Merge pull request #4929 from TacoTheDank/murder-all-the-annoying-lints

Various code improvements

app/src/main/java/androidx/fragment/app/FragmentStatePagerAdapterMenuWorkaround.java

@@ -86,8 +86,8 @@ public abstract class FragmentStatePagerAdapterMenuWorkaround extends PagerAdapt
     private final int mBehavior;
     private FragmentTransaction mCurTransaction = null;
 
-    private ArrayList<Fragment.SavedState> mSavedState = new ArrayList<Fragment.SavedState>();
+    private final ArrayList<Fragment.SavedState> mSavedState = new ArrayList<Fragment.SavedState>();
-    private ArrayList<Fragment> mFragments = new ArrayList<Fragment>();
+    private final ArrayList<Fragment> mFragments = new ArrayList<Fragment>();
     private Fragment mCurrentPrimaryItem = null;
 
     /**

app/src/main/java/org/schabi/newpipe/DownloaderImpl.java

@@ -50,8 +50,8 @@ public final class DownloaderImpl extends Downloader {
     public static final String YOUTUBE_DOMAIN = "youtube.com";
 
     private static DownloaderImpl instance;
-    private Map<String, String> mCookies;
+    private final Map<String, String> mCookies;
-    private OkHttpClient client;
+    private final OkHttpClient client;
 
     private DownloaderImpl(final OkHttpClient.Builder builder) {
         if (Build.VERSION.SDK_INT == Build.VERSION_CODES.KITKAT) {

app/src/main/java/org/schabi/newpipe/MainActivity.java

@@ -139,8 +139,7 @@ public class MainActivity extends AppCompatActivity {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
-        if (getSupportFragmentManager() != null
+        if (getSupportFragmentManager().getBackStackEntryCount() == 0) {
-                && getSupportFragmentManager().getBackStackEntryCount() == 0) {
             initFragments();
         }
 

app/src/main/java/org/schabi/newpipe/RouterActivity.java

@@ -519,7 +519,7 @@ public class RouterActivity extends AppCompatActivity {
         disposables.add(ExtractorHelper.getStreamInfo(currentServiceId, currentUrl, true)
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
-                .subscribe((@NonNull StreamInfo result) -> {
+                .subscribe(result -> {
                     final List<VideoStream> sortedVideoStreams = ListHelper
                             .getSortedStreamVideosList(this, result.getVideoStreams(),
                                     result.getVideoOnlyStreams(), false);
@@ -534,9 +534,8 @@ public class RouterActivity extends AppCompatActivity {
                     downloadDialog.show(fm, "downloadDialog");
                     fm.executePendingTransactions();
                     downloadDialog.requireDialog().setOnDismissListener(dialog -> finish());
-                }, (@NonNull Throwable throwable) -> {
+                }, throwable ->
-                    showUnsupportedUrlDialog(currentUrl);
+                        showUnsupportedUrlDialog(currentUrl)));
-                }));
     }
 
     @Override

app/src/main/java/org/schabi/newpipe/about/AboutActivity.java

@@ -31,7 +31,7 @@ public class AboutActivity extends AppCompatActivity {
     /**
      * List of all software components.
      */
-    private static final SoftwareComponent[] SOFTWARE_COMPONENTS = new SoftwareComponent[]{
+    private static final SoftwareComponent[] SOFTWARE_COMPONENTS = {
             new SoftwareComponent("Giga Get", "2014 - 2015", "Peter Cai",
                     "https://github.com/PaperAirplane-Dev-Team/GigaGet", StandardLicenses.GPL3),
             new SoftwareComponent("NewPipe Extractor", "2017 - 2020", "Christian Schabesberger",

app/src/main/java/org/schabi/newpipe/about/License.java

@@ -23,7 +23,7 @@ public class License implements Parcelable, Serializable {
     };
     private final String abbreviation;
     private final String name;
-    private String filename;
+    private final String filename;
 
     public License(final String name, final String abbreviation, final String filename) {
         if (name == null) {

app/src/main/java/org/schabi/newpipe/fragments/MainFragment.java

@@ -43,7 +43,7 @@ public class MainFragment extends BaseFragment implements TabLayout.OnTabSelecte
     private SelectedTabsPagerAdapter pagerAdapter;
     private ScrollableTabLayout tabLayout;
 
-    private List<Tab> tabsList = new ArrayList<>();
+    private final List<Tab> tabsList = new ArrayList<>();
     private TabsManager tabsManager;
 
     private boolean hasTabsChanged = false;

app/src/main/java/org/schabi/newpipe/fragments/OnScrollBelowItemsListener.java

@@ -14,12 +14,10 @@ public abstract class OnScrollBelowItemsListener extends RecyclerView.OnScrollLi
         super.onScrolled(recyclerView, dx, dy);
         if (dy > 0) {
             int pastVisibleItems = 0;
-            final int visibleItemCount;
-            final int totalItemCount;
             final RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
 
-            visibleItemCount = layoutManager.getChildCount();
+            final int visibleItemCount = layoutManager.getChildCount();
-            totalItemCount = layoutManager.getItemCount();
+            final int totalItemCount = layoutManager.getItemCount();
 
             // Already covers the GridLayoutManager case
             if (layoutManager instanceof LinearLayoutManager) {

app/src/main/java/org/schabi/newpipe/fragments/detail/VideoDetailFragment.java

@@ -19,7 +19,6 @@ import android.view.ViewTreeObserver;
 import androidx.core.text.HtmlCompat;
 import androidx.preference.PreferenceManager;
 import android.provider.Settings;
-import android.text.Spanned;
 import android.text.TextUtils;
 import android.text.util.Linkify;
 import android.util.DisplayMetrics;
@@ -731,7 +730,7 @@ public final class VideoDetailFragment
     }
 
     private View.OnTouchListener getOnControlsTouchListener() {
-        return (View view, MotionEvent motionEvent) -> {
+        return (view, motionEvent) -> {
             if (!PreferenceManager.getDefaultSharedPreferences(activity)
                     .getBoolean(getString(R.string.show_hold_to_append_key), true)) {
                 return false;
@@ -948,7 +947,7 @@ public final class VideoDetailFragment
         currentWorker = ExtractorHelper.getStreamInfo(serviceId, url, forceLoad)
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
-                .subscribe((@NonNull final StreamInfo result) -> {
+                .subscribe(result -> {
                     isLoading.set(false);
                     hideMainPlayer();
                     if (result.getAgeLimit() != NO_AGE_LIMIT && !prefs.getBoolean(
@@ -969,7 +968,7 @@ public final class VideoDetailFragment
                             openVideoPlayer();
                         }
                     }
-                }, (@NonNull final Throwable throwable) -> {
+                }, throwable -> {
                     isLoading.set(false);
                     onError(throwable);
                 });
@@ -1140,7 +1139,7 @@ public final class VideoDetailFragment
 
         PlayQueue queue = playQueue;
         // Size can be 0 because queue removes bad stream automatically when error occurs
-        if (queue == null || queue.size() == 0) {
+        if (queue == null || queue.isEmpty()) {
             queue = new SinglePlayQueue(currentInfo);
         }
 
@@ -1224,12 +1223,12 @@ public final class VideoDetailFragment
 
         if (description.getType() == Description.HTML) {
             disposables.add(Single.just(description.getContent())
-                    .map((@NonNull final String descriptionText) ->
+                    .map(descriptionText ->
                             HtmlCompat.fromHtml(descriptionText,
                                     HtmlCompat.FROM_HTML_MODE_LEGACY))
                     .subscribeOn(Schedulers.computation())
                     .observeOn(AndroidSchedulers.mainThread())
-                    .subscribe((@NonNull final Spanned spanned) -> {
+                    .subscribe(spanned -> {
                         videoDescriptionView.setText(spanned);
                         videoDescriptionView.setVisibility(View.VISIBLE);
                     }));
@@ -1346,19 +1345,24 @@ public final class VideoDetailFragment
         broadcastReceiver = new BroadcastReceiver() {
             @Override
             public void onReceive(final Context context, final Intent intent) {
-                if (intent.getAction().equals(ACTION_SHOW_MAIN_PLAYER)) {
+                switch (intent.getAction()) {
-                    bottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
+                    case ACTION_SHOW_MAIN_PLAYER:
-                } else if (intent.getAction().equals(ACTION_HIDE_MAIN_PLAYER)) {
+                        bottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
-                    bottomSheetBehavior.setState(BottomSheetBehavior.STATE_HIDDEN);
+                        break;
-                } else if (intent.getAction().equals(ACTION_PLAYER_STARTED)) {
+                    case ACTION_HIDE_MAIN_PLAYER:
-                    // If the state is not hidden we don't need to show the mini player
+                        bottomSheetBehavior.setState(BottomSheetBehavior.STATE_HIDDEN);
-                    if (bottomSheetBehavior.getState() == BottomSheetBehavior.STATE_HIDDEN) {
+                        break;
-                        bottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
+                    case ACTION_PLAYER_STARTED:
-                    }
+                        // If the state is not hidden we don't need to show the mini player
-                    // Rebound to the service if it was closed via notification or mini player
+                        if (bottomSheetBehavior.getState() == BottomSheetBehavior.STATE_HIDDEN) {
-                    if (!PlayerHolder.bound) {
+                            bottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
-                        PlayerHolder.startService(App.getApp(), false, VideoDetailFragment.this);
+                        }
-                    }
+                        // Rebound to the service if it was closed via notification or mini player
+                        if (!PlayerHolder.bound) {
+                            PlayerHolder.startService(
+                                    App.getApp(), false, VideoDetailFragment.this);
+                        }
+                        break;
                 }
             }
         };

app/src/main/java/org/schabi/newpipe/fragments/list/BaseListInfoFragment.java

@@ -204,7 +204,7 @@ public abstract class BaseListInfoFragment<I extends ListInfo>
         name = result.getName();
         setTitle(name);
 
-        if (infoListAdapter.getItemsList().size() == 0) {
+        if (infoListAdapter.getItemsList().isEmpty()) {
             if (result.getRelatedItems().size() > 0) {
                 infoListAdapter.addInfoItemList(result.getRelatedItems());
                 showListFooter(hasMoreItems());

app/src/main/java/org/schabi/newpipe/fragments/list/comments/CommentsFragment.java

@@ -24,7 +24,7 @@ import io.reactivex.Single;
 import io.reactivex.disposables.CompositeDisposable;
 
 public class CommentsFragment extends BaseListInfoFragment<CommentsInfo> {
-    private CompositeDisposable disposables = new CompositeDisposable();
+    private final CompositeDisposable disposables = new CompositeDisposable();
 
     public static CommentsFragment getInstance(final int serviceId, final  String url,
                                                final String name) {

app/src/main/java/org/schabi/newpipe/fragments/list/search/SearchFragment.java

@@ -256,7 +256,7 @@ public class SearchFragment extends BaseListFragment<SearchInfo, ListExtractor.I
         if (!TextUtils.isEmpty(searchString)) {
             if (wasLoading.getAndSet(false)) {
                 search(searchString, contentFilter, sortFilter);
-            } else if (infoListAdapter.getItemsList().size() == 0) {
+            } else if (infoListAdapter.getItemsList().isEmpty()) {
                 if (savedState == null) {
                     search(searchString, contentFilter, sortFilter);
                 } else if (!isLoading.get() && !wasSearchFocused) {
@@ -977,7 +977,7 @@ public class SearchFragment extends BaseListFragment<SearchInfo, ListExtractor.I
         lastSearchedString = searchString;
         nextPage = result.getNextPage();
 
-        if (infoListAdapter.getItemsList().size() == 0) {
+        if (infoListAdapter.getItemsList().isEmpty()) {
             if (!result.getRelatedItems().isEmpty()) {
                 infoListAdapter.addInfoItemList(result.getRelatedItems());
             } else {

app/src/main/java/org/schabi/newpipe/fragments/list/videos/RelatedVideosFragment.java

@@ -31,7 +31,7 @@ import io.reactivex.disposables.CompositeDisposable;
 public class RelatedVideosFragment extends BaseListInfoFragment<RelatedStreamInfo>
         implements SharedPreferences.OnSharedPreferenceChangeListener {
     private static final String INFO_KEY = "related_info_key";
-    private CompositeDisposable disposables = new CompositeDisposable();
+    private final CompositeDisposable disposables = new CompositeDisposable();
     private RelatedStreamInfo relatedStreamInfo;
 
     /*//////////////////////////////////////////////////////////////////////////

app/src/main/java/org/schabi/newpipe/info_list/InfoListAdapter.java

@@ -371,7 +371,7 @@ public class InfoListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolde
         };
     }
 
-    public class HFHolder extends RecyclerView.ViewHolder {
+    public static class HFHolder extends RecyclerView.ViewHolder {
         public View view;
 
         HFHolder(final View v) {

app/src/main/java/org/schabi/newpipe/local/dialog/PlaylistAppendDialog.java

@@ -38,7 +38,7 @@ public final class PlaylistAppendDialog extends PlaylistDialog {
     private RecyclerView playlistRecyclerView;
     private LocalItemListAdapter playlistAdapter;
 
-    private CompositeDisposable playlistDisposables = new CompositeDisposable();
+    private final CompositeDisposable playlistDisposables = new CompositeDisposable();
 
     public static Disposable onPlaylistFound(
             final Context context, final Runnable onSuccess, final Runnable onFailed

app/src/main/java/org/schabi/newpipe/local/feed/FeedFragment.kt

@@ -29,6 +29,7 @@ import android.view.MenuItem
 import android.view.View
 import android.view.ViewGroup
 import androidx.appcompat.app.AlertDialog
+import androidx.core.content.edit
 import androidx.core.os.bundleOf
 import androidx.core.view.isVisible
 import androidx.lifecycle.Observer
@@ -142,9 +143,9 @@ class FeedFragment : BaseListFragment<FeedState, Unit>() {
             AlertDialog.Builder(requireContext())
                     .setMessage(R.string.feed_use_dedicated_fetch_method_help_text)
                     .setNeutralButton(enableDisableButtonText) { _, _ ->
-                        sharedPreferences.edit()
+                        sharedPreferences.edit {
-                                .putBoolean(getString(R.string.feed_use_dedicated_fetch_method_key), !usingDedicatedMethod)
+                            putBoolean(getString(R.string.feed_use_dedicated_fetch_method_key), !usingDedicatedMethod)
-                                .apply()
+                        }
                     }
                     .setPositiveButton(resources.getString(R.string.finish), null)
                     .create()
@@ -255,8 +256,9 @@ class FeedFragment : BaseListFragment<FeedState, Unit>() {
 
         oldestSubscriptionUpdate = loadedState.oldestUpdate
 
-        refresh_subtitle_text.isVisible = loadedState.notLoadedCount > 0
+        val loadedCount = loadedState.notLoadedCount > 0
-        if (loadedState.notLoadedCount > 0) {
+        refresh_subtitle_text.isVisible = loadedCount
+        if (loadedCount) {
             refresh_subtitle_text.text = getString(R.string.feed_subscription_not_loaded_count, loadedState.notLoadedCount)
         }
 

app/src/main/java/org/schabi/newpipe/local/feed/FeedViewModel.kt

@@ -48,8 +48,7 @@ class FeedViewModel(applicationContext: Context, val groupId: Long = FeedGroupEn
             .throttleLatest(DEFAULT_THROTTLE_TIMEOUT, TimeUnit.MILLISECONDS)
             .subscribeOn(Schedulers.io())
             .observeOn(AndroidSchedulers.mainThread())
-            .subscribe {
+            .subscribe { (event, listFromDB, notLoadedCount, oldestUpdate) ->
-                val (event, listFromDB, notLoadedCount, oldestUpdate) = it
 
                 val oldestUpdateCalendar = oldestUpdate?.toCalendar()
 

app/src/main/java/org/schabi/newpipe/local/subscription/dialog/FeedGroupDialog.kt

@@ -3,7 +3,6 @@ package org.schabi.newpipe.local.subscription.dialog
 import android.app.Dialog
 import android.os.Bundle
 import android.os.Parcelable
-import android.text.TextUtils
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
@@ -225,7 +224,7 @@ class FeedGroupDialog : DialogFragment(), BackPressable {
         }
 
         toolbar_search_clear.setOnClickListener {
-            if (TextUtils.isEmpty(toolbar_search_edit_text.text)) {
+            if (toolbar_search_edit_text.text.isEmpty()) {
                 hideSearch()
                 return@setOnClickListener
             }

app/src/main/java/org/schabi/newpipe/player/BasePlayer.java

@@ -1545,8 +1545,7 @@ public abstract class BasePlayer implements
         if (simpleExoPlayer == null) {
             return PlaybackParameters.DEFAULT;
         }
-        final PlaybackParameters parameters = simpleExoPlayer.getPlaybackParameters();
+        return simpleExoPlayer.getPlaybackParameters();
-        return parameters == null ? PlaybackParameters.DEFAULT : parameters;
     }
 
     /**

app/src/main/java/org/schabi/newpipe/player/NotificationUtil.java

@@ -48,7 +48,7 @@ public final class NotificationUtil {
     @Nullable private static NotificationUtil instance = null;
 
     @NotificationConstants.Action
-    private int[] notificationSlots = NotificationConstants.SLOT_DEFAULTS.clone();
+    private final int[] notificationSlots = NotificationConstants.SLOT_DEFAULTS.clone();
 
     private NotificationManagerCompat notificationManager;
     private NotificationCompat.Builder notificationBuilder;

app/src/main/java/org/schabi/newpipe/player/VideoPlayerImpl.java

@@ -337,7 +337,7 @@ public class VideoPlayerImpl extends VideoPlayer
             view.setFixedTextSize(TypedValue.COMPLEX_UNIT_PX,
                     (float) minimumLength / captionRatioInverse);
         }
-        view.setApplyEmbeddedStyles(captionStyle.equals(CaptionStyleCompat.DEFAULT));
+        view.setApplyEmbeddedStyles(captionStyle == CaptionStyleCompat.DEFAULT);
         view.setStyle(captionStyle);
     }
 

app/src/main/java/org/schabi/newpipe/player/event/BasePlayerGestureListener.kt

@@ -15,6 +15,7 @@ import org.schabi.newpipe.util.AnimationUtils
 import kotlin.math.abs
 import kotlin.math.hypot
 import kotlin.math.max
+import kotlin.math.min
 
 /**
  * Base gesture handling for [VideoPlayerImpl]
@@ -117,7 +118,7 @@ abstract class BasePlayerGestureListener(
             initSecPointerX = event.getX(1)
             initSecPointerY = event.getY(1)
             // record distance between fingers
-            initPointerDistance = Math.hypot(initFirstPointerX - initSecPointerX.toDouble(),
+            initPointerDistance = hypot(initFirstPointerX - initSecPointerX.toDouble(),
                 initFirstPointerY - initSecPointerY.toDouble())
 
             isResizing = true
@@ -185,7 +186,7 @@ abstract class BasePlayerGestureListener(
                 playerImpl.updateScreenSize()
 
                 playerImpl.updatePopupSize(
-                    Math.min(playerImpl.screenWidth.toDouble(), newWidth).toInt(),
+                    min(playerImpl.screenWidth.toDouble(), newWidth).toInt(),
                     -1)
                 return true
             }

app/src/main/java/org/schabi/newpipe/player/playback/MediaSourceManager.java

@@ -123,7 +123,7 @@ public class MediaSourceManager {
     @NonNull
     private ManagedMediaSourcePlaylist playlist;
 
-    private Handler removeMediaSourceHandler = new Handler();
+    private final Handler removeMediaSourceHandler = new Handler();
 
     public MediaSourceManager(@NonNull final PlaybackListener listener,
                               @NonNull final PlayQueue playQueue) {

app/src/main/java/org/schabi/newpipe/player/playqueue/PlayQueueAdapter.java

@@ -215,7 +215,7 @@ public class PlayQueueAdapter extends RecyclerView.Adapter<RecyclerView.ViewHold
         }
     }
 
-    public class HFHolder extends RecyclerView.ViewHolder {
+    public static class HFHolder extends RecyclerView.ViewHolder {
         public View view;
 
         public HFHolder(final View v) {

app/src/main/java/org/schabi/newpipe/report/ErrorActivity.java

@@ -154,7 +154,7 @@ public class ErrorActivity extends AppCompatActivity {
 
     public static void reportError(final Context context, final CrashReportData report,
                                    final ErrorInfo errorInfo) {
-        final String[] el = new String[]{report.getString(ReportField.STACK_TRACE)};
+        final String[] el = {report.getString(ReportField.STACK_TRACE)};
 
         final Intent intent = new Intent(context, ErrorActivity.class);
         intent.putExtra(ERROR_INFO, errorInfo);
@@ -216,15 +216,15 @@ public class ErrorActivity extends AppCompatActivity {
         addGuruMeditation();
         currentTimeStamp = getCurrentTimeStamp();
 
-        reportEmailButton.setOnClickListener((View v) ->
+        reportEmailButton.setOnClickListener(v ->
                 openPrivacyPolicyDialog(this, "EMAIL"));
 
-        copyButton.setOnClickListener((View v) -> {
+        copyButton.setOnClickListener(v -> {
             ShareUtils.copyToClipboard(this, buildMarkdown());
             Toast.makeText(this, R.string.msg_copied, Toast.LENGTH_SHORT).show();
         });
 
-        reportGithubButton.setOnClickListener((View v) ->
+        reportGithubButton.setOnClickListener(v ->
                 openPrivacyPolicyDialog(this, "GITHUB"));
 
 

app/src/main/java/org/schabi/newpipe/settings/ContentSettingsFragment.java

@@ -3,7 +3,6 @@ package org.schabi.newpipe.settings;
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.content.Context;
-import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Bundle;
@@ -134,7 +133,7 @@ public class ContentSettingsFragment extends BasePreferenceFragment {
         addPreferencesFromResource(R.xml.content_settings);
 
         final Preference importDataPreference = findPreference(getString(R.string.import_data));
-        importDataPreference.setOnPreferenceClickListener((Preference p) -> {
+        importDataPreference.setOnPreferenceClickListener(p -> {
             final Intent i = new Intent(getActivity(), FilePickerActivityHelper.class)
                     .putExtra(FilePickerActivityHelper.EXTRA_ALLOW_MULTIPLE, false)
                     .putExtra(FilePickerActivityHelper.EXTRA_ALLOW_CREATE_DIR, false)
@@ -145,7 +144,7 @@ public class ContentSettingsFragment extends BasePreferenceFragment {
         });
 
         final Preference exportDataPreference = findPreference(getString(R.string.export_data));
-        exportDataPreference.setOnPreferenceClickListener((Preference p) -> {
+        exportDataPreference.setOnPreferenceClickListener(p -> {
             final Intent i = new Intent(getActivity(), FilePickerActivityHelper.class)
                     .putExtra(FilePickerActivityHelper.EXTRA_ALLOW_MULTIPLE, false)
                     .putExtra(FilePickerActivityHelper.EXTRA_ALLOW_CREATE_DIR, true)
@@ -199,9 +198,9 @@ public class ContentSettingsFragment extends BasePreferenceFragment {
                 final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
                 builder.setMessage(R.string.override_current_data)
                         .setPositiveButton(getString(R.string.finish),
-                                (DialogInterface d, int id) -> importDatabase(path))
+                                (d, id) -> importDatabase(path))
                         .setNegativeButton(android.R.string.cancel,
-                                (DialogInterface d, int id) -> d.cancel());
+                                (d, id) -> d.cancel());
                 builder.create().show();
             }
         }

app/src/main/java/org/schabi/newpipe/settings/PeertubeInstanceListFragment.java

@@ -53,7 +53,7 @@ import io.reactivex.schedulers.Schedulers;
 public class PeertubeInstanceListFragment extends Fragment {
     private static final int MENU_ITEM_RESTORE_ID = 123456;
 
-    private List<PeertubeInstance> instanceList = new ArrayList<>();
+    private final List<PeertubeInstance> instanceList = new ArrayList<>();
     private PeertubeInstance selectedInstance;
     private String savedInstanceListKey;
     private InstanceListAdapter instanceListAdapter;
@@ -344,7 +344,7 @@ public class PeertubeInstanceListFragment extends Fragment {
     private class InstanceListAdapter
             extends RecyclerView.Adapter<InstanceListAdapter.TabViewHolder> {
         private final LayoutInflater inflater;
-        private ItemTouchHelper itemTouchHelper;
+        private final ItemTouchHelper itemTouchHelper;
         private RadioButton lastChecked;
 
         InstanceListAdapter(final Context context, final ItemTouchHelper itemTouchHelper) {
@@ -377,11 +377,11 @@ public class PeertubeInstanceListFragment extends Fragment {
         }
 
         class TabViewHolder extends RecyclerView.ViewHolder {
-            private AppCompatImageView instanceIconView;
+            private final AppCompatImageView instanceIconView;
-            private TextView instanceNameView;
+            private final TextView instanceNameView;
-            private TextView instanceUrlView;
+            private final TextView instanceUrlView;
-            private RadioButton instanceRB;
+            private final RadioButton instanceRB;
-            private ImageView handle;
+            private final ImageView handle;
 
             TabViewHolder(final View itemView) {
                 super(itemView);

app/src/main/java/org/schabi/newpipe/settings/UpdateSettingsFragment.java

@@ -8,7 +8,7 @@ import androidx.preference.Preference;
 import org.schabi.newpipe.R;
 
 public class UpdateSettingsFragment extends BasePreferenceFragment {
-    private Preference.OnPreferenceChangeListener updatePreferenceChange
+    private final Preference.OnPreferenceChangeListener updatePreferenceChange
             = (preference, newValue) -> {
         defaultPreferences.edit()
                 .putBoolean(getString(R.string.update_app_key), (boolean) newValue).apply();

app/src/main/java/org/schabi/newpipe/settings/tabs/ChooseTabsFragment.java

@@ -334,7 +334,7 @@ public class ChooseTabsFragment extends Fragment {
     private class SelectedTabsAdapter
             extends RecyclerView.Adapter<ChooseTabsFragment.SelectedTabsAdapter.TabViewHolder> {
         private final LayoutInflater inflater;
-        private ItemTouchHelper itemTouchHelper;
+        private final ItemTouchHelper itemTouchHelper;
 
         SelectedTabsAdapter(final Context context, final ItemTouchHelper itemTouchHelper) {
             this.itemTouchHelper = itemTouchHelper;
@@ -367,9 +367,9 @@ public class ChooseTabsFragment extends Fragment {
         }
 
         class TabViewHolder extends RecyclerView.ViewHolder {
-            private AppCompatImageView tabIconView;
+            private final AppCompatImageView tabIconView;
-            private TextView tabNameView;
+            private final TextView tabNameView;
-            private ImageView handle;
+            private final ImageView handle;
 
             TabViewHolder(final View itemView) {
                 super(itemView);

app/src/main/java/org/schabi/newpipe/settings/tabs/Tab.java

@@ -116,7 +116,7 @@ public abstract class Tab {
             return true;
         }
 
-        return obj instanceof Tab && obj.getClass().equals(this.getClass())
+        return obj instanceof Tab && obj.getClass() == this.getClass()
                 && ((Tab) obj).getTabId() == this.getTabId();
     }
 
@@ -156,7 +156,7 @@ public abstract class Tab {
         CHANNEL(new ChannelTab()),
         PLAYLIST(new PlaylistTab());
 
-        private Tab tab;
+        private final Tab tab;
 
         Type(final Tab tab) {
             this.tab = tab;

app/src/main/java/org/schabi/newpipe/streams/Mp4DashReader.java

@@ -743,24 +743,24 @@ public class Mp4DashReader {
         return readFullBox(b);
     }
 
-    class Box {
+    static class Box {
         int type;
         long offset;
         long size;
     }
 
-    public class Moof {
+    public static class Moof {
         int mfhdSequenceNumber;
         public Traf traf;
     }
 
-    public class Traf {
+    public static class Traf {
         public Tfhd tfhd;
         long tfdt;
         public Trun trun;
     }
 
-    public class Tfhd {
+    public static class Tfhd {
         int bFlags;
         public int trackId;
         int defaultSampleDuration;
@@ -768,7 +768,7 @@ public class Mp4DashReader {
         int defaultSampleFlags;
     }
 
-    class TrunEntry {
+    static class TrunEntry {
         int sampleDuration;
         int sampleSize;
         int sampleFlags;
@@ -779,7 +779,7 @@ public class Mp4DashReader {
 
     }
 
-    public class Trun {
+    public static class Trun {
         public int chunkDuration;
         public int chunkSize;
 
@@ -837,7 +837,7 @@ public class Mp4DashReader {
         }
     }
 
-    public class Tkhd {
+    public static class Tkhd {
         int trackId;
         long duration;
         short bVolume;
@@ -848,25 +848,25 @@ public class Mp4DashReader {
         short bAlternateGroup;
     }
 
-    public class Trak {
+    public static class Trak {
         public Tkhd tkhd;
         public Elst edstElst;
         public Mdia mdia;
 
     }
 
-    class Mvhd {
+    static class Mvhd {
         long timeScale;
         long nextTrackId;
     }
 
-    class Moov {
+    static class Moov {
         Mvhd mvhd;
         Trak[] trak;
         Trex[] mvexTrex;
     }
 
-    public class Trex {
+    public static class Trex {
         private int trackId;
         int defaultSampleDescriptionIndex;
         int defaultSampleDuration;
@@ -874,37 +874,37 @@ public class Mp4DashReader {
         int defaultSampleFlags;
     }
 
-    public class Elst {
+    public static class Elst {
         public long mediaTime;
         public int bMediaRate;
     }
 
-    public class Mdia {
+    public static class Mdia {
         public int mdhdTimeScale;
         public byte[] mdhd;
         public Hdlr hdlr;
         public Minf minf;
     }
 
-    public class Hdlr {
+    public static class Hdlr {
         public int type;
         public int subType;
         public byte[] bReserved;
     }
 
-    public class Minf {
+    public static class Minf {
         public byte[] dinf;
         public byte[] stblStsd;
         public byte[] mhd;
     }
 
-    public class Mp4Track {
+    public static class Mp4Track {
         public TrackKind kind;
         public Trak trak;
         public Trex trex;
     }
 
-    public class Mp4DashChunk {
+    public static class Mp4DashChunk {
         public InputStream data;
         public Moof moof;
         private int i = 0;
@@ -936,7 +936,7 @@ public class Mp4DashReader {
         }
     }
 
-    public class Mp4DashSample {
+    public static class Mp4DashSample {
         public TrunEntry info;
         public byte[] data;
     }

app/src/main/java/org/schabi/newpipe/streams/Mp4FromDashWriter.java

@@ -897,7 +897,7 @@ public class Mp4FromDashWriter {
         return buffer.array();
     }
 
-    class TablesInfo {
+    static class TablesInfo {
         int stts;
         int stsc;
         int[] stscBEntries;

app/src/main/java/org/schabi/newpipe/streams/OggFromWebMWriter.java

@@ -31,8 +31,8 @@ public class OggFromWebMWriter implements Closeable {
     private boolean done = false;
     private boolean parsed = false;
 
-    private SharpStream source;
+    private final SharpStream source;
-    private SharpStream output;
+    private final SharpStream output;
 
     private int sequenceCount = 0;
     private final int streamId;

app/src/main/java/org/schabi/newpipe/streams/SrtFromTtmlWriter.java

@@ -20,8 +20,8 @@ import java.nio.charset.StandardCharsets;
 public class SrtFromTtmlWriter {
     private static final String NEW_LINE = "\r\n";
 
-    private SharpStream out;
+    private final SharpStream out;
-    private boolean ignoreEmptyFrames;
+    private final boolean ignoreEmptyFrames;
     private final Charset charset = StandardCharsets.UTF_8;
 
     private int frameIndex = 0;

app/src/main/java/org/schabi/newpipe/streams/WebMReader.java

@@ -49,7 +49,7 @@ public class WebMReader {
         Audio/*2*/, Video/*1*/, Other
     }
 
-    private DataReader stream;
+    private final DataReader stream;
     private Segment segment;
     private WebMTrack[] tracks;
     private int selectedTrack;
@@ -397,19 +397,19 @@ public class WebMReader {
         return obj;
     }
 
-    class Element {
+    static class Element {
         int type;
         long offset;
         long contentSize;
         long size;
     }
 
-    public class Info {
+    public static class Info {
         public long timecodeScale;
         public long duration;
     }
 
-    public class WebMTrack {
+    public static class WebMTrack {
         public long trackNumber;
         protected int trackType;
         public String codecId;
@@ -454,7 +454,7 @@ public class WebMReader {
         }
     }
 
-    public class SimpleBlock {
+    public static class SimpleBlock {
         public InputStream data;
         public boolean createdFromBlock;
 

app/src/main/java/org/schabi/newpipe/util/AnimationUtils.java

@@ -157,7 +157,7 @@ public final class AnimationUtils {
                     + "colorStart = [" + colorStart + "], colorEnd = [" + colorEnd + "]");
         }
 
-        final int[][] empty = new int[][]{new int[0]};
+        final int[][] empty = {new int[0]};
         final ValueAnimator viewPropertyAnimator = ValueAnimator
                 .ofObject(new ArgbEvaluator(), colorStart, colorEnd);
         viewPropertyAnimator.setInterpolator(new FastOutSlowInInterpolator());

app/src/main/java/org/schabi/newpipe/util/KoreUtil.java

@@ -2,7 +2,6 @@ package org.schabi.newpipe.util;
 
 
 import android.content.Context;
-import android.content.DialogInterface;
 
 import androidx.appcompat.app.AlertDialog;
 
@@ -20,9 +19,9 @@ public final class KoreUtil {
     public static void showInstallKoreDialog(final Context context) {
         final AlertDialog.Builder builder = new AlertDialog.Builder(context);
         builder.setMessage(R.string.kore_not_found)
-                .setPositiveButton(R.string.install, (DialogInterface dialog, int which) ->
+                .setPositiveButton(R.string.install, (dialog, which) ->
                         NavigationHelper.installKore(context))
-                .setNegativeButton(R.string.cancel, (DialogInterface dialog, int which) -> {
+                .setNegativeButton(R.string.cancel, (dialog, which) -> {
                 });
         builder.create().show();
     }

app/src/main/java/org/schabi/newpipe/util/TLSSocketFactoryCompat.java

@@ -24,7 +24,7 @@ public class TLSSocketFactoryCompat extends SSLSocketFactory {
 
     private static TLSSocketFactoryCompat instance = null;
 
-    private SSLSocketFactory internalSSLSocketFactory;
+    private final SSLSocketFactory internalSSLSocketFactory;
 
     public TLSSocketFactoryCompat() throws KeyManagementException, NoSuchAlgorithmException {
         final SSLContext context = SSLContext.getInstance("TLS");

app/src/main/java/org/schabi/newpipe/views/FocusAwareSeekBar.java

@@ -109,7 +109,7 @@ public final class FocusAwareSeekBar extends AppCompatSeekBar {
         }
     }
 
-    private final class NestedListener implements OnSeekBarChangeListener {
+    private static final class NestedListener implements OnSeekBarChangeListener {
         private final OnSeekBarChangeListener delegate;
 
         boolean isSeeking;

app/src/main/java/org/schabi/newpipe/views/NewPipeRecyclerView.java

@@ -33,8 +33,8 @@ import androidx.recyclerview.widget.RecyclerView;
 public class NewPipeRecyclerView extends RecyclerView {
     private static final String TAG = "NewPipeRecyclerView";
 
-    private Rect focusRect = new Rect();
+    private final Rect focusRect = new Rect();
-    private Rect tempFocus = new Rect();
+    private final Rect tempFocus = new Rect();
 
     private boolean allowDpadScroll = true;
 

app/src/main/java/us/shandian/giga/get/DownloadInitializer.java

@@ -23,7 +23,7 @@ public class DownloadInitializer extends Thread {
     private final static int RESERVE_SPACE_DEFAULT = 5 * 1024 * 1024;// 5 MiB
     private final static int RESERVE_SPACE_MAXIMUM = 150 * 1024 * 1024;// 150 MiB
 
-    private DownloadMission mMission;
+    private final DownloadMission mMission;
     private HttpURLConnection mConn;
 
     DownloadInitializer(@NonNull DownloadMission mission) {

app/src/main/java/us/shandian/giga/get/sqlite/FinishedMissionStore.java

@@ -68,7 +68,7 @@ public class FinishedMissionStore extends SQLiteOpenHelper {
                     " UNIQUE(" + KEY_TIMESTAMP + ", " + KEY_PATH + "));";
 
 
-    private Context context;
+    private final Context context;
 
     public FinishedMissionStore(Context context) {
         super(context, DATABASE_NAME, null, DATABASE_VERSION);

app/src/main/java/us/shandian/giga/io/CircularFileWriter.java

@@ -15,7 +15,7 @@ public class CircularFileWriter extends SharpStream {
     private final static int NOTIFY_BYTES_INTERVAL = 64 * 1024;// 64 KiB
     private final static int THRESHOLD_AUX_LENGTH = 15 * 1024 * 1024;// 15 MiB
 
-    private OffsetChecker callback;
+    private final OffsetChecker callback;
 
     public ProgressReport onProgress;
     public WriteErrorHandle onWriteError;

app/src/main/java/us/shandian/giga/io/StoredDirectoryHelper.java

@@ -31,7 +31,7 @@ public class StoredDirectoryHelper {
 
     private Context context;
 
-    private String tag;
+    private final String tag;
 
     public StoredDirectoryHelper(@NonNull Context context, @NonNull Uri path, String tag) throws IOException {
         this.tag = tag;
@@ -82,7 +82,7 @@ public class StoredDirectoryHelper {
                     docTree.getUri(), DocumentsContract.getDocumentId(docTree.getUri())
             );
 
-            String[] projection = new String[]{COLUMN_DISPLAY_NAME};
+            String[] projection = {COLUMN_DISPLAY_NAME};
             String selection = "(LOWER(" + COLUMN_DISPLAY_NAME + ") LIKE ?%";
             ContentResolver cr = context.getContentResolver();
 

app/src/main/java/us/shandian/giga/postprocessing/Postprocessing.java

@@ -73,7 +73,7 @@ public abstract class Postprocessing implements Serializable {
     /**
      * Gets the given algorithm short name
      */
-    private String name;
+    private final String name;
 
 
     private String[] args;

app/src/main/java/us/shandian/giga/service/DownloadManager.java

@@ -686,7 +686,7 @@ public class DownloadManager {
         }
     }
 
-    public class MissionItem {
+    public static class MissionItem {
         public int special;
         public Mission mission;
 

app/src/main/java/us/shandian/giga/service/DownloadManagerService.java

@@ -109,7 +109,7 @@ public class DownloadManagerService extends Service {
 
     private int downloadFailedNotificationID = DOWNLOADS_NOTIFICATION_ID + 1;
     private Builder downloadFailedNotification = null;
-    private SparseArray<DownloadMission> mFailedDownloads = new SparseArray<>(5);
+    private final SparseArray<DownloadMission> mFailedDownloads = new SparseArray<>(5);
 
     private Bitmap icLauncher;
     private Bitmap icDownloadDone;

app/src/main/java/us/shandian/giga/ui/adapter/MissionAdapter.java

@@ -96,21 +96,21 @@ public class MissionAdapter extends Adapter<ViewHolder> implements Handler.Callb
         ALGORITHMS.put(R.id.sha1, "SHA1");
     }
 
-    private Context mContext;
+    private final Context mContext;
-    private LayoutInflater mInflater;
+    private final LayoutInflater mInflater;
-    private DownloadManager mDownloadManager;
+    private final DownloadManager mDownloadManager;
-    private Deleter mDeleter;
+    private final Deleter mDeleter;
     private int mLayout;
-    private DownloadManager.MissionIterator mIterator;
+    private final DownloadManager.MissionIterator mIterator;
-    private ArrayList<ViewHolderItem> mPendingDownloadsItems = new ArrayList<>();
+    private final ArrayList<ViewHolderItem> mPendingDownloadsItems = new ArrayList<>();
-    private Handler mHandler;
+    private final Handler mHandler;
     private MenuItem mClear;
     private MenuItem mStartButton;
     private MenuItem mPauseButton;
-    private View mEmptyMessage;
+    private final View mEmptyMessage;
     private RecoverHelper mRecover;
-    private View mView;
+    private final View mView;
-    private ArrayList<Mission> mHidden;
+    private final ArrayList<Mission> mHidden;
     private Snackbar mSnackbar;
 
     private final Runnable rUpdater = this::updater;
@@ -976,7 +976,7 @@ public class MissionAdapter extends Adapter<ViewHolder> implements Handler.Callb
         }
     }
 
-    class ViewHolderHeader extends RecyclerView.ViewHolder {
+    static class ViewHolderHeader extends RecyclerView.ViewHolder {
         TextView header;
 
         ViewHolderHeader(View view) {

app/src/main/java/us/shandian/giga/ui/common/Deleter.java

@@ -27,12 +27,12 @@ public class Deleter {
     private ArrayList<Mission> items;
     private boolean running = true;
 
-    private Context mContext;
+    private final Context mContext;
-    private MissionAdapter mAdapter;
+    private final MissionAdapter mAdapter;
-    private DownloadManager mDownloadManager;
+    private final DownloadManager mDownloadManager;
-    private MissionIterator mIterator;
+    private final MissionIterator mIterator;
-    private Handler mHandler;
+    private final Handler mHandler;
-    private View mView;
+    private final View mView;
 
     private final Runnable rShow;
     private final Runnable rNext;

app/src/main/java/us/shandian/giga/ui/fragment/MissionsFragment.java

@@ -66,7 +66,7 @@ public class MissionsFragment extends Fragment {
 
     private DownloadMission unsafeMissionTarget = null;
 
-    private ServiceConnection mConnection = new ServiceConnection() {
+    private final ServiceConnection mConnection = new ServiceConnection() {
 
         @Override
         public void onServiceConnected(ComponentName name, IBinder binder) {

app/src/test/java/org/schabi/newpipe/settings/tabs/TabsJsonHelperTest.java

@@ -81,7 +81,7 @@ public class TabsJsonHelperTest {
     private boolean isTabsArrayEmpty(final String returnedJson) throws JsonParserException {
         final JsonObject jsonObject = JsonParser.object().from(returnedJson);
         assertTrue(jsonObject.containsKey(JSON_TABS_ARRAY_KEY));
-        return jsonObject.getArray(JSON_TABS_ARRAY_KEY).size() == 0;
+        return jsonObject.getArray(JSON_TABS_ARRAY_KEY).isEmpty();
     }
 
     @Test

build.gradle

@@ -7,7 +7,7 @@ buildscript {
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.1.0'
+        classpath 'com.android.tools.build:gradle:4.1.1'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong