@ -11,12 +11,14 @@ import androidx.sqlite.db.SimpleSQLiteQuery
 import com.todoroo.andlib.sql.Criterion
 import com.todoroo.andlib.sql.Field
 import com.todoroo.andlib.sql.Functions
+import com.todoroo.andlib.utility.AndroidUtilities.assertNotMainThread
 import com.todoroo.andlib.utility.DateUtilities
 import com.todoroo.astrid.api.Filter
 import com.todoroo.astrid.api.PermaSql
 import com.todoroo.astrid.data.Task
 import com.todoroo.astrid.data.Task.Companion.NO_ID
 import com.todoroo.astrid.helper.UUIDHelper
+import kotlinx.coroutines.runBlocking
 import org.tasks.BuildConfig
 import org.tasks.data.Place
 import org.tasks.data.SubtaskInfo
@@ -116,11 +118,15 @@ abstract class TaskDao(private val database: Database) {
 
     @Transaction
     open fun fetchTasks(callback: (SubtaskInfo) -> List<String>): List<TaskContainer> {
-        return fetchTasks(callback, getSubtaskInfo())
+        return runBlocking {
+            fetchTasks(callback, getSubtaskInfo())
+        }
     }
 
     @Transaction
     open fun fetchTasks(callback: (SubtaskInfo) -> List<String>, subtasks: SubtaskInfo): List<TaskContainer> {
+        assertNotMainThread()
+
         val start = if (BuildConfig.DEBUG) DateUtilities.now() else 0
         val queries = callback.invoke(subtasks)
         val db = database.openHelper.writableDatabase
@@ -145,11 +151,16 @@ abstract class TaskDao(private val database: Database) {
     @RawQuery
     abstract fun count(query: SimpleSQLiteQuery): Int
 
-    @Query("SELECT EXISTS(SELECT 1 FROM tasks WHERE parent > 0 AND deleted = 0) AS hasSubtasks,"
-            + "EXISTS(SELECT 1 FROM google_tasks "
-            + "  INNER JOIN tasks ON gt_task = _id "
-            + " WHERE deleted = 0 AND gt_parent > 0 AND gt_deleted = 0) AS hasGoogleSubtasks")
-    abstract fun getSubtaskInfo(): SubtaskInfo
+    @Query("""
+SELECT EXISTS(SELECT 1 FROM tasks WHERE parent > 0 AND deleted = 0) AS hasSubtasks,
+       EXISTS(SELECT 1
+              FROM google_tasks
+                       INNER JOIN tasks ON gt_task = _id
+              WHERE deleted = 0
+                AND gt_parent > 0
+                AND gt_deleted = 0)                                 AS hasGoogleSubtasks
+    """)
+    abstract suspend fun getSubtaskInfo(): SubtaskInfo
 
     @RawQuery(observedEntities = [Place::class])
     abstract fun getTaskFactory(

app/src/main/java/org/tasks/ui/TaskListViewModel.kt

@@ -9,11 +9,9 @@ import com.todoroo.andlib.utility.AndroidUtilities
 import com.todoroo.andlib.utility.DateUtilities
 import com.todoroo.astrid.api.Filter
 import com.todoroo.astrid.dao.TaskDao
-import io.reactivex.Completable
-import io.reactivex.Single
-import io.reactivex.android.schedulers.AndroidSchedulers
-import io.reactivex.disposables.CompositeDisposable
-import io.reactivex.schedulers.Schedulers
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import org.tasks.BuildConfig
 import org.tasks.data.SubtaskInfo
 import org.tasks.data.TaskContainer
@@ -28,7 +26,6 @@ class TaskListViewModel @ViewModelInject constructor(
     private var tasks = MutableLiveData<List<TaskContainer>>()
     private var filter: Filter? = null
     private var manualSortFilter = false
-    private val disposable = CompositeDisposable()
     private var internal: LiveData<PagedList<TaskContainer>>? = null
 
     fun setFilter(filter: Filter) {
@@ -58,26 +55,27 @@ class TaskListViewModel @ViewModelInject constructor(
         if (filter == null) {
             return
         }
-        disposable.add(
-                Single.fromCallable { taskDao.getSubtaskInfo() }
-                        .subscribeOn(Schedulers.io())
-                        .observeOn(AndroidSchedulers.mainThread())
-                        .subscribe(
-                                { subtasks: SubtaskInfo ->
-                                    if (manualSortFilter || !preferences.usePagedQueries()) {
-                                        performNonPagedQuery(subtasks)
-                                    } else {
-                                        performPagedListQuery()
-                                    }
-                                }) { t: Throwable? -> Timber.e(t) })
+        try {
+            viewModelScope.launch {
+                val subtasks = taskDao.getSubtaskInfo()
+                if (manualSortFilter || !preferences.usePagedQueries()) {
+                    performNonPagedQuery(subtasks)
+                } else {
+                    performPagedListQuery()
+                }
+            }
+        } catch (e: Exception) {
+            Timber.e(e)
+        }
     }
 
-    private fun performNonPagedQuery(subtasks: SubtaskInfo) =
-            disposable.add(
-                    Single.fromCallable { taskDao.fetchTasks({ s: SubtaskInfo? -> getQuery(preferences, filter!!, s!!) }, subtasks) }
-                            .subscribeOn(Schedulers.io())
-                            .observeOn(AndroidSchedulers.mainThread())
-                            .subscribe({ value: List<TaskContainer> -> tasks.postValue(value) }) { t: Throwable? -> Timber.e(t) })
+    private suspend fun performNonPagedQuery(subtasks: SubtaskInfo) {
+        tasks.value = withContext(Dispatchers.IO) {
+            taskDao.fetchTasks(
+                    { s: SubtaskInfo? -> getQuery(preferences, filter!!, s!!) },
+                    subtasks)
+        }
+    }
 
     private fun performPagedListQuery() {
         val queries = getQuery(preferences, filter!!, SubtaskInfo())
@@ -97,14 +95,11 @@ class TaskListViewModel @ViewModelInject constructor(
         }
         if (BuildConfig.DEBUG) {
             builder.setFetchExecutor { command: Runnable ->
-                Completable.fromAction {
-                    AndroidUtilities.assertNotMainThread()
+                viewModelScope.launch(Dispatchers.IO) {
                     val start = DateUtilities.now()
                     command.run()
                     Timber.d("*** paged list execution took %sms", DateUtilities.now() - start)
                 }
-                        .subscribeOn(Schedulers.io())
-                        .subscribe()
             }
         }
         internal = builder.build()
@@ -112,7 +107,6 @@ class TaskListViewModel @ViewModelInject constructor(
     }
 
     override fun onCleared() {
-        disposable.dispose()
         removeObserver()
     }