Testing Paging 3 library.

app/build.gradle

@@ -51,8 +51,10 @@ dependencies {
     def lifecycleVersion = "2.2.0"
     implementation "androidx.lifecycle:lifecycle-livedata:$lifecycleVersion"
     implementation "androidx.lifecycle:lifecycle-viewmodel:$lifecycleVersion"
+    implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycleVersion"
     annotationProcessor "androidx.lifecycle:lifecycle-common-java8:$lifecycleVersion"
-    implementation 'androidx.paging:paging-runtime:3.0.0'
+    implementation 'androidx.paging:paging-runtime:3.0.1'
+    implementation "androidx.paging:paging-guava:3.0.1"
     implementation 'androidx.preference:preference:1.1.1'
     def roomVersion = "2.3.0"
     implementation "androidx.room:room-runtime:$roomVersion"
@@ -85,6 +87,7 @@ dependencies {
     def retrofitVersion = "2.9.0"
     implementation "com.squareup.retrofit2:retrofit:$retrofitVersion"
     implementation "com.squareup.retrofit2:converter-scalars:$retrofitVersion"
+    implementation "com.squareup.retrofit2:adapter-guava:$retrofitVersion"
     implementation 'com.squareup.okhttp3:okhttp:4.9.1'
 
     // Dependency injection

app/src/main/AndroidManifest.xml

@@ -34,7 +34,11 @@
         android:theme="@style/AppTheme"
         android:usesCleartextTraffic="true"
         tools:replace="android:label">
-        <activity android:name=".activities.WikiActivity"
+        <activity
+            android:name=".activities.Paging3TestActivity"
+            android:exported="true" />
+        <activity
+            android:name=".activities.WikiActivity"
             android:label="@string/wiki_activity_label"
             android:parentActivityName=".activities.MainActivity"
             android:theme="@style/AppTheme.Slidable" />

app/src/main/java/ml/docilealligator/infinityforreddit/AppComponent.java

@@ -25,6 +25,7 @@ import ml.docilealligator.infinityforreddit.activities.LockScreenActivity;
 import ml.docilealligator.infinityforreddit.activities.LoginActivity;
 import ml.docilealligator.infinityforreddit.activities.MainActivity;
 import ml.docilealligator.infinityforreddit.activities.MultiredditSelectionActivity;
+import ml.docilealligator.infinityforreddit.activities.Paging3TestActivity;
 import ml.docilealligator.infinityforreddit.activities.PostFilterPreferenceActivity;
 import ml.docilealligator.infinityforreddit.activities.PostFilterUsageListingActivity;
 import ml.docilealligator.infinityforreddit.activities.PostGalleryActivity;
@@ -286,4 +287,6 @@ public interface AppComponent {
     void inject(WikiActivity wikiActivity);
 
     void inject(Infinity infinity);
+
+    void inject(Paging3TestActivity paging3TestActivity);
 }

app/src/main/java/ml/docilealligator/infinityforreddit/AppModule.java

@@ -31,6 +31,7 @@ import ml.docilealligator.infinityforreddit.utils.SharedPreferencesUtils;
 import okhttp3.ConnectionPool;
 import okhttp3.OkHttpClient;
 import retrofit2.Retrofit;
+import retrofit2.adapter.guava.GuavaCallAdapterFactory;
 import retrofit2.converter.scalars.ScalarsConverterFactory;
 
 @Module
@@ -52,6 +53,18 @@ class AppModule {
                 .build();
     }
 
+    @Provides
+    @Named("paging_3_test")
+    @Singleton
+    Retrofit providePaging3TestRetrofit(@Named("default") OkHttpClient okHttpClient) {
+        return new Retrofit.Builder()
+                .baseUrl(APIUtils.OAUTH_API_BASE_URI)
+                .client(okHttpClient)
+                .addConverterFactory(ScalarsConverterFactory.create())
+                .addCallAdapterFactory(GuavaCallAdapterFactory.create())
+                .build();
+    }
+
     @Provides
     @Named("oauth_without_authenticator")
     @Singleton

app/src/main/java/ml/docilealligator/infinityforreddit/activities/MainActivity.java

@@ -729,8 +729,10 @@ public class MainActivity extends BaseActivity implements SortTypeSelectionCallb
                     }
                     break;
                 default:
-                    PostTypeBottomSheetFragment postTypeBottomSheetFragment = new PostTypeBottomSheetFragment();
-                    postTypeBottomSheetFragment.show(getSupportFragmentManager(), postTypeBottomSheetFragment.getTag());
+                    Intent intent = new Intent(this, Paging3TestActivity.class);
+                    startActivity(intent);
+                    /*PostTypeBottomSheetFragment postTypeBottomSheetFragment = new PostTypeBottomSheetFragment();
+                    postTypeBottomSheetFragment.show(getSupportFragmentManager(), postTypeBottomSheetFragment.getTag());*/
                     break;
             }
         });

app/src/main/java/ml/docilealligator/infinityforreddit/activities/Paging3TestActivity.java

@@ -0,0 +1,166 @@
+package ml.docilealligator.infinityforreddit.activities;
+
+import android.content.SharedPreferences;
+import android.os.Bundle;
+import android.util.DisplayMetrics;
+
+import androidx.lifecycle.ViewModelProvider;
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.transition.AutoTransition;
+import androidx.transition.TransitionManager;
+
+import java.util.Locale;
+import java.util.concurrent.Executor;
+
+import javax.inject.Inject;
+import javax.inject.Named;
+
+import im.ene.toro.exoplayer.ExoCreator;
+import ml.docilealligator.infinityforreddit.Infinity;
+import ml.docilealligator.infinityforreddit.R;
+import ml.docilealligator.infinityforreddit.RedditDataRoomDatabase;
+import ml.docilealligator.infinityforreddit.SortType;
+import ml.docilealligator.infinityforreddit.adapters.Paging3TestAdapter;
+import ml.docilealligator.infinityforreddit.customtheme.CustomThemeWrapper;
+import ml.docilealligator.infinityforreddit.fragments.PostFragment;
+import ml.docilealligator.infinityforreddit.post.PostDataSource;
+import ml.docilealligator.infinityforreddit.post.PostPaging3ViewModel;
+import ml.docilealligator.infinityforreddit.utils.SharedPreferencesUtils;
+import retrofit2.Retrofit;
+
+public class Paging3TestActivity extends BaseActivity {
+
+    @Inject
+    @Named("no_oauth")
+    Retrofit mRetrofit;
+    @Inject
+    @Named("oauth")
+    Retrofit mOauthRetrofit;
+    @Inject
+    @Named("paging_3_test")
+    Retrofit mPaging3Retrofit;
+    @Inject
+    @Named("gfycat")
+    Retrofit mGfycatRetrofit;
+    @Inject
+    @Named("redgifs")
+    Retrofit mRedgifsRetrofit;
+    @Inject
+    RedditDataRoomDatabase mRedditDataRoomDatabase;
+    @Inject
+    @Named("default")
+    SharedPreferences mSharedPreferences;
+    @Inject
+    @Named("post_layout")
+    SharedPreferences mPostLayoutSharedPreferences;
+    @Inject
+    @Named("nsfw_and_spoiler")
+    SharedPreferences mNsfwAndSpoilerSharedPreferences;
+    @Inject
+    @Named("post_history")
+    SharedPreferences mPostHistorySharedPreferences;
+    @Inject
+    @Named("post_feed_scrolled_position_cache")
+    SharedPreferences mPostFeedScrolledPositionSharedPreferences;
+    @Inject
+    @Named("current_account")
+    SharedPreferences mCurrentAccountSharedPreferences;
+    @Inject
+    @Named("sort_type")
+    SharedPreferences mSortTypeSharedPreferences;
+    @Inject
+    CustomThemeWrapper mCustomThemeWrapper;
+    @Inject
+    ExoCreator mExoCreator;
+    @Inject
+    Executor mExecutor;
+    public PostPaging3ViewModel viewModel;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        ((Infinity) getApplication()).getAppComponent().inject(this);
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_paging3_test);
+
+        String accessToken = mCurrentAccountSharedPreferences.getString(SharedPreferencesUtils.ACCESS_TOKEN, null);
+        String accountName = mCurrentAccountSharedPreferences.getString(SharedPreferencesUtils.ACCOUNT_NAME, null);
+        int defaultPostLayout = Integer.parseInt(mSharedPreferences.getString(SharedPreferencesUtils.DEFAULT_POST_LAYOUT_KEY, "0"));
+        boolean savePostFeedScrolledPosition = mSharedPreferences.getBoolean(SharedPreferencesUtils.SAVE_FRONT_PAGE_SCROLLED_POSITION, false);
+        boolean rememberMutingOptionInPostFeed = mSharedPreferences.getBoolean(SharedPreferencesUtils.REMEMBER_MUTING_OPTION_IN_POST_FEED, false);
+        Locale locale = getResources().getConfiguration().locale;
+        DisplayMetrics displayMetrics = new DisplayMetrics();
+        getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
+        int windowWidth = displayMetrics.widthPixels;
+        int postLayout = mPostLayoutSharedPreferences.getInt(SharedPreferencesUtils.POST_LAYOUT_FRONT_PAGE_POST, defaultPostLayout);
+        int postType = PostDataSource.TYPE_FRONT_PAGE;
+        String sort = mSortTypeSharedPreferences.getString(SharedPreferencesUtils.SORT_TYPE_BEST_POST, SortType.Type.BEST.name());
+        SortType sortType;
+        if (sort.equals(SortType.Type.CONTROVERSIAL.name()) || sort.equals(SortType.Type.TOP.name())) {
+            String sortTime = mSortTypeSharedPreferences.getString(SharedPreferencesUtils.SORT_TIME_BEST_POST, SortType.Time.ALL.name());
+            sortType = new SortType(SortType.Type.valueOf(sort), SortType.Time.valueOf(sortTime));
+        } else {
+            sortType = new SortType(SortType.Type.valueOf(sort));
+        }
+
+        RecyclerView recyclerView = findViewById(R.id.recycler_view);
+        Paging3TestAdapter adapter = new Paging3TestAdapter(this, new PostFragment(), mExecutor,
+                mOauthRetrofit, mGfycatRetrofit,
+                mRedgifsRetrofit, mCustomThemeWrapper, locale,
+                windowWidth, accessToken, accountName, postType, postLayout, true,
+                mSharedPreferences, mNsfwAndSpoilerSharedPreferences, mPostHistorySharedPreferences,
+                mExoCreator, new Paging3TestAdapter.Callback() {
+            @Override
+            public void retryLoadingMore() {
+
+            }
+
+            @Override
+            public void typeChipClicked(int filter) {
+
+            }
+
+            @Override
+            public void flairChipClicked(String flair) {
+
+            }
+
+            @Override
+            public void nsfwChipClicked() {
+
+            }
+
+            @Override
+            public void currentlyBindItem(int position) {
+
+            }
+
+            @Override
+            public void delayTransition() {
+                TransitionManager.beginDelayedTransition(recyclerView, new AutoTransition());
+            }
+        });
+        recyclerView.setAdapter(adapter);
+
+        viewModel = new ViewModelProvider(this, new PostPaging3ViewModel.Factory(mExecutor, mPaging3Retrofit,
+                accessToken, accountName, mSharedPreferences, mPostFeedScrolledPositionSharedPreferences,
+                null, null, null, postType, sortType, null, null,
+                null, null, null)).get(PostPaging3ViewModel.class);
+
+        viewModel.getPosts().observe(this, postPagingData -> adapter.submitData(getLifecycle(), postPagingData));
+    }
+
+    @Override
+    protected SharedPreferences getDefaultSharedPreferences() {
+        return mSharedPreferences;
+    }
+
+    @Override
+    protected CustomThemeWrapper getCustomThemeWrapper() {
+        return mCustomThemeWrapper;
+    }
+
+    @Override
+    protected void applyCustomTheme() {
+
+    }
+}

app/src/main/java/ml/docilealligator/infinityforreddit/apis/RedditAPI.java

@@ -1,10 +1,13 @@
 package ml.docilealligator.infinityforreddit.apis;
 
+import com.google.common.util.concurrent.ListenableFuture;
+
 import java.util.Map;
 
 import okhttp3.MultipartBody;
 import okhttp3.RequestBody;
 import retrofit2.Call;
+import retrofit2.Response;
 import retrofit2.http.Body;
 import retrofit2.http.DELETE;
 import retrofit2.http.FieldMap;
@@ -368,4 +371,11 @@ public interface RedditAPI {
 
     @GET("/r/{subredditName}/wiki/index.json?raw_json=1")
     Call<String> getWiki(@Path("subredditName") String subredditName);
+
+    @GET("{sortType}?raw_json=1")
+    ListenableFuture<Response<String>> getBestPostsListenableFuture(@Path("sortType") String sortType, @Query("after") String lastItem, @HeaderMap Map<String, String> headers);
+
+    @GET("{sortType}?raw_json=1")
+    ListenableFuture<Response<String>> getBestPostsListenableFuture(@Path("sortType") String sortType, @Query("t") String sortTime,
+                                                                   @Query("after") String lastItem, @HeaderMap Map<String, String> headers);
 }

app/src/main/java/ml/docilealligator/infinityforreddit/post/ParsePost.java

@@ -73,6 +73,58 @@ public class ParsePost {
         });
     }
 
+    public static LinkedHashSet<Post> parsePostsSync(String response, int nPosts, PostFilter postFilter, List<ReadPost> readPostList) {
+        LinkedHashSet<Post> newPosts = new LinkedHashSet<>();
+        try {
+            JSONObject jsonResponse = new JSONObject(response);
+            JSONArray allData = jsonResponse.getJSONObject(JSONUtils.DATA_KEY).getJSONArray(JSONUtils.CHILDREN_KEY);
+
+            //Posts listing
+            int size;
+            if (nPosts < 0 || nPosts > allData.length()) {
+                size = allData.length();
+            } else {
+                size = nPosts;
+            }
+
+            HashSet<ReadPost> readPostHashSet = null;
+            if (readPostList != null) {
+                readPostHashSet = new HashSet<>(readPostList);
+            }
+            for (int i = 0; i < size; i++) {
+                try {
+                    if (allData.getJSONObject(i).getString(JSONUtils.KIND_KEY).equals("t3")) {
+                        JSONObject data = allData.getJSONObject(i).getJSONObject(JSONUtils.DATA_KEY);
+                        Post post = parseBasicData(data);
+                        if (readPostHashSet != null && readPostHashSet.contains(ReadPost.convertPost(post))) {
+                            post.markAsRead(false);
+                        }
+                        if (PostFilter.isPostAllowed(post, postFilter)) {
+                            newPosts.add(post);
+                        }
+                    }
+                } catch (JSONException e) {
+                    e.printStackTrace();
+                }
+            }
+
+            return newPosts;
+        } catch (JSONException e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    public static String getLastItem(String response) {
+        try {
+            return new JSONObject(response).getJSONObject(JSONUtils.DATA_KEY).getString(JSONUtils.AFTER_KEY);
+        } catch (JSONException e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+
     public static void parsePost(Executor executor, Handler handler, String response, ParsePostListener parsePostListener) {
         PostFilter postFilter = new PostFilter();
         postFilter.allowNSFW = true;

app/src/main/java/ml/docilealligator/infinityforreddit/post/PostPaging3PagingSource.java

@@ -0,0 +1,159 @@
+package ml.docilealligator.infinityforreddit.post;
+
+import android.content.SharedPreferences;
+
+import androidx.annotation.NonNull;
+import androidx.lifecycle.MutableLiveData;
+import androidx.paging.ListenableFuturePagingSource;
+import androidx.paging.PagingState;
+
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+
+import org.jetbrains.annotations.Nullable;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.concurrent.Executor;
+
+import ml.docilealligator.infinityforreddit.NetworkState;
+import ml.docilealligator.infinityforreddit.SortType;
+import ml.docilealligator.infinityforreddit.apis.RedditAPI;
+import ml.docilealligator.infinityforreddit.postfilter.PostFilter;
+import ml.docilealligator.infinityforreddit.readpost.ReadPost;
+import ml.docilealligator.infinityforreddit.utils.APIUtils;
+import retrofit2.HttpException;
+import retrofit2.Response;
+import retrofit2.Retrofit;
+
+public class PostPaging3PagingSource extends ListenableFuturePagingSource<String, Post> {
+    private Executor executor;
+    private Retrofit retrofit;
+    private String accessToken;
+    private String accountName;
+    private SharedPreferences sharedPreferences;
+    private SharedPreferences postFeedScrolledPositionSharedPreferences;
+    private String subredditOrUserName;
+    private String query;
+    private String trendingSource;
+    private int postType;
+    private SortType sortType;
+    private PostFilter postFilter;
+    private List<ReadPost> readPostList;
+    private String userWhere;
+    private String multiRedditPath;
+    private LinkedHashSet<Post> postLinkedHashSet;
+
+    private MutableLiveData<NetworkState> paginationNetworkStateLiveData;
+    private MutableLiveData<NetworkState> initialLoadStateLiveData;
+    private MutableLiveData<Boolean> hasPostLiveData;
+
+    PostPaging3PagingSource(Executor executor, Retrofit retrofit, String accessToken, String accountName,
+                   SharedPreferences sharedPreferences,
+                   SharedPreferences postFeedScrolledPositionSharedPreferences, int postType,
+                   SortType sortType, PostFilter postFilter, List<ReadPost> readPostList) {
+        this.executor = executor;
+        this.retrofit = retrofit;
+        this.accessToken = accessToken;
+        this.accountName = accountName;
+        this.sharedPreferences = sharedPreferences;
+        this.postFeedScrolledPositionSharedPreferences = postFeedScrolledPositionSharedPreferences;
+        paginationNetworkStateLiveData = new MutableLiveData<>();
+        initialLoadStateLiveData = new MutableLiveData<>();
+        hasPostLiveData = new MutableLiveData<>();
+        this.postType = postType;
+        this.sortType = sortType == null ? new SortType(SortType.Type.BEST) : sortType;
+        this.postFilter = postFilter;
+        this.readPostList = readPostList;
+        postLinkedHashSet = new LinkedHashSet<>();
+    }
+
+    @Nullable
+    @Override
+    public String getRefreshKey(@NonNull PagingState<String, Post> pagingState) {
+        return null;
+    }
+
+    /*@Nullable
+    @Override
+    public Object load(@NonNull LoadParams<String> loadParams, @NonNull Continuation<? super LoadResult<String, Post>> continuation) {
+        RedditAPI api = retrofit.create(RedditAPI.class);
+        Call<String> bestPost;
+        if(sortType.getTime() != null) {
+            bestPost = api.getBestPosts(sortType.getType().value, sortType.getTime().value, loadParams.getKey(),
+                    APIUtils.getOAuthHeader(accessToken));
+        } else {
+            bestPost = api.getBestPosts(sortType.getType().value, loadParams.getKey(), APIUtils.getOAuthHeader(accessToken));
+        }
+
+        try {
+            Response<String> response = bestPost.execute();
+            if (response.isSuccessful()) {
+                String responseString = response.body();
+                LinkedHashSet<Post> newPosts = ParsePost.parsePostsSync(responseString, -1, postFilter, readPostList);
+                String lastItem = ParsePost.getLastItem(responseString);
+                if (newPosts == null) {
+                    return new LoadResult.Error<>(new Exception("Error parsing more posts"));
+                } else {
+                    int currentPostsSize = postLinkedHashSet.size();
+                    postLinkedHashSet.addAll(newPosts);
+                    if (currentPostsSize == postLinkedHashSet.size()) {
+                        return new LoadResult.Page<>(new ArrayList<>(), null, lastItem);
+                    } else {
+                        return new LoadResult.Page<>(new ArrayList<>(postLinkedHashSet).subList(currentPostsSize, postLinkedHashSet.size()), null, lastItem);
+                    }
+                }
+            } else {
+                return new LoadResult.Error<>(new Exception("Response failed"));
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+            return new LoadResult.Error<>(e);
+        }
+    }*/
+
+    @NonNull
+    @Override
+    public ListenableFuture<LoadResult<String, Post>> loadFuture(@NonNull LoadParams<String> loadParams) {
+        RedditAPI api = retrofit.create(RedditAPI.class);
+        ListenableFuture<Response<String>> bestPost;
+        if(sortType.getTime() != null) {
+            bestPost = api.getBestPostsListenableFuture(sortType.getType().value, sortType.getTime().value, loadParams.getKey(),
+                    APIUtils.getOAuthHeader(accessToken));
+        } else {
+            bestPost = api.getBestPostsListenableFuture(sortType.getType().value, loadParams.getKey(), APIUtils.getOAuthHeader(accessToken));
+        }
+
+        ListenableFuture<LoadResult<String, Post>> pageFuture = Futures.transform(bestPost, this::transformData, executor);
+
+        ListenableFuture<LoadResult<String, Post>> partialLoadResultFuture =
+                Futures.catching(pageFuture, HttpException.class,
+                        LoadResult.Error::new, executor);
+
+        return Futures.catching(partialLoadResultFuture,
+                IOException.class, LoadResult.Error::new, executor);
+    }
+
+    public LoadResult<String, Post> transformData(Response<String> response) {
+        if (response.isSuccessful()) {
+            String responseString = response.body();
+            LinkedHashSet<Post> newPosts = ParsePost.parsePostsSync(responseString, -1, postFilter, readPostList);
+            String lastItem = ParsePost.getLastItem(responseString);
+            if (newPosts == null) {
+                return new LoadResult.Error<>(new Exception("Error parsing more posts"));
+            } else {
+                int currentPostsSize = postLinkedHashSet.size();
+                postLinkedHashSet.addAll(newPosts);
+                if (currentPostsSize == postLinkedHashSet.size()) {
+                    return new LoadResult.Page<>(new ArrayList<>(), null, lastItem);
+                } else {
+                    return new LoadResult.Page<>(new ArrayList<>(postLinkedHashSet).subList(currentPostsSize, postLinkedHashSet.size()), null, lastItem);
+                }
+            }
+        } else {
+            return new LoadResult.Error<>(new Exception("Response failed"));
+        }
+    }
+}

app/src/main/java/ml/docilealligator/infinityforreddit/post/PostPaging3Repository.java

@@ -0,0 +1,71 @@
+package ml.docilealligator.infinityforreddit.post;
+
+import android.content.SharedPreferences;
+
+import androidx.lifecycle.LiveData;
+import androidx.paging.Pager;
+import androidx.paging.PagingConfig;
+import androidx.paging.PagingData;
+import androidx.paging.PagingLiveData;
+
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.concurrent.Executor;
+
+import ml.docilealligator.infinityforreddit.SortType;
+import ml.docilealligator.infinityforreddit.postfilter.PostFilter;
+import ml.docilealligator.infinityforreddit.readpost.ReadPost;
+import retrofit2.Retrofit;
+
+public class PostPaging3Repository {
+    private Executor executor;
+    private Retrofit retrofit;
+    private String accessToken;
+    private String accountName;
+    private SharedPreferences sharedPreferences;
+    private SharedPreferences postFeedScrolledPositionSharedPreferences;
+    private String subredditOrUserName;
+    private String query;
+    private String trendingSource;
+    private int postType;
+    private SortType sortType;
+    private PostFilter postFilter;
+    private List<ReadPost> readPostList;
+    private String userWhere;
+    private String multiRedditPath;
+    private LinkedHashSet<Post> postLinkedHashSet;
+
+    public PostPaging3Repository(Executor executor, Retrofit retrofit, String accessToken, String accountName,
+                                 SharedPreferences sharedPreferences,
+                                 SharedPreferences postFeedScrolledPositionSharedPreferences,
+                                 String subredditOrUserName, String query, String trendingSource, int postType,
+                                 SortType sortType, PostFilter postFilter, List<ReadPost> readPostList,
+                                 String userWhere, String multiRedditPath, LinkedHashSet<Post> postLinkedHashSet) {
+        this.executor = executor;
+        this.retrofit = retrofit;
+        this.accessToken = accessToken;
+        this.accountName = accountName;
+        this.sharedPreferences = sharedPreferences;
+        this.postFeedScrolledPositionSharedPreferences = postFeedScrolledPositionSharedPreferences;
+        this.subredditOrUserName = subredditOrUserName;
+        this.query = query;
+        this.trendingSource = trendingSource;
+        this.postType = postType;
+        this.sortType = sortType;
+        this.postFilter = postFilter;
+        this.readPostList = readPostList;
+        this.userWhere = userWhere;
+        this.multiRedditPath = multiRedditPath;
+        this.postLinkedHashSet = postLinkedHashSet;
+    }
+
+    public LiveData<PagingData<Post>> getPostsLiveData() {
+        return PagingLiveData.getLiveData(new Pager<>(new PagingConfig(25, 50, false),
+                this::returnPagingSoruce));
+    }
+
+    private PostPaging3PagingSource returnPagingSoruce() {
+        return new PostPaging3PagingSource(executor, retrofit, accessToken, accountName, sharedPreferences,
+                postFeedScrolledPositionSharedPreferences, postType, sortType, postFilter, readPostList);
+    }
+}

app/src/main/java/ml/docilealligator/infinityforreddit/post/PostPaging3ViewModel.java

@@ -0,0 +1,91 @@
+package ml.docilealligator.infinityforreddit.post;
+
+import android.content.SharedPreferences;
+
+import androidx.annotation.NonNull;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.ViewModel;
+import androidx.lifecycle.ViewModelKt;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.paging.PagingData;
+import androidx.paging.PagingLiveData;
+
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.concurrent.Executor;
+
+import ml.docilealligator.infinityforreddit.SortType;
+import ml.docilealligator.infinityforreddit.postfilter.PostFilter;
+import ml.docilealligator.infinityforreddit.readpost.ReadPost;
+import retrofit2.Retrofit;
+
+public class PostPaging3ViewModel extends ViewModel {
+
+    private PostPaging3Repository repository;
+    private LiveData<PagingData<Post>> posts;
+
+    public PostPaging3ViewModel(Executor executor, Retrofit retrofit, String accessToken, String accountName,
+                                SharedPreferences sharedPreferences,
+                                SharedPreferences postFeedScrolledPositionSharedPreferences,
+                                String subredditOrUserName, String query, String trendingSource, int postType,
+                                SortType sortType, PostFilter postFilter, List<ReadPost> readPostList,
+                                String userWhere, String multiRedditPath, LinkedHashSet<Post> postLinkedHashSet) {
+        repository = new PostPaging3Repository(executor, retrofit, accessToken, accountName, sharedPreferences, postFeedScrolledPositionSharedPreferences,
+                subredditOrUserName, query, trendingSource, postType, sortType, postFilter, readPostList, userWhere, multiRedditPath, postLinkedHashSet);
+    }
+
+    public LiveData<PagingData<Post>> getPosts() {
+        posts = PagingLiveData.cachedIn(repository.getPostsLiveData(), ViewModelKt.getViewModelScope(this));
+        return posts;
+    }
+
+    public static class Factory extends ViewModelProvider.NewInstanceFactory {
+        private Executor executor;
+        private Retrofit retrofit;
+        private String accessToken;
+        private String accountName;
+        private SharedPreferences sharedPreferences;
+        private SharedPreferences postFeedScrolledPositionSharedPreferences;
+        private String subredditOrUserName;
+        private String query;
+        private String trendingSource;
+        private int postType;
+        private SortType sortType;
+        private PostFilter postFilter;
+        private List<ReadPost> readPostList;
+        private String userWhere;
+        private String multiRedditPath;
+        private LinkedHashSet<Post> postLinkedHashSet;
+
+        public Factory(Executor executor, Retrofit retrofit, String accessToken, String accountName, SharedPreferences sharedPreferences,
+                       SharedPreferences postFeedScrolledPositionSharedPreferences, String subredditOrUserName,
+                       String query, String trendingSource, int postType, SortType sortType, PostFilter postFilter,
+                       List<ReadPost> readPostList, String userWhere, String multiRedditPath,
+                       LinkedHashSet<Post> postLinkedHashSet) {
+            this.executor = executor;
+            this.retrofit = retrofit;
+            this.accessToken = accessToken;
+            this.accountName = accountName;
+            this.sharedPreferences = sharedPreferences;
+            this.postFeedScrolledPositionSharedPreferences = postFeedScrolledPositionSharedPreferences;
+            this.subredditOrUserName = subredditOrUserName;
+            this.query = query;
+            this.trendingSource = trendingSource;
+            this.postType = postType;
+            this.sortType = sortType;
+            this.postFilter = postFilter;
+            this.readPostList = readPostList;
+            this.userWhere = userWhere;
+            this.multiRedditPath = multiRedditPath;
+            this.postLinkedHashSet = postLinkedHashSet;
+        }
+
+        @NonNull
+        @Override
+        public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
+            return (T) new PostPaging3ViewModel(executor, retrofit, accessToken, accountName, sharedPreferences,
+                    postFeedScrolledPositionSharedPreferences, subredditOrUserName, query, trendingSource,
+                    postType, sortType, postFilter, readPostList, userWhere, multiRedditPath, postLinkedHashSet);
+        }
+    }
+}

app/src/main/res/layout/activity_paging3_test.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".activities.Paging3TestActivity"
+    android:id="@+id/recycler_view"
+    app:layoutManager=".customviews.LinearLayoutManagerBugFixed" />