Java tutorial
/* Copyright 2017 Andrew Dawson * * This file is a part of Tusky. * * This program is free software; you can redistribute it and/or modify it under the terms of the * GNU General Public License as published by the Free Software Foundation; either version 3 of the * License, or (at your option) any later version. * * Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General * Public License for more details. * * You should have received a copy of the GNU General Public License along with Tusky; if not, * see <http://www.gnu.org/licenses>. */ package com.keylesspalace.tusky.fragment; import android.arch.core.util.Function; import android.arch.lifecycle.Lifecycle; import android.content.Context; import android.content.SharedPreferences; import android.graphics.drawable.Drawable; import android.os.Bundle; import android.preference.PreferenceManager; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.TabLayout; import android.support.v4.util.Pair; import android.support.v4.widget.SwipeRefreshLayout; import android.support.v7.content.res.AppCompatResources; import android.support.v7.recyclerview.extensions.AsyncDifferConfig; import android.support.v7.recyclerview.extensions.AsyncListDiffer; import android.support.v7.util.DiffUtil; import android.support.v7.util.ListUpdateCallback; import android.support.v7.widget.DividerItemDecoration; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.support.v7.widget.SimpleItemAnimator; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ProgressBar; import android.widget.TextView; import com.keylesspalace.tusky.R; import com.keylesspalace.tusky.adapter.TimelineAdapter; import com.keylesspalace.tusky.appstore.BlockEvent; import com.keylesspalace.tusky.appstore.EventHub; import com.keylesspalace.tusky.appstore.FavoriteEvent; import com.keylesspalace.tusky.appstore.MuteEvent; import com.keylesspalace.tusky.appstore.ReblogEvent; import com.keylesspalace.tusky.appstore.StatusComposedEvent; import com.keylesspalace.tusky.appstore.StatusDeletedEvent; import com.keylesspalace.tusky.appstore.UnfollowEvent; import com.keylesspalace.tusky.di.Injectable; import com.keylesspalace.tusky.entity.Status; import com.keylesspalace.tusky.interfaces.ActionButtonActivity; import com.keylesspalace.tusky.interfaces.StatusActionListener; import com.keylesspalace.tusky.network.MastodonApi; import com.keylesspalace.tusky.network.TimelineCases; import com.keylesspalace.tusky.util.CollectionUtil; import com.keylesspalace.tusky.util.Either; import com.keylesspalace.tusky.util.HttpHeaderLink; import com.keylesspalace.tusky.util.ListUtils; import com.keylesspalace.tusky.util.PairedList; import com.keylesspalace.tusky.util.ThemeUtils; import com.keylesspalace.tusky.util.ViewDataUtils; import com.keylesspalace.tusky.view.EndlessOnScrollListener; import com.keylesspalace.tusky.viewdata.StatusViewData; import java.util.Iterator; import java.util.List; import java.util.Objects; import java.util.regex.Matcher; import java.util.regex.Pattern; import javax.inject.Inject; import at.connyduck.sparkbutton.helpers.Utils; import io.reactivex.android.schedulers.AndroidSchedulers; import retrofit2.Call; import retrofit2.Callback; import retrofit2.Response; import static com.uber.autodispose.AutoDispose.autoDisposable; import static com.uber.autodispose.android.lifecycle.AndroidLifecycleScopeProvider.from; public class TimelineFragment extends SFragment implements SwipeRefreshLayout.OnRefreshListener, StatusActionListener, SharedPreferences.OnSharedPreferenceChangeListener, Injectable { private static final String TAG = "TimelineF"; // logging tag private static final String KIND_ARG = "kind"; private static final String HASHTAG_OR_ID_ARG = "hashtag_or_id"; private static final int LOAD_AT_ONCE = 30; public enum Kind { HOME, PUBLIC_LOCAL, PUBLIC_FEDERATED, TAG, USER, USER_WITH_REPLIES, FAVOURITES, LIST } private enum FetchEnd { TOP, BOTTOM, MIDDLE } @Inject public TimelineCases timelineCases; @Inject public EventHub eventHub; private SwipeRefreshLayout swipeRefreshLayout; private RecyclerView recyclerView; private ProgressBar progressBar; private TextView nothingMessageView; private TimelineAdapter adapter; private Kind kind; private String hashtagOrId; private LinearLayoutManager layoutManager; private EndlessOnScrollListener scrollListener; private TabLayout.OnTabSelectedListener onTabSelectedListener; private boolean filterRemoveReplies; private boolean filterRemoveReblogs; private boolean filterRemoveRegex; private Matcher filterRemoveRegexMatcher; private boolean hideFab; private boolean bottomLoading; @Nullable private String bottomId; @Nullable private String topId; private long maxPlaceholderId = -1; private boolean didLoadEverythingBottom; private boolean alwaysShowSensitiveMedia; @Override protected TimelineCases timelineCases() { return timelineCases; } private PairedList<Either<Placeholder, Status>, StatusViewData> statuses = new PairedList<>( new Function<Either<Placeholder, Status>, StatusViewData>() { @Override public StatusViewData apply(Either<Placeholder, Status> input) { Status status = input.getAsRightOrNull(); if (status != null) { return ViewDataUtils.statusToViewData(status, alwaysShowSensitiveMedia); } else { Placeholder placeholder = input.getAsLeft(); return new StatusViewData.Placeholder(placeholder.id, false); } } }); public static TimelineFragment newInstance(Kind kind) { TimelineFragment fragment = new TimelineFragment(); Bundle arguments = new Bundle(); arguments.putString(KIND_ARG, kind.name()); fragment.setArguments(arguments); return fragment; } public static TimelineFragment newInstance(Kind kind, String hashtagOrId) { TimelineFragment fragment = new TimelineFragment(); Bundle arguments = new Bundle(); arguments.putString(KIND_ARG, kind.name()); arguments.putString(HASHTAG_OR_ID_ARG, hashtagOrId); fragment.setArguments(arguments); return fragment; } private static final class Placeholder { final long id; public static Placeholder getInstance(long id) { return new Placeholder(id); } private Placeholder(long id) { this.id = id; } } @Override public void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); Bundle arguments = Objects.requireNonNull(getArguments()); kind = Kind.valueOf(arguments.getString(KIND_ARG)); if (kind == Kind.TAG || kind == Kind.USER || kind == Kind.USER_WITH_REPLIES || kind == Kind.LIST) { hashtagOrId = arguments.getString(HASHTAG_OR_ID_ARG); } adapter = new TimelineAdapter(dataSource, this); } @Override public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { final View rootView = inflater.inflate(R.layout.fragment_timeline, container, false); recyclerView = rootView.findViewById(R.id.recycler_view); swipeRefreshLayout = rootView.findViewById(R.id.swipe_refresh_layout); progressBar = rootView.findViewById(R.id.progress_bar); nothingMessageView = rootView.findViewById(R.id.nothing_message); setupSwipeRefreshLayout(); setupRecyclerView(); updateAdapter(); setupTimelinePreferences(); setupNothingView(); bottomId = null; topId = null; if (statuses.isEmpty()) { progressBar.setVisibility(View.VISIBLE); bottomLoading = true; sendFetchTimelineRequest(null, null, FetchEnd.BOTTOM, -1); } else { progressBar.setVisibility(View.GONE); } return rootView; } private void setupTimelinePreferences() { SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getActivity()); preferences.registerOnSharedPreferenceChangeListener(this); alwaysShowSensitiveMedia = preferences.getBoolean("alwaysShowSensitiveMedia", false); boolean mediaPreviewEnabled = preferences.getBoolean("mediaPreviewEnabled", true); adapter.setMediaPreviewEnabled(mediaPreviewEnabled); boolean filter = preferences.getBoolean("tabFilterHomeReplies", true); filterRemoveReplies = kind == Kind.HOME && !filter; filter = preferences.getBoolean("tabFilterHomeBoosts", true); filterRemoveReblogs = kind == Kind.HOME && !filter; String regexFilter = preferences.getString("tabFilterRegex", ""); filterRemoveRegex = (kind == Kind.HOME || kind == Kind.PUBLIC_LOCAL || kind == Kind.PUBLIC_FEDERATED) && !regexFilter.isEmpty(); if (filterRemoveRegex) { filterRemoveRegexMatcher = Pattern.compile(regexFilter, Pattern.CASE_INSENSITIVE).matcher(""); } } private void setupSwipeRefreshLayout() { Context context = swipeRefreshLayout.getContext(); swipeRefreshLayout.setOnRefreshListener(this); swipeRefreshLayout.setColorSchemeResources(R.color.primary); swipeRefreshLayout.setProgressBackgroundColorSchemeColor( ThemeUtils.getColor(context, android.R.attr.colorBackground)); } private void setupRecyclerView() { Context context = recyclerView.getContext(); recyclerView.setHasFixedSize(true); layoutManager = new LinearLayoutManager(context); recyclerView.setLayoutManager(layoutManager); DividerItemDecoration divider = new DividerItemDecoration(context, layoutManager.getOrientation()); Drawable drawable = ThemeUtils.getDrawable(context, R.attr.status_divider_drawable, R.drawable.status_divider_dark); divider.setDrawable(drawable); recyclerView.addItemDecoration(divider); // CWs are expanded without animation, buttons animate itself, we don't need it basically ((SimpleItemAnimator) recyclerView.getItemAnimator()).setSupportsChangeAnimations(false); recyclerView.setAdapter(adapter); } private void deleteStatusById(String id) { for (int i = 0; i < statuses.size(); i++) { Either<Placeholder, Status> either = statuses.get(i); if (either.isRight() && id.equals(either.getAsRight().getId())) { statuses.remove(either); updateAdapter(); break; } } } @Override public void onActivityCreated(@Nullable Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); if (jumpToTopAllowed()) { TabLayout layout = requireActivity().findViewById(R.id.tab_layout); if (layout != null) { onTabSelectedListener = new TabLayout.OnTabSelectedListener() { @Override public void onTabSelected(TabLayout.Tab tab) { } @Override public void onTabUnselected(TabLayout.Tab tab) { } @Override public void onTabReselected(TabLayout.Tab tab) { jumpToTop(); } }; layout.addOnTabSelectedListener(onTabSelectedListener); } } /* This is delayed until onActivityCreated solely because MainActivity.composeButton isn't * guaranteed to be set until then. */ if (actionButtonPresent()) { /* Use a modified scroll listener that both loads more statuses as it goes, and hides * the follow button on down-scroll. */ SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getContext()); hideFab = preferences.getBoolean("fabHide", false); scrollListener = new EndlessOnScrollListener(layoutManager) { @Override public void onScrolled(RecyclerView view, int dx, int dy) { super.onScrolled(view, dx, dy); ActionButtonActivity activity = (ActionButtonActivity) getActivity(); FloatingActionButton composeButton = activity.getActionButton(); if (composeButton != null) { if (hideFab) { if (dy > 0 && composeButton.isShown()) { composeButton.hide(); // hides the button if we're scrolling down } else if (dy < 0 && !composeButton.isShown()) { composeButton.show(); // shows it if we are scrolling up } } else if (!composeButton.isShown()) { composeButton.show(); } } } @Override public void onLoadMore(int totalItemsCount, RecyclerView view) { TimelineFragment.this.onLoadMore(); } }; } else { // Just use the basic scroll listener to load more statuses. scrollListener = new EndlessOnScrollListener(layoutManager) { @Override public void onLoadMore(int totalItemsCount, RecyclerView view) { TimelineFragment.this.onLoadMore(); } }; } recyclerView.addOnScrollListener(scrollListener); eventHub.getEvents().observeOn(AndroidSchedulers.mainThread()) .as(autoDisposable(from(this, Lifecycle.Event.ON_DESTROY))).subscribe(event -> { if (event instanceof FavoriteEvent) { FavoriteEvent favEvent = ((FavoriteEvent) event); handleFavEvent(favEvent); } else if (event instanceof ReblogEvent) { ReblogEvent reblogEvent = (ReblogEvent) event; handleReblogEvent(reblogEvent); } else if (event instanceof UnfollowEvent) { if (kind == Kind.HOME) { String id = ((UnfollowEvent) event).getAccountId(); removeAllByAccountId(id); } } else if (event instanceof BlockEvent) { if (kind != Kind.USER && kind != Kind.USER_WITH_REPLIES) { String id = ((BlockEvent) event).getAccountId(); removeAllByAccountId(id); } } else if (event instanceof MuteEvent) { if (kind != Kind.USER && kind != Kind.USER_WITH_REPLIES) { String id = ((MuteEvent) event).getAccountId(); removeAllByAccountId(id); } } else if (event instanceof StatusDeletedEvent) { if (kind != Kind.USER && kind != Kind.USER_WITH_REPLIES) { String id = ((StatusDeletedEvent) event).getStatusId(); deleteStatusById(id); } } else if (event instanceof StatusComposedEvent) { Status status = ((StatusComposedEvent) event).getStatus(); handleStatusComposeEvent(status); } }); } @Override public void onDestroyView() { if (jumpToTopAllowed()) { TabLayout tabLayout = requireActivity().findViewById(R.id.tab_layout); if (tabLayout != null) { tabLayout.removeOnTabSelectedListener(onTabSelectedListener); } } super.onDestroyView(); } private void setupNothingView() { Drawable top = AppCompatResources.getDrawable(requireContext(), R.drawable.elephant_friend_empty); nothingMessageView.setCompoundDrawablesWithIntrinsicBounds(null, top, null, null); nothingMessageView.setVisibility(View.GONE); } @Override public void onRefresh() { sendFetchTimelineRequest(null, topId, FetchEnd.TOP, -1); } @Override public void onReply(int position) { super.reply(statuses.get(position).getAsRight()); } @Override public void onReblog(final boolean reblog, final int position) { final Status status = statuses.get(position).getAsRight(); timelineCases.reblogWithCallback(status, reblog, new Callback<Status>() { @Override public void onResponse(@NonNull Call<Status> call, @NonNull Response<Status> response) { if (response.isSuccessful()) { setRebloggedForStatus(position, status, reblog); } } @Override public void onFailure(@NonNull Call<Status> call, @NonNull Throwable t) { Log.d(TAG, "Failed to reblog status " + status.getId(), t); } }); } private void setRebloggedForStatus(int position, Status status, boolean reblog) { status.setReblogged(reblog); if (status.getReblog() != null) { status.getReblog().setReblogged(reblog); } Pair<StatusViewData.Concrete, Integer> actual = findStatusAndPosition(position, status); if (actual == null) return; StatusViewData newViewData = new StatusViewData.Builder(actual.first).setReblogged(reblog) .createStatusViewData(); statuses.setPairedItem(actual.second, newViewData); updateAdapter(); } @Override public void onFavourite(final boolean favourite, final int position) { final Status status = statuses.get(position).getAsRight(); timelineCases.favouriteWithCallback(status, favourite, new Callback<Status>() { @Override public void onResponse(@NonNull Call<Status> call, @NonNull Response<Status> response) { if (response.isSuccessful()) { setFavouriteForStatus(position, status, favourite); } } @Override public void onFailure(@NonNull Call<Status> call, @NonNull Throwable t) { Log.d(TAG, "Failed to favourite status " + status.getId(), t); } }); } private void setFavouriteForStatus(int position, Status status, boolean favourite) { status.setFavourited(favourite); if (status.getReblog() != null) { status.getReblog().setFavourited(favourite); } Pair<StatusViewData.Concrete, Integer> actual = findStatusAndPosition(position, status); if (actual == null) return; StatusViewData newViewData = new StatusViewData.Builder(actual.first).setFavourited(favourite) .createStatusViewData(); statuses.setPairedItem(actual.second, newViewData); updateAdapter(); } @Override public void onMore(View view, final int position) { super.more(statuses.get(position).getAsRight(), view, position); } @Override public void onOpenReblog(int position) { super.openReblog(statuses.get(position).getAsRight()); } @Override public void onExpandedChange(boolean expanded, int position) { StatusViewData newViewData = new StatusViewData.Builder( ((StatusViewData.Concrete) statuses.getPairedItem(position))).setIsExpanded(expanded) .createStatusViewData(); statuses.setPairedItem(position, newViewData); updateAdapter(); } @Override public void onContentHiddenChange(boolean isShowing, int position) { StatusViewData newViewData = new StatusViewData.Builder( ((StatusViewData.Concrete) statuses.getPairedItem(position))) .setIsShowingSensitiveContent(isShowing).createStatusViewData(); statuses.setPairedItem(position, newViewData); updateAdapter(); } @Override public void onLoadMore(int position) { //check bounds before accessing list, if (statuses.size() >= position && position > 0) { Status fromStatus = statuses.get(position - 1).getAsRightOrNull(); Status toStatus = statuses.get(position + 1).getAsRightOrNull(); if (fromStatus == null || toStatus == null) { Log.e(TAG, "Failed to load more at " + position + ", wrong placeholder position"); return; } sendFetchTimelineRequest(fromStatus.getId(), toStatus.getId(), FetchEnd.MIDDLE, position); Placeholder placeholder = statuses.get(position).getAsLeft(); StatusViewData newViewData = new StatusViewData.Placeholder(placeholder.id, true); statuses.setPairedItem(position, newViewData); updateAdapter(); } else { Log.e(TAG, "error loading more"); } } @Override public void onViewMedia(int position, int attachmentIndex, View view) { Status status = statuses.get(position).getAsRightOrNull(); if (status == null) return; super.viewMedia(attachmentIndex, status, view); } @Override public void onViewThread(int position) { super.viewThread(statuses.get(position).getAsRight()); } @Override public void onViewTag(String tag) { if (kind == Kind.TAG && hashtagOrId.equals(tag)) { // If already viewing a tag page, then ignore any request to view that tag again. return; } super.viewTag(tag); } @Override public void onViewAccount(String id) { if ((kind == Kind.USER || kind == Kind.USER_WITH_REPLIES) && hashtagOrId.equals(id)) { /* If already viewing an account page, then any requests to view that account page * should be ignored. */ return; } super.viewAccount(id); } @Override public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { switch (key) { case "fabHide": { hideFab = sharedPreferences.getBoolean("fabHide", false); break; } case "mediaPreviewEnabled": { boolean enabled = sharedPreferences.getBoolean("mediaPreviewEnabled", true); boolean oldMediaPreviewEnabled = adapter.getMediaPreviewEnabled(); if (enabled != oldMediaPreviewEnabled) { adapter.setMediaPreviewEnabled(enabled); fullyRefresh(); } break; } case "tabFilterHomeReplies": { boolean filter = sharedPreferences.getBoolean("tabFilterHomeReplies", true); boolean oldRemoveReplies = filterRemoveReplies; filterRemoveReplies = kind == Kind.HOME && !filter; if (adapter.getItemCount() > 1 && oldRemoveReplies != filterRemoveReplies) { fullyRefresh(); } break; } case "tabFilterHomeBoosts": { boolean filter = sharedPreferences.getBoolean("tabFilterHomeBoosts", true); boolean oldRemoveReblogs = filterRemoveReblogs; filterRemoveReblogs = kind == Kind.HOME && !filter; if (adapter.getItemCount() > 1 && oldRemoveReblogs != filterRemoveReblogs) { fullyRefresh(); } break; } case "tabFilterRegex": { boolean oldFilterRemoveRegex = filterRemoveRegex; String newFilterRemoveRegexPattern = sharedPreferences.getString("tabFilterRegex", ""); boolean patternChanged; if (filterRemoveRegexMatcher != null) { patternChanged = !newFilterRemoveRegexPattern .equalsIgnoreCase(filterRemoveRegexMatcher.pattern().pattern()); } else { patternChanged = !newFilterRemoveRegexPattern.isEmpty(); } filterRemoveRegex = (kind == Kind.HOME || kind == Kind.PUBLIC_LOCAL || kind == Kind.PUBLIC_FEDERATED) && !newFilterRemoveRegexPattern.isEmpty(); if (oldFilterRemoveRegex != filterRemoveRegex || patternChanged) { filterRemoveRegexMatcher = Pattern.compile(newFilterRemoveRegexPattern, Pattern.CASE_INSENSITIVE) .matcher(""); fullyRefresh(); } break; } case "alwaysShowSensitiveMedia": { //it is ok if only newly loaded statuses are affected, no need to fully refresh alwaysShowSensitiveMedia = sharedPreferences.getBoolean("alwaysShowSensitiveMedia", false); } } } @Override public void removeItem(int position) { statuses.remove(position); updateAdapter(); } private void removeAllByAccountId(String accountId) { // using iterator to safely remove items while iterating Iterator<Either<Placeholder, Status>> iterator = statuses.iterator(); while (iterator.hasNext()) { Status status = iterator.next().getAsRightOrNull(); if (status != null && status.getAccount().getId().equals(accountId)) { iterator.remove(); } } updateAdapter(); } private void onLoadMore() { if (didLoadEverythingBottom || bottomLoading) { return; } bottomLoading = true; Either<Placeholder, Status> last = statuses.get(statuses.size() - 1); Placeholder placeholder; if (last.isRight()) { placeholder = newPlaceholder(); statuses.add(Either.left(placeholder)); } else { placeholder = last.getAsLeft(); } statuses.setPairedItem(statuses.size() - 1, new StatusViewData.Placeholder(placeholder.id, true)); updateAdapter(); sendFetchTimelineRequest(bottomId, null, FetchEnd.BOTTOM, -1); } private void fullyRefresh() { statuses.clear(); updateAdapter(); bottomLoading = true; sendFetchTimelineRequest(null, null, FetchEnd.BOTTOM, -1); } private boolean jumpToTopAllowed() { return kind != Kind.TAG && kind != Kind.FAVOURITES; } private boolean actionButtonPresent() { return kind != Kind.TAG && kind != Kind.FAVOURITES && getActivity() instanceof ActionButtonActivity; } private void jumpToTop() { layoutManager.scrollToPosition(0); recyclerView.stopScroll(); scrollListener.reset(); } private Call<List<Status>> getFetchCallByTimelineType(Kind kind, String tagOrId, String fromId, String uptoId) { MastodonApi api = mastodonApi; switch (kind) { default: case HOME: return api.homeTimeline(fromId, uptoId, LOAD_AT_ONCE); case PUBLIC_FEDERATED: return api.publicTimeline(null, fromId, uptoId, LOAD_AT_ONCE); case PUBLIC_LOCAL: return api.publicTimeline(true, fromId, uptoId, LOAD_AT_ONCE); case TAG: return api.hashtagTimeline(tagOrId, null, fromId, uptoId, LOAD_AT_ONCE); case USER: return api.accountStatuses(tagOrId, fromId, uptoId, LOAD_AT_ONCE, true, null); case USER_WITH_REPLIES: return api.accountStatuses(tagOrId, fromId, uptoId, LOAD_AT_ONCE, null, null); case FAVOURITES: return api.favourites(fromId, uptoId, LOAD_AT_ONCE); case LIST: return api.listTimeline(tagOrId, fromId, uptoId, LOAD_AT_ONCE); } } private void sendFetchTimelineRequest(@Nullable String fromId, @Nullable String uptoId, final FetchEnd fetchEnd, final int pos) { Callback<List<Status>> callback = new Callback<List<Status>>() { @Override public void onResponse(@NonNull Call<List<Status>> call, @NonNull Response<List<Status>> response) { if (response.isSuccessful()) { String linkHeader = response.headers().get("Link"); onFetchTimelineSuccess(response.body(), linkHeader, fetchEnd, pos); } else { onFetchTimelineFailure(new Exception(response.message()), fetchEnd, pos); } } @Override public void onFailure(@NonNull Call<List<Status>> call, @NonNull Throwable t) { onFetchTimelineFailure((Exception) t, fetchEnd, pos); } }; Call<List<Status>> listCall = getFetchCallByTimelineType(kind, hashtagOrId, fromId, uptoId); callList.add(listCall); listCall.enqueue(callback); } private void onFetchTimelineSuccess(List<Status> statuses, String linkHeader, FetchEnd fetchEnd, int pos) { // We filled the hole (or reached the end) if the server returned less statuses than we // we asked for. boolean fullFetch = statuses.size() >= LOAD_AT_ONCE; filterStatuses(statuses); List<HttpHeaderLink> links = HttpHeaderLink.parse(linkHeader); switch (fetchEnd) { case TOP: { HttpHeaderLink previous = HttpHeaderLink.findByRelationType(links, "prev"); String uptoId = null; if (previous != null) { uptoId = previous.uri.getQueryParameter("since_id"); } updateStatuses(statuses, null, uptoId, fullFetch); break; } case MIDDLE: { replacePlaceholderWithStatuses(statuses, fullFetch, pos); break; } case BOTTOM: { HttpHeaderLink next = HttpHeaderLink.findByRelationType(links, "next"); String fromId = null; if (next != null) { fromId = next.uri.getQueryParameter("max_id"); } if (!this.statuses.isEmpty() && !this.statuses.get(this.statuses.size() - 1).isRight()) { this.statuses.remove(this.statuses.size() - 1); updateAdapter(); } int oldSize = this.statuses.size(); if (this.statuses.size() > 1) { addItems(statuses, fromId); } else { /* If this is the first fetch, also save the id from the "previous" link and * treat this operation as a refresh so the scroll position doesn't get pushed * down to the end. */ HttpHeaderLink previous = HttpHeaderLink.findByRelationType(links, "prev"); String uptoId = null; if (previous != null) { uptoId = previous.uri.getQueryParameter("since_id"); } updateStatuses(statuses, fromId, uptoId, fullFetch); } if (this.statuses.size() == oldSize) { // This may be a brittle check but seems like it works // Can we check it using headers somehow? Do all server support them? didLoadEverythingBottom = true; } break; } } fulfillAnyQueuedFetches(fetchEnd); progressBar.setVisibility(View.GONE); swipeRefreshLayout.setRefreshing(false); if (this.statuses.size() == 0) { nothingMessageView.setVisibility(View.VISIBLE); } } private void onFetchTimelineFailure(Exception exception, FetchEnd fetchEnd, int position) { if (isAdded()) { swipeRefreshLayout.setRefreshing(false); if (fetchEnd == FetchEnd.MIDDLE && !statuses.get(position).isRight()) { Placeholder placeholder = statuses.get(position).getAsLeftOrNull(); StatusViewData newViewData; if (placeholder == null) { placeholder = newPlaceholder(); } newViewData = new StatusViewData.Placeholder(placeholder.id, false); statuses.setPairedItem(position, newViewData); updateAdapter(); } Log.e(TAG, "Fetch Failure: " + exception.getMessage()); fulfillAnyQueuedFetches(fetchEnd); progressBar.setVisibility(View.GONE); } } private void fulfillAnyQueuedFetches(FetchEnd fetchEnd) { switch (fetchEnd) { case BOTTOM: { bottomLoading = false; break; } } } private void filterStatuses(List<Status> statuses) { Iterator<Status> it = statuses.iterator(); while (it.hasNext()) { Status status = it.next(); if ((status.getInReplyToId() != null && filterRemoveReplies) || (status.getReblog() != null && filterRemoveReblogs) || (filterRemoveRegex && (filterRemoveRegexMatcher.reset(status.getContent()).find() || (!status.getSpoilerText().isEmpty() && filterRemoveRegexMatcher.reset(status.getSpoilerText()).find())))) { it.remove(); } } } private void updateStatuses(List<Status> newStatuses, @Nullable String fromId, @Nullable String toId, boolean fullFetch) { if (ListUtils.isEmpty(newStatuses)) { return; } if (fromId != null) { bottomId = fromId; } if (toId != null) { topId = toId; } List<Either<Placeholder, Status>> liftedNew = liftStatusList(newStatuses); if (statuses.isEmpty()) { statuses.addAll(liftedNew); } else { Either<Placeholder, Status> lastOfNew = liftedNew.get(newStatuses.size() - 1); int index = statuses.indexOf(lastOfNew); for (int i = 0; i < index; i++) { statuses.remove(0); } int newIndex = liftedNew.indexOf(statuses.get(0)); if (newIndex == -1) { if (index == -1 && fullFetch) { liftedNew.add(Either.left(newPlaceholder())); } statuses.addAll(0, liftedNew); } else { statuses.addAll(0, liftedNew.subList(0, newIndex)); } } updateAdapter(); } private void addItems(List<Status> newStatuses, @Nullable String fromId) { if (ListUtils.isEmpty(newStatuses)) { return; } Status last = null; for (int i = statuses.size() - 1; i >= 0; i--) { if (statuses.get(i).isRight()) { last = statuses.get(i).getAsRight(); break; } } // I was about to replace findStatus with indexOf but it is incorrect to compare value // types by ID anyway and we should change equals() for Status, I think, so this makes sense if (last != null && !findStatus(newStatuses, last.getId())) { statuses.addAll(liftStatusList(newStatuses)); if (fromId != null) { bottomId = fromId; } updateAdapter(); } } private void replacePlaceholderWithStatuses(List<Status> newStatuses, boolean fullFetch, int pos) { Status status = statuses.get(pos).getAsRightOrNull(); if (status == null) { statuses.remove(pos); } if (ListUtils.isEmpty(newStatuses)) { updateAdapter(); return; } List<Either<Placeholder, Status>> liftedNew = liftStatusList(newStatuses); if (fullFetch) { liftedNew.add(Either.left(newPlaceholder())); } statuses.addAll(pos, liftedNew); updateAdapter(); } private static boolean findStatus(List<Status> statuses, String id) { for (Status status : statuses) { if (status.getId().equals(id)) { return true; } } return false; } private int findStatusOrReblogPositionById(@NonNull String statusId) { for (int i = 0; i < statuses.size(); i++) { Status status = statuses.get(i).getAsRightOrNull(); if (status != null && (statusId.equals(status.getId()) || (status.getReblog() != null && statusId.equals(status.getReblog().getId())))) { return i; } } return -1; } private final Function<Status, Either<Placeholder, Status>> statusLifter = Either::right; private @Nullable Pair<StatusViewData.Concrete, Integer> findStatusAndPosition(int position, Status status) { StatusViewData.Concrete statusToUpdate; int positionToUpdate; StatusViewData someOldViewData = statuses.getPairedItem(position); // Unlikely, but data could change between the request and response if ((someOldViewData instanceof StatusViewData.Placeholder) || !((StatusViewData.Concrete) someOldViewData).getId().equals(status.getId())) { // try to find the status we need to update int foundPos = statuses.indexOf(Either.<Placeholder, Status>right(status)); if (foundPos < 0) return null; // okay, it's hopeless, give up statusToUpdate = ((StatusViewData.Concrete) statuses.getPairedItem(foundPos)); positionToUpdate = position; } else { statusToUpdate = (StatusViewData.Concrete) someOldViewData; positionToUpdate = position; } return new Pair<>(statusToUpdate, positionToUpdate); } private void handleReblogEvent(@NonNull ReblogEvent reblogEvent) { int pos = findStatusOrReblogPositionById(reblogEvent.getStatusId()); if (pos < 0) return; Status status = statuses.get(pos).getAsRight(); setRebloggedForStatus(pos, status, reblogEvent.getReblog()); } private void handleFavEvent(@NonNull FavoriteEvent favEvent) { int pos = findStatusOrReblogPositionById(favEvent.getStatusId()); if (pos < 0) return; Status status = statuses.get(pos).getAsRight(); setFavouriteForStatus(pos, status, favEvent.getFavourite()); } private void handleStatusComposeEvent(@NonNull Status status) { switch (kind) { case HOME: case PUBLIC_FEDERATED: case PUBLIC_LOCAL: break; case USER: case USER_WITH_REPLIES: if (status.getAccount().getId().equals(hashtagOrId)) { break; } else { return; } case TAG: case FAVOURITES: case LIST: return; } onRefresh(); } private List<Either<Placeholder, Status>> liftStatusList(List<Status> list) { return CollectionUtil.map(list, statusLifter); } private Placeholder newPlaceholder() { Placeholder placeholder = Placeholder.getInstance(maxPlaceholderId); maxPlaceholderId--; return placeholder; } private void updateAdapter() { differ.submitList(statuses.getPairedCopy()); } private final ListUpdateCallback listUpdateCallback = new ListUpdateCallback() { @Override public void onInserted(int position, int count) { if (isAdded()) { adapter.notifyItemRangeInserted(position, count); Context context = getContext(); if (position == 0 && context != null) { recyclerView.scrollBy(0, Utils.dpToPx(context, -30)); } } } @Override public void onRemoved(int position, int count) { adapter.notifyItemRangeRemoved(position, count); } @Override public void onMoved(int fromPosition, int toPosition) { adapter.notifyItemMoved(fromPosition, toPosition); } @Override public void onChanged(int position, int count, Object payload) { adapter.notifyItemRangeChanged(position, count, payload); } }; private final AsyncListDiffer<StatusViewData> differ = new AsyncListDiffer<>(listUpdateCallback, new AsyncDifferConfig.Builder<>(diffCallback).build()); private final TimelineAdapter.AdapterDataSource<StatusViewData> dataSource = new TimelineAdapter.AdapterDataSource<StatusViewData>() { @Override public int getItemCount() { return differ.getCurrentList().size(); } @Override public StatusViewData getItemAt(int pos) { return differ.getCurrentList().get(pos); } }; private static final DiffUtil.ItemCallback<StatusViewData> diffCallback = new DiffUtil.ItemCallback<StatusViewData>() { @Override public boolean areItemsTheSame(StatusViewData oldItem, StatusViewData newItem) { return oldItem.getViewDataId() == newItem.getViewDataId(); } @Override public boolean areContentsTheSame(StatusViewData oldItem, StatusViewData newItem) { return oldItem.deepEquals(newItem); } }; }