diff --git a/app/src/main/java/com/dkanada/gramophone/activities/details/AlbumDetailActivity.java b/app/src/main/java/com/dkanada/gramophone/activities/details/AlbumDetailActivity.java
index 2e0da8cf..4e59f5f2 100644
--- a/app/src/main/java/com/dkanada/gramophone/activities/details/AlbumDetailActivity.java
+++ b/app/src/main/java/com/dkanada/gramophone/activities/details/AlbumDetailActivity.java
@@ -210,22 +210,7 @@ public class AlbumDetailActivity extends AbsMusicContentActivity implements Pale
                 .setMenu(menuRes)
                 .setCloseDrawableRes(R.drawable.ic_close_white_24dp)
                 .setBackgroundColor(ThemeUtil.shiftBackgroundColorForLightText(getPaletteColor()))
-                .start(new MaterialCab.Callback() {
-                    @Override
-                    public boolean onCabCreated(MaterialCab materialCab, Menu menu) {
-                        return callback.onCabCreated(materialCab, menu);
-                    }
-
-                    @Override
-                    public boolean onCabItemClicked(MenuItem menuItem) {
-                        return callback.onCabItemClicked(menuItem);
-                    }
-
-                    @Override
-                    public boolean onCabFinished(MaterialCab materialCab) {
-                        return callback.onCabFinished(materialCab);
-                    }
-                });
+                .start(callback);
         return cab;
     }
 
diff --git a/app/src/main/java/com/dkanada/gramophone/activities/details/ArtistDetailActivity.java b/app/src/main/java/com/dkanada/gramophone/activities/details/ArtistDetailActivity.java
index 030d33c5..83d3167a 100644
--- a/app/src/main/java/com/dkanada/gramophone/activities/details/ArtistDetailActivity.java
+++ b/app/src/main/java/com/dkanada/gramophone/activities/details/ArtistDetailActivity.java
@@ -238,22 +238,7 @@ public class ArtistDetailActivity extends AbsMusicContentActivity implements Pal
                 .setMenu(menuRes)
                 .setCloseDrawableRes(R.drawable.ic_close_white_24dp)
                 .setBackgroundColor(ThemeUtil.shiftBackgroundColorForLightText(getPaletteColor()))
-                .start(new MaterialCab.Callback() {
-                    @Override
-                    public boolean onCabCreated(MaterialCab materialCab, Menu menu) {
-                        return callback.onCabCreated(materialCab, menu);
-                    }
-
-                    @Override
-                    public boolean onCabItemClicked(MenuItem menuItem) {
-                        return callback.onCabItemClicked(menuItem);
-                    }
-
-                    @Override
-                    public boolean onCabFinished(MaterialCab materialCab) {
-                        return callback.onCabFinished(materialCab);
-                    }
-                });
+                .start(callback);
         return cab;
     }
 
diff --git a/app/src/main/java/com/dkanada/gramophone/activities/details/GenreDetailActivity.java b/app/src/main/java/com/dkanada/gramophone/activities/details/GenreDetailActivity.java
index d11a6bf5..cbff21a5 100644
--- a/app/src/main/java/com/dkanada/gramophone/activities/details/GenreDetailActivity.java
+++ b/app/src/main/java/com/dkanada/gramophone/activities/details/GenreDetailActivity.java
@@ -74,7 +74,7 @@ public class GenreDetailActivity extends AbsMusicContentActivity implements CabH
     }
 
     private void setUpRecyclerView() {
-        ViewUtil.setUpFastScrollRecyclerViewColor(this, ((FastScrollRecyclerView) binding.recyclerView), ThemeStore.accentColor(this));
+        ViewUtil.setUpFastScrollRecyclerViewColor(this, binding.recyclerView, ThemeStore.accentColor(this));
         binding.recyclerView.setLayoutManager(new LinearLayoutManager(this));
 
         adapter = new SongAdapter(this, new ArrayList<>(), R.layout.item_list, false, this);
diff --git a/app/src/main/java/com/dkanada/gramophone/adapter/AlbumCoverPagerAdapter.java b/app/src/main/java/com/dkanada/gramophone/adapter/AlbumCoverPagerAdapter.java
index 43db60df..3e0c1d72 100644
--- a/app/src/main/java/com/dkanada/gramophone/adapter/AlbumCoverPagerAdapter.java
+++ b/app/src/main/java/com/dkanada/gramophone/adapter/AlbumCoverPagerAdapter.java
@@ -17,7 +17,7 @@ import com.dkanada.gramophone.model.Song;
 import java.util.List;
 
 public class AlbumCoverPagerAdapter extends CustomFragmentStatePagerAdapter {
-    private List<Song> dataSet;
+    private final List<Song> dataSet;
 
     private AlbumCoverFragment.ColorReceiver currentColorReceiver;
     private int currentColorReceiverPosition = -1;
diff --git a/app/src/main/java/com/dkanada/gramophone/adapter/MusicLibraryPagerAdapter.java b/app/src/main/java/com/dkanada/gramophone/adapter/MusicLibraryPagerAdapter.java
index 980b0d44..7f5b3681 100644
--- a/app/src/main/java/com/dkanada/gramophone/adapter/MusicLibraryPagerAdapter.java
+++ b/app/src/main/java/com/dkanada/gramophone/adapter/MusicLibraryPagerAdapter.java
@@ -19,6 +19,8 @@ import com.dkanada.gramophone.fragments.library.PlaylistsFragment;
 import com.dkanada.gramophone.fragments.library.SongsFragment;
 import com.dkanada.gramophone.util.PreferenceUtil;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -31,7 +33,6 @@ public class MusicLibraryPagerAdapter extends FragmentPagerAdapter {
 
     private final List<Holder> mHolderList = new ArrayList<>();
 
-    @NonNull
     private final Context mContext;
 
     public MusicLibraryPagerAdapter(@NonNull final Context context, final FragmentManager fragmentManager) {
@@ -99,15 +100,18 @@ public class MusicLibraryPagerAdapter extends FragmentPagerAdapter {
         return mFragment;
     }
 
+    @NotNull
     @Override
     public Fragment getItem(final int position) {
         final Holder mCurrentHolder = mHolderList.get(position);
+
         return Fragment.instantiate(mContext, mCurrentHolder.mClassName, mCurrentHolder.mParams);
     }
 
     @Override
-    public void destroyItem(final ViewGroup container, final int position, final Object object) {
+    public void destroyItem(@NotNull ViewGroup container, int position, @NotNull Object object) {
         super.destroyItem(container, position, object);
+
         final WeakReference<Fragment> mWeakFragment = mFragmentArray.get(position);
         if (mWeakFragment != null) {
             mWeakFragment.clear();
@@ -125,9 +129,6 @@ public class MusicLibraryPagerAdapter extends FragmentPagerAdapter {
         return mHolderList.get(position).title;
     }
 
-    /**
-     * Aligns the fragment cache with the current category layout.
-     */
     private void alignCache() {
         if (mFragmentArray.size() == 0) return;
 
@@ -176,7 +177,7 @@ public class MusicLibraryPagerAdapter extends FragmentPagerAdapter {
                 }
             }
 
-            throw new IllegalArgumentException("Unknown music fragment " + cl);
+            throw new IllegalArgumentException(String.format("unknown music fragment: %s", cl));
         }
 
         private static class All {
diff --git a/app/src/main/java/com/dkanada/gramophone/adapter/PlaylistAdapter.java b/app/src/main/java/com/dkanada/gramophone/adapter/PlaylistAdapter.java
index 67f3af6b..d1eb1f1d 100644
--- a/app/src/main/java/com/dkanada/gramophone/adapter/PlaylistAdapter.java
+++ b/app/src/main/java/com/dkanada/gramophone/adapter/PlaylistAdapter.java
@@ -63,11 +63,7 @@ public class PlaylistAdapter extends AbsMultiSelectAdapter<PlaylistAdapter.ViewH
     public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         View view = LayoutInflater.from(activity).inflate(itemLayoutRes, parent, false);
 
-        return createViewHolder(view, viewType);
-    }
-
-    protected ViewHolder createViewHolder(View view, int viewType) {
-        return new ViewHolder(view, viewType);
+        return new ViewHolder(view);
     }
 
     @Override
@@ -143,7 +139,7 @@ public class PlaylistAdapter extends AbsMultiSelectAdapter<PlaylistAdapter.ViewH
     }
 
     public class ViewHolder extends MediaEntryViewHolder implements PopupMenu.OnMenuItemClickListener {
-        public ViewHolder(@NonNull View itemView, int itemViewType) {
+        public ViewHolder(@NonNull View itemView) {
             super(itemView);
 
             if (menu != null) {
diff --git a/app/src/main/java/com/dkanada/gramophone/adapter/album/HorizontalAlbumAdapter.java b/app/src/main/java/com/dkanada/gramophone/adapter/album/HorizontalAlbumAdapter.java
index b92de9c0..45393979 100644
--- a/app/src/main/java/com/dkanada/gramophone/adapter/album/HorizontalAlbumAdapter.java
+++ b/app/src/main/java/com/dkanada/gramophone/adapter/album/HorizontalAlbumAdapter.java
@@ -29,6 +29,7 @@ public class HorizontalAlbumAdapter extends AlbumAdapter {
     protected ViewHolder createViewHolder(View view, int viewType) {
         ViewGroup.MarginLayoutParams params = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
         HorizontalAdapterHelper.applyMarginToLayoutParams(activity, params, viewType);
+
         return new ViewHolder(view);
     }
 
diff --git a/app/src/main/java/com/dkanada/gramophone/adapter/artist/ArtistAdapter.java b/app/src/main/java/com/dkanada/gramophone/adapter/artist/ArtistAdapter.java
index f7c28257..b2df2462 100644
--- a/app/src/main/java/com/dkanada/gramophone/adapter/artist/ArtistAdapter.java
+++ b/app/src/main/java/com/dkanada/gramophone/adapter/artist/ArtistAdapter.java
@@ -72,10 +72,7 @@ public class ArtistAdapter extends AbsMultiSelectAdapter<ArtistAdapter.ViewHolde
     @NonNull
     public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         View view = LayoutInflater.from(activity).inflate(itemLayoutRes, parent, false);
-        return createViewHolder(view);
-    }
 
-    protected ViewHolder createViewHolder(View view) {
         return new ViewHolder(view);
     }
 
diff --git a/app/src/main/java/com/dkanada/gramophone/helper/menu/SongMenuHelper.java b/app/src/main/java/com/dkanada/gramophone/helper/menu/SongMenuHelper.java
index 00780957..aa1ff44e 100644
--- a/app/src/main/java/com/dkanada/gramophone/helper/menu/SongMenuHelper.java
+++ b/app/src/main/java/com/dkanada/gramophone/helper/menu/SongMenuHelper.java
@@ -50,6 +50,7 @@ public class SongMenuHelper {
                 NavigationUtil.startArtist(activity, new Artist(song), null);
                 return true;
         }
+
         return false;
     }
 
diff --git a/app/src/main/res/values-de/strings.xml b/app/src/main/res/values-de/strings.xml
index 348ee7f9..b5745768 100644
--- a/app/src/main/res/values-de/strings.xml
+++ b/app/src/main/res/values-de/strings.xml
@@ -153,7 +153,6 @@
     <string name="action_sort_method">Sortierungsmethode</string>
     <string name="action_new_playlist">Neue Wiedergabeliste</string>
     <string name="black_theme_name">Schwarz</string>
-    <string name="pref_header_images">Bilder</string>
     <string name="pref_title_maximum_bitrate">Maximale Bitrate</string>
     <string name="pref_title_remember_queue">Warteschlange merken</string>
     <string name="pref_title_page_size">Maximale Listengröße</string>
@@ -170,8 +169,4 @@
     <string name="error_version">Bitte update den Server auf die aktuellste Version.</string>
     <string name="error_share_file">Die Datei konnte nicht geteilt werden.</string>
     <string name="pref_title_transcode_codec">Transkodierungs-Codec</string>
-    <string name="field_cannot_be_empty">Das Feld darf nicht leer sein.</string>
-    <string name="server_is_unreachable">Server nicht erreichbar.</string>
-    <string name="authentication_failed">Authentifizierung fehlgeschlagen.</string>
-    <string name="no_network_connection_available">Keine Netzwerkverbindung verfügbar.</string>
 </resources>
diff --git a/app/src/main/res/values-fr/strings.xml b/app/src/main/res/values-fr/strings.xml
index d15fb443..9f06c980 100644
--- a/app/src/main/res/values-fr/strings.xml
+++ b/app/src/main/res/values-fr/strings.xml
@@ -140,7 +140,6 @@
     <string name="sort_method_year">Année</string>
     <string name="error_unreachable_server">Impossible de contacter le serveur.</string>
     <string name="error_login_credentials">Identifiants de connexion invalides.</string>
-    <string name="error_login_empty_address">Veuillez saisir l\'adresse du serveur.</string>
     <string name="error_unexpected">Une erreur inattendue s\'est produite.</string>
     <string name="action_add_to_playlist">Ajouter à une playlist</string>
     <string name="action_add_to_queue">Ajouter à la liste de lecture</string>
@@ -160,7 +159,6 @@
     <string name="flat">Flat</string>
     <string name="logout">Déconnexion</string>
     <string name="name">Nom</string>
-    <string name="pref_header_images">Images</string>
     <string name="pref_summary_remember_queue">Enregistrer la liste de lecture à la fermeture de l\'application pour la conserver entre différentes utilisations.</string>
     <string name="pref_summary_remember_shuffle">Le mode aléatoire sera conservé au choix d\'une nouvelle liste de titres pour la liste de lecture.</string>
     <string name="pref_title_image_cache_size">Taille du cache</string>
@@ -177,5 +175,4 @@
     <string name="source">Source</string>
     <string name="unlimited">Illimité</string>
     <string name="select_all_title">Sélectionner tout</string>
-    <string name="error_no_username">Veuillez saisir votre nom d\'utilisateur.</string>
 </resources>