From f98222c372199d0d64a4fd3650294509e528610e Mon Sep 17 00:00:00 2001
From: Eugene Cheung <ey.cheung@outlook.com>
Date: Wed, 5 Sep 2018 23:01:45 -0400
Subject: [PATCH] Some NonNull annotations

---
 app/src/main/java/com/kabouzeid/gramophone/App.java    |  3 ++-
 .../gramophone/adapter/AlbumCoverPagerAdapter.java     |  7 ++++---
 .../gramophone/adapter/CategoryInfoAdapter.java        |  7 ++++---
 .../com/kabouzeid/gramophone/adapter/GenreAdapter.java |  2 +-
 .../kabouzeid/gramophone/adapter/PlaylistAdapter.java  |  4 ++--
 .../kabouzeid/gramophone/adapter/SearchAdapter.java    |  4 ++--
 .../kabouzeid/gramophone/adapter/SongFileAdapter.java  |  7 ++++---
 .../gramophone/adapter/album/AlbumAdapter.java         |  4 ++--
 .../gramophone/adapter/artist/ArtistAdapter.java       |  3 ++-
 .../gramophone/adapter/song/ArtistSongAdapter.java     |  4 ++--
 .../kabouzeid/gramophone/adapter/song/SongAdapter.java |  4 ++--
 .../kabouzeid/gramophone/dialogs/DonationsDialog.java  |  5 +++--
 .../preferences/NowPlayingScreenPreferenceDialog.java  |  7 ++++---
 .../com/kabouzeid/gramophone/service/MultiPlayer.java  |  4 ++--
 .../gramophone/ui/activities/GenreDetailActivity.java  |  5 +++--
 .../ui/fragments/AbsMusicServiceFragment.java          |  3 ++-
 .../mainactivity/folders/FoldersFragment.java          | 10 +++++-----
 .../mainactivity/library/pager/GenresFragment.java     |  5 +++--
 .../ui/fragments/player/MiniPlayerFragment.java        |  3 ++-
 .../ui/fragments/player/PlayerAlbumCoverFragment.java  |  6 +++---
 .../ui/fragments/player/card/CardPlayerFragment.java   |  5 +++--
 .../card/CardPlayerPlaybackControlsFragment.java       |  4 ++--
 .../ui/fragments/player/flat/FlatPlayerFragment.java   |  5 +++--
 .../flat/FlatPlayerPlaybackControlsFragment.java       |  6 +++---
 24 files changed, 65 insertions(+), 52 deletions(-)

diff --git a/app/src/main/java/com/kabouzeid/gramophone/App.java b/app/src/main/java/com/kabouzeid/gramophone/App.java
index 951c7df7..76a0b111 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/App.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/App.java
@@ -2,6 +2,7 @@ package com.kabouzeid.gramophone;
 
 import android.app.Application;
 import android.os.Build;
+import android.support.annotation.NonNull;
 
 import com.anjlab.android.iab.v3.BillingProcessor;
 import com.anjlab.android.iab.v3.TransactionDetails;
@@ -42,7 +43,7 @@ public class App extends Application {
         // automatically restores purchases
         billingProcessor = new BillingProcessor(this, App.GOOGLE_PLAY_LICENSE_KEY, new BillingProcessor.IBillingHandler() {
             @Override
-            public void onProductPurchased(String productId, TransactionDetails details) {
+            public void onProductPurchased(@NonNull String productId, TransactionDetails details) {
             }
 
             @Override
diff --git a/app/src/main/java/com/kabouzeid/gramophone/adapter/AlbumCoverPagerAdapter.java b/app/src/main/java/com/kabouzeid/gramophone/adapter/AlbumCoverPagerAdapter.java
index 674de0fd..abaeea28 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/adapter/AlbumCoverPagerAdapter.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/adapter/AlbumCoverPagerAdapter.java
@@ -2,6 +2,7 @@ package com.kabouzeid.gramophone.adapter;
 
 import android.content.SharedPreferences;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentManager;
 import android.view.LayoutInflater;
@@ -49,6 +50,7 @@ public class AlbumCoverPagerAdapter extends CustomFragmentStatePagerAdapter {
     }
 
     @Override
+    @NonNull
     public Object instantiateItem(ViewGroup container, int position) {
         Object o = super.instantiateItem(container, position);
         if (currentColorReceiver != null && currentColorReceiverPosition == position) {
@@ -101,15 +103,14 @@ public class AlbumCoverPagerAdapter extends CustomFragmentStatePagerAdapter {
         }
 
         @Override
-        public View onCreateView(LayoutInflater inflater, ViewGroup container,
-                                 Bundle savedInstanceState) {
+        public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
             View view = inflater.inflate(R.layout.fragment_album_cover, container, false);
             unbinder = ButterKnife.bind(this, view);
             return view;
         }
 
         @Override
-        public void onViewCreated(View view, Bundle savedInstanceState) {
+        public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
             super.onViewCreated(view, savedInstanceState);
             forceSquareAlbumCover(false);
             // TODO
diff --git a/app/src/main/java/com/kabouzeid/gramophone/adapter/CategoryInfoAdapter.java b/app/src/main/java/com/kabouzeid/gramophone/adapter/CategoryInfoAdapter.java
index 7dead410..7026290a 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/adapter/CategoryInfoAdapter.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/adapter/CategoryInfoAdapter.java
@@ -1,6 +1,7 @@
 package com.kabouzeid.gramophone.adapter;
 
 import android.annotation.SuppressLint;
+import android.support.annotation.NonNull;
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.helper.ItemTouchHelper;
 import android.view.LayoutInflater;
@@ -28,14 +29,15 @@ public class CategoryInfoAdapter extends RecyclerView.Adapter<CategoryInfoAdapte
     }
 
     @Override
-    public CategoryInfoAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    @NonNull
+    public CategoryInfoAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.preference_dialog_library_categories_listitem, parent, false);
         return new ViewHolder(view);
     }
 
     @SuppressLint("ClickableViewAccessibility")
     @Override
-    public void onBindViewHolder(CategoryInfoAdapter.ViewHolder holder, int position) {
+    public void onBindViewHolder(@NonNull CategoryInfoAdapter.ViewHolder holder, int position) {
         CategoryInfo categoryInfo = categoryInfos.get(position);
 
         holder.checkBox.setChecked(categoryInfo.visible);
@@ -64,7 +66,6 @@ public class CategoryInfoAdapter extends RecyclerView.Adapter<CategoryInfoAdapte
         return categoryInfos.size();
     }
 
-
     public void setCategoryInfos(ArrayList<CategoryInfo> categoryInfos) {
         this.categoryInfos = categoryInfos;
         notifyDataSetChanged();
diff --git a/app/src/main/java/com/kabouzeid/gramophone/adapter/GenreAdapter.java b/app/src/main/java/com/kabouzeid/gramophone/adapter/GenreAdapter.java
index 32e178bf..b6cbe3ec 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/adapter/GenreAdapter.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/adapter/GenreAdapter.java
@@ -45,7 +45,7 @@ public class GenreAdapter extends RecyclerView.Adapter<GenreAdapter.ViewHolder>
 
     @NonNull
     @Override
-    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         View view = LayoutInflater.from(activity).inflate(itemLayoutRes, parent, false);
         return new ViewHolder(view);
     }
diff --git a/app/src/main/java/com/kabouzeid/gramophone/adapter/PlaylistAdapter.java b/app/src/main/java/com/kabouzeid/gramophone/adapter/PlaylistAdapter.java
index cf09942e..9d4360d2 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/adapter/PlaylistAdapter.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/adapter/PlaylistAdapter.java
@@ -73,9 +73,9 @@ public class PlaylistAdapter extends AbsMultiSelectAdapter<PlaylistAdapter.ViewH
         return dataSet.get(position).id;
     }
 
-    @NonNull
     @Override
-    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    @NonNull
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         View view = LayoutInflater.from(activity).inflate(itemLayoutRes, parent, false);
         return createViewHolder(view, viewType);
     }
diff --git a/app/src/main/java/com/kabouzeid/gramophone/adapter/SearchAdapter.java b/app/src/main/java/com/kabouzeid/gramophone/adapter/SearchAdapter.java
index 225423bf..d5b18621 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/adapter/SearchAdapter.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/adapter/SearchAdapter.java
@@ -57,9 +57,9 @@ public class SearchAdapter extends RecyclerView.Adapter<SearchAdapter.ViewHolder
         return HEADER;
     }
 
-    @NonNull
     @Override
-    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    @NonNull
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         if (viewType == HEADER)
             return new ViewHolder(LayoutInflater.from(activity).inflate(R.layout.sub_header, parent, false), viewType);
         return new ViewHolder(LayoutInflater.from(activity).inflate(R.layout.item_list, parent, false), viewType);
diff --git a/app/src/main/java/com/kabouzeid/gramophone/adapter/SongFileAdapter.java b/app/src/main/java/com/kabouzeid/gramophone/adapter/SongFileAdapter.java
index 2745423f..2d58b900 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/adapter/SongFileAdapter.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/adapter/SongFileAdapter.java
@@ -64,12 +64,13 @@ public class SongFileAdapter extends AbsMultiSelectAdapter<SongFileAdapter.ViewH
     }
 
     @Override
-    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    @NonNull
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         return new ViewHolder(LayoutInflater.from(activity).inflate(itemLayoutRes, parent, false));
     }
 
     @Override
-    public void onBindViewHolder(final ViewHolder holder, int index) {
+    public void onBindViewHolder(@NonNull ViewHolder holder, int index) {
         final File file = dataSet.get(index);
 
         holder.itemView.setActivated(isChecked(file));
@@ -207,4 +208,4 @@ public class SongFileAdapter extends AbsMultiSelectAdapter<SongFileAdapter.ViewH
 
         void onMultipleItemAction(MenuItem item, ArrayList<File> files);
     }
-}
\ No newline at end of file
+}
diff --git a/app/src/main/java/com/kabouzeid/gramophone/adapter/album/AlbumAdapter.java b/app/src/main/java/com/kabouzeid/gramophone/adapter/album/AlbumAdapter.java
index 02d8f960..a805223d 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/adapter/album/AlbumAdapter.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/adapter/album/AlbumAdapter.java
@@ -68,9 +68,9 @@ public class AlbumAdapter extends AbsMultiSelectAdapter<AlbumAdapter.ViewHolder,
         return dataSet;
     }
 
-    @NonNull
     @Override
-    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    @NonNull
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         View view = LayoutInflater.from(activity).inflate(itemLayoutRes, parent, false);
         return createViewHolder(view, viewType);
     }
diff --git a/app/src/main/java/com/kabouzeid/gramophone/adapter/artist/ArtistAdapter.java b/app/src/main/java/com/kabouzeid/gramophone/adapter/artist/ArtistAdapter.java
index 1d89aee6..3d176ff8 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/adapter/artist/ArtistAdapter.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/adapter/artist/ArtistAdapter.java
@@ -73,7 +73,8 @@ public class ArtistAdapter extends AbsMultiSelectAdapter<ArtistAdapter.ViewHolde
     }
 
     @Override
-    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    @NonNull
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         View view = LayoutInflater.from(activity).inflate(itemLayoutRes, parent, false);
         return createViewHolder(view);
     }
diff --git a/app/src/main/java/com/kabouzeid/gramophone/adapter/song/ArtistSongAdapter.java b/app/src/main/java/com/kabouzeid/gramophone/adapter/song/ArtistSongAdapter.java
index 3f4f7377..70bde8e7 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/adapter/song/ArtistSongAdapter.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/adapter/song/ArtistSongAdapter.java
@@ -59,9 +59,9 @@ public class ArtistSongAdapter extends ArrayAdapter<Song> implements MaterialCab
         notifyDataSetChanged();
     }
 
-    @Nullable
     @Override
-    public View getView(final int position, @Nullable View convertView, ViewGroup parent) {
+    @NonNull
+    public View getView(final int position, View convertView, @NonNull ViewGroup parent) {
         final Song song = getItem(position);
         if (convertView == null) {
             convertView = LayoutInflater.from(getContext()).inflate(R.layout.item_list, parent, false);
diff --git a/app/src/main/java/com/kabouzeid/gramophone/adapter/song/SongAdapter.java b/app/src/main/java/com/kabouzeid/gramophone/adapter/song/SongAdapter.java
index f959e7c2..209c0098 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/adapter/song/SongAdapter.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/adapter/song/SongAdapter.java
@@ -79,9 +79,9 @@ public class SongAdapter extends AbsMultiSelectAdapter<SongAdapter.ViewHolder, S
         return dataSet.get(position).id;
     }
 
-    @NonNull
     @Override
-    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    @NonNull
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         View view = LayoutInflater.from(activity).inflate(itemLayoutRes, parent, false);
         return createViewHolder(view);
     }
diff --git a/app/src/main/java/com/kabouzeid/gramophone/dialogs/DonationsDialog.java b/app/src/main/java/com/kabouzeid/gramophone/dialogs/DonationsDialog.java
index 5aafba0d..214a3f2b 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/dialogs/DonationsDialog.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/dialogs/DonationsDialog.java
@@ -83,7 +83,7 @@ public class DonationsDialog extends DialogFragment implements BillingProcessor.
     }
 
     @Override
-    public void onProductPurchased(String productId, TransactionDetails details) {
+    public void onProductPurchased(@NonNull String productId, TransactionDetails details) {
         loadSkuDetails();
         Toast.makeText(getContext(), R.string.thank_you, Toast.LENGTH_SHORT).show();
     }
@@ -183,7 +183,8 @@ public class DonationsDialog extends DialogFragment implements BillingProcessor.
         }
 
         @Override
-        public View getView(final int position, View convertView, ViewGroup parent) {
+        @NonNull
+        public View getView(final int position, View convertView, @NonNull ViewGroup parent) {
             if (convertView == null) {
                 convertView = LayoutInflater.from(getContext()).inflate(LAYOUT_RES_ID, parent, false);
             }
diff --git a/app/src/main/java/com/kabouzeid/gramophone/preferences/NowPlayingScreenPreferenceDialog.java b/app/src/main/java/com/kabouzeid/gramophone/preferences/NowPlayingScreenPreferenceDialog.java
index a1e11ba4..d3a509ce 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/preferences/NowPlayingScreenPreferenceDialog.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/preferences/NowPlayingScreenPreferenceDialog.java
@@ -95,7 +95,8 @@ public class NowPlayingScreenPreferenceDialog extends DialogFragment implements
         }
 
         @Override
-        public Object instantiateItem(ViewGroup collection, int position) {
+        @NonNull
+        public Object instantiateItem(@NonNull ViewGroup collection, int position) {
             NowPlayingScreen nowPlayingScreen = NowPlayingScreen.values()[position];
 
             LayoutInflater inflater = LayoutInflater.from(context);
@@ -111,7 +112,7 @@ public class NowPlayingScreenPreferenceDialog extends DialogFragment implements
         }
 
         @Override
-        public void destroyItem(ViewGroup collection, int position, Object view) {
+        public void destroyItem(@NonNull ViewGroup collection, int position, @NonNull Object view) {
             collection.removeView((View) view);
         }
 
@@ -121,7 +122,7 @@ public class NowPlayingScreenPreferenceDialog extends DialogFragment implements
         }
 
         @Override
-        public boolean isViewFromObject(View view, Object object) {
+        public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
             return view == object;
         }
 
diff --git a/app/src/main/java/com/kabouzeid/gramophone/service/MultiPlayer.java b/app/src/main/java/com/kabouzeid/gramophone/service/MultiPlayer.java
index 8a89b71f..ebed4d17 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/service/MultiPlayer.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/service/MultiPlayer.java
@@ -144,7 +144,7 @@ public class MultiPlayer implements Playback, MediaPlayer.OnErrorListener, Media
      * @param callbacks The callbacks to use
      */
     @Override
-    public void setCallbacks(final Playback.PlaybackCallbacks callbacks) {
+    public void setCallbacks(@Nullable Playback.PlaybackCallbacks callbacks) {
         this.callbacks = callbacks;
     }
 
@@ -329,4 +329,4 @@ public class MultiPlayer implements Playback, MediaPlayer.OnErrorListener, Media
                 callbacks.onTrackEnded();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/app/src/main/java/com/kabouzeid/gramophone/ui/activities/GenreDetailActivity.java b/app/src/main/java/com/kabouzeid/gramophone/ui/activities/GenreDetailActivity.java
index fb2df74a..45b52552 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/ui/activities/GenreDetailActivity.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/ui/activities/GenreDetailActivity.java
@@ -173,18 +173,19 @@ public class GenreDetailActivity extends AbsSlidingMusicPanelActivity implements
     }
 
     @Override
+    @NonNull
     public Loader<ArrayList<Song>> onCreateLoader(int id, Bundle args) {
         return new GenreDetailActivity.AsyncGenreSongLoader(this, genre);
     }
 
     @Override
-    public void onLoadFinished(Loader<ArrayList<Song>> loader, ArrayList<Song> data) {
+    public void onLoadFinished(@NonNull Loader<ArrayList<Song>> loader, ArrayList<Song> data) {
         if (adapter != null)
             adapter.swapDataSet(data);
     }
 
     @Override
-    public void onLoaderReset(Loader<ArrayList<Song>> loader) {
+    public void onLoaderReset(@NonNull Loader<ArrayList<Song>> loader) {
         if (adapter != null)
             adapter.swapDataSet(new ArrayList<>());
     }
diff --git a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/AbsMusicServiceFragment.java b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/AbsMusicServiceFragment.java
index 05193ab3..17baf1e8 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/AbsMusicServiceFragment.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/AbsMusicServiceFragment.java
@@ -2,6 +2,7 @@ package com.kabouzeid.gramophone.ui.fragments;
 
 import android.content.Context;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.Fragment;
 import android.view.View;
 
@@ -31,7 +32,7 @@ public class AbsMusicServiceFragment extends Fragment implements MusicServiceEve
     }
 
     @Override
-    public void onViewCreated(View view, Bundle savedInstanceState) {
+    public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
         activity.addMusicServiceEventListener(this);
     }
diff --git a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/mainactivity/folders/FoldersFragment.java b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/mainactivity/folders/FoldersFragment.java
index b5fec7ac..172f606c 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/mainactivity/folders/FoldersFragment.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/mainactivity/folders/FoldersFragment.java
@@ -130,7 +130,7 @@ public class FoldersFragment extends AbsMainActivityFragment implements MainActi
     }
 
     @Override
-    public void onSaveInstanceState(Bundle outState) {
+    public void onSaveInstanceState(@NonNull Bundle outState) {
         super.onSaveInstanceState(outState);
         outState.putParcelable(CRUMBS, breadCrumbs.getStateWrapper());
     }
@@ -147,14 +147,14 @@ public class FoldersFragment extends AbsMainActivityFragment implements MainActi
     }
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View view = inflater.inflate(R.layout.fragment_folder, container, false);
         unbinder = ButterKnife.bind(this, view);
         return view;
     }
 
     @Override
-    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
         getMainActivity().setStatusbarColorAuto();
         getMainActivity().setNavigationbarColorAuto();
         getMainActivity().setTaskDescriptionColorAuto();
@@ -466,12 +466,12 @@ public class FoldersFragment extends AbsMainActivityFragment implements MainActi
     }
 
     @Override
-    public void onLoadFinished(Loader<List<File>> loader, List<File> data) {
+    public void onLoadFinished(@NonNull Loader<List<File>> loader, List<File> data) {
         updateAdapter(data);
     }
 
     @Override
-    public void onLoaderReset(Loader<List<File>> loader) {
+    public void onLoaderReset(@NonNull Loader<List<File>> loader) {
         updateAdapter(new LinkedList<>());
     }
 
diff --git a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/mainactivity/library/pager/GenresFragment.java b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/mainactivity/library/pager/GenresFragment.java
index e6a5c8ed..e856b6ab 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/mainactivity/library/pager/GenresFragment.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/mainactivity/library/pager/GenresFragment.java
@@ -50,17 +50,18 @@ public class GenresFragment extends AbsLibraryPagerRecyclerViewFragment<GenreAda
     }
 
     @Override
+    @NonNull
     public Loader<ArrayList<Genre>> onCreateLoader(int id, Bundle args) {
         return new GenresFragment.AsyncGenreLoader(getActivity());
     }
 
     @Override
-    public void onLoadFinished(Loader<ArrayList<Genre>> loader, ArrayList<Genre> data) {
+    public void onLoadFinished(@NonNull Loader<ArrayList<Genre>> loader, ArrayList<Genre> data) {
         getAdapter().swapDataSet(data);
     }
 
     @Override
-    public void onLoaderReset(Loader<ArrayList<Genre>> loader) {
+    public void onLoaderReset(@NonNull Loader<ArrayList<Genre>> loader) {
         getAdapter().swapDataSet(new ArrayList<>());
     }
 
diff --git a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/MiniPlayerFragment.java b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/MiniPlayerFragment.java
index ccfe700e..bd2af36e 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/MiniPlayerFragment.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/MiniPlayerFragment.java
@@ -4,6 +4,7 @@ import android.content.Context;
 import android.content.res.ColorStateList;
 import android.graphics.PorterDuff;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.view.GestureDetector;
 import android.view.LayoutInflater;
@@ -53,7 +54,7 @@ public class MiniPlayerFragment extends AbsMusicServiceFragment implements Music
 
     @Nullable
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         return inflater.inflate(R.layout.fragment_mini_player, container, false);
     }
 
diff --git a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/PlayerAlbumCoverFragment.java b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/PlayerAlbumCoverFragment.java
index 70d8aaa5..723f021d 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/PlayerAlbumCoverFragment.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/PlayerAlbumCoverFragment.java
@@ -2,6 +2,7 @@ package com.kabouzeid.gramophone.ui.fragments.player;
 
 import android.animation.Animator;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.view.ViewPager;
 import android.view.GestureDetector;
 import android.view.LayoutInflater;
@@ -57,15 +58,14 @@ public class PlayerAlbumCoverFragment extends AbsMusicServiceFragment implements
     private MusicProgressViewUpdateHelper progressViewUpdateHelper;
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container,
-                             Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View view = inflater.inflate(R.layout.fragment_player_album_cover, container, false);
         unbinder = ButterKnife.bind(this, view);
         return view;
     }
 
     @Override
-    public void onViewCreated(View view, Bundle savedInstanceState) {
+    public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
         viewPager.addOnPageChangeListener(this);
         viewPager.setOnTouchListener(new View.OnTouchListener() {
diff --git a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/card/CardPlayerFragment.java b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/card/CardPlayerFragment.java
index 81f0da0b..4732b4dc 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/card/CardPlayerFragment.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/card/CardPlayerFragment.java
@@ -10,6 +10,7 @@ import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Bundle;
 import android.support.annotation.ColorInt;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.CardView;
@@ -98,7 +99,7 @@ public class CardPlayerFragment extends AbsPlayerFragment implements PlayerAlbum
     private Impl impl;
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         if (Util.isLandscape(getResources())) {
             impl = new LandscapeImpl(this);
         } else {
@@ -111,7 +112,7 @@ public class CardPlayerFragment extends AbsPlayerFragment implements PlayerAlbum
     }
 
     @Override
-    public void onViewCreated(final View view, Bundle savedInstanceState) {
+    public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
 
         impl.init();
diff --git a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/card/CardPlayerPlaybackControlsFragment.java b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/card/CardPlayerPlaybackControlsFragment.java
index 44b66859..e855dba0 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/card/CardPlayerPlaybackControlsFragment.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/card/CardPlayerPlaybackControlsFragment.java
@@ -3,6 +3,7 @@ package com.kabouzeid.gramophone.ui.fragments.player.card;
 import android.graphics.Color;
 import android.graphics.PorterDuff;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.design.widget.FloatingActionButton;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -68,8 +69,7 @@ public class CardPlayerPlaybackControlsFragment extends AbsMusicServiceFragment
     }
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container,
-                             Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         return inflater.inflate(R.layout.fragment_card_player_playback_controls, container, false);
     }
 
diff --git a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/flat/FlatPlayerFragment.java b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/flat/FlatPlayerFragment.java
index 624df918..c11e015e 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/flat/FlatPlayerFragment.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/flat/FlatPlayerFragment.java
@@ -9,6 +9,7 @@ import android.graphics.drawable.Drawable;
 import android.os.AsyncTask;
 import android.os.Bundle;
 import android.support.annotation.ColorInt;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.LinearLayoutManager;
@@ -94,7 +95,7 @@ public class FlatPlayerFragment extends AbsPlayerFragment implements PlayerAlbum
     private Impl impl;
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         if (Util.isLandscape(getResources())) {
             impl = new LandscapeImpl(this);
         } else {
@@ -107,7 +108,7 @@ public class FlatPlayerFragment extends AbsPlayerFragment implements PlayerAlbum
     }
 
     @Override
-    public void onViewCreated(final View view, Bundle savedInstanceState) {
+    public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
 
         impl.init();
diff --git a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/flat/FlatPlayerPlaybackControlsFragment.java b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/flat/FlatPlayerPlaybackControlsFragment.java
index c28d8fa5..b7b7f467 100644
--- a/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/flat/FlatPlayerPlaybackControlsFragment.java
+++ b/app/src/main/java/com/kabouzeid/gramophone/ui/fragments/player/flat/FlatPlayerPlaybackControlsFragment.java
@@ -7,6 +7,7 @@ import android.animation.TimeInterpolator;
 import android.graphics.Color;
 import android.graphics.PorterDuff;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.view.animation.FastOutSlowInInterpolator;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -76,13 +77,12 @@ public class FlatPlayerPlaybackControlsFragment extends AbsMusicServiceFragment
     }
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container,
-                             Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         return inflater.inflate(R.layout.fragment_flat_player_playback_controls, container, false);
     }
 
     @Override
-    public void onViewCreated(View view, Bundle savedInstanceState) {
+    public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
         unbinder = ButterKnife.bind(this, view);
         setUpMusicControllers();