Start loading posts after the last viewed post in PostFragment when refreshing and first load.

app/build.gradle

@@ -95,6 +95,7 @@ dependencies {
     implementation 'me.zhanghai.android.fastscroll:library:1.1.2'
     implementation "com.thefuntasty.hauler:core:3.1.0"
     implementation 'com.github.Piasy:BigImageViewer:1.6.5'
+    implementation 'com.fewlaps.quitnowcache:quitnow-cache:3.4.0'
 
     def toroVersion = '3.7.0.2010003'
     implementation "im.ene.toro3:toro:$toroVersion"

app/src/main/java/ml/docilealligator/infinityforreddit/Activity/AccountPostsActivity.java

@@ -191,6 +191,7 @@ public class AccountPostsActivity extends BaseActivity implements SortTypeSelect
         bundle.putString(PostFragment.EXTRA_USER_WHERE, mUserWhere);
         bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
         bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+        bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
         mFragment.setArguments(bundle);
         getSupportFragmentManager().beginTransaction().replace(R.id.frame_layout_account_posts_activity, mFragment).commit();
     }

app/src/main/java/ml/docilealligator/infinityforreddit/Activity/AccountSavedThingActivity.java

@@ -338,6 +338,7 @@ public class AccountSavedThingActivity extends BaseActivity implements ActivityT
                 bundle.putString(PostFragment.EXTRA_USER_WHERE, PostDataSource.USER_WHERE_SAVED);
                 bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                 bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                 fragment.setArguments(bundle);
                 return fragment;
             }

app/src/main/java/ml/docilealligator/infinityforreddit/Activity/FilteredThingActivity.java

@@ -58,6 +58,7 @@ public class FilteredThingActivity extends BaseActivity implements SortTypeSelec
     private static final String IS_IN_LAZY_MODE_STATE = "IILMS";
     private static final String NULL_ACCESS_TOKEN_STATE = "NATS";
     private static final String ACCESS_TOKEN_STATE = "ATS";
+    private static final String ACCOUNT_NAME_STATE = "ANS";
     private static final String FRAGMENT_OUT_STATE = "FOS";
 
     @BindView(R.id.coordinator_layout_filtered_thing_activity)
@@ -81,6 +82,7 @@ public class FilteredThingActivity extends BaseActivity implements SortTypeSelec
     private boolean isInLazyMode = false;
     private boolean mNullAccessToken = false;
     private String mAccessToken;
+    private String mAccountName;
     private String name;
     private String userWhere;
     private int postType;
@@ -148,6 +150,7 @@ public class FilteredThingActivity extends BaseActivity implements SortTypeSelec
             isInLazyMode = savedInstanceState.getBoolean(IS_IN_LAZY_MODE_STATE);
             mNullAccessToken = savedInstanceState.getBoolean(NULL_ACCESS_TOKEN_STATE);
             mAccessToken = savedInstanceState.getString(ACCESS_TOKEN_STATE);
+            mAccountName = savedInstanceState.getString(ACCOUNT_NAME_STATE);
 
             mFragment = getSupportFragmentManager().getFragment(savedInstanceState, FRAGMENT_OUT_STATE);
             getSupportFragmentManager().beginTransaction().replace(R.id.frame_layout_filtered_posts_activity, mFragment).commit();
@@ -195,6 +198,7 @@ public class FilteredThingActivity extends BaseActivity implements SortTypeSelec
                 mNullAccessToken = true;
             } else {
                 mAccessToken = account.getAccessToken();
+                mAccountName = account.getUsername();
             }
             bindView(filter, true);
         }).execute();
@@ -291,6 +295,7 @@ public class FilteredThingActivity extends BaseActivity implements SortTypeSelec
             bundle.putInt(PostFragment.EXTRA_POST_TYPE, postType);
             bundle.putInt(PostFragment.EXTRA_FILTER, filter);
             bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+            bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
             if (postType == PostDataSource.TYPE_USER) {
                 bundle.putString(PostFragment.EXTRA_USER_NAME, name);
                 bundle.putString(PostFragment.EXTRA_USER_WHERE, userWhere);
@@ -393,6 +398,7 @@ public class FilteredThingActivity extends BaseActivity implements SortTypeSelec
         getSupportFragmentManager().putFragment(outState, FRAGMENT_OUT_STATE, mFragment);
         outState.putBoolean(IS_IN_LAZY_MODE_STATE, isInLazyMode);
         outState.putString(ACCESS_TOKEN_STATE, mAccessToken);
+        outState.putString(ACCOUNT_NAME_STATE, mAccountName);
         outState.putBoolean(NULL_ACCESS_TOKEN_STATE, mNullAccessToken);
     }
 

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

@@ -945,6 +945,7 @@ public class MainActivity extends BaseActivity implements SortTypeSelectionCallb
                     bundle.putString(PostFragment.EXTRA_NAME, "popular");
                     bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                     bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                    bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                     fragment.setArguments(bundle);
                     return fragment;
                 } else {
@@ -954,6 +955,7 @@ public class MainActivity extends BaseActivity implements SortTypeSelectionCallb
                     bundle.putString(PostFragment.EXTRA_NAME, "all");
                     bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                     bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                    bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                     fragment.setArguments(bundle);
                     return fragment;
                 }
@@ -981,6 +983,7 @@ public class MainActivity extends BaseActivity implements SortTypeSelectionCallb
                 bundle.putInt(PostFragment.EXTRA_POST_TYPE, PostDataSource.TYPE_FRONT_PAGE);
                 bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                 bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                 fragment.setArguments(bundle);
                 return fragment;
             } else if (postType.equals(SharedPreferencesUtils.MAIN_PAGE_TAB_POST_TYPE_ALL)) {
@@ -990,6 +993,7 @@ public class MainActivity extends BaseActivity implements SortTypeSelectionCallb
                 bundle.putString(PostFragment.EXTRA_NAME, "all");
                 bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                 bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                 fragment.setArguments(bundle);
                 return fragment;
             } else if (postType.equals(SharedPreferencesUtils.MAIN_PAGE_TAB_POST_TYPE_SUBREDDIT)) {
@@ -999,6 +1003,7 @@ public class MainActivity extends BaseActivity implements SortTypeSelectionCallb
                 bundle.putString(PostFragment.EXTRA_NAME, name);
                 bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                 bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                 fragment.setArguments(bundle);
                 return fragment;
             } else if (postType.equals(SharedPreferencesUtils.MAIN_PAGE_TAB_POST_TYPE_MULTIREDDIT)) {
@@ -1008,6 +1013,7 @@ public class MainActivity extends BaseActivity implements SortTypeSelectionCallb
                 bundle.putInt(PostFragment.EXTRA_POST_TYPE, PostDataSource.TYPE_MULTI_REDDIT);
                 bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                 bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                 fragment.setArguments(bundle);
                 return fragment;
             } else if (postType.equals(SharedPreferencesUtils.MAIN_PAGE_TAB_POST_TYPE_USER)) {
@@ -1018,6 +1024,7 @@ public class MainActivity extends BaseActivity implements SortTypeSelectionCallb
                 bundle.putString(PostFragment.EXTRA_USER_WHERE, PostDataSource.USER_WHERE_SUBMITTED);
                 bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                 bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                 fragment.setArguments(bundle);
                 return fragment;
             } else {
@@ -1027,6 +1034,7 @@ public class MainActivity extends BaseActivity implements SortTypeSelectionCallb
                 bundle.putString(PostFragment.EXTRA_NAME, "popular");
                 bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                 bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                 fragment.setArguments(bundle);
                 return fragment;
             }

app/src/main/java/ml/docilealligator/infinityforreddit/Activity/ViewMultiRedditDetailActivity.java

@@ -193,6 +193,7 @@ public class ViewMultiRedditDetailActivity extends BaseActivity implements SortT
         bundle.putInt(PostFragment.EXTRA_POST_TYPE, PostDataSource.TYPE_MULTI_REDDIT);
         bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
         bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+        bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
         mFragment.setArguments(bundle);
         getSupportFragmentManager().beginTransaction().replace(R.id.frame_layout_view_multi_reddit_detail_activity, mFragment).commit();
     }

app/src/main/java/ml/docilealligator/infinityforreddit/Activity/ViewSubredditDetailActivity.java

@@ -904,6 +904,7 @@ public class ViewSubredditDetailActivity extends BaseActivity implements SortTyp
                 bundle.putInt(PostFragment.EXTRA_POST_TYPE, PostDataSource.TYPE_SUBREDDIT);
                 bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                 bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                 fragment.setArguments(bundle);
                 return fragment;
             }

app/src/main/java/ml/docilealligator/infinityforreddit/Activity/ViewUserDetailActivity.java

@@ -819,6 +819,7 @@ public class ViewUserDetailActivity extends BaseActivity implements SortTypeSele
                 bundle.putString(PostFragment.EXTRA_USER_WHERE, PostDataSource.USER_WHERE_SUBMITTED);
                 bundle.putInt(PostFragment.EXTRA_FILTER, PostFragment.EXTRA_NO_FILTER);
                 bundle.putString(PostFragment.EXTRA_ACCESS_TOKEN, mAccessToken);
+                bundle.putString(PostFragment.EXTRA_ACCOUNT_NAME, mAccountName);
                 fragment.setArguments(bundle);
                 return fragment;
             }

app/src/main/java/ml/docilealligator/infinityforreddit/Adapter/PostRecyclerViewAdapter.java

@@ -612,6 +612,7 @@ public class PostRecyclerViewAdapter extends PagedListAdapter<Post, RecyclerView
                         ((PostTextTypeViewHolder) holder).contentTextView.setText(post.getSelfTextPlainTrimmed());
                     }
                 }
+                mCallback.currentlyBindItem(holder.getAdapterPosition());
             }
         } else if (holder instanceof PostCompactBaseViewHolder) {
             Post post = getItem(position);
@@ -864,6 +865,8 @@ public class PostRecyclerViewAdapter extends PagedListAdapter<Post, RecyclerView
                 } else {
                     ((PostCompactBaseViewHolder) holder).saveButton.setImageResource(R.drawable.ic_bookmark_border_grey_24dp);
                 }
+
+                mCallback.currentlyBindItem(holder.getAdapterPosition());
             }
         }
     }
@@ -1052,6 +1055,15 @@ public class PostRecyclerViewAdapter extends PagedListAdapter<Post, RecyclerView
         return super.getItemCount();
     }
 
+    @Nullable
+    public Post getItemByPosition(int position) {
+        if (position >= 0 && super.getItemCount() > position) {
+            return super.getItem(position);
+        }
+
+        return null;
+    }
+
     public void setVoteButtonsPosition(boolean voteButtonsOnTheRight) {
         mVoteButtonsOnTheRight = voteButtonsOnTheRight;
     }
@@ -1231,6 +1243,8 @@ public class PostRecyclerViewAdapter extends PagedListAdapter<Post, RecyclerView
         void retryLoadingMore();
 
         void typeChipClicked(int filter);
+
+        void currentlyBindItem(int position);
     }
 
     class PostBaseViewHolder extends RecyclerView.ViewHolder {

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

@@ -6,6 +6,7 @@ import android.content.SharedPreferences;
 
 import androidx.preference.PreferenceManager;
 
+import com.fewlaps.quitnowcache.QNCache;
 import com.google.android.exoplayer2.database.ExoDatabaseProvider;
 import com.google.android.exoplayer2.upstream.cache.LeastRecentlyUsedCacheEvictor;
 import com.google.android.exoplayer2.upstream.cache.SimpleCache;
@@ -216,4 +217,10 @@ class AppModule {
                 .build();
         return ToroExo.with(mApplication).getCreator(config);
     }
+
+    @Provides
+    @Singleton
+    QNCache<String> provideQNCache() {
+        return new QNCache.Builder().build();
+    }
 }

app/src/main/java/ml/docilealligator/infinityforreddit/Fragment/PostFragment.java

@@ -38,6 +38,7 @@ import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 
 import com.bumptech.glide.Glide;
 import com.bumptech.glide.RequestManager;
+import com.fewlaps.quitnowcache.QNCache;
 
 import org.greenrobot.eventbus.EventBus;
 import org.greenrobot.eventbus.Subscribe;
@@ -86,6 +87,7 @@ import ml.docilealligator.infinityforreddit.Post.PostViewModel;
 import ml.docilealligator.infinityforreddit.R;
 import ml.docilealligator.infinityforreddit.RedditDataRoomDatabase;
 import ml.docilealligator.infinityforreddit.SortType;
+import ml.docilealligator.infinityforreddit.Utils.CacheUtils;
 import ml.docilealligator.infinityforreddit.Utils.SharedPreferencesUtils;
 import ml.docilealligator.infinityforreddit.Utils.Utils;
 import retrofit2.Retrofit;
@@ -107,6 +109,7 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
     public static final String EXTRA_FILTER = "EF";
     public static final int EXTRA_NO_FILTER = -2;
     public static final String EXTRA_ACCESS_TOKEN = "EAT";
+    public static final String EXTRA_ACCOUNT_NAME = "EAN";
 
     private static final String IS_IN_LAZY_MODE_STATE = "IILMS";
     private static final String RECYCLER_VIEW_POSITION_STATE = "RVPS";
@@ -143,6 +146,8 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
     CustomThemeWrapper customThemeWrapper;
     @Inject
     ExoCreator exoCreator;
+    @Inject
+    QNCache<String> cache;
     private RequestManager mGlide;
     private AppCompatActivity activity;
     private LinearLayoutManager mLinearLayoutManager;
@@ -151,6 +156,7 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
     private boolean isInLazyMode = false;
     private boolean isLazyModePaused = false;
     private boolean hasPost = false;
+    private boolean isShown = false;
     private PostRecyclerViewAdapter mAdapter;
     private RecyclerView.SmoothScroller smoothScroller;
     private Window window;
@@ -158,6 +164,11 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
     private LazyModeRunnable lazyModeRunnable;
     private CountDownTimer resumeLazyModeCountDownTimer;
     private float lazyModeInterval;
+    private String accountName;
+    private String subredditName;
+    private String username;
+    private String multiRedditPath;
+    private int maxPosition = -1;
     private int postLayout;
     private SortType sortType;
 
@@ -168,6 +179,7 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
     @Override
     public void onResume() {
         super.onResume();
+        isShown = true;
         if (mPostRecyclerView.getAdapter() != null) {
             ((PostRecyclerViewAdapter) mPostRecyclerView.getAdapter()).setCanStartActivity(true);
         }
@@ -353,12 +365,13 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
 
         int filter = getArguments().getInt(EXTRA_FILTER);
         String accessToken = getArguments().getString(EXTRA_ACCESS_TOKEN);
+        accountName = getArguments().getString(EXTRA_ACCOUNT_NAME);
         boolean nsfw = mSharedPreferences.getBoolean(SharedPreferencesUtils.NSFW_KEY, false);
         int defaultPostLayout = Integer.parseInt(mSharedPreferences.getString(SharedPreferencesUtils.DEFAULT_POST_LAYOUT_KEY, "0"));
         Locale locale = getResources().getConfiguration().locale;
 
         if (postType == PostDataSource.TYPE_SEARCH) {
-            String subredditName = getArguments().getString(EXTRA_NAME);
+            subredditName = getArguments().getString(EXTRA_NAME);
             String query = getArguments().getString(EXTRA_QUERY);
 
             String sort = mSortTypeSharedPreferences.getString(SharedPreferencesUtils.SORT_TYPE_SEARCH_POST, SortType.Type.RELEVANCE.name());
@@ -369,33 +382,40 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
             mAdapter = new PostRecyclerViewAdapter(activity, mOauthRetrofit, mRetrofit, mRedditDataRoomDatabase,
                     customThemeWrapper, locale, windowWidth, accessToken, postType, postLayout, true,
                     mSharedPreferences, exoCreator, new PostRecyclerViewAdapter.Callback() {
-                        @Override
+                @Override
-                        public void retryLoadingMore() {
+                public void retryLoadingMore() {
-                            mPostViewModel.retryLoadingMore();
+                    mPostViewModel.retryLoadingMore();
-                        }
+                }
 
-                        @Override
+                @Override
-                        public void typeChipClicked(int filter) {
+                public void typeChipClicked(int filter) {
-                            Intent intent = new Intent(activity, FilteredThingActivity.class);
+                    Intent intent = new Intent(activity, FilteredThingActivity.class);
-                            intent.putExtra(FilteredThingActivity.EXTRA_NAME, subredditName);
+                    intent.putExtra(FilteredThingActivity.EXTRA_NAME, subredditName);
-                            intent.putExtra(FilteredThingActivity.EXTRA_QUERY, query);
+                    intent.putExtra(FilteredThingActivity.EXTRA_QUERY, query);
-                            intent.putExtra(FilteredThingActivity.EXTRA_POST_TYPE, postType);
+                    intent.putExtra(FilteredThingActivity.EXTRA_POST_TYPE, postType);
-                            intent.putExtra(FilteredThingActivity.EXTRA_FILTER, filter);
+                    intent.putExtra(FilteredThingActivity.EXTRA_FILTER, filter);
-                            startActivity(intent);
+                    startActivity(intent);
-                        }
+                }
-                    });
+
+                @Override
+                public void currentlyBindItem(int position) {
+                    if (maxPosition < position) {
+                        maxPosition = position;
+                    }
+                }
+            });
 
             if (accessToken == null) {
                 mPostViewModel = new ViewModelProvider(this, new PostViewModel.Factory(mRetrofit, null,
-                        getResources().getConfiguration().locale, subredditName, query, postType,
+                        accountName, getResources().getConfiguration().locale, cache, subredditName, query, postType,
                         sortType, filter, nsfw)).get(PostViewModel.class);
             } else {
                 mPostViewModel = new ViewModelProvider(this, new PostViewModel.Factory(mOauthRetrofit, accessToken,
-                        getResources().getConfiguration().locale, subredditName, query, postType,
+                        accountName, getResources().getConfiguration().locale, cache, subredditName, query, postType,
                         sortType, filter, nsfw)).get(PostViewModel.class);
             }
         } else if (postType == PostDataSource.TYPE_SUBREDDIT) {
-            String subredditName = getArguments().getString(EXTRA_NAME);
+            subredditName = getArguments().getString(EXTRA_NAME);
             String sort;
             String sortTime = null;
 
@@ -431,32 +451,39 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
             mAdapter = new PostRecyclerViewAdapter(activity, mOauthRetrofit, mRetrofit, mRedditDataRoomDatabase,
                     customThemeWrapper, locale, windowWidth, accessToken, postType, postLayout, displaySubredditName,
                     mSharedPreferences, exoCreator, new PostRecyclerViewAdapter.Callback() {
-                        @Override
+                @Override
-                        public void retryLoadingMore() {
+                public void retryLoadingMore() {
-                            mPostViewModel.retryLoadingMore();
+                    mPostViewModel.retryLoadingMore();
-                        }
+                }
 
-                        @Override
+                @Override
-                        public void typeChipClicked(int filter) {
+                public void typeChipClicked(int filter) {
-                            Intent intent = new Intent(activity, FilteredThingActivity.class);
+                    Intent intent = new Intent(activity, FilteredThingActivity.class);
-                            intent.putExtra(FilteredThingActivity.EXTRA_NAME, subredditName);
+                    intent.putExtra(FilteredThingActivity.EXTRA_NAME, subredditName);
-                            intent.putExtra(FilteredThingActivity.EXTRA_POST_TYPE, postType);
+                    intent.putExtra(FilteredThingActivity.EXTRA_POST_TYPE, postType);
-                            intent.putExtra(FilteredThingActivity.EXTRA_FILTER, filter);
+                    intent.putExtra(FilteredThingActivity.EXTRA_FILTER, filter);
-                            startActivity(intent);
+                    startActivity(intent);
-                        }
+                }
-                    });
+
+                @Override
+                public void currentlyBindItem(int position) {
+                    if (maxPosition < position) {
+                        maxPosition = position;
+                    }
+                }
+            });
 
             if (accessToken == null) {
                 mPostViewModel = new ViewModelProvider(this, new PostViewModel.Factory(mRetrofit, accessToken,
-                        getResources().getConfiguration().locale, subredditName, postType, sortType,
+                        accountName, getResources().getConfiguration().locale, cache, subredditName, postType, sortType,
                         filter, nsfw)).get(PostViewModel.class);
             } else {
                 mPostViewModel = new ViewModelProvider(this, new PostViewModel.Factory(mOauthRetrofit, accessToken,
-                        getResources().getConfiguration().locale, subredditName, postType, sortType,
+                        accountName, getResources().getConfiguration().locale, cache, subredditName, postType, sortType,
                         filter, nsfw)).get(PostViewModel.class);
             }
         } else if(postType == PostDataSource.TYPE_MULTI_REDDIT) {
-            String multiRedditPath = getArguments().getString(EXTRA_NAME);
+            multiRedditPath = getArguments().getString(EXTRA_NAME);
             String sort;
             String sortTime = null;
 
@@ -491,19 +518,26 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
                     intent.putExtra(FilteredThingActivity.EXTRA_FILTER, filter);
                     startActivity(intent);
                 }
+
+                @Override
+                public void currentlyBindItem(int position) {
+                    if (maxPosition < position) {
+                        maxPosition = position;
+                    }
+                }
             });
 
             if (accessToken == null) {
                 mPostViewModel = new ViewModelProvider(this, new PostViewModel.Factory(mRetrofit, null,
-                        getResources().getConfiguration().locale, multiRedditPath, postType, sortType,
+                        accountName, getResources().getConfiguration().locale, cache, multiRedditPath, postType, sortType,
                         filter, nsfw)).get(PostViewModel.class);
             } else {
                 mPostViewModel = new ViewModelProvider(this, new PostViewModel.Factory(mOauthRetrofit, accessToken,
-                        getResources().getConfiguration().locale, multiRedditPath, postType, sortType,
+                        accountName, getResources().getConfiguration().locale, cache, multiRedditPath, postType, sortType,
                         filter, nsfw)).get(PostViewModel.class);
             }
         } else if (postType == PostDataSource.TYPE_USER) {
-            String username = getArguments().getString(EXTRA_USER_NAME);
+            username = getArguments().getString(EXTRA_USER_NAME);
             String where = getArguments().getString(EXTRA_USER_WHERE);
             if (where != null && where.equals(PostDataSource.USER_WHERE_SUBMITTED)) {
                 CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) mFetchPostInfoLinearLayout.getLayoutParams();
@@ -523,29 +557,36 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
             mAdapter = new PostRecyclerViewAdapter(activity, mOauthRetrofit, mRetrofit, mRedditDataRoomDatabase,
                     customThemeWrapper, locale, windowWidth, accessToken, postType, postLayout, true,
                     mSharedPreferences, exoCreator, new PostRecyclerViewAdapter.Callback() {
-                        @Override
+                @Override
-                        public void retryLoadingMore() {
+                public void retryLoadingMore() {
-                            mPostViewModel.retryLoadingMore();
+                    mPostViewModel.retryLoadingMore();
-                        }
+                }
 
-                        @Override
+                @Override
-                        public void typeChipClicked(int filter) {
+                public void typeChipClicked(int filter) {
-                            Intent intent = new Intent(activity, FilteredThingActivity.class);
+                    Intent intent = new Intent(activity, FilteredThingActivity.class);
-                            intent.putExtra(FilteredThingActivity.EXTRA_NAME, username);
+                    intent.putExtra(FilteredThingActivity.EXTRA_NAME, username);
-                            intent.putExtra(FilteredThingActivity.EXTRA_POST_TYPE, postType);
+                    intent.putExtra(FilteredThingActivity.EXTRA_POST_TYPE, postType);
-                            intent.putExtra(FilteredThingActivity.EXTRA_USER_WHERE, where);
+                    intent.putExtra(FilteredThingActivity.EXTRA_USER_WHERE, where);
-                            intent.putExtra(FilteredThingActivity.EXTRA_FILTER, filter);
+                    intent.putExtra(FilteredThingActivity.EXTRA_FILTER, filter);
-                            startActivity(intent);
+                    startActivity(intent);
-                        }
+                }
-                    });
+
+                @Override
+                public void currentlyBindItem(int position) {
+                    if (maxPosition < position) {
+                        maxPosition = position;
+                    }
+                }
+            });
 
             if (accessToken == null) {
                 mPostViewModel = new ViewModelProvider(this, new PostViewModel.Factory(mRetrofit, accessToken,
-                        getResources().getConfiguration().locale, username, postType, sortType, where,
+                        accountName, getResources().getConfiguration().locale, cache, username, postType, sortType, where,
                         filter, nsfw)).get(PostViewModel.class);
             } else {
                 mPostViewModel = new ViewModelProvider(this, new PostViewModel.Factory(mOauthRetrofit, accessToken,
-                        getResources().getConfiguration().locale, username, postType, sortType, where,
+                        accountName, getResources().getConfiguration().locale, cache, username, postType, sortType, where,
                         filter, nsfw)).get(PostViewModel.class);
             }
         } else {
@@ -561,23 +602,30 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
             mAdapter = new PostRecyclerViewAdapter(activity, mOauthRetrofit, mRetrofit, mRedditDataRoomDatabase,
                     customThemeWrapper, locale, windowWidth, accessToken, postType, postLayout, true,
                     mSharedPreferences, exoCreator, new PostRecyclerViewAdapter.Callback() {
-                        @Override
+                @Override
-                        public void retryLoadingMore() {
+                public void retryLoadingMore() {
-                            mPostViewModel.retryLoadingMore();
+                    mPostViewModel.retryLoadingMore();
-                        }
+                }
 
-                        @Override
+                @Override
-                        public void typeChipClicked(int filter) {
+                public void typeChipClicked(int filter) {
-                            Intent intent = new Intent(activity, FilteredThingActivity.class);
+                    Intent intent = new Intent(activity, FilteredThingActivity.class);
-                            intent.putExtra(FilteredThingActivity.EXTRA_NAME, activity.getString(R.string.best));
+                    intent.putExtra(FilteredThingActivity.EXTRA_NAME, activity.getString(R.string.best));
-                            intent.putExtra(FilteredThingActivity.EXTRA_POST_TYPE, postType);
+                    intent.putExtra(FilteredThingActivity.EXTRA_POST_TYPE, postType);
-                            intent.putExtra(FilteredThingActivity.EXTRA_FILTER, filter);
+                    intent.putExtra(FilteredThingActivity.EXTRA_FILTER, filter);
-                            startActivity(intent);
+                    startActivity(intent);
-                        }
+                }
-                    });
+
+                @Override
+                public void currentlyBindItem(int position) {
+                    if (maxPosition < position) {
+                        maxPosition = position;
+                    }
+                }
+            });
 
             mPostViewModel = new ViewModelProvider(this, new PostViewModel.Factory(mOauthRetrofit, accessToken,
-                    getResources().getConfiguration().locale, postType, sortType, filter, nsfw)).get(PostViewModel.class);
+                    accountName, getResources().getConfiguration().locale, cache, postType, sortType, filter, nsfw)).get(PostViewModel.class);
         }
 
         if (activity instanceof ActivityToolbarInterface) {
@@ -659,6 +707,40 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
         }
     }
 
+    @Override
+    public void onStop() {
+        super.onStop();
+        saveCache();
+    }
+
+    private void saveCache() {
+        if (isShown && mAdapter != null) {
+            String key;
+            Post currentPost = mAdapter.getItemByPosition(maxPosition);
+            if (currentPost != null) {
+                String accountNameForCache = accountName == null ? CacheUtils.ANONYMOUS : accountName;
+                String value = currentPost.getFullName();
+                switch (postType) {
+                    case PostDataSource.TYPE_FRONT_PAGE:
+                        key = accountNameForCache + CacheUtils.FRONT_PAGE_BASE;
+                        break;
+                    case PostDataSource.TYPE_SUBREDDIT:
+                        key = accountNameForCache + CacheUtils.SUBREDDIT_BASE + subredditName;
+                        break;
+                    case PostDataSource.TYPE_USER:
+                        key = accountNameForCache + CacheUtils.USER_BASE + username;
+                        break;
+                    case PostDataSource.TYPE_MULTI_REDDIT:
+                        key = accountNameForCache + CacheUtils.MULTI_REDDIT_BASE + multiRedditPath;
+                        break;
+                    default:
+                        return;
+                }
+                cache.set(key, value);
+            }
+        }
+    }
+
     @Override
     public void refresh() {
         mAdapter.removeFooter();
@@ -667,6 +749,7 @@ public class PostFragment extends Fragment implements FragmentCommunicator {
         if (isInLazyMode) {
             stopLazyMode();
         }
+        saveCache();
         mPostViewModel.refresh();
     }
 

app/src/main/java/ml/docilealligator/infinityforreddit/Post/PostDataSource.java

@@ -4,15 +4,18 @@ import androidx.annotation.NonNull;
 import androidx.lifecycle.MutableLiveData;
 import androidx.paging.PageKeyedDataSource;
 
+import com.fewlaps.quitnowcache.QNCache;
+
 import java.util.ArrayList;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Locale;
 
-import ml.docilealligator.infinityforreddit.NetworkState;
 import ml.docilealligator.infinityforreddit.API.RedditAPI;
+import ml.docilealligator.infinityforreddit.NetworkState;
 import ml.docilealligator.infinityforreddit.SortType;
 import ml.docilealligator.infinityforreddit.Utils.APIUtils;
+import ml.docilealligator.infinityforreddit.Utils.CacheUtils;
 import retrofit2.Call;
 import retrofit2.Callback;
 import retrofit2.Retrofit;
@@ -34,7 +37,9 @@ public class PostDataSource extends PageKeyedDataSource<String, Post> {
 
     private Retrofit retrofit;
     private String accessToken;
+    private String accountName;
     private Locale locale;
+    private QNCache<String> cache;
     private String subredditOrUserName;
     private String query;
     private int postType;
@@ -52,11 +57,13 @@ public class PostDataSource extends PageKeyedDataSource<String, Post> {
     private LoadParams<String> params;
     private LoadCallback<String, Post> callback;
 
-    PostDataSource(Retrofit retrofit, String accessToken, Locale locale, int postType, SortType sortType,
+    PostDataSource(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                   int filter, boolean nsfw) {
+                   int postType, SortType sortType, int filter, boolean nsfw) {
         this.retrofit = retrofit;
         this.accessToken = accessToken;
+        this.accountName = accountName;
         this.locale = locale;
+        this.cache = cache;
         paginationNetworkStateLiveData = new MutableLiveData<>();
         initialLoadStateLiveData = new MutableLiveData<>();
         hasPostLiveData = new MutableLiveData<>();
@@ -67,11 +74,13 @@ public class PostDataSource extends PageKeyedDataSource<String, Post> {
         postLinkedHashSet = new LinkedHashSet<>();
     }
 
-    PostDataSource(Retrofit retrofit, String accessToken, Locale locale, String path, int postType,
+    PostDataSource(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                   SortType sortType, int filter, boolean nsfw) {
+                   String path, int postType, SortType sortType, int filter, boolean nsfw) {
         this.retrofit = retrofit;
         this.accessToken = accessToken;
+        this.accountName = accountName;
         this.locale = locale;
+        this.cache = cache;
         if (postType == TYPE_SUBREDDIT) {
             this.subredditOrUserName = path;
         } else {
@@ -103,11 +112,14 @@ public class PostDataSource extends PageKeyedDataSource<String, Post> {
         postLinkedHashSet = new LinkedHashSet<>();
     }
 
-    PostDataSource(Retrofit retrofit, String accessToken, Locale locale, String subredditOrUserName, int postType,
+    PostDataSource(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                   SortType sortType, String where, int filter, boolean nsfw) {
+                   String subredditOrUserName, int postType, SortType sortType, String where, int filter,
+                   boolean nsfw) {
         this.retrofit = retrofit;
         this.accessToken = accessToken;
+        this.accountName = accountName;
         this.locale = locale;
+        this.cache = cache;
         this.subredditOrUserName = subredditOrUserName;
         paginationNetworkStateLiveData = new MutableLiveData<>();
         initialLoadStateLiveData = new MutableLiveData<>();
@@ -120,11 +132,14 @@ public class PostDataSource extends PageKeyedDataSource<String, Post> {
         postLinkedHashSet = new LinkedHashSet<>();
     }
 
-    PostDataSource(Retrofit retrofit, String accessToken, Locale locale, String subredditOrUserName, String query,
+    PostDataSource(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                   int postType, SortType sortType, int filter, boolean nsfw) {
+                   String subredditOrUserName, String query, int postType, SortType sortType, int filter,
+                   boolean nsfw) {
         this.retrofit = retrofit;
         this.accessToken = accessToken;
+        this.accountName = accountName;
         this.locale = locale;
+        this.cache = cache;
         this.subredditOrUserName = subredditOrUserName;
         this.query = query;
         paginationNetworkStateLiveData = new MutableLiveData<>();
@@ -153,21 +168,22 @@ public class PostDataSource extends PageKeyedDataSource<String, Post> {
     public void loadInitial(@NonNull LoadInitialParams<String> params, @NonNull final LoadInitialCallback<String, Post> callback) {
         initialLoadStateLiveData.postValue(NetworkState.LOADING);
 
+        String accountNameForCache = accountName == null ? CacheUtils.ANONYMOUS : accountName;
         switch (postType) {
             case TYPE_FRONT_PAGE:
-                loadBestPostsInitial(callback, null);
+                loadBestPostsInitial(callback, cache.get(accountNameForCache + CacheUtils.FRONT_PAGE_BASE));
                 break;
             case TYPE_SUBREDDIT:
-                loadSubredditPostsInitial(callback, null);
+                loadSubredditPostsInitial(callback, cache.get(accountNameForCache + CacheUtils.SUBREDDIT_BASE + subredditOrUserName));
                 break;
             case TYPE_USER:
-                loadUserPostsInitial(callback, null);
+                loadUserPostsInitial(callback, cache.get(accountNameForCache + CacheUtils.USER_BASE + subredditOrUserName));
                 break;
             case TYPE_SEARCH:
                 loadSearchPostsInitial(callback, null);
                 break;
             case TYPE_MULTI_REDDIT:
-                loadMultiRedditPostsInitial(callback, null);
+                loadMultiRedditPostsInitial(callback, cache.get(accountNameForCache + CacheUtils.MULTI_REDDIT_BASE + multiRedditPath));
                 break;
         }
     }

app/src/main/java/ml/docilealligator/infinityforreddit/Post/PostDataSourceFactory.java

@@ -4,6 +4,8 @@ import androidx.annotation.NonNull;
 import androidx.lifecycle.MutableLiveData;
 import androidx.paging.DataSource;
 
+import com.fewlaps.quitnowcache.QNCache;
+
 import java.util.Locale;
 
 import ml.docilealligator.infinityforreddit.SortType;
@@ -12,7 +14,9 @@ import retrofit2.Retrofit;
 class PostDataSourceFactory extends DataSource.Factory {
     private Retrofit retrofit;
     private String accessToken;
+    private String accountName;
     private Locale locale;
+    private QNCache<String> cache;
     private String subredditName;
     private String query;
     private int postType;
@@ -24,11 +28,13 @@ class PostDataSourceFactory extends DataSource.Factory {
     private PostDataSource postDataSource;
     private MutableLiveData<PostDataSource> postDataSourceLiveData;
 
-    PostDataSourceFactory(Retrofit retrofit, String accessToken, Locale locale, int postType, SortType sortType,
+    PostDataSourceFactory(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                          int filter, boolean nsfw) {
+                          int postType, SortType sortType, int filter, boolean nsfw) {
         this.retrofit = retrofit;
         this.accessToken = accessToken;
+        this.accountName = accountName;
         this.locale = locale;
+        this.cache = cache;
         postDataSourceLiveData = new MutableLiveData<>();
         this.postType = postType;
         this.sortType = sortType;
@@ -36,11 +42,13 @@ class PostDataSourceFactory extends DataSource.Factory {
         this.nsfw = nsfw;
     }
 
-    PostDataSourceFactory(Retrofit retrofit, String accessToken, Locale locale, String subredditName,
+    PostDataSourceFactory(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                          int postType, SortType sortType, int filter, boolean nsfw) {
+                          String subredditName, int postType, SortType sortType, int filter, boolean nsfw) {
         this.retrofit = retrofit;
         this.accessToken = accessToken;
+        this.accountName = accountName;
         this.locale = locale;
+        this.cache = cache;
         this.subredditName = subredditName;
         postDataSourceLiveData = new MutableLiveData<>();
         this.postType = postType;
@@ -49,11 +57,14 @@ class PostDataSourceFactory extends DataSource.Factory {
         this.nsfw = nsfw;
     }
 
-    PostDataSourceFactory(Retrofit retrofit, String accessToken, Locale locale, String subredditName,
+    PostDataSourceFactory(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                          int postType, SortType sortType, String where, int filter, boolean nsfw) {
+                          String subredditName, int postType, SortType sortType, String where, int filter,
+                          boolean nsfw) {
         this.retrofit = retrofit;
         this.accessToken = accessToken;
+        this.accountName = accountName;
         this.locale = locale;
+        this.cache = cache;
         this.subredditName = subredditName;
         postDataSourceLiveData = new MutableLiveData<>();
         this.postType = postType;
@@ -63,11 +74,14 @@ class PostDataSourceFactory extends DataSource.Factory {
         this.nsfw = nsfw;
     }
 
-    PostDataSourceFactory(Retrofit retrofit, String accessToken, Locale locale, String subredditName,
+    PostDataSourceFactory(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                          String query, int postType, SortType sortType, int filter, boolean nsfw) {
+                          String subredditName, String query, int postType, SortType sortType, int filter,
+                          boolean nsfw) {
         this.retrofit = retrofit;
         this.accessToken = accessToken;
+        this.accountName = accountName;
         this.locale = locale;
+        this.cache = cache;
         this.subredditName = subredditName;
         this.query = query;
         postDataSourceLiveData = new MutableLiveData<>();
@@ -81,17 +95,17 @@ class PostDataSourceFactory extends DataSource.Factory {
     @Override
     public DataSource<String, Post> create() {
         if (postType == PostDataSource.TYPE_FRONT_PAGE) {
-            postDataSource = new PostDataSource(retrofit, accessToken, locale, postType, sortType,
+            postDataSource = new PostDataSource(retrofit, accessToken, accountName, locale, cache,
-                    filter, nsfw);
-        } else if (postType == PostDataSource.TYPE_SEARCH) {
-            postDataSource = new PostDataSource(retrofit, accessToken, locale, subredditName, query,
                     postType, sortType, filter, nsfw);
+        } else if (postType == PostDataSource.TYPE_SEARCH) {
+            postDataSource = new PostDataSource(retrofit, accessToken, accountName, locale, cache,
+                    subredditName, query, postType, sortType, filter, nsfw);
         } else if (postType == PostDataSource.TYPE_SUBREDDIT || postType == PostDataSource.TYPE_MULTI_REDDIT) {
-            postDataSource = new PostDataSource(retrofit, accessToken, locale, subredditName, postType,
+            postDataSource = new PostDataSource(retrofit, accessToken, accountName, locale, cache,
-                    sortType, filter, nsfw);
+                    subredditName, postType, sortType, filter, nsfw);
         } else {
-            postDataSource = new PostDataSource(retrofit, accessToken, locale, subredditName, postType,
+            postDataSource = new PostDataSource(retrofit, accessToken, accountName, locale, cache,
-                    sortType, userWhere, filter, nsfw);
+                    subredditName, postType, sortType, userWhere, filter, nsfw);
         }
 
         postDataSourceLiveData.postValue(postDataSource);

app/src/main/java/ml/docilealligator/infinityforreddit/Post/PostViewModel.java

@@ -11,6 +11,8 @@ import androidx.lifecycle.ViewModelProvider;
 import androidx.paging.LivePagedListBuilder;
 import androidx.paging.PagedList;
 
+import com.fewlaps.quitnowcache.QNCache;
+
 import java.util.Locale;
 
 import ml.docilealligator.infinityforreddit.NetworkState;
@@ -27,40 +29,9 @@ public class PostViewModel extends ViewModel {
     private MutableLiveData<SortType> sortTypeLiveData;
     private NSFWAndSortTypeLiveData nsfwAndSortTypeLiveData;
 
-    public PostViewModel(Retrofit retrofit, String accessToken, Locale locale, int postType, SortType sortType,
+    public PostViewModel(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                         int filter, boolean nsfw) {
+                         int postType, SortType sortType, int filter, boolean nsfw) {
-        postDataSourceFactory = new PostDataSourceFactory(retrofit, accessToken, locale, postType,
+        postDataSourceFactory = new PostDataSourceFactory(retrofit, accessToken, accountName, locale, cache,
-                sortType, filter, nsfw);
-
-        initialLoadingState = Transformations.switchMap(postDataSourceFactory.getPostDataSourceLiveData(),
-                PostDataSource::getInitialLoadStateLiveData);
-        paginationNetworkState = Transformations.switchMap(postDataSourceFactory.getPostDataSourceLiveData(),
-                PostDataSource::getPaginationNetworkStateLiveData);
-        hasPostLiveData = Transformations.switchMap(postDataSourceFactory.getPostDataSourceLiveData(),
-                PostDataSource::hasPostLiveData);
-
-        nsfwLiveData = new MutableLiveData<>();
-        nsfwLiveData.postValue(nsfw);
-        sortTypeLiveData = new MutableLiveData<>();
-        sortTypeLiveData.postValue(sortType);
-
-        nsfwAndSortTypeLiveData = new NSFWAndSortTypeLiveData(nsfwLiveData, sortTypeLiveData);
-
-        PagedList.Config pagedListConfig =
-                (new PagedList.Config.Builder())
-                        .setEnablePlaceholders(false)
-                        .setPageSize(25)
-                        .build();
-
-        posts = Transformations.switchMap(nsfwAndSortTypeLiveData, nsfwAndSort -> {
-            postDataSourceFactory.changeNSFWAndSortType(nsfwLiveData.getValue(), sortTypeLiveData.getValue());
-            return (new LivePagedListBuilder(postDataSourceFactory, pagedListConfig)).build();
-        });
-    }
-
-    public PostViewModel(Retrofit retrofit, String accessToken, Locale locale, String subredditName, int postType,
-                         SortType sortType, int filter, boolean nsfw) {
-        postDataSourceFactory = new PostDataSourceFactory(retrofit, accessToken, locale, subredditName,
                 postType, sortType, filter, nsfw);
 
         initialLoadingState = Transformations.switchMap(postDataSourceFactory.getPostDataSourceLiveData(),
@@ -89,10 +60,10 @@ public class PostViewModel extends ViewModel {
         });
     }
 
-    public PostViewModel(Retrofit retrofit, String accessToken, Locale locale, String subredditName, int postType,
+    public PostViewModel(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                         SortType sortType, String where, int filter, boolean nsfw) {
+                         String subredditName, int postType, SortType sortType, int filter, boolean nsfw) {
-        postDataSourceFactory = new PostDataSourceFactory(retrofit, accessToken, locale, subredditName,
+        postDataSourceFactory = new PostDataSourceFactory(retrofit, accessToken, accountName, locale, cache,
-                postType, sortType, where, filter, nsfw);
+                subredditName, postType, sortType, filter, nsfw);
 
         initialLoadingState = Transformations.switchMap(postDataSourceFactory.getPostDataSourceLiveData(),
                 PostDataSource::getInitialLoadStateLiveData);
@@ -120,10 +91,43 @@ public class PostViewModel extends ViewModel {
         });
     }
 
-    public PostViewModel(Retrofit retrofit, String accessToken, Locale locale, String subredditName, String query,
+    public PostViewModel(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                         int postType, SortType sortType, int filter, boolean nsfw) {
+                         String subredditName, int postType, SortType sortType, String where, int filter,
-        postDataSourceFactory = new PostDataSourceFactory(retrofit, accessToken, locale, subredditName,
+                         boolean nsfw) {
-                query, postType, sortType, filter, nsfw);
+        postDataSourceFactory = new PostDataSourceFactory(retrofit, accessToken, accountName, locale, cache,
+                subredditName, postType, sortType, where, filter, nsfw);
+
+        initialLoadingState = Transformations.switchMap(postDataSourceFactory.getPostDataSourceLiveData(),
+                PostDataSource::getInitialLoadStateLiveData);
+        paginationNetworkState = Transformations.switchMap(postDataSourceFactory.getPostDataSourceLiveData(),
+                PostDataSource::getPaginationNetworkStateLiveData);
+        hasPostLiveData = Transformations.switchMap(postDataSourceFactory.getPostDataSourceLiveData(),
+                PostDataSource::hasPostLiveData);
+
+        nsfwLiveData = new MutableLiveData<>();
+        nsfwLiveData.postValue(nsfw);
+        sortTypeLiveData = new MutableLiveData<>();
+        sortTypeLiveData.postValue(sortType);
+
+        nsfwAndSortTypeLiveData = new NSFWAndSortTypeLiveData(nsfwLiveData, sortTypeLiveData);
+
+        PagedList.Config pagedListConfig =
+                (new PagedList.Config.Builder())
+                        .setEnablePlaceholders(false)
+                        .setPageSize(25)
+                        .build();
+
+        posts = Transformations.switchMap(nsfwAndSortTypeLiveData, nsfwAndSort -> {
+            postDataSourceFactory.changeNSFWAndSortType(nsfwLiveData.getValue(), sortTypeLiveData.getValue());
+            return (new LivePagedListBuilder(postDataSourceFactory, pagedListConfig)).build();
+        });
+    }
+
+    public PostViewModel(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
+                         String subredditName, String query, int postType, SortType sortType, int filter,
+                         boolean nsfw) {
+        postDataSourceFactory = new PostDataSourceFactory(retrofit, accessToken, accountName, locale, cache,
+                subredditName, query, postType, sortType, filter, nsfw);
 
         initialLoadingState = Transformations.switchMap(postDataSourceFactory.getPostDataSourceLiveData(),
                 PostDataSource::getInitialLoadStateLiveData);
@@ -186,7 +190,9 @@ public class PostViewModel extends ViewModel {
     public static class Factory extends ViewModelProvider.NewInstanceFactory {
         private Retrofit retrofit;
         private String accessToken;
+        private String accountName;
         private Locale locale;
+        private QNCache<String> cache;
         private String subredditName;
         private String query;
         private int postType;
@@ -195,22 +201,26 @@ public class PostViewModel extends ViewModel {
         private int filter;
         private boolean nsfw;
 
-        public Factory(Retrofit retrofit, String accessToken, Locale locale, int postType, SortType sortType,
+        public Factory(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                       int filter, boolean nsfw) {
+                       int postType, SortType sortType, int filter, boolean nsfw) {
             this.retrofit = retrofit;
             this.accessToken = accessToken;
+            this.accountName = accountName;
             this.locale = locale;
+            this.cache = cache;
             this.postType = postType;
             this.sortType = sortType;
             this.filter = filter;
             this.nsfw = nsfw;
         }
 
-        public Factory(Retrofit retrofit, String accessToken, Locale locale, String subredditName, int postType,
+        public Factory(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                       SortType sortType, int filter, boolean nsfw) {
+                       String subredditName, int postType, SortType sortType, int filter, boolean nsfw) {
             this.retrofit = retrofit;
             this.accessToken = accessToken;
+            this.accountName = accountName;
             this.locale = locale;
+            this.cache = cache;
             this.subredditName = subredditName;
             this.postType = postType;
             this.sortType = sortType;
@@ -219,11 +229,14 @@ public class PostViewModel extends ViewModel {
         }
 
         //User posts
-        public Factory(Retrofit retrofit, String accessToken, Locale locale, String subredditName, int postType,
+        public Factory(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                       SortType sortType, String where, int filter, boolean nsfw) {
+                       String subredditName, int postType, SortType sortType, String where, int filter,
+                       boolean nsfw) {
             this.retrofit = retrofit;
             this.accessToken = accessToken;
+            this.accountName = accountName;
             this.locale = locale;
+            this.cache = cache;
             this.subredditName = subredditName;
             this.postType = postType;
             this.sortType = sortType;
@@ -232,11 +245,14 @@ public class PostViewModel extends ViewModel {
             this.nsfw = nsfw;
         }
 
-        public Factory(Retrofit retrofit, String accessToken, Locale locale, String subredditName, String query,
+        public Factory(Retrofit retrofit, String accessToken, String accountName, Locale locale, QNCache<String> cache,
-                       int postType, SortType sortType, int filter, boolean nsfw) {
+                       String subredditName, String query, int postType, SortType sortType, int filter,
+                       boolean nsfw) {
             this.retrofit = retrofit;
             this.accessToken = accessToken;
+            this.accountName = accountName;
             this.locale = locale;
+            this.cache = cache;
             this.subredditName = subredditName;
             this.query = query;
             this.postType = postType;
@@ -249,17 +265,17 @@ public class PostViewModel extends ViewModel {
         @Override
         public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
             if (postType == PostDataSource.TYPE_FRONT_PAGE) {
-                return (T) new PostViewModel(retrofit, accessToken, locale, postType, sortType, filter,
+                return (T) new PostViewModel(retrofit, accessToken, accountName, locale, cache, postType,
-                        nsfw);
-            } else if (postType == PostDataSource.TYPE_SEARCH) {
-                return (T) new PostViewModel(retrofit, accessToken, locale, subredditName, query,
-                        postType, sortType, filter, nsfw);
-            } else if (postType == PostDataSource.TYPE_SUBREDDIT || postType == PostDataSource.TYPE_MULTI_REDDIT) {
-                return (T) new PostViewModel(retrofit, accessToken, locale, subredditName, postType,
                         sortType, filter, nsfw);
+            } else if (postType == PostDataSource.TYPE_SEARCH) {
+                return (T) new PostViewModel(retrofit, accessToken, accountName, locale, cache, subredditName,
+                        query, postType, sortType, filter, nsfw);
+            } else if (postType == PostDataSource.TYPE_SUBREDDIT || postType == PostDataSource.TYPE_MULTI_REDDIT) {
+                return (T) new PostViewModel(retrofit, accessToken, accountName, locale, cache, subredditName,
+                        postType, sortType, filter, nsfw);
             } else {
-                return (T) new PostViewModel(retrofit, accessToken, locale, subredditName, postType,
+                return (T) new PostViewModel(retrofit, accessToken, accountName, locale, cache, subredditName,
-                        sortType, userWhere, filter, nsfw);
+                        postType, sortType, userWhere, filter, nsfw);
             }
         }
     }

app/src/main/java/ml/docilealligator/infinityforreddit/Utils/CacheUtils.java

@@ -0,0 +1,9 @@
+package ml.docilealligator.infinityforreddit.Utils;
+
+public class CacheUtils {
+    public static final String FRONT_PAGE_BASE = "_front_page";
+    public static final String SUBREDDIT_BASE = "_subreddit_";
+    public static final String USER_BASE = "_user_";
+    public static final String MULTI_REDDIT_BASE = "_multireddit_";
+    public static final String ANONYMOUS = ".anonymous";
+}