[GSoC] migrated AnkiStatsTaskHandler.createReviewSummaryStatistics() to suspend function

AnkiDroid/build.gradle

@@ -324,6 +324,7 @@ dependencies {
     testImplementation 'androidx.test.ext:junit:1.1.3'
     testImplementation "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
     testImplementation "org.jetbrains.kotlin:kotlin-test:$kotlin_version"
+    testImplementation "org.jetbrains.kotlinx:kotlinx-coroutines-test:$coroutines_version"
     testImplementation "io.mockk:mockk:1.12.4"
     testImplementation 'org.apache.commons:commons-exec:1.3' // obtaining the OS
 

AnkiDroid/src/main/java/com/ichi2/anki/DeckPicker.kt

@@ -49,6 +49,7 @@ import androidx.core.content.ContextCompat
 import androidx.core.content.pm.ShortcutInfoCompat
 import androidx.core.content.pm.ShortcutManagerCompat
 import androidx.core.graphics.drawable.IconCompat
+import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.DividerItemDecoration
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
@@ -1943,7 +1944,7 @@ open class DeckPicker : NavigationDrawerActivity(), StudyOptionsListener, SyncEr
         return UpdateDeckListListener(this)
     }
 
-    private class UpdateDeckListListener<T : AbstractDeckTreeNode>(deckPicker: DeckPicker?) : TaskListenerWithContext<DeckPicker, Void, List<TreeNode<T>>?>(deckPicker) {
+    private class UpdateDeckListListener<T : AbstractDeckTreeNode>(private val deckPicker: DeckPicker?) : TaskListenerWithContext<DeckPicker, Void, List<TreeNode<T>>?>(deckPicker) {
         override fun actualOnPreExecute(context: DeckPicker) {
             if (!context.colIsOpen()) {
                 context.showProgressBar()
@@ -1966,7 +1967,9 @@ open class DeckPicker : NavigationDrawerActivity(), StudyOptionsListener, SyncEr
             context.mDueTree = result.map { x -> x.unsafeCastToType(AbstractDeckTreeNode::class.java) }
             context.renderPage()
             // Update the mini statistics bar as well
-            AnkiStatsTaskHandler.createReviewSummaryStatistics(context.col, context.mReviewSummaryTextView)
+            deckPicker?.lifecycleScope?.launchCatching {
+                AnkiStatsTaskHandler.createReviewSummaryStatistics(context.col, context.mReviewSummaryTextView)
+            }
             Timber.d("Startup - Deck List UI Completed")
         }
     }

AnkiDroid/src/main/java/com/ichi2/anki/stats/AnkiStatsTaskHandler.kt

@@ -16,7 +16,6 @@
 package com.ichi2.anki.stats
 
 import android.R
-import android.util.Pair
 import android.view.View
 import android.webkit.WebView
 import android.widget.ProgressBar
@@ -33,10 +32,7 @@ import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import kotlinx.coroutines.withContext
 import timber.log.Timber
-import java.lang.ref.WeakReference
 import java.net.URLEncoder
-import java.util.concurrent.locks.Lock
-import java.util.concurrent.locks.ReentrantLock
 import kotlin.math.roundToInt
 
 class AnkiStatsTaskHandler private constructor(
@@ -112,64 +108,10 @@ class AnkiStatsTaskHandler private constructor(
             }
         }
 
-    @Suppress("deprecation") // #7108: AsyncTask
-    class DeckPreviewStatistics : android.os.AsyncTask<Pair<Collection, TextView?>?, Void?, String?>() {
-        private var mTextView: WeakReference<TextView>? = null
-        private var mIsRunning = true
-        override fun doInBackground(vararg params: Pair<Collection, TextView?>?): String? {
-            // make sure only one task of CreateChartTask is running, first to run should get sLock
-            // only necessary on lower APIs because after honeycomb only one thread is used for all asynctasks
-            sLock.lock()
-            return try {
-                val collection = params[0]!!.first
-                val textView = params[0]!!.second
-                mTextView = WeakReference(textView)
-                if (!mIsRunning || collection == null || collection.dbClosed) {
-                    Timber.d("Quitting DeckPreviewStatistics before execution")
-                    return null
-                } else {
-                    Timber.d("Starting DeckPreviewStatistics")
-                }
-
-                // eventually put this in Stats (in desktop it is not though)
-                var cards: Int
-                var minutes: Int
-                val query = "select sum(case when ease > 0 then 1 else 0 end), " + /* cards, excludes rescheduled cards https://github.com/ankidroid/Anki-Android/issues/8592 */
-                    "sum(time)/1000 from revlog where id > " + (collection.sched.dayCutoff - Stats.SECONDS_PER_DAY) * 1000
-                Timber.d("DeckPreviewStatistics query: %s", query)
-                collection.db
-                    .query(query).use { cur ->
-                        cur.moveToFirst()
-                        cards = cur.getInt(0)
-                        minutes = (cur.getInt(1) / 60.0).roundToInt()
-                    }
-                val res = textView!!.resources
-                val span = res.getQuantityString(com.ichi2.anki.R.plurals.in_minutes, minutes, minutes)
-                res.getQuantityString(com.ichi2.anki.R.plurals.studied_cards_today, cards, cards, span)
-            } finally {
-                sLock.unlock()
-            }
-        }
-
-        override fun onCancelled() {
-            mIsRunning = false
-        }
-
-        override fun onPostExecute(todayStatString: String?) {
-            val textView = mTextView!!.get()
-            if (todayStatString != null && mIsRunning && textView != null) {
-                textView.text = todayStatString
-                textView.visibility = View.VISIBLE
-                textView.invalidate()
-            }
-        }
-    }
-
     companion object {
         @JvmStatic
         var instance: AnkiStatsTaskHandler? = null
             private set
-        private val sLock: Lock = ReentrantLock()
         private val mutex = Mutex()
         @JvmStatic
         @Synchronized
@@ -184,12 +126,46 @@ class AnkiStatsTaskHandler private constructor(
             return instance
         }
 
-        @Suppress("deprecation") // #7108: AsyncTask
         @JvmStatic
-        fun createReviewSummaryStatistics(col: Collection, view: TextView): DeckPreviewStatistics {
-            val deckPreviewStatistics = DeckPreviewStatistics()
-            deckPreviewStatistics.execute(Pair(col, view))
-            return deckPreviewStatistics
+        suspend fun createReviewSummaryStatistics(
+            col: Collection,
+            view: TextView,
+            mainDispatcher: CoroutineDispatcher = Dispatchers.Main,
+            defaultDispatcher: CoroutineDispatcher = Dispatchers.Main
+        ): Unit = mutex.withLock {
+            withContext(defaultDispatcher) {
+                val todayStatString = if (!isActive || col.dbClosed) {
+                    Timber.d("Quitting DeckPreviewStatistics before execution")
+                    null
+                } else {
+                    Timber.d("Starting DeckPreviewStatistics")
+                    // eventually put this in Stats (in desktop it is not though)
+                    var cards: Int
+                    var minutes: Int
+                    /* cards, excludes rescheduled cards https://github.com/ankidroid/Anki-Android/issues/8592 */
+                    val query = "select sum(case when ease > 0 then 1 else 0 end), " +
+                        "sum(time)/1000 from revlog where id > " + (col.sched.dayCutoff - Stats.SECONDS_PER_DAY) * 1000
+                    Timber.d("DeckPreviewStatistics query: %s", query)
+                    col.db
+                        .query(query).use { cur ->
+                            cur.moveToFirst()
+                            cards = cur.getInt(0)
+                            minutes = (cur.getInt(1) / 60.0).roundToInt()
+                        }
+                    val res = view.resources
+                    val span = res.getQuantityString(com.ichi2.anki.R.plurals.in_minutes, minutes, minutes)
+                    res.getQuantityString(com.ichi2.anki.R.plurals.studied_cards_today, cards, cards, span)
+                }
+                todayStatString?.let {
+                    withContext(mainDispatcher) {
+                        view.apply {
+                            text = it
+                            visibility = View.VISIBLE
+                            invalidate()
+                        }
+                    }
+                }
+            }
         }
     }
 }

AnkiDroid/src/main/java/com/ichi2/async/CoroutineHelpers.kt

@@ -0,0 +1,37 @@
+/****************************************************************************************
+ * Copyright (c) 2022 Divyansh Kushwaha <kushwaha.divyansh.dxn@gmail.com>               *
+ *                                                                                      *
+ * This program is free software; you can redistribute it and/or modify it under        *
+ * the terms of the GNU General Public License as published by the Free Software        *
+ * Foundation; either version 3 of the License, or (at your option) any later           *
+ * version.                                                                             *
+ *                                                                                      *
+ * This program is distributed in the hope that it will be useful, but WITHOUT ANY      *
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A      *
+ * PARTICULAR PURPOSE. See the GNU General Public License for more details.             *
+ *                                                                                      *
+ * You should have received a copy of the GNU General Public License along with         *
+ * this program.  If not, see <http://www.gnu.org/licenses/>.                           *
+ ****************************************************************************************/
+
+/*
+* This file contains extension functions for different coroutine related actions.
+*/
+package com.ichi2.async
+
+import androidx.lifecycle.LifecycleCoroutineScope
+import kotlinx.coroutines.CoroutineExceptionHandler
+import kotlinx.coroutines.launch
+import timber.log.Timber
+
+/*
+ * Launch a job that catches any uncaught errors and prints it to Log.
+ */
+fun LifecycleCoroutineScope.launchCatching(block: suspend () -> Unit) =
+    this.launch(
+        CoroutineExceptionHandler { _, throwable ->
+            Timber.w(throwable)
+        }
+    ) {
+        block()
+    }

AnkiDroid/src/test/java/com/ichi2/anki/stats/AnkiStatsTaskHandlerTest.kt

@@ -21,6 +21,10 @@ import com.ichi2.anki.RobolectricTest
 import com.ichi2.anki.stats.AnkiStatsTaskHandler.Companion.createReviewSummaryStatistics
 import com.ichi2.annotations.NeedsTest
 import com.ichi2.libanki.Collection
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.advanceUntilIdle
+import kotlinx.coroutines.test.runTest
 import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -30,6 +34,7 @@ import org.mockito.MockitoAnnotations
 import org.mockito.kotlin.whenever
 import java.util.concurrent.ExecutionException
 
+@OptIn(ExperimentalCoroutinesApi::class)
 @RunWith(AndroidJUnit4::class)
 class AnkiStatsTaskHandlerTest : RobolectricTest() {
     @Mock
@@ -38,6 +43,8 @@ class AnkiStatsTaskHandlerTest : RobolectricTest() {
     @Mock
     private lateinit var mView: TextView
 
+    private val testDispatcher = StandardTestDispatcher()
+
     @Before
     override fun setUp() {
         super.setUp()
@@ -49,12 +56,10 @@ class AnkiStatsTaskHandlerTest : RobolectricTest() {
     @Test
     @Throws(ExecutionException::class, InterruptedException::class)
     @NeedsTest("explain this test")
-    @Suppress("deprecation") // #7108: AsyncTask
-    fun testCreateReviewSummaryStatistics() {
+    fun testCreateReviewSummaryStatistics() = runTest(testDispatcher) {
         verify(mCol, atMost(0))!!.db
-        val result = createReviewSummaryStatistics(mCol, mView)
-        result.get()
-        advanceRobolectricLooper()
+        createReviewSummaryStatistics(mCol, mView, testDispatcher, testDispatcher)
+        advanceUntilIdle()
         verify(mCol, atLeast(0))!!.db
         verify(mCol, atLeast(1))!!.dbClosed
     }

build.gradle

@@ -12,6 +12,7 @@ buildscript {
     ext.ankidroid_backend_version = '0.1.11'
     ext.hamcrest_version = '2.2'
     ext.junit_version = '5.8.2'
+    ext.coroutines_version = '1.6.2'
 
     repositories {
         google()