#2966 RxJava2 null - explicit mark underlying Rx sources as NonNull

to be on the safe side, for cases that the consuming observers checks null
unnecessarily.

Rx observer : underlying sources marked as NonNull
OnlineFeedViewActivity.startFeedDownload : Downloader.getResult
AllEpisodesFragment.loadItems : AllEpisodesFragment.loadData
PlaybackHistoryFragment.loadItems : DBReader.getPlaybackHistory
QueueFragment.loadItems : DBReader.getQueue
SearchFragment.search : .performSearch

app/src/main/java/de/danoeh/antennapod/activity/OnlineFeedViewActivity.java

@@ -5,6 +5,7 @@ import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.annotation.UiThread;
 import android.support.v4.app.NavUtils;
 import android.support.v7.app.ActionBar;
@@ -27,7 +28,6 @@ import android.widget.Spinner;
 import android.widget.TextView;
 
 import com.bumptech.glide.Glide;
-
 import com.bumptech.glide.request.RequestOptions;
 
 import org.apache.commons.lang3.StringUtils;
@@ -288,12 +288,7 @@ public class OnlineFeedViewActivity extends AppCompatActivity {
                         error -> Log.e(TAG, Log.getStackTraceString(error)));
     }
 
-    private void checkDownloadResult(DownloadStatus status) {
+    private void checkDownloadResult(@NonNull DownloadStatus status) {
-        if (status == null) {
-            Log.wtf(TAG, "DownloadStatus returned by Downloader was null");
-            finish();
-            return;
-        }
         if (status.isCancelled()) {
             return;
         }

app/src/main/java/de/danoeh/antennapod/fragment/AllEpisodesFragment.java

@@ -5,6 +5,7 @@ import android.content.DialogInterface;
 import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.os.Handler;
+import android.support.annotation.NonNull;
 import android.support.design.widget.Snackbar;
 import android.support.v4.app.Fragment;
 import android.support.v4.view.MenuItemCompat;
@@ -498,16 +499,15 @@ public class AllEpisodesFragment extends Fragment {
                 .subscribe(data -> {
                     recyclerView.setVisibility(View.VISIBLE);
                     progLoading.setVisibility(View.GONE);
-                    if (data != null) {
+                    episodes = data;
-                        episodes = data;
+                    itemsLoaded = true;
-                        itemsLoaded = true;
+                    if (viewsCreated) {
-                        if (viewsCreated) {
+                        onFragmentLoaded();
-                            onFragmentLoaded();
-                        }
                     }
                 }, error -> Log.e(TAG, Log.getStackTraceString(error)));
     }
 
+    @NonNull
     List<FeedItem> loadData() {
         return DBReader.getRecentlyPublishedEpisodes(RECENT_EPISODES_LIMIT);
     }

app/src/main/java/de/danoeh/antennapod/fragment/PlaybackHistoryFragment.java

@@ -3,6 +3,7 @@ package de.danoeh.antennapod.fragment;
 import android.content.Context;
 import android.content.res.TypedArray;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.ListFragment;
 import android.support.v4.view.MenuItemCompat;
 import android.util.Log;
@@ -293,6 +294,7 @@ public class PlaybackHistoryFragment extends ListFragment {
                 }, error -> Log.e(TAG, Log.getStackTraceString(error)));
     }
 
+    @NonNull
     private List<FeedItem> loadData() {
         List<FeedItem> history = DBReader.getPlaybackHistory();
         DBReader.loadAdditionalFeedItemListData(history);

app/src/main/java/de/danoeh/antennapod/fragment/QueueFragment.java

@@ -639,13 +639,11 @@ public class QueueFragment extends Fragment {
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(items -> {
-                    if(items != null) {
+                    progLoading.setVisibility(View.GONE);
-                        progLoading.setVisibility(View.GONE);
+                    queue = items;
-                        queue = items;
+                    onFragmentLoaded(restoreScrollPosition);
-                        onFragmentLoaded(restoreScrollPosition);
+                    if(recyclerAdapter != null) {
-                        if(recyclerAdapter != null) {
+                        recyclerAdapter.notifyDataSetChanged();
-                            recyclerAdapter.notifyDataSetChanged();
-                        }
                     }
                 }, error -> Log.e(TAG, Log.getStackTraceString(error)));
     }

app/src/main/java/de/danoeh/antennapod/fragment/SearchFragment.java

@@ -2,6 +2,7 @@ package de.danoeh.antennapod.fragment;
 
 import android.content.Context;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.v4.app.ListFragment;
 import android.support.v4.view.MenuItemCompat;
 import android.support.v7.app.AppCompatActivity;
@@ -215,16 +216,15 @@ public class SearchFragment extends ListFragment {
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(result -> {
-                    if (result != null) {
+                    itemsLoaded = true;
-                        itemsLoaded = true;
+                    searchResults = result;
-                        searchResults = result;
+                    if (viewCreated) {
-                        if (viewCreated) {
+                        onFragmentLoaded();
-                            onFragmentLoaded();
-                        }
                     }
                 }, error -> Log.e(TAG, Log.getStackTraceString(error)));
     }
 
+    @NonNull
     private List<SearchResult> performSearch() {
         Bundle args = getArguments();
         String query = args.getString(ARG_QUERY);

core/src/main/java/de/danoeh/antennapod/core/service/download/Downloader.java

@@ -2,6 +2,7 @@ package de.danoeh.antennapod.core.service.download;
 
 import android.content.Context;
 import android.net.wifi.WifiManager;
+import android.support.annotation.NonNull;
 
 import java.util.concurrent.Callable;
 
@@ -18,10 +19,12 @@ public abstract class Downloader implements Callable<Downloader> {
 
     volatile boolean cancelled;
 
+    @NonNull
     final DownloadRequest request;
+    @NonNull
     final DownloadStatus result;
 
-    Downloader(DownloadRequest request) {
+    Downloader(@NonNull DownloadRequest request) {
         super();
         this.request = request;
         this.request.setStatusMsg(R.string.download_pending);
@@ -54,10 +57,12 @@ public abstract class Downloader implements Callable<Downloader> {
         return this;
     }
 
+    @NonNull
     public DownloadRequest getDownloadRequest() {
         return request;
     }
 
+    @NonNull
     public DownloadStatus getResult() {
         return result;
     }

core/src/main/java/de/danoeh/antennapod/core/service/download/HttpDownloader.java

@@ -1,5 +1,6 @@
 package de.danoeh.antennapod.core.service.download;
 
+import android.support.annotation.NonNull;
 import android.text.TextUtils;
 import android.util.Log;
 
@@ -38,7 +39,7 @@ public class HttpDownloader extends Downloader {
 
     private static final int BUFFER_SIZE = 8 * 1024;
 
-    public HttpDownloader(DownloadRequest request) {
+    public HttpDownloader(@NonNull DownloadRequest request) {
         super(request);
     }
 

core/src/main/java/de/danoeh/antennapod/core/storage/DBReader.java

@@ -202,6 +202,7 @@ public final class DBReader {
         }
     }
 
+    @NonNull
     private static List<FeedItem> extractItemlistFromCursor(PodDBAdapter adapter, Cursor cursor) {
         List<FeedItem> result = new ArrayList<>(cursor.getCount());
 
@@ -254,6 +255,7 @@ public final class DBReader {
         return feed;
     }
 
+    @NonNull
     static List<FeedItem> getQueue(PodDBAdapter adapter) {
         Log.d(TAG, "getQueue()");
         Cursor cursor = null;
@@ -310,6 +312,7 @@ public final class DBReader {
      * @return A list of FeedItems sorted by the same order as the queue. The caller can wrap the returned
      * list in a {@link de.danoeh.antennapod.core.util.QueueAccess} object for easier access to the queue's properties.
      */
+    @NonNull
     public static List<FeedItem> getQueue() {
         Log.d(TAG, "getQueue() called");
 
@@ -418,6 +421,7 @@ public final class DBReader {
      *
      * @param limit The maximum number of episodes that should be loaded.
      */
+    @NonNull
     public static List<FeedItem> getRecentlyPublishedEpisodes(int limit) {
         Log.d(TAG, "getRecentlyPublishedEpisodes() called with: " + "limit = [" + limit + "]");
 
@@ -444,6 +448,7 @@ public final class DBReader {
      * @return The playback history. The FeedItems are sorted by their media's playbackCompletionDate in descending order.
      * The size of the returned list is limited by {@link #PLAYBACK_HISTORY_SIZE}.
      */
+    @NonNull
     public static List<FeedItem> getPlaybackHistory() {
         Log.d(TAG, "getPlaybackHistory() called");
 

core/src/main/java/de/danoeh/antennapod/core/storage/FeedSearcher.java

@@ -1,6 +1,7 @@
 package de.danoeh.antennapod.core.storage;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -35,6 +36,7 @@ public class FeedSearcher {
      * @param selectedFeed feed to search, 0 to search through all feeds
      * @return list of episodes containing the query
      */
+    @NonNull
     public static List<SearchResult> performSearch(final Context context,
                                                    final String query, final long selectedFeed) {
         final int values[] = {2, 1, 0, 0, 0, 0};
@@ -45,7 +47,7 @@ public class FeedSearcher {
                 context.getString(R.string.found_in_authors_label),
                 context.getString(R.string.found_in_feeds_label)};
 
-        List<SearchResult> result = new ArrayList<>();
+        final List<SearchResult> result = new ArrayList<>();
 
         List<FutureTask<List<FeedItem>>> tasks = new ArrayList<>();
         tasks.add(DBTasks.searchFeedItemTitle(context, selectedFeed, query));