JDK8, lint fixing (#2888)

* Use Kotlin JDK8

* Satisfy a ton of lints

* Run res/layout files (and manifest) through reformatter

app/build.gradle

@@ -254,7 +254,7 @@ dependencies {
     testImplementation "org.robolectric:shadows-multidex:$robolectric_version"
     testImplementation "org.robolectric:shadows-play-services:$robolectric_version"
 
-    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
 
     final coroutines_version = '1.3.4'
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"

app/src/main/AndroidManifest.xml

@@ -18,15 +18,15 @@
         android:name=".App"
         android:allowBackup="true"
         android:fullBackupContent="@xml/backup_rules"
-        android:hasFragileUserData="true"
         android:hardwareAccelerated="true"
-        android:usesCleartextTraffic="true"
+        android:hasFragileUserData="true"
         android:icon="@mipmap/ic_launcher"
-        android:requestLegacyExternalStorage="true"
-        android:roundIcon="@mipmap/ic_launcher_round"
         android:label="@string/app_name"
         android:largeHeap="true"
-        android:theme="@style/Theme.Tachiyomi.Light">
+        android:requestLegacyExternalStorage="true"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:theme="@style/Theme.Tachiyomi.Light"
+        android:usesCleartextTraffic="true">
         <activity
             android:name=".ui.main.MainActivity"
             android:launchMode="singleTop"
@@ -36,7 +36,9 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
             <!--suppress AndroidDomInspection -->
-            <meta-data android:name="android.app.shortcuts" android:resource="@xml/shortcuts"/>
+            <meta-data
+                android:name="android.app.shortcuts"
+                android:resource="@xml/shortcuts" />
         </activity>
         <activity
             android:name=".ui.main.DeepLinkActivity"
@@ -44,17 +46,20 @@
             android:theme="@android:style/Theme.NoDisplay">
             <intent-filter>
                 <action android:name="android.intent.action.SEARCH" />
-                <action android:name="com.google.android.gms.actions.SEARCH_ACTION"/>
-                <category android:name="android.intent.category.DEFAULT"/>
+                <action android:name="com.google.android.gms.actions.SEARCH_ACTION" />
+
+                <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
             <intent-filter>
                 <action android:name="eu.kanade.tachiyomi.SEARCH" />
-                <category android:name="android.intent.category.DEFAULT"/>
+                <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
-            <meta-data android:name="android.app.searchable" android:resource="@xml/searchable"/>
+
+            <meta-data
+                android:name="android.app.searchable"
+                android:resource="@xml/searchable" />
         </activity>
-        <activity
-            android:name=".ui.reader.ReaderActivity" />
+        <activity android:name=".ui.reader.ReaderActivity" />
         <activity
             android:name=".ui.security.BiometricUnlockActivity"
             android:theme="@style/Theme.Splash" />
@@ -110,7 +115,7 @@
 
         <activity
             android:name=".extension.util.ExtensionInstallActivity"
-            android:theme="@android:style/Theme.Translucent.NoTitleBar"/>
+            android:theme="@android:style/Theme.Translucent.NoTitleBar" />
 
         <provider
             android:name="androidx.core.content.FileProvider"
@@ -140,11 +145,11 @@
 
         <service
             android:name=".data.backup.BackupCreateService"
-            android:exported="false"/>
+            android:exported="false" />
 
         <service
             android:name=".data.backup.BackupRestoreService"
-            android:exported="false"/>
+            android:exported="false" />
 
     </application>
 

app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupManager.kt

@@ -128,7 +128,7 @@ class BackupManager(val context: Context, version: Int = CURRENT_VERSION) {
         val categoryEntries = JsonArray()
 
         // Add value's to root
-        root[Backup.VERSION] = Backup.CURRENT_VERSION
+        root[Backup.VERSION] = CURRENT_VERSION
         root[Backup.MANGAS] = mangaEntries
         root[CATEGORIES] = categoryEntries
 
@@ -303,8 +303,8 @@ class BackupManager(val context: Context, version: Int = CURRENT_VERSION) {
     fun restoreChapterFetchObservable(source: Source, manga: Manga, chapters: List<Chapter>): Observable<Pair<List<Chapter>, List<Chapter>>> {
         return source.fetchChapterList(manga)
                 .map { syncChaptersWithSource(databaseHelper, it, manga, source) }
-                .doOnNext {
-                    if (it.first.isNotEmpty()) {
+                .doOnNext { pair ->
+                    if (pair.first.isNotEmpty()) {
                         chapters.forEach { it.manga_id = manga.id }
                         insertChapters(chapters)
                     }

app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupRestoreService.kt

@@ -164,7 +164,7 @@ class BackupRestoreService : Service() {
      * @return the start value of the command.
      */
     override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
-        if (intent == null) return Service.START_NOT_STICKY
+        if (intent == null) return START_NOT_STICKY
 
         val uri = intent.getParcelableExtra<Uri>(BackupConst.EXTRA_URI)
 
@@ -179,7 +179,7 @@ class BackupRestoreService : Service() {
                 .subscribeOn(Schedulers.from(executor))
                 .subscribe()
 
-        return Service.START_NOT_STICKY
+        return START_NOT_STICKY
     }
 
     /**

app/src/main/java/eu/kanade/tachiyomi/data/cache/ChapterCache.kt

@@ -80,13 +80,13 @@ class ChapterCache(private val context: Context) {
         if (file == "journal" || file.startsWith("journal."))
             return false
 
-        try {
+        return try {
             // Remove the extension from the file to get the key of the cache
             val key = file.substringBeforeLast(".")
             // Remove file from cache.
-            return diskCache.remove(key)
+            diskCache.remove(key)
         } catch (e: Exception) {
-            return false
+            false
         }
     }
 
@@ -149,10 +149,10 @@ class ChapterCache(private val context: Context) {
      * @return true if in cache otherwise false.
      */
     fun isImageInCache(imageUrl: String): Boolean {
-        try {
-            return diskCache.get(DiskUtil.hashKeyForDisk(imageUrl)) != null
+        return try {
+            diskCache.get(DiskUtil.hashKeyForDisk(imageUrl)) != null
         } catch (e: IOException) {
-            return false
+            false
         }
     }
 

app/src/main/java/eu/kanade/tachiyomi/data/database/resolvers/HistoryLastReadPutResolver.kt

@@ -27,17 +27,15 @@ class HistoryLastReadPutResolver : HistoryPutResolver() {
 
         val putResult: PutResult
 
-        try {
-            if (cursor.count == 0) {
+        putResult = cursor.use { putCursor ->
+            if (putCursor.count == 0) {
                 val insertQuery = mapToInsertQuery(history)
                 val insertedId = db.lowLevel().insert(insertQuery, mapToContentValues(history))
-                putResult = PutResult.newInsertResult(insertedId, insertQuery.table())
+                PutResult.newInsertResult(insertedId, insertQuery.table())
             } else {
                 val numberOfRowsUpdated = db.lowLevel().update(updateQuery, mapToUpdateContentValues(history))
-                putResult = PutResult.newUpdateResult(numberOfRowsUpdated, updateQuery.table())
+                PutResult.newUpdateResult(numberOfRowsUpdated, updateQuery.table())
             }
-        } finally {
-            cursor.close()
         }
 
         putResult

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt

@@ -259,7 +259,7 @@ class DownloadCache(
      */
     private inline fun <K, V, R> Map<out K, V>.mapNotNullKeys(transform: (Map.Entry<K?, V>) -> R?): Map<R, V> {
         val destination = LinkedHashMap<R, V>()
-        forEach { element -> transform(element)?.let { destination.put(it, element.value) } }
+        forEach { element -> transform(element)?.let { destination[it] = element.value } }
         return destination
     }
 

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadService.kt

@@ -106,7 +106,7 @@ class DownloadService : Service() {
      * Not used.
      */
     override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
-        return Service.START_NOT_STICKY
+        return START_NOT_STICKY
     }
 
     /**

app/src/main/java/eu/kanade/tachiyomi/data/download/Downloader.kt

@@ -283,7 +283,7 @@ class Downloader(
                 // Do when page is downloaded.
                 .doOnNext { notifier.onProgressChange(download) }
                 .toList()
-                .map { _ -> download }
+                .map { download }
                 // Do after download completes
                 .doOnNext { ensureSuccessfulDownload(download, mangaDir, tmpDir, chapterDirname) }
                 // If the page list threw, it will resume here

app/src/main/java/eu/kanade/tachiyomi/data/glide/FileFetcher.kt

@@ -5,6 +5,7 @@ import android.util.Log
 import com.bumptech.glide.Priority
 import com.bumptech.glide.load.DataSource
 import com.bumptech.glide.load.data.DataFetcher
+import timber.log.Timber
 import java.io.File
 import java.io.FileInputStream
 import java.io.FileNotFoundException
@@ -24,7 +25,7 @@ open class FileFetcher(private val file: File) : DataFetcher<InputStream> {
             data = FileInputStream(file)
         } catch (e: FileNotFoundException) {
             if (Log.isLoggable(TAG, Log.DEBUG)) {
-                Log.d(TAG, "Failed to open file", e)
+                Timber.d(e, "Failed to open file")
             }
             callback.onLoadFailed(e)
             return

app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateService.kt

@@ -246,7 +246,7 @@ class LibraryUpdateService(
                     stopSelf(startId)
                 })
 
-        return Service.START_REDELIVER_INTENT
+        return START_REDELIVER_INTENT
     }
 
     /**

app/src/main/java/eu/kanade/tachiyomi/data/track/anilist/Anilist.kt

@@ -97,13 +97,13 @@ class Anilist(private val context: Context, id: Int) : TrackService(id) {
             // 100 point
             POINT_100 -> index.toFloat()
             // 5 stars
-            POINT_5 -> when {
-                index == 0 -> 0f
+            POINT_5 -> when (index) {
+                0 -> 0f
                 else -> index * 20f - 10f
             }
             // Smiley
-            POINT_3 -> when {
-                index == 0 -> 0f
+            POINT_3 -> when (index) {
+                0 -> 0f
                 else -> index * 25f + 10f
             }
             // 10 point decimal
@@ -116,8 +116,8 @@ class Anilist(private val context: Context, id: Int) : TrackService(id) {
         val score = track.score
 
         return when (scorePreference.getOrDefault()) {
-            POINT_5 -> when {
-                score == 0f -> "0 ★"
+            POINT_5 -> when (score) {
+                0f -> "0 ★"
                 else -> "${((score + 10) / 20).toInt()} ★"
             }
             POINT_3 -> when {

app/src/main/java/eu/kanade/tachiyomi/data/track/kitsu/KitsuApi.kt

@@ -38,7 +38,7 @@ class KitsuApi(private val client: OkHttpClient, interceptor: KitsuInterceptor)
             .addConverterFactory(GsonConverterFactory.create(GsonBuilder().serializeNulls().create()))
             .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
             .build()
-            .create(KitsuApi.Rest::class.java)
+            .create(Rest::class.java)
 
     private val searchRest = Retrofit.Builder()
             .baseUrl(algoliaKeyUrl)
@@ -46,7 +46,7 @@ class KitsuApi(private val client: OkHttpClient, interceptor: KitsuInterceptor)
             .addConverterFactory(GsonConverterFactory.create())
             .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
             .build()
-            .create(KitsuApi.SearchKeyRest::class.java)
+            .create(SearchKeyRest::class.java)
 
     private val algoliaRest = Retrofit.Builder()
             .baseUrl(algoliaUrl)
@@ -54,7 +54,7 @@ class KitsuApi(private val client: OkHttpClient, interceptor: KitsuInterceptor)
             .addConverterFactory(GsonConverterFactory.create())
             .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
             .build()
-            .create(KitsuApi.AgoliaSearchRest::class.java)
+            .create(AgoliaSearchRest::class.java)
 
     fun addLibManga(track: Track, userId: String): Observable<Track> {
         return Observable.defer {
@@ -162,7 +162,7 @@ class KitsuApi(private val client: OkHttpClient, interceptor: KitsuInterceptor)
                 .addConverterFactory(GsonConverterFactory.create())
                 .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                 .build()
-                .create(KitsuApi.LoginRest::class.java)
+                .create(LoginRest::class.java)
                 .requestAccessToken(username, password)
     }
 

app/src/main/java/eu/kanade/tachiyomi/data/track/kitsu/KitsuModels.kt

@@ -36,10 +36,10 @@ class KitsuSearchManga(obj: JsonObject) {
         cover_url = original ?: ""
         summary = synopsis
         tracking_url = KitsuApi.mangaUrl(media_id)
-        if (endDate == null) {
-            publishing_status = "Publishing"
+        publishing_status = if (endDate == null) {
+            "Publishing"
         } else {
-            publishing_status = "Finished"
+            "Finished"
         }
         publishing_type = subType ?: ""
         start_date = startDate ?: ""

app/src/main/java/eu/kanade/tachiyomi/extension/util/ExtensionInstallReceiver.kt

@@ -49,8 +49,7 @@ internal class ExtensionInstallReceiver(private val listener: Listener) :
         when (intent.action) {
             Intent.ACTION_PACKAGE_ADDED -> {
                 if (!isReplacing(intent)) launchNow {
-                    val result = getExtensionFromIntent(context, intent)
-                    when (result) {
+                    when (val result = getExtensionFromIntent(context, intent)) {
                         is LoadResult.Success -> listener.onExtensionInstalled(result.extension)
                         is LoadResult.Untrusted -> listener.onExtensionUntrusted(result.extension)
                     }
@@ -58,8 +57,7 @@ internal class ExtensionInstallReceiver(private val listener: Listener) :
             }
             Intent.ACTION_PACKAGE_REPLACED -> {
                 launchNow {
-                    val result = getExtensionFromIntent(context, intent)
-                    when (result) {
+                    when (val result = getExtensionFromIntent(context, intent)) {
                         is LoadResult.Success -> listener.onExtensionUpdated(result.extension)
                         // Not needed as a package can't be upgraded if the signature is different
                         is LoadResult.Untrusted -> {

app/src/main/java/eu/kanade/tachiyomi/extension/util/ExtensionLoader.kt

@@ -94,8 +94,7 @@ internal object ExtensionLoader {
             return LoadResult.Error(error)
         }
 
-        val extName = pkgManager.getApplicationLabel(appInfo).toString()
-                .orEmpty().substringAfter("Tachiyomi: ")
+        val extName = pkgManager.getApplicationLabel(appInfo).toString().substringAfter("Tachiyomi: ")
         val versionName = pkgInfo.versionName
         val versionCode = pkgInfo.versionCode
 
@@ -137,8 +136,7 @@ internal object ExtensionLoader {
                 }
                 .flatMap {
                     try {
-                        val obj = Class.forName(it, false, classLoader).newInstance()
-                        when (obj) {
+                        when (val obj = Class.forName(it, false, classLoader).newInstance()) {
                             is Source -> listOf(obj)
                             is SourceFactory -> obj.createSources()
                             else -> throw Exception("Unknown source class type! ${obj.javaClass}")

app/src/main/java/eu/kanade/tachiyomi/source/LocalSource.kt

@@ -81,16 +81,16 @@ class LocalSource(private val context: Context) : CatalogueSource {
         val state = ((if (filters.isEmpty()) POPULAR_FILTERS else filters)[0] as OrderBy).state
         when (state?.index) {
             0 -> {
-                if (state.ascending)
-                    mangaDirs = mangaDirs.sortedBy { it.name.toLowerCase(Locale.ENGLISH) }
+                mangaDirs = if (state.ascending)
+                    mangaDirs.sortedBy { it.name.toLowerCase(Locale.ENGLISH) }
                 else
-                    mangaDirs = mangaDirs.sortedByDescending { it.name.toLowerCase(Locale.ENGLISH) }
+                    mangaDirs.sortedByDescending { it.name.toLowerCase(Locale.ENGLISH) }
             }
             1 -> {
-                if (state.ascending)
-                    mangaDirs = mangaDirs.sortedBy(File::lastModified)
+                mangaDirs = if (state.ascending)
+                    mangaDirs.sortedBy(File::lastModified)
                 else
-                    mangaDirs = mangaDirs.sortedByDescending(File::lastModified)
+                    mangaDirs.sortedByDescending(File::lastModified)
             }
         }
 
@@ -131,17 +131,14 @@ class LocalSource(private val context: Context) : CatalogueSource {
         getBaseDirectories(context)
                 .mapNotNull { File(it, manga.url).listFiles()?.toList() }
                 .flatten()
-                .filter { it.extension.equals("json") }
-                .firstOrNull()
+                .firstOrNull { it.extension == "json" }
                 ?.apply {
                     val json = Gson().fromJson(Scanner(this).useDelimiter("\\Z").next(), JsonObject::class.java)
                     manga.title = json["title"]?.asString ?: manga.title
                     manga.author = json["author"]?.asString ?: manga.author
                     manga.artist = json["artist"]?.asString ?: manga.artist
                     manga.description = json["description"]?.asString ?: manga.description
-                    manga.genre = json["genre"]?.asJsonArray
-                            ?.map { it.asString }
-                            ?.joinToString(", ")
+                    manga.genre = json["genre"]?.asJsonArray?.joinToString(", ") { it.asString }
                             ?: manga.genre
                     manga.status = json["status"]?.asInt ?: manga.status
                 }
@@ -150,6 +147,7 @@ class LocalSource(private val context: Context) : CatalogueSource {
 
     override fun fetchChapterList(manga: SManga): Observable<List<SChapter>> {
         val chapters = getBaseDirectories(context)
+                .asSequence()
                 .mapNotNull { File(it, manga.url).listFiles()?.toList() }
                 .flatten()
                 .filter { it.isDirectory || isSupportedFile(it.extension) }
@@ -171,6 +169,7 @@ class LocalSource(private val context: Context) : CatalogueSource {
                     val c = c2.chapter_number.compareTo(c1.chapter_number)
                     if (c == 0) c2.name.compareToCaseInsensitiveNaturalOrder(c1.name) else c
                 })
+                .toList()
 
         return Observable.just(chapters)
     }
@@ -211,8 +210,7 @@ class LocalSource(private val context: Context) : CatalogueSource {
     }
 
     private fun updateCover(chapter: SChapter, manga: SManga): File? {
-        val format = getFormat(chapter)
-        return when (format) {
+        return when (val format = getFormat(chapter)) {
             is Format.Directory -> {
                 val entry = format.file.listFiles()
                         .sortedWith(Comparator<File> { f1, f2 -> f1.name.compareToCaseInsensitiveNaturalOrder(f2.name) })
@@ -250,7 +248,7 @@ class LocalSource(private val context: Context) : CatalogueSource {
         }
     }
 
-    private class OrderBy : Filter.Sort("Order by", arrayOf("Title", "Date"), Filter.Sort.Selection(0, true))
+    private class OrderBy : Filter.Sort("Order by", arrayOf("Title", "Date"), Selection(0, true))
 
     override fun getFilterList() = FilterList(OrderBy())
 

app/src/main/java/eu/kanade/tachiyomi/source/online/HttpSource.kt

@@ -207,14 +207,14 @@ abstract class HttpSource : CatalogueSource {
      * @param manga the manga to look for chapters.
      */
     override fun fetchChapterList(manga: SManga): Observable<List<SChapter>> {
-        if (manga.status != SManga.LICENSED) {
-            return client.newCall(chapterListRequest(manga))
+        return if (manga.status != SManga.LICENSED) {
+            client.newCall(chapterListRequest(manga))
                     .asObservableSuccess()
                     .map { response ->
                         chapterListParse(response)
                     }
         } else {
-            return Observable.error(Exception("Licensed - No chapters to show"))
+            Observable.error(Exception("Licensed - No chapters to show"))
         }
     }
 
@@ -340,16 +340,16 @@ abstract class HttpSource : CatalogueSource {
      * @param orig the full url.
      */
     private fun getUrlWithoutDomain(orig: String): String {
-        try {
+        return try {
             val uri = URI(orig)
             var out = uri.path
             if (uri.query != null)
                 out += "?" + uri.query
             if (uri.fragment != null)
                 out += "#" + uri.fragment
-            return out
+            out
         } catch (e: URISyntaxException) {
-            return orig
+            orig
         }
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/base/holder/SlicedHolder.kt

@@ -31,13 +31,13 @@ interface SlicedHolder {
 
         when {
             // Only one item in the card
-            count == 1 -> applySlice(2f, false, false, true, true)
+            count == 1 -> applySlice(2f, topRect = false, bottomRect = false, topShadow = true, bottomShadow = true)
             // First item of the card
-            position == 0 -> applySlice(2f, false, true, true, false)
+            position == 0 -> applySlice(2f, topRect = false, bottomRect = true, topShadow = true, bottomShadow = false)
             // Last item of the card
-            position == count - 1 -> applySlice(2f, true, false, false, true)
+            position == count - 1 -> applySlice(2f, topRect = true, bottomRect = false, topShadow = false, bottomShadow = true)
             // Middle item
-            else -> applySlice(0f, false, false, false, false)
+            else -> applySlice(0f, topRect = false, bottomRect = false, topShadow = false, bottomShadow = false)
         }
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/extension/ExtensionAdapter.kt

@@ -22,7 +22,7 @@ class ExtensionAdapter(val controller: ExtensionController) :
     /**
      * Listener for browse item clicks.
      */
-    val buttonClickListener: ExtensionAdapter.OnButtonClickListener = controller
+    val buttonClickListener: OnButtonClickListener = controller
 
     interface OnButtonClickListener {
         fun onButtonClick(position: Int)

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryCategoryView.kt

@@ -229,13 +229,13 @@ class LibraryCategoryView @JvmOverloads constructor(context: Context, attrs: Att
     override fun onItemClick(view: View?, position: Int): Boolean {
         // If the action mode is created and the position is valid, toggle the selection.
         val item = adapter.getItem(position) ?: return false
-        if (adapter.mode == SelectableAdapter.Mode.MULTI) {
+        return if (adapter.mode == SelectableAdapter.Mode.MULTI) {
             lastClickPosition = position
             toggleSelection(position)
-            return true
+            true
         } else {
             openManga(item.manga)
-            return false
+            false
         }
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryPresenter.kt

@@ -303,7 +303,7 @@ class LibraryPresenter(
         if (mangas.isEmpty()) return emptyList()
         return mangas.toSet()
                 .map { db.getCategoriesForManga(it).executeAsBlocking() }
-                .reduce { set1: Iterable<Category>, set2 -> set1.intersect(set2) }
+                .reduce { set1: Iterable<Category>, set2 -> set1.intersect(set2).toMutableList() }
     }
 
     /**

app/src/main/java/eu/kanade/tachiyomi/ui/manga/chapter/ChaptersController.kt

@@ -306,13 +306,13 @@ class ChaptersController : NucleusController<ChaptersControllerBinding, Chapters
     override fun onItemClick(view: View?, position: Int): Boolean {
         val adapter = adapter ?: return false
         val item = adapter.getItem(position) ?: return false
-        if (actionMode != null && adapter.mode == SelectableAdapter.Mode.MULTI) {
+        return if (actionMode != null && adapter.mode == SelectableAdapter.Mode.MULTI) {
             lastClickPosition = position
             toggleSelection(position)
-            return true
+            true
         } else {
             openChapter(item.chapter)
-            return false
+            false
         }
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/manga/chapter/ChaptersPresenter.kt

@@ -67,8 +67,8 @@ class ChaptersPresenter(
         // Prepare the relay.
         chaptersRelay.flatMap { applyChapterFilters(it) }
                 .observeOn(AndroidSchedulers.mainThread())
-                .subscribeLatestCache(ChaptersController::onNextChapters,
-                        { _, error -> Timber.e(error) })
+                .subscribeLatestCache(ChaptersController::onNextChapters)
+                { _, error -> Timber.e(error) }
 
         // Add the subscription that retrieves the chapters from the database, keeps subscribed to
         // changes, and sends the list of chapters to the relay.

app/src/main/java/eu/kanade/tachiyomi/ui/manga/info/MangaInfoController.kt

@@ -262,13 +262,11 @@ class MangaInfoController(private val fromSource: Boolean = false) :
                     .centerCrop()
                     .into(binding.mangaCover)
 
-            if (binding.backdrop != null) {
-                GlideApp.with(view.context)
-                        .load(manga)
-                        .diskCacheStrategy(DiskCacheStrategy.RESOURCE)
-                        .centerCrop()
-                        .into(binding.backdrop!!)
-            }
+            GlideApp.with(view.context)
+                    .load(manga)
+                    .diskCacheStrategy(DiskCacheStrategy.RESOURCE)
+                    .centerCrop()
+                    .into(binding.backdrop)
         }
 
         // Manga info section
@@ -618,8 +616,7 @@ class MangaInfoController(private val fromSource: Boolean = false) :
             return
         }
 
-        val previousController = router.backstack[router.backstackSize - 2].controller()
-        when (previousController) {
+        when (val previousController = router.backstack[router.backstackSize - 2].controller()) {
             is LibraryController -> {
                 router.handleBack()
                 previousController.search(query)

app/src/main/java/eu/kanade/tachiyomi/ui/manga/track/SetTrackStatusDialog.kt

@@ -33,7 +33,7 @@ class SetTrackStatusDialog<T> : DialogController
     override fun onCreateDialog(savedViewState: Bundle?): Dialog {
         val item = item
         val statusList = item.service.getStatusList()
-        val statusString = statusList.mapNotNull { item.service.getStatus(it) }
+        val statusString = statusList.map { item.service.getStatus(it) }
         val selectedIndex = statusList.indexOf(item.track?.status)
 
         return MaterialDialog.Builder(activity!!)

app/src/main/java/eu/kanade/tachiyomi/ui/manga/track/TrackController.kt

@@ -90,7 +90,7 @@ class TrackController : NucleusController<TrackControllerBinding, TrackPresenter
     override fun onLogoClick(position: Int) {
         val track = adapter?.getItem(position)?.track ?: return
 
-        if (track.tracking_url.isNullOrBlank()) {
+        if (track.tracking_url.isBlank()) {
             activity?.toast(R.string.url_not_set)
         } else {
             activity?.startActivity(Intent(Intent.ACTION_VIEW, Uri.parse(track.tracking_url)))

app/src/main/java/eu/kanade/tachiyomi/ui/manga/track/TrackSearchAdapter.kt

@@ -54,7 +54,7 @@ class TrackSearchAdapter(context: Context) :
             view.track_search_title.text = track.title
             view.track_search_summary.text = track.summary
             GlideApp.with(view.context).clear(view.track_search_cover)
-            if (!track.cover_url.isNullOrEmpty()) {
+            if (!track.cover_url.isEmpty()) {
                 GlideApp.with(view.context)
                         .load(track.cover_url)
                         .diskCacheStrategy(DiskCacheStrategy.RESOURCE)
@@ -62,21 +62,21 @@ class TrackSearchAdapter(context: Context) :
                         .into(view.track_search_cover)
             }
 
-            if (track.publishing_status.isNullOrBlank()) {
+            if (track.publishing_status.isBlank()) {
                 view.track_search_status.gone()
                 view.track_search_status_result.gone()
             } else {
                 view.track_search_status_result.text = track.publishing_status.capitalize()
             }
 
-            if (track.publishing_type.isNullOrBlank()) {
+            if (track.publishing_type.isBlank()) {
                 view.track_search_type.gone()
                 view.track_search_type_result.gone()
             } else {
                 view.track_search_type_result.text = track.publishing_type.capitalize()
             }
 
-            if (track.start_date.isNullOrBlank()) {
+            if (track.start_date.isBlank()) {
                 view.track_search_start.gone()
                 view.track_search_start_result.gone()
             } else {

app/src/main/java/eu/kanade/tachiyomi/ui/migration/MangaHolder.kt

@@ -9,8 +9,8 @@ import kotlinx.android.synthetic.main.source_list_item.thumbnail
 import kotlinx.android.synthetic.main.source_list_item.title
 
 class MangaHolder(
-    private val view: View,
-    private val adapter: FlexibleAdapter<*>
+    view: View,
+    adapter: FlexibleAdapter<*>
 ) : BaseFlexibleViewHolder(view, adapter) {
 
     fun bind(item: MangaItem) {

app/src/main/java/eu/kanade/tachiyomi/ui/migration/SelectionHeader.kt

@@ -25,7 +25,7 @@ class SelectionHeader : AbstractHeaderItem<SelectionHeader.Holder>() {
      * Creates a new view holder for this item.
      */
     override fun createViewHolder(view: View, adapter: FlexibleAdapter<IFlexible<RecyclerView.ViewHolder>>): Holder {
-        return SelectionHeader.Holder(view, adapter)
+        return Holder(view, adapter)
     }
 
     /**

app/src/main/java/eu/kanade/tachiyomi/ui/more/AboutController.kt

@@ -171,7 +171,7 @@ class AboutController : SettingsController() {
     }
 
     private fun getFormattedBuildTime(): String {
-        try {
+        return try {
             val inputDf = SimpleDateFormat("yyyy-MM-dd'T'HH:mm'Z'", Locale.US)
             inputDf.timeZone = TimeZone.getTimeZone("UTC")
             val buildTime = inputDf.parse(BuildConfig.BUILD_TIME)
@@ -180,9 +180,9 @@ class AboutController : SettingsController() {
                     DateFormat.MEDIUM, DateFormat.SHORT, Locale.getDefault())
             outputDf.timeZone = TimeZone.getDefault()
 
-            return buildTime.toDateTimestampString(dateFormat)
+            buildTime.toDateTimestampString(dateFormat)
         } catch (e: ParseException) {
-            return BuildConfig.BUILD_TIME
+            BuildConfig.BUILD_TIME
         }
     }
 }

app/src/main/java/eu/kanade/tachiyomi/ui/reader/PageIndicatorTextView.kt

@@ -7,7 +7,6 @@ import android.text.Spannable
 import android.text.SpannableString
 import android.text.style.ScaleXSpan
 import android.util.AttributeSet
-import android.widget.TextView
 import androidx.appcompat.widget.AppCompatTextView
 import eu.kanade.tachiyomi.widget.OutlineSpan
 
@@ -39,7 +38,7 @@ class PageIndicatorTextView(
             }
         }
 
-        super.setText(finalText, TextView.BufferType.SPANNABLE)
+        super.setText(finalText, BufferType.SPANNABLE)
     }
 
     private companion object {

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderPresenter.kt

@@ -361,7 +361,7 @@ class ReaderPresenter(
 
         if (selectedChapter != currentChapters.currChapter) {
             Timber.d("Setting ${selectedChapter.chapter.url} as active")
-            onChapterChanged(currentChapters.currChapter, selectedChapter)
+            onChapterChanged(currentChapters.currChapter)
             loadNewChapter(selectedChapter)
         }
     }
@@ -370,7 +370,7 @@ class ReaderPresenter(
      * Called when a chapter changed from [fromChapter] to [toChapter]. It updates [fromChapter]
      * on the database.
      */
-    private fun onChapterChanged(fromChapter: ReaderChapter, toChapter: ReaderChapter) {
+    private fun onChapterChanged(fromChapter: ReaderChapter) {
         saveChapterProgress(fromChapter)
         saveChapterHistory(fromChapter)
     }

app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/ChapterLoader.kt

@@ -33,10 +33,10 @@ class ChapterLoader(
         return Observable.just(chapter)
                 .doOnNext { chapter.state = ReaderChapter.State.Loading }
                 .observeOn(Schedulers.io())
-                .flatMap {
+                .flatMap { readerChapter ->
                     Timber.d("Loading pages for ${chapter.chapter.name}")
 
-                    val loader = getPageLoader(it)
+                    val loader = getPageLoader(readerChapter)
                     chapter.pageLoader = loader
 
                     loader.getPages().take(1).doOnNext { pages ->

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/ReaderProgressBar.kt

@@ -122,7 +122,7 @@ class ReaderProgressBar @JvmOverloads constructor(
      */
     override fun setVisibility(visibility: Int) {
         super.setVisibility(visibility)
-        val isVisible = visibility == View.VISIBLE
+        val isVisible = visibility == VISIBLE
         if (isVisible) {
             startAnimation()
         } else {
@@ -134,7 +134,7 @@ class ReaderProgressBar @JvmOverloads constructor(
      * Starts the rotation animation if needed.
      */
     private fun startAnimation() {
-        if (visibility != View.VISIBLE || windowVisibility != View.VISIBLE || animation != null) {
+        if (visibility != VISIBLE || windowVisibility != VISIBLE || animation != null) {
             return
         }
 
@@ -153,7 +153,7 @@ class ReaderProgressBar @JvmOverloads constructor(
      * Hides this progress bar with an optional fade out if [animate] is true.
      */
     fun hide(animate: Boolean = false) {
-        if (visibility == View.GONE) return
+        if (visibility == GONE) return
 
         if (!animate) {
             gone()

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerPageHolder.kt

@@ -285,7 +285,7 @@ class PagerPageHolder(
         return ReaderProgressBar(context, null).apply {
 
             val size = 48.dpToPx
-            layoutParams = FrameLayout.LayoutParams(size, size).apply {
+            layoutParams = LayoutParams(size, size).apply {
                 gravity = Gravity.CENTER
             }
         }
@@ -300,7 +300,7 @@ class PagerPageHolder(
         val config = viewer.config
 
         subsamplingImageView = SubsamplingScaleImageView(context).apply {
-            layoutParams = FrameLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT)
+            layoutParams = LayoutParams(MATCH_PARENT, MATCH_PARENT)
             setMaxTileSize(viewer.activity.maxBitmapSize)
             setDoubleTapZoomStyle(SubsamplingScaleImageView.ZOOM_FOCUS_CENTER)
             setDoubleTapZoomDuration(config.doubleTapAnimDuration)
@@ -335,7 +335,7 @@ class PagerPageHolder(
         if (imageView != null) return imageView!!
 
         imageView = PhotoView(context, null).apply {
-            layoutParams = FrameLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT)
+            layoutParams = LayoutParams(MATCH_PARENT, MATCH_PARENT)
             adjustViewBounds = true
             setZoomTransitionDuration(viewer.config.doubleTapAnimDuration)
             setScaleLevels(1f, 2f, 3f)
@@ -362,7 +362,7 @@ class PagerPageHolder(
         if (retryButton != null) return retryButton!!
 
         retryButton = PagerButton(context, viewer).apply {
-            layoutParams = FrameLayout.LayoutParams(WRAP_CONTENT, WRAP_CONTENT).apply {
+            layoutParams = LayoutParams(WRAP_CONTENT, WRAP_CONTENT).apply {
                 gravity = Gravity.CENTER
             }
             setText(R.string.action_retry)
@@ -399,7 +399,7 @@ class PagerPageHolder(
         }
 
         PagerButton(context, viewer).apply {
-            layoutParams = FrameLayout.LayoutParams(WRAP_CONTENT, WRAP_CONTENT).apply {
+            layoutParams = LayoutParams(WRAP_CONTENT, WRAP_CONTENT).apply {
                 setMargins(margins, margins, margins, margins)
             }
             setText(R.string.action_retry)
@@ -413,7 +413,7 @@ class PagerPageHolder(
         val imageUrl = page.imageUrl
         if (imageUrl.orEmpty().startsWith("http")) {
             PagerButton(context, viewer).apply {
-                layoutParams = FrameLayout.LayoutParams(WRAP_CONTENT, WRAP_CONTENT).apply {
+                layoutParams = LayoutParams(WRAP_CONTENT, WRAP_CONTENT).apply {
                     setMargins(margins, margins, margins, margins)
                 }
                 setText(R.string.action_open_in_web_view)

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerTransitionHolder.kt

@@ -55,7 +55,7 @@ class PagerTransitionHolder(
      * dynamically.
      */
     private var pagesContainer = LinearLayout(context).apply {
-        layoutParams = LinearLayout.LayoutParams(MATCH_PARENT, WRAP_CONTENT)
+        layoutParams = LayoutParams(MATCH_PARENT, WRAP_CONTENT)
         orientation = VERTICAL
         gravity = Gravity.CENTER
     }

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewer.kt

@@ -209,7 +209,7 @@ abstract class PagerViewer(val activity: ReaderActivity) : BaseViewer {
      */
     private fun setChaptersInternal(chapters: ViewerChapters) {
         Timber.d("setChaptersInternal")
-        var forceTransition = config.alwaysShowChapterTransition || adapter.items.getOrNull(pager.currentItem) is ChapterTransition
+        val forceTransition = config.alwaysShowChapterTransition || adapter.items.getOrNull(pager.currentItem) is ChapterTransition
         adapter.setChapters(chapters, forceTransition)
 
         // Layout the pager once a chapter is being set

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewerAdapter.kt

@@ -2,7 +2,6 @@ package eu.kanade.tachiyomi.ui.reader.viewer.pager
 
 import android.view.View
 import android.view.ViewGroup
-import androidx.viewpager.widget.PagerAdapter
 import eu.kanade.tachiyomi.ui.reader.model.ChapterTransition
 import eu.kanade.tachiyomi.ui.reader.model.ReaderChapter
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
@@ -93,8 +92,7 @@ class PagerViewerAdapter(private val viewer: PagerViewer) : ViewPagerAdapter() {
      * Creates a new view for the item at the given [position].
      */
     override fun createView(container: ViewGroup, position: Int): View {
-        val item = items[position]
-        return when (item) {
+        return when (val item = items[position]) {
             is ReaderPage -> PagerPageHolder(viewer, item)
             is ChapterTransition -> PagerTransitionHolder(viewer, item)
             else -> throw NotImplementedError("Holder for ${item.javaClass} not implemented")
@@ -113,6 +111,6 @@ class PagerViewerAdapter(private val viewer: PagerViewer) : ViewPagerAdapter() {
                 Timber.d("Position for ${view.item} not found")
             }
         }
-        return PagerAdapter.POSITION_NONE
+        return POSITION_NONE
     }
 }

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonAdapter.kt

@@ -82,8 +82,7 @@ class WebtoonAdapter(val viewer: WebtoonViewer) : RecyclerView.Adapter<RecyclerV
      * Returns the view type for the item at the given [position].
      */
     override fun getItemViewType(position: Int): Int {
-        val item = items[position]
-        return when (item) {
+        return when (val item = items[position]) {
             is ReaderPage -> PAGE_VIEW
             is ChapterTransition -> TRANSITION_VIEW
             else -> error("Unknown view type for ${item.javaClass}")

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonViewer.kt

@@ -202,7 +202,7 @@ class WebtoonViewer(val activity: ReaderActivity, val isContinuous: Boolean = tr
      */
     override fun setChapters(chapters: ViewerChapters) {
         Timber.d("setChapters")
-        var forceTransition = config.alwaysShowChapterTransition || currentPage is ChapterTransition
+        val forceTransition = config.alwaysShowChapterTransition || currentPage is ChapterTransition
         adapter.setChapters(chapters, forceTransition)
 
         if (recycler.visibility == View.GONE) {

app/src/main/java/eu/kanade/tachiyomi/ui/recent/history/HistoryPresenter.kt

@@ -53,9 +53,9 @@ class HistoryPresenter : BasePresenter<HistoryController>() {
                     val map = TreeMap<Date, MutableList<MangaChapterHistory>> { d1, d2 -> d2.compareTo(d1) }
                     val byDay = recents
                             .groupByTo(map, { it.history.last_read.toDateKey() })
-                    byDay.flatMap {
-                        val dateItem = DateSectionItem(it.key)
-                        it.value.map { HistoryItem(it, dateItem) }
+                    byDay.flatMap { entry ->
+                        val dateItem = DateSectionItem(entry.key)
+                        entry.value.map { HistoryItem(it, dateItem) }
                     }
                 }
                 .observeOn(AndroidSchedulers.mainThread())
@@ -102,7 +102,7 @@ class HistoryPresenter : BasePresenter<HistoryController>() {
         }
 
         val chapters = db.getChapters(manga).executeAsBlocking()
-                .sortedWith(Comparator<Chapter> { c1, c2 -> sortFunction(c1, c2) })
+                .sortedWith(Comparator { c1, c2 -> sortFunction(c1, c2) })
 
         val currChapterIndex = chapters.indexOfFirst { chapter.id == it.id }
         return when (manga.sorting) {

app/src/main/java/eu/kanade/tachiyomi/ui/recent/updates/UpdatesController.kt

@@ -156,12 +156,12 @@ class UpdatesController : NucleusController<UpdatesControllerBinding, UpdatesPre
 
         // Get item from position
         val item = adapter.getItem(position) as? UpdatesItem ?: return false
-        if (actionMode != null && adapter.mode == SelectableAdapter.Mode.MULTI) {
+        return if (actionMode != null && adapter.mode == SelectableAdapter.Mode.MULTI) {
             toggleSelection(position)
-            return true
+            true
         } else {
             openChapter(item)
-            return false
+            false
         }
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/recent/updates/UpdatesPresenter.kt

@@ -63,15 +63,15 @@ class UpdatesPresenter(
                     val map = TreeMap<Date, MutableList<MangaChapter>> { d1, d2 -> d2.compareTo(d1) }
                     val byDay = mangaChapters
                             .groupByTo(map, { it.chapter.date_fetch.toDateKey() })
-                    byDay.flatMap {
-                        val dateItem = DateSectionItem(it.key)
-                        it.value
+                    byDay.flatMap { entry ->
+                        val dateItem = DateSectionItem(entry.key)
+                        entry.value
                                 .sortedWith(compareBy({ it.chapter.date_fetch }, { it.chapter.chapter_number })).asReversed()
                                 .map { UpdatesItem(it.chapter, it.manga, dateItem) }
                     }
                 }
-                .doOnNext {
-                    it.forEach { item ->
+                .doOnNext { list ->
+                    list.forEach { item ->
                         // Find an active download for this chapter.
                         val download = downloadManager.queue.find { it.chapter.id == item.chapter.id }
 
@@ -81,8 +81,8 @@ class UpdatesPresenter(
                             item.download = download
                         }
                     }
-                    setDownloadedChapters(it)
-                    chapters = it
+                    setDownloadedChapters(list)
+                    chapters = list
                 }
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsDownloadController.kt

@@ -101,8 +101,8 @@ class SettingsDownloadController : SettingsController() {
                         .subscribeUntilDestroy { isVisible = it }
 
                 preferences.downloadNewCategories().asObservable()
-                        .subscribeUntilDestroy {
-                            val selectedCategories = it
+                        .subscribeUntilDestroy { mutableSet ->
+                            val selectedCategories = mutableSet
                                     .mapNotNull { id -> categories.find { it.id == id.toInt() } }
                                     .sortedBy { it.order }
 

app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsLibraryController.kt

@@ -118,8 +118,8 @@ class SettingsLibraryController : SettingsController() {
                 entries = categories.map { it.name }.toTypedArray()
                 entryValues = categories.map { it.id.toString() }.toTypedArray()
                 preferences.libraryUpdateCategories().asObservable()
-                        .subscribeUntilDestroy {
-                            val selectedCategories = it
+                        .subscribeUntilDestroy { mutableSet ->
+                            val selectedCategories = mutableSet
                                     .mapNotNull { id -> categories.find { it.id == id.toInt() } }
                                     .sortedBy { it.order }
 

app/src/main/java/eu/kanade/tachiyomi/ui/source/SourcePresenter.kt

@@ -87,7 +87,7 @@ class SourcePresenter(
                 sharedObs.take(1),
                 sharedObs.skip(1).delay(500, TimeUnit.MILLISECONDS, AndroidSchedulers.mainThread()))
                 .distinctUntilChanged()
-                .map { (sourceManager.get(it) as? CatalogueSource)?.let { SourceItem(it) } }
+                .map { item -> (sourceManager.get(item) as? CatalogueSource)?.let { SourceItem(it) } }
                 .subscribeLatestCache(SourceController::setLastUsedSource)
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/source/browse/BrowseSourcePresenter.kt

@@ -149,9 +149,9 @@ open class BrowseSourcePresenter(
         pagerSubscription?.let { remove(it) }
         pagerSubscription = pager.results()
                 .observeOn(Schedulers.io())
-                .map { it.first to it.second.map { networkToLocalManga(it, sourceId) } }
+                .map { pair -> pair.first to pair.second.map { networkToLocalManga(it, sourceId) } }
                 .doOnNext { initializeMangas(it.second) }
-                .map { it.first to it.second.map { SourceItem(it, catalogueAsList) } }
+                .map { pair -> pair.first to pair.second.map { SourceItem(it, catalogueAsList) } }
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribeReplay({ view, (page, mangas) ->
                     view.onAddPage(page, mangas)
@@ -292,17 +292,17 @@ open class BrowseSourcePresenter(
     }
 
     private fun FilterList.toItems(): List<IFlexible<*>> {
-        return mapNotNull {
-            when (it) {
-                is Filter.Header -> HeaderItem(it)
-                is Filter.Separator -> SeparatorItem(it)
-                is Filter.CheckBox -> CheckboxItem(it)
-                is Filter.TriState -> TriStateItem(it)
-                is Filter.Text -> TextItem(it)
-                is Filter.Select<*> -> SelectItem(it)
+        return mapNotNull { filter ->
+            when (filter) {
+                is Filter.Header -> HeaderItem(filter)
+                is Filter.Separator -> SeparatorItem(filter)
+                is Filter.CheckBox -> CheckboxItem(filter)
+                is Filter.TriState -> TriStateItem(filter)
+                is Filter.Text -> TextItem(filter)
+                is Filter.Select<*> -> SelectItem(filter)
                 is Filter.Group<*> -> {
-                    val group = GroupItem(it)
-                    val subItems = it.state.mapNotNull {
+                    val group = GroupItem(filter)
+                    val subItems = filter.state.mapNotNull {
                         when (it) {
                             is Filter.CheckBox -> CheckboxSectionItem(it)
                             is Filter.TriState -> TriStateSectionItem(it)
@@ -316,8 +316,8 @@ open class BrowseSourcePresenter(
                     group
                 }
                 is Filter.Sort -> {
-                    val group = SortGroup(it)
-                    val subItems = it.values.map {
+                    val group = SortGroup(filter)
+                    val subItems = filter.values.map {
                         SortItem(it, group)
                     }
                     group.subItems = subItems

app/src/main/java/eu/kanade/tachiyomi/ui/source/browse/ProgressItem.kt

@@ -43,6 +43,10 @@ class ProgressItem : AbstractFlexibleItem<ProgressItem.Holder>() {
         return this === other
     }
 
+    override fun hashCode(): Int {
+        return loadMore.hashCode()
+    }
+
     class Holder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter) {
 
         val progressBar: ProgressBar = view.findViewById(R.id.progress_bar)

app/src/main/java/eu/kanade/tachiyomi/ui/source/global_search/GlobalSearchPresenter.kt

@@ -163,9 +163,9 @@ open class GlobalSearchPresenter(
                             .subscribeOn(Schedulers.io())
                             .onErrorReturn { MangasPage(emptyList(), false) } // Ignore timeouts or other exceptions
                             .map { it.mangas.take(10) } // Get at most 10 manga from search result.
-                            .map { it.map { networkToLocalManga(it, source.id) } } // Convert to local manga.
+                            .map { list -> list.map { networkToLocalManga(it, source.id) } } // Convert to local manga.
                             .doOnNext { fetchImage(it, source) } // Load manga covers.
-                            .map { createCatalogueSearchItem(source, it.map { GlobalSearchCardItem(it) }) }
+                            .map { list -> createCatalogueSearchItem(source, list.map { GlobalSearchCardItem(it) }) }
                 }, 5)
                 .observeOn(AndroidSchedulers.mainThread())
                 // Update matching source with the obtained results
@@ -198,9 +198,9 @@ open class GlobalSearchPresenter(
     private fun initializeFetchImageSubscription() {
         fetchImageSubscription?.unsubscribe()
         fetchImageSubscription = fetchImageSubject.observeOn(Schedulers.io())
-                .flatMap {
-                    val source = it.second
-                    Observable.from(it.first).filter { it.thumbnail_url == null && !it.initialized }
+                .flatMap { pair ->
+                    val source = pair.second
+                    Observable.from(pair.first).filter { it.thumbnail_url == null && !it.initialized }
                             .map { Pair(it, source) }
                             .concatMap { getMangaDetailsObservable(it.first, it.second) }
                             .map { Pair(source as CatalogueSource, it) }

app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterRecognition.kt

@@ -123,11 +123,11 @@ object ChapterRecognition {
             if (alpha.contains("special"))
                 return .97f
 
-            if (alpha[0] == '.') {
+            return if (alpha[0] == '.') {
                 // Take value after (.)
-                return parseAlphaPostFix(alpha[1])
+                parseAlphaPostFix(alpha[1])
             } else {
-                return parseAlphaPostFix(alpha[0])
+                parseAlphaPostFix(alpha[0])
             }
         }
 

app/src/main/java/eu/kanade/tachiyomi/util/storage/DiskUtil.kt

@@ -85,7 +85,7 @@ object DiskUtil {
      */
     fun buildValidFilename(origName: String): String {
         val name = origName.trim('.', ' ')
-        if (name.isNullOrEmpty()) {
+        if (name.isEmpty()) {
             return "(invalid)"
         }
         val sb = StringBuilder(name.length)

app/src/main/java/eu/kanade/tachiyomi/widget/EmptyView.kt

@@ -2,7 +2,6 @@ package eu.kanade.tachiyomi.widget
 
 import android.content.Context
 import android.util.AttributeSet
-import android.view.View
 import android.widget.LinearLayout
 import android.widget.RelativeLayout
 import androidx.annotation.StringRes
@@ -77,6 +76,6 @@ class EmptyView @JvmOverloads constructor(context: Context, attrs: AttributeSet?
 
     data class Action(
         @StringRes val resId: Int,
-        val listener: View.OnClickListener
+        val listener: OnClickListener
     )
 }

app/src/main/java/eu/kanade/tachiyomi/widget/ExtendedNavigationView.kt

@@ -3,7 +3,6 @@ package eu.kanade.tachiyomi.widget
 import android.content.Context
 import android.graphics.drawable.Drawable
 import android.util.AttributeSet
-import android.view.View
 import android.view.ViewGroup
 import androidx.annotation.CallSuper
 import androidx.core.content.ContextCompat
@@ -160,7 +159,7 @@ open class ExtendedNavigationView @JvmOverloads constructor(
      */
     abstract inner class Adapter(private val items: List<Item>) : RecyclerView.Adapter<Holder>() {
 
-        private val onClick = View.OnClickListener {
+        private val onClick = OnClickListener {
             val pos = recycler.getChildAdapterPosition(it)
             val item = items[pos]
             onItemClicked(item)

app/src/main/java/eu/kanade/tachiyomi/widget/SimpleNavigationView.kt

@@ -76,7 +76,7 @@ open class SimpleNavigationView @JvmOverloads constructor(
     /**
      * Clickable view holder.
      */
-    abstract class ClickableHolder(view: View, listener: View.OnClickListener?) : Holder(view) {
+    abstract class ClickableHolder(view: View, listener: OnClickListener?) : Holder(view) {
         init {
             itemView.setOnClickListener(listener)
         }
@@ -85,7 +85,7 @@ open class SimpleNavigationView @JvmOverloads constructor(
     /**
      * Radio view holder.
      */
-    class RadioHolder(parent: ViewGroup, listener: View.OnClickListener?) :
+    class RadioHolder(parent: ViewGroup, listener: OnClickListener?) :
         ClickableHolder(parent.inflate(TR.layout.navigation_view_radio), listener) {
 
         val radio: RadioButton = itemView.findViewById(TR.id.nav_view_item)
@@ -94,7 +94,7 @@ open class SimpleNavigationView @JvmOverloads constructor(
     /**
      * Checkbox view holder.
      */
-    class CheckboxHolder(parent: ViewGroup, listener: View.OnClickListener?) :
+    class CheckboxHolder(parent: ViewGroup, listener: OnClickListener?) :
         ClickableHolder(parent.inflate(TR.layout.navigation_view_checkbox), listener) {
 
         val check: CheckBox = itemView.findViewById(TR.id.nav_view_item)
@@ -103,7 +103,7 @@ open class SimpleNavigationView @JvmOverloads constructor(
     /**
      * Multi state view holder.
      */
-    class MultiStateHolder(parent: ViewGroup, listener: View.OnClickListener?) :
+    class MultiStateHolder(parent: ViewGroup, listener: OnClickListener?) :
         ClickableHolder(parent.inflate(TR.layout.navigation_view_checkedtext), listener) {
 
         val text: CheckedTextView = itemView.findViewById(TR.id.nav_view_item)

app/src/main/res/layout/categories_item.xml

@@ -33,7 +33,7 @@
         android:layout_height="@dimen/material_component_lists_single_line_with_avatar_height"
         android:layout_gravity="end"
         android:scaleType="center"
-        android:tint="?android:attr/textColorPrimary"
-        app:srcCompat="@drawable/ic_reorder_grey_24dp" />
+        app:srcCompat="@drawable/ic_reorder_grey_24dp"
+        app:tint="?android:attr/textColorPrimary" />
 
 </FrameLayout>

app/src/main/res/layout/chapters_controller.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.coordinatorlayout.widget.CoordinatorLayout
-    xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
@@ -13,7 +12,7 @@
         android:layout_height="match_parent"
         android:background="?attr/colorAccent"
         android:elevation="5dp"
-        android:visibility="invisible"/>
+        android:visibility="invisible" />
 
     <eu.kanade.tachiyomi.widget.ThemedSwipeRefreshLayout
         android:id="@+id/swipe_refresh"
@@ -28,9 +27,9 @@
             android:layout_height="match_parent"
             android:layout_marginStart="16dp"
             android:layout_marginEnd="16dp"
-            android:paddingBottom="@dimen/fab_list_padding"
             android:clipToPadding="false"
             android:descendantFocusability="blocksDescendants"
+            android:paddingBottom="@dimen/fab_list_padding"
             tools:listitem="@layout/chapters_item" />
 
     </eu.kanade.tachiyomi.widget.ThemedSwipeRefreshLayout>
@@ -42,7 +41,7 @@
         android:layout_centerHorizontal="true"
         android:layout_gravity="end"
         app:fastScrollerBubbleEnabled="false"
-        tools:visibility="visible"/>
+        tools:visibility="visible" />
 
     <eu.kanade.tachiyomi.widget.ActionToolbar
         android:id="@+id/action_toolbar"
@@ -54,7 +53,7 @@
         android:id="@+id/fab"
         style="@style/Theme.Widget.FAB"
         android:text="@string/action_resume"
-        app:layout_anchor="@id/recycler"
-        app:icon="@drawable/ic_play_arrow_24dp" />
+        app:icon="@drawable/ic_play_arrow_24dp"
+        app:layout_anchor="@id/recycler" />
 
 </androidx.coordinatorlayout.widget.CoordinatorLayout>

app/src/main/res/layout/chapters_item.xml

@@ -5,8 +5,8 @@
     android:layout_width="fill_parent"
     android:layout_height="?android:attr/listPreferredItemHeight"
     android:background="@drawable/list_item_selector"
-    android:paddingEnd="16dp"
-    android:paddingStart="16dp">
+    android:paddingStart="16dp"
+    android:paddingEnd="16dp">
 
     <TextView
         android:id="@+id/chapter_title"
@@ -29,8 +29,8 @@
         android:layout_marginBottom="8dp"
         android:ellipsize="end"
         android:singleLine="true"
-        app:layout_constraintEnd_toStartOf="@+id/download_text"
         app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toStartOf="@+id/download_text"
         app:layout_constraintStart_toStartOf="parent"
         tools:text="22/02/2016 • Scanlator • Page: 45" />
 

app/src/main/res/layout/common_action_toolbar.xml

@@ -10,11 +10,11 @@
         android:layout_height="?attr/actionBarSize"
         android:layout_gravity="bottom"
         android:background="?attr/colorPrimary"
+        android:elevation="2dp"
         android:theme="?attr/actionBarTheme"
         android:visibility="gone"
-        android:elevation="2dp"
-        app:contentInsetStart="8dp"
-        app:contentInsetEnd="8dp">
+        app:contentInsetEnd="8dp"
+        app:contentInsetStart="8dp">
 
         <androidx.appcompat.widget.ActionMenuView
             android:id="@+id/common_action_menu"

app/src/main/res/layout/common_listitem_dir.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/nnf_item_container"
     android:layout_width="match_parent"
@@ -18,8 +19,8 @@
         android:adjustViewBounds="true"
         android:scaleType="center"
         android:src="@drawable/nnf_ic_file_folder"
-        android:tint="?attr/colorAccent"
         android:visibility="visible"
+        app:tint="?attr/colorAccent"
         tools:ignore="ContentDescription" />
 
     <TextView

app/src/main/res/layout/download_item.xml

@@ -14,11 +14,11 @@
         android:layout_alignParentStart="true"
         android:layout_gravity="start"
         android:scaleType="center"
-        android:tint="?android:attr/textColorPrimary"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent"
-        app:srcCompat="@drawable/ic_reorder_grey_24dp" />
+        app:srcCompat="@drawable/ic_reorder_grey_24dp"
+        app:tint="?android:attr/textColorPrimary" />
 
     <TextView
         android:id="@+id/manga_full_title"

app/src/main/res/layout/extension_controller.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
     xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
@@ -25,6 +25,6 @@
         android:layout_centerHorizontal="true"
         android:layout_gravity="end"
         app:fastScrollerBubbleEnabled="false"
-        tools:visibility="visible"/>
+        tools:visibility="visible" />
 
 </FrameLayout>

app/src/main/res/layout/manga_info_controller.xml

@@ -80,8 +80,8 @@
                     style="@style/TextAppearance.Medium.Title"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
-                    android:paddingBottom="8dp"
                     android:maxLines="2"
+                    android:paddingBottom="8dp"
                     android:text="@string/manga_info_full_title_label"
                     android:textIsSelectable="false"
                     app:autoSizeMaxTextSize="20sp"

app/src/main/res/layout/navigation_view_spinner.xml

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="?attr/listPreferredItemHeightSmall"
-    xmlns:tools="http://schemas.android.com/tools"
     android:background="?attr/selectableItemBackground"
     android:focusable="true"
     android:paddingStart="?attr/listPreferredItemPaddingStart"

app/src/main/res/layout/navigation_view_text.xml

@@ -3,6 +3,7 @@
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:background="?attr/selectableItemBackground"
+    android:baselineAligned="false"
     android:focusable="true"
     android:paddingStart="?attr/listPreferredItemPaddingStart"
     android:paddingEnd="?attr/listPreferredItemPaddingEnd">

app/src/main/res/layout/pref_library_columns.xml

@@ -3,6 +3,7 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:baselineAligned="false"
     android:orientation="horizontal"
     android:paddingStart="@dimen/dialog_content_padding"
     android:paddingTop="@dimen/dialog_margin_top_content"

app/src/main/res/layout/reader_page_sheet.xml

@@ -19,8 +19,8 @@
         <ImageView
             android:layout_width="24dp"
             android:layout_height="24dp"
-            android:tint="@color/md_white_1000_54"
-            app:srcCompat="@drawable/ic_photo_24dp" />
+            app:srcCompat="@drawable/ic_photo_24dp"
+            app:tint="@color/md_white_1000_54" />
 
         <TextView
             android:layout_width="match_parent"
@@ -44,8 +44,8 @@
         <ImageView
             android:layout_width="24dp"
             android:layout_height="24dp"
-            android:tint="@color/md_white_1000_54"
-            app:srcCompat="@drawable/ic_share_24dp" />
+            app:srcCompat="@drawable/ic_share_24dp"
+            app:tint="@color/md_white_1000_54" />
 
         <TextView
             android:layout_width="match_parent"
@@ -69,8 +69,8 @@
         <ImageView
             android:layout_width="24dp"
             android:layout_height="24dp"
-            android:tint="@color/md_white_1000_54"
-            app:srcCompat="@drawable/ic_file_download_black_24dp" />
+            app:srcCompat="@drawable/ic_file_download_black_24dp"
+            app:tint="@color/md_white_1000_54" />
 
         <TextView
             android:layout_width="match_parent"

app/src/main/res/layout/reader_settings_sheet.xml

@@ -260,9 +260,9 @@
         android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:text="@string/pref_webtoon_side_padding"
+        app:layout_constraintBaseline_toBaselineOf="@id/webtoon_side_padding"
         app:layout_constraintLeft_toLeftOf="parent"
-        app:layout_constraintRight_toLeftOf="@id/verticalcenter"
-        app:layout_constraintBaseline_toBaselineOf="@id/webtoon_side_padding"/>
+        app:layout_constraintRight_toLeftOf="@id/verticalcenter" />
 
     <androidx.appcompat.widget.AppCompatSpinner
         android:id="@+id/webtoon_side_padding"
@@ -272,7 +272,7 @@
         android:entries="@array/webtoon_side_padding"
         app:layout_constraintLeft_toRightOf="@id/verticalcenter"
         app:layout_constraintRight_toRightOf="@id/spinner_end"
-        app:layout_constraintTop_toBottomOf="@id/crop_borders_webtoon"/>
+        app:layout_constraintTop_toBottomOf="@id/crop_borders_webtoon" />
 
     <!-- Groups of preferences -->
 

app/src/main/res/layout/source_filter_sheet.xml

@@ -21,10 +21,10 @@
             android:alpha="0.5"
             android:scaleType="fitCenter"
             android:src="@drawable/ic_drag_pill_24dp"
-            android:tint="?attr/colorOnBackground"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toTopOf="parent" />
+            app:layout_constraintTop_toTopOf="parent"
+            app:tint="?attr/colorOnBackground" />
 
         <Button
             android:id="@+id/reset_btn"

app/src/main/res/layout/source_grid_item.xml

@@ -98,6 +98,7 @@
             android:layout_height="wrap_content"
             android:layout_gravity="bottom"
             android:ellipsize="end"
+            android:fontFamily="@font/ptsans_narrow_bold"
             android:lineSpacingExtra="-4dp"
             android:maxLines="2"
             android:padding="8dp"
@@ -105,7 +106,6 @@
             android:shadowDx="0"
             android:shadowDy="0"
             android:shadowRadius="4"
-            android:fontFamily="@font/ptsans_narrow_bold"
             tools:text="Sample name" />
 
         <ProgressBar

app/src/main/res/layout/source_main_controller.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
     xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="wrap_content">
 
@@ -18,6 +18,6 @@
         android:layout_centerHorizontal="true"
         android:layout_gravity="end"
         app:fastScrollerBubbleEnabled="false"
-        tools:visibility="visible"/>
+        tools:visibility="visible" />
 
 </FrameLayout>

app/src/main/res/layout/updates_controller.xml

@@ -13,9 +13,9 @@
             android:id="@+id/recycler"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
+            android:clipToPadding="false"
             android:descendantFocusability="blocksDescendants"
             android:paddingBottom="?attr/actionBarSize"
-            android:clipToPadding="false"
             tools:listitem="@layout/updates_item" />
 
         <eu.kanade.tachiyomi.widget.ActionToolbar

app/src/main/res/layout/updates_item.xml

@@ -4,8 +4,8 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="@dimen/material_component_lists_two_line_height"
-    android:paddingEnd="16dp"
-    android:background="@drawable/list_item_selector">
+    android:background="@drawable/list_item_selector"
+    android:paddingEnd="16dp">
 
     <ImageView
         android:id="@+id/manga_cover"

app/src/test/java/eu/kanade/tachiyomi/data/backup/BackupTest.kt

@@ -40,7 +40,7 @@ import uy.kohesive.injekt.api.addSingleton
  * Test class for the [BackupManager].
  * Note that this does not include the backup create/restore services.
  */
-@Config(constants = BuildConfig::class, sdk = intArrayOf(Build.VERSION_CODES.LOLLIPOP))
+@Config(constants = BuildConfig::class, sdk = [Build.VERSION_CODES.LOLLIPOP])
 @RunWith(CustomRobolectricGradleTestRunner::class)
 class BackupTest {
     // Create root object

app/src/test/java/eu/kanade/tachiyomi/data/database/CategoryTest.kt

@@ -72,7 +72,7 @@ class CategoryTest {
 
         // It should not have 0 as id
         val c = db.getCategories().executeAsBlocking()[0]
-        assertThat(c.id).isNotZero()
+        assertThat(c.id).isNotZero
 
         // Add a manga to a category
         val m = db.getMangas().executeAsBlocking()[0]