Use local filtering. Use long class instead of primitives again for database keys (they can be null)

app/src/main/java/eu/kanade/mangafeed/data/database/models/Chapter.java

@@ -10,10 +10,10 @@ import eu.kanade.mangafeed.util.UrlUtil;
 public class Chapter {
 
     @StorIOSQLiteColumn(name = ChapterTable.COLUMN_ID, key = true)
-    public long id;
+    public Long id;
 
     @StorIOSQLiteColumn(name = ChapterTable.COLUMN_MANGA_ID)
-    public long manga_id;
+    public Long manga_id;
 
     @StorIOSQLiteColumn(name = ChapterTable.COLUMN_URL)
     public String url;

app/src/main/java/eu/kanade/mangafeed/data/database/models/Manga.java

@@ -10,7 +10,7 @@ import eu.kanade.mangafeed.util.UrlUtil;
 public class Manga {
 
     @StorIOSQLiteColumn(name = MangaTable.COLUMN_ID, key = true)
-    public long id;
+    public Long id;
 
     @StorIOSQLiteColumn(name = MangaTable.COLUMN_SOURCE)
     public int source;

app/src/main/java/eu/kanade/mangafeed/data/download/DownloadManager.java

@@ -133,7 +133,7 @@ public class DownloadManager {
     private boolean prepareDownload(Download download) {
         // If the chapter is already queued, don't add it again
         for (Download queuedDownload : queue.get()) {
-            if (download.chapter.id == queuedDownload.chapter.id)
+            if (download.chapter.id.equals(queuedDownload.chapter.id))
                 return true;
         }
 

app/src/main/java/eu/kanade/mangafeed/data/download/model/DownloadQueue.java

@@ -31,7 +31,7 @@ public class DownloadQueue {
 
     public void remove(Chapter chapter) {
         for (Download download : queue) {
-            if (download.chapter.id == chapter.id) {
+            if (download.chapter.id.equals(chapter.id)) {
                 remove(download);
                 break;
             }

app/src/main/java/eu/kanade/mangafeed/ui/catalogue/CatalogueFragment.java

@@ -155,7 +155,7 @@ public class CatalogueFragment extends BaseRxFragment<CataloguePresenter> {
 
     private int getMangaIndex(Manga manga) {
         for (int i = adapter.getCount() - 1; i >= 0; i--) {
-            if (manga.id == adapter.getItem(i).id) {
+            if (manga.id.equals(adapter.getItem(i).id)) {
                 return i;
             }
         }

app/src/main/java/eu/kanade/mangafeed/ui/manga/chapter/ChaptersFragment.java

@@ -160,13 +160,13 @@ public class ChaptersFragment extends BaseRxFragment<ChaptersPresenter> implemen
     public void onEventMainThread(DownloadStatusEvent event) {
         Manga manga = getPresenter().getManga();
         // If the download status is from another manga, don't bother
-        if (manga != null && event.getChapter().manga_id != manga.id)
+        if (manga != null && !event.getChapter().manga_id.equals(manga.id))
             return;
 
         Chapter chapter;
         for (int i = 0; i < adapter.getItemCount(); i++) {
             chapter = adapter.getItem(i);
-            if (event.getChapter().id == chapter.id) {
+            if (event.getChapter().id.equals(chapter.id)) {
                 chapter.status = event.getStatus();
                 adapter.notifyItemChanged(i);
                 break;

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

@@ -24,6 +24,7 @@ import eu.kanade.mangafeed.util.PostResult;
 import rx.Observable;
 import rx.android.schedulers.AndroidSchedulers;
 import rx.schedulers.Schedulers;
+import rx.subjects.PublishSubject;
 
 public class ChaptersPresenter extends BasePresenter<ChaptersFragment> {
 
@@ -34,11 +35,14 @@ public class ChaptersPresenter extends BasePresenter<ChaptersFragment> {
 
     private Manga manga;
     private Source source;
+    private List<Chapter> chapters;
     private boolean isCatalogueManga;
     private boolean sortOrderAToZ = true;
     private boolean onlyUnread = true;
     private boolean onlyDownloaded;
 
+    private PublishSubject<List<Chapter>> chaptersSubject;
+
     private static final int DB_CHAPTERS = 1;
     private static final int FETCH_CHAPTERS = 2;
 
@@ -46,12 +50,11 @@ public class ChaptersPresenter extends BasePresenter<ChaptersFragment> {
     protected void onCreate(Bundle savedState) {
         super.onCreate(savedState);
 
+        chaptersSubject = PublishSubject.create();
+
         restartableLatestCache(DB_CHAPTERS,
                 this::getDbChaptersObs,
-                (view, chapters) -> {
-                    view.onNextChapters(chapters);
-                    EventBus.getDefault().postSticky(new ChapterCountEvent(chapters.size()));
-                }
+                ChaptersFragment::onNextChapters
         );
 
         restartableLatestCache(FETCH_CHAPTERS,
@@ -85,6 +88,14 @@ public class ChaptersPresenter extends BasePresenter<ChaptersFragment> {
             source = sourceManager.get(manga.source);
             start(DB_CHAPTERS);
 
+            add(db.getChapters(manga).createObservable()
+                    .subscribeOn(Schedulers.io())
+                    .doOnNext(chapters -> {
+                        this.chapters = chapters;
+                        EventBus.getDefault().postSticky(new ChapterCountEvent(chapters.size()));
+                    })
+                    .subscribe(chaptersSubject::onNext));
+
             // Get chapters if it's an online source
             if (isCatalogueManga) {
                 fetchChapters();
@@ -96,14 +107,6 @@ public class ChaptersPresenter extends BasePresenter<ChaptersFragment> {
         start(FETCH_CHAPTERS);
     }
 
-    private Observable<List<Chapter>> getDbChaptersObs() {
-        return db.getChapters(manga.id, sortOrderAToZ, onlyUnread).createObservable()
-                .doOnNext(this::checkChaptersStatus)
-                .flatMap(this::applyDownloadedFilter)
-                .subscribeOn(Schedulers.io())
-                .observeOn(AndroidSchedulers.mainThread());
-    }
-
     private Observable<PostResult> getOnlineChaptersObs() {
         return source
                 .pullChaptersFromNetwork(manga.url)
@@ -112,16 +115,54 @@ public class ChaptersPresenter extends BasePresenter<ChaptersFragment> {
                 .observeOn(AndroidSchedulers.mainThread());
     }
 
+    private Observable<List<Chapter>> getDbChaptersObs() {
+        return chaptersSubject
+                .observeOn(Schedulers.io())
+                .flatMap(this::applyChapterFilters)
+                .observeOn(AndroidSchedulers.mainThread());
+    }
+
+    private Observable<List<Chapter>> applyChapterFilters(List<Chapter> chapters) {
+        Observable<Chapter> observable = Observable.from(chapters);
+        if (onlyUnread) {
+            observable = observable.filter(chapter -> !chapter.read);
+        }
+
+        observable = observable.doOnNext(this::setChapterStatus);
+        if (onlyDownloaded) {
+            observable = observable.filter(chapter -> chapter.status == Download.DOWNLOADED);
+        }
+        return observable.toSortedList((chapter, chapter2) -> {
+            if (sortOrderAToZ) {
+                return Float.compare(chapter.chapter_number, chapter2.chapter_number);
+            } else {
+                return Float.compare(chapter2.chapter_number, chapter.chapter_number);
+            }
+        });
+    }
+
+    private void setChapterStatus(Chapter chapter) {
+        for (Download download : downloadManager.getQueue().get()) {
+            if (chapter.id.equals(download.chapter.id)) {
+                chapter.status = download.getStatus();
+                return;
+            }
+        }
+
+        if (downloadManager.isChapterDownloaded(source, manga, chapter)) {
+            chapter.status = Download.DOWNLOADED;
+        } else {
+            chapter.status = Download.NOT_DOWNLOADED;
+        }
+    }
+
     public void onOpenChapter(Chapter chapter) {
         EventBus.getDefault().postSticky(new ReaderEvent(source, manga, chapter));
     }
 
     public Chapter getNextUnreadChapter() {
         List<Chapter> chapters = db.getNextUnreadChapter(manga).executeAsBlocking();
-        if (chapters.isEmpty()) {
-            return null;
-        }
-        return chapters.get(0);
+        return !chapters.isEmpty() ? chapters.get(0) : null;
     }
 
     public void markChaptersRead(Observable<Chapter> selectedChapters, boolean read) {
@@ -154,51 +195,21 @@ public class ChaptersPresenter extends BasePresenter<ChaptersFragment> {
                 }));
     }
 
-    private void checkChaptersStatus(List<Chapter> chapters) {
-        for (Chapter chapter : chapters) {
-            checkIsChapterDownloaded(chapter);
-        }
-    }
-
-    private void checkIsChapterDownloaded(Chapter chapter) {
-        for (Download download : downloadManager.getQueue().get()) {
-            if (chapter.id == download.chapter.id) {
-                chapter.status = download.getStatus();
-                return;
-            }
-        }
-
-        if (downloadManager.isChapterDownloaded(source, manga, chapter)) {
-            chapter.status = Download.DOWNLOADED;
-        } else {
-            chapter.status = Download.NOT_DOWNLOADED;
-        }
-    }
-
-    private Observable<List<Chapter>> applyDownloadedFilter(List<Chapter> chapters) {
-        if (onlyDownloaded)
-            return Observable.from(chapters)
-                    .filter(chapter -> chapter.status == Download.DOWNLOADED)
-                    .toList();
-
-        return Observable.just(chapters);
-    }
-
     public void revertSortOrder() {
         //TODO manga.chapter_order
         sortOrderAToZ = !sortOrderAToZ;
-        start(DB_CHAPTERS);
+        chaptersSubject.onNext(chapters);
     }
 
     public void setReadFilter(boolean onlyUnread) {
         //TODO do we need save filter for manga?
         this.onlyUnread = onlyUnread;
-        start(DB_CHAPTERS);
+        chaptersSubject.onNext(chapters);
     }
 
     public void setDownloadedFilter(boolean onlyDownloaded) {
         this.onlyDownloaded = onlyDownloaded;
-        start(DB_CHAPTERS);
+        chaptersSubject.onNext(chapters);
     }
 
     public void setIsCatalogueManga(boolean value) {

app/src/main/java/eu/kanade/mangafeed/ui/reader/ReaderPresenter.java

@@ -215,10 +215,7 @@ public class ReaderPresenter extends BasePresenter<ReaderActivity> {
 
     // Check whether the given chapter is downloaded
     public boolean isChapterDownloaded(Chapter chapter) {
-        File dir = downloadManager.getAbsoluteChapterDirectory(source, manga, chapter);
-        List<Page> pageList = downloadManager.getSavedPageList(source, manga, chapter);
-
-        return pageList != null && pageList.size() + 1 == dir.listFiles().length;
+        return downloadManager.isChapterDownloaded(source, manga, chapter);
     }
 
     // Called before loading another chapter or leaving the reader. It allows to do operations