fluffychat/lib/views/chat.dart

import 'dart:async';
import 'dart:io';
import 'dart:math';

import 'package:adaptive_dialog/adaptive_dialog.dart';
import 'package:emoji_picker/emoji_picker.dart';
import 'package:famedlysdk/famedlysdk.dart';
import 'package:file_picker_cross/file_picker_cross.dart';
import 'package:fluffychat/components/adaptive_page_layout.dart';
import 'package:fluffychat/components/avatar.dart';
import 'package:fluffychat/components/chat_settings_popup_menu.dart';
import 'package:fluffychat/components/connection_status_header.dart';
import 'package:fluffychat/components/dialogs/recording_dialog.dart';
import 'package:fluffychat/components/dialogs/simple_dialogs.dart';
import 'package:fluffychat/components/encryption_button.dart';
import 'package:fluffychat/components/list_items/message.dart';
import 'package:fluffychat/components/matrix.dart';
import 'package:fluffychat/components/reply_content.dart';
import 'package:fluffychat/components/user_bottom_sheet.dart';
import 'package:fluffychat/config/app_emojis.dart';
import 'package:fluffychat/utils/app_route.dart';
import 'package:fluffychat/utils/matrix_locals.dart';
import 'package:fluffychat/utils/platform_infos.dart';
import 'package:fluffychat/utils/room_status_extension.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/scheduler.dart';
import 'package:flutter/services.dart';
import 'package:flutter_gen/gen_l10n/l10n.dart';
import 'package:image_picker/image_picker.dart';
import 'package:pedantic/pedantic.dart';
import 'package:scroll_to_index/scroll_to_index.dart';
import 'package:swipe_to_action/swipe_to_action.dart';
import 'package:shared_preferences/shared_preferences.dart';

import '../components/dialogs/send_file_dialog.dart';
import '../components/input_bar.dart';
import '../app_config.dart';
import '../utils/matrix_file_extension.dart';
import 'chat_details.dart';
import 'chat_list.dart';

class ChatView extends StatelessWidget {
  final String id;
  final String scrollToEventId;

  const ChatView(this.id, {Key key, this.scrollToEventId}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return AdaptivePageLayout(
      primaryPage: FocusPage.SECOND,
      firstScaffold: ChatList(
        activeChat: id,
      ),
      secondScaffold: _Chat(id, scrollToEventId: scrollToEventId),
    );
  }
}

class _Chat extends StatefulWidget {
  final String id;
  final String scrollToEventId;

  const _Chat(this.id, {Key key, this.scrollToEventId}) : super(key: key);

  @override
  _ChatState createState() => _ChatState();
}

class _ChatState extends State<_Chat> {
  Room room;

  Timeline timeline;

  MatrixState matrix;

  String seenByText = '';

  final AutoScrollController _scrollController = AutoScrollController();

  FocusNode inputFocus = FocusNode();

  Timer typingCoolDown;
  Timer typingTimeout;
  bool currentlyTyping = false;

  List<Event> selectedEvents = [];

  bool _collapseRoomCreate = true;

  Event replyEvent;

  Event editEvent;

  bool showScrollDownButton = false;

  bool get selectMode => selectedEvents.isNotEmpty;

  bool _loadingHistory = false;

  final int _loadHistoryCount = 100;

  String inputText = '';

  String pendingText = '';

  bool get _canLoadMore => timeline.events.last.type != EventTypes.RoomCreate;

  void requestHistory() async {
    if (_canLoadMore) {
      setState(() => _loadingHistory = true);

      await SimpleDialogs(context).tryRequestWithErrorToast(
        timeline.requestHistory(historyCount: _loadHistoryCount),
      );

      // we do NOT setState() here as then the event order will be wrong.
      // instead, we just set our variable to false, and rely on timeline update to set the
      // new state, thus triggering a re-render, for us
      _loadingHistory = false;
    }
  }

  void _updateScrollController() {
    if (!mounted) {
      return;
    }
    if (_scrollController.position.pixels ==
            _scrollController.position.maxScrollExtent &&
        timeline.events.isNotEmpty &&
        timeline.events[timeline.events.length - 1].type !=
            EventTypes.RoomCreate) {
      requestHistory();
    }
    if (_scrollController.position.pixels > 0 &&
        showScrollDownButton == false) {
      setState(() => showScrollDownButton = true);
    } else if (_scrollController.position.pixels == 0 &&
        showScrollDownButton == true) {
      setState(() => showScrollDownButton = false);
    }
  }

  @override
  void initState() {
    _scrollController.addListener(_updateScrollController);
    super.initState();
  }

  void updateView() {
    if (!mounted) return;

    var seenByText = '';
    if (timeline.events.isNotEmpty) {
      final filteredEvents = getFilteredEvents();
      final lastReceipts = <User>{};
      // now we iterate the timeline events until we hit the first rendered event
      for (final event in timeline.events) {
        lastReceipts.addAll(event.receipts.map((r) => r.user));
        if (event.eventId == filteredEvents.first.eventId) {
          break;
        }
      }
      lastReceipts.removeWhere((user) =>
          user.id == room.client.userID ||
          user.id == filteredEvents.first.senderId);
      if (lastReceipts.length == 1) {
        seenByText =
            L10n.of(context).seenByUser(lastReceipts.first.calcDisplayname());
      } else if (lastReceipts.length == 2) {
        seenByText = seenByText = L10n.of(context).seenByUserAndUser(
            lastReceipts.first.calcDisplayname(),
            lastReceipts.last.calcDisplayname());
      } else if (lastReceipts.length > 2) {
        seenByText = L10n.of(context).seenByUserAndCountOthers(
            lastReceipts.first.calcDisplayname(),
            (lastReceipts.length - 1).toString());
      }
    }
    if (timeline != null) {
      setState(() {
        this.seenByText = seenByText;
      });
    }
  }

  Future<bool> getTimeline(BuildContext context) async {
    if (timeline == null) {
      timeline = await room.getTimeline(onUpdate: updateView);
      if (timeline.events.isNotEmpty) {
        unawaited(room.setUnread(false).catchError((err) {
          if (err is MatrixException && err.errcode == 'M_FORBIDDEN') {
            // ignore if the user is not in the room (still joining)
            return;
          }
          throw err;
        }));
      }

      // when the scroll controller is attached we want to scroll to an event id, if specified
      // and update the scroll controller...which will trigger a request history, if the
      // "load more" button is visible on the screen
      SchedulerBinding.instance.addPostFrameCallback((_) async {
        if (mounted) {
          if (widget.scrollToEventId != null) {
            _scrollToEventId(widget.scrollToEventId, context: context);
          }
          _updateScrollController();
        }
      });
    }
    updateView();
    return true;
  }

  @override
  void dispose() {
    timeline?.cancelSubscriptions();
    timeline = null;
    matrix.activeRoomId = '';
    super.dispose();
  }

  TextEditingController sendController = TextEditingController();

  void send() {
    if (sendController.text.isEmpty) return;
    room.sendTextEvent(sendController.text,
        inReplyTo: replyEvent, editEventId: editEvent?.eventId);
    sendController.text = pendingText;

    setState(() {
      inputText = pendingText;
      replyEvent = null;
      editEvent = null;
      pendingText = '';
    });
  }

  void sendFileAction(BuildContext context) async {
    final result =
        await FilePickerCross.importFromStorage(type: FileTypeCross.any);
    if (result == null) return;
    await showDialog(
      context: context,
      builder: (context) => SendFileDialog(
        file: MatrixFile(
          bytes: result.toUint8List(),
          name: result.fileName,
        ).detectFileType,
        room: room,
      ),
    );
  }

  void sendImageAction(BuildContext context) async {
    final result =
        await FilePickerCross.importFromStorage(type: FileTypeCross.image);
    if (result == null) return;
    await showDialog(
      context: context,
      builder: (context) => SendFileDialog(
        file: MatrixImageFile(
          bytes: result.toUint8List(),
          name: result.fileName,
        ),
        room: room,
      ),
    );
  }

  void openCameraAction(BuildContext context) async {
    var file = await ImagePicker().getImage(source: ImageSource.camera);
    if (file == null) return;
    final bytes = await file.readAsBytes();
    await showDialog(
      context: context,
      builder: (context) => SendFileDialog(
        file: MatrixImageFile(
          bytes: bytes,
          name: file.path,
        ),
        room: room,
      ),
    );
  }

  void voiceMessageAction(BuildContext context) async {
    String result;
    await showDialog(
        context: context,
        builder: (context) => RecordingDialog(
              onFinished: (r) => result = r,
            ));
    if (result == null) return;
    final audioFile = File(result);
    // as we already explicitly say send in the recording dialog,
    // we do not need the send file dialog anymore. We can just send this straight away.
    await SimpleDialogs(context).tryRequestWithLoadingDialog(
      room.sendFileEvent(
        MatrixAudioFile(
            bytes: audioFile.readAsBytesSync(), name: audioFile.path),
      ),
    );
  }

  String _getSelectedEventString(BuildContext context) {
    var copyString = '';
    if (selectedEvents.length == 1) {
      return selectedEvents.first
          .getDisplayEvent(timeline)
          .getLocalizedBody(MatrixLocals(L10n.of(context)));
    }
    for (var event in selectedEvents) {
      if (copyString.isNotEmpty) copyString += '\n\n';
      copyString += event.getDisplayEvent(timeline).getLocalizedBody(
          MatrixLocals(L10n.of(context)),
          withSenderNamePrefix: true);
    }
    return copyString;
  }

  void copyEventsAction(BuildContext context) {
    Clipboard.setData(ClipboardData(text: _getSelectedEventString(context)));
    setState(() => selectedEvents.clear());
  }

  void redactEventsAction(BuildContext context) async {
    var confirmed = await showOkCancelAlertDialog(
          context: context,
          title: L10n.of(context).messageWillBeRemovedWarning,
          okLabel: L10n.of(context).remove,
        ) ==
        OkCancelResult.ok;
    if (!confirmed) return;
    for (var event in selectedEvents) {
      await SimpleDialogs(context).tryRequestWithLoadingDialog(
          event.status > 0 ? event.redact() : event.remove());
    }
    setState(() => selectedEvents.clear());
  }

  bool get canRedactSelectedEvents {
    for (var event in selectedEvents) {
      if (event.canRedact == false) return false;
    }
    return true;
  }

  void forwardEventsAction(BuildContext context) async {
    if (selectedEvents.length == 1) {
      Matrix.of(context).shareContent = selectedEvents.first.content;
    } else {
      Matrix.of(context).shareContent = {
        'msgtype': 'm.text',
        'body': _getSelectedEventString(context),
      };
    }
    setState(() => selectedEvents.clear());
    Navigator.of(context).popUntil((r) => r.isFirst);
  }

  void sendAgainAction(Timeline timeline) {
    final event = selectedEvents.first;
    if (event.status == -1) {
      event.sendAgain();
    }
    final allEditEvents = event
        .aggregatedEvents(timeline, RelationshipTypes.Edit)
        .where((e) => e.status == -1);
    for (final e in allEditEvents) {
      e.sendAgain();
    }
    setState(() => selectedEvents.clear());
  }

  void replyAction({Event replyTo}) {
    setState(() {
      replyEvent = replyTo ?? selectedEvents.first;
      selectedEvents.clear();
    });
    inputFocus.requestFocus();
  }

  void _scrollToEventId(String eventId, {BuildContext context}) async {
    var eventIndex =
        getFilteredEvents().indexWhere((e) => e.eventId == eventId);
    if (eventIndex == -1) {
      // event id not found...maybe we can fetch it?
      // the try...finally is here to start and close the loading dialog reliably
      final task = Future.microtask(() async {
        // okay, we first have to fetch if the event is in the room
        try {
          final event = await timeline.getEventById(eventId);
          if (event == null) {
            // event is null...meaning something is off
            return;
          }
        } catch (err) {
          if (err is MatrixException && err.errcode == 'M_NOT_FOUND') {
            // event wasn't found, as the server gave a 404 or something
            return;
          }
          rethrow;
        }
        // okay, we know that the event *is* in the room
        while (eventIndex == -1) {
          if (!_canLoadMore) {
            // we can't load any more events but still haven't found ours yet...better stop here
            return;
          }
          try {
            await timeline.requestHistory(historyCount: _loadHistoryCount);
          } catch (err) {
            if (err is TimeoutException) {
              // loading the history timed out...so let's do nothing
              return;
            }
            rethrow;
          }
          eventIndex =
              getFilteredEvents().indexWhere((e) => e.eventId == eventId);
        }
      });
      if (context != null) {
        await SimpleDialogs(context).tryRequestWithLoadingDialog(task);
      } else {
        await task;
      }
    }
    if (!mounted) {
      return;
    }
    await _scrollController.scrollToIndex(eventIndex,
        preferPosition: AutoScrollPosition.middle);
    _updateScrollController();
  }

  List<Event> getFilteredEvents() {
    final filteredEvents = timeline.events
        .where((e) =>
            // always filter out edit and reaction relationships
            !{RelationshipTypes.Edit, RelationshipTypes.Reaction}
                .contains(e.relationshipType) &&
            // always filter out m.key.* events
            !e.type.startsWith('m.key.verification.') &&
            // event types to hide: redaction and reaction events
            // if a reaction has been redacted we also want it to be hidden in the timeline
            !{EventTypes.Reaction, EventTypes.Redaction}.contains(e.type) &&
            // if we enabled to hide all redacted events, don't show those
            (!AppConfig.hideRedactedEvents || !e.redacted) &&
            // if we enabled to hide all unknown events, don't show those
            (!AppConfig.hideUnknownEvents || e.isEventTypeKnown) &&
            // remove state events that we don't want to render
            (!{EventTypes.Message, EventTypes.Sticker, EventTypes.Encrypted}
                    .contains(e.type) ||
                !AppConfig.hideAllStateEvents))
        .toList();

    // Hide state events from the room creater right after the room created event
    if (_collapseRoomCreate &&
        filteredEvents[filteredEvents.length - 1].type ==
            EventTypes.RoomCreate) {
      while (filteredEvents.length >= 3 &&
          filteredEvents[filteredEvents.length - 2].senderId ==
              filteredEvents[filteredEvents.length - 1].senderId &&
          ![EventTypes.Message, EventTypes.Sticker, EventTypes.Encrypted]
              .contains(filteredEvents[filteredEvents.length - 2].type)) {
        filteredEvents.removeAt(filteredEvents.length - 2);
      }
    }
    return filteredEvents;
  }

  void _pickEmojiAction(
      BuildContext context, Iterable<Event> allReactionEvents) async {
    final emoji = await showModalBottomSheet(
      context: context,
      backgroundColor: Colors.transparent,
      builder: (context) => Column(
        children: [
          Spacer(),
          EmojiPicker(
            onEmojiSelected: (emoji, category) {
              // recent emojis don't work, so we sadly have to re-implement them
              // https://github.com/JeffG05/emoji_picker/issues/31
              SharedPreferences.getInstance().then((prefs) {
                final recents = prefs.getStringList('recents') ?? <String>[];
                recents.insert(0, emoji.name);
                // make sure we remove duplicates
                prefs.setStringList('recents', recents.toSet().toList());
              });
              Navigator.of(context).pop<Emoji>(emoji);
            },
          ),
        ],
      ),
    );
    if (emoji == null) return;
    // make sure we don't send the same emoji twice
    if (allReactionEvents
        .any((e) => e.content['m.relates_to']['key'] == emoji.emoji)) return;
    return _sendEmojiAction(context, emoji.emoji);
  }

  void _sendEmojiAction(BuildContext context, String emoji) {
    SimpleDialogs(context).tryRequestWithLoadingDialog(
      room.sendReaction(
        selectedEvents.first.eventId,
        emoji,
      ),
    );
    setState(() => selectedEvents.clear());
  }

  @override
  Widget build(BuildContext context) {
    matrix = Matrix.of(context);
    var client = matrix.client;
    room ??= client.getRoomById(widget.id);
    if (room == null) {
      return Scaffold(
        appBar: AppBar(
          title: Text(L10n.of(context).oopsSomethingWentWrong),
        ),
        body: Center(
          child: Text(L10n.of(context).youAreNoLongerParticipatingInThisChat),
        ),
      );
    }
    matrix.activeRoomId = widget.id;

    if (room.membership == Membership.invite) {
      SimpleDialogs(context).tryRequestWithLoadingDialog(room.join());
    }

    final typingText = room.getLocalizedTypingText(context);
    return Scaffold(
      appBar: AppBar(
        leading: selectMode
            ? IconButton(
                icon: Icon(Icons.close),
                onPressed: () => setState(() => selectedEvents.clear()),
              )
            : null,
        titleSpacing: 0,
        title: selectedEvents.isEmpty
            ? StreamBuilder<Object>(
                stream: room.onUpdate.stream,
                builder: (context, snapshot) => ListTile(
                      leading: Avatar(room.avatar, room.displayname),
                      contentPadding: EdgeInsets.zero,
                      onTap: room.isDirectChat
                          ? () => showModalBottomSheet(
                                context: context,
                                builder: (context) => UserBottomSheet(
                                  user: room.getUserByMXIDSync(
                                      room.directChatMatrixID),
                                  onMention: () => sendController.text +=
                                      ' ${room.directChatMatrixID}',
                                ),
                              )
                          : () => Navigator.of(context).push(
                                AppRoute.defaultRoute(
                                  context,
                                  ChatDetails(room),
                                ),
                              ),
                      title: Text(
                          room.getLocalizedDisplayname(
                              MatrixLocals(L10n.of(context))),
                          maxLines: 1),
                      subtitle: typingText.isEmpty
                          ? StreamBuilder<Object>(
                              stream: Matrix.of(context)
                                  .client
                                  .onPresence
                                  .stream
                                  .where((p) =>
                                      p.senderId == room.directChatMatrixID),
                              builder: (context, snapshot) => Text(
                                    room.getLocalizedStatus(context),
                                    maxLines: 1,
                                  ))
                          : Row(
                              children: <Widget>[
                                Icon(Icons.edit_outlined,
                                    color: Theme.of(context).primaryColor,
                                    size: 13),
                                SizedBox(width: 4),
                                Text(
                                  typingText,
                                  maxLines: 1,
                                  style: TextStyle(
                                    color: Theme.of(context).primaryColor,
                                    fontStyle: FontStyle.italic,
                                    fontSize: 16,
                                  ),
                                ),
                              ],
                            ),
                    ))
            : Text(L10n.of(context)
                .numberSelected(selectedEvents.length.toString())),
        actions: selectMode
            ? <Widget>[
                if (selectedEvents.length == 1 &&
                    selectedEvents.first.status > 0 &&
                    selectedEvents.first.senderId == client.userID)
                  IconButton(
                    icon: Icon(Icons.edit_outlined),
                    onPressed: () {
                      setState(() {
                        pendingText = sendController.text;
                        editEvent = selectedEvents.first;
                        inputText = sendController.text = editEvent
                            .getDisplayEvent(timeline)
                            .getLocalizedBody(MatrixLocals(L10n.of(context)),
                                withSenderNamePrefix: false, hideReply: true);
                        selectedEvents.clear();
                      });
                      inputFocus.requestFocus();
                    },
                  ),
                IconButton(
                  icon: Icon(Icons.content_copy_outlined),
                  onPressed: () => copyEventsAction(context),
                ),
                if (canRedactSelectedEvents)
                  IconButton(
                    icon: Icon(Icons.delete_outlined),
                    onPressed: () => redactEventsAction(context),
                  ),
              ]
            : <Widget>[ChatSettingsPopupMenu(room, !room.isDirectChat)],
      ),
      floatingActionButton: showScrollDownButton
          ? Padding(
              padding: const EdgeInsets.only(bottom: 56.0),
              child: FloatingActionButton(
                child: Icon(Icons.arrow_downward_outlined,
                    color: Theme.of(context).primaryColor),
                onPressed: () => _scrollController.jumpTo(0),
                foregroundColor: Theme.of(context).textTheme.bodyText2.color,
                backgroundColor: Theme.of(context).scaffoldBackgroundColor,
                mini: true,
              ),
            )
          : null,
      body: Stack(
        children: <Widget>[
          if (Matrix.of(context).wallpaper != null)
            Image.file(
              Matrix.of(context).wallpaper,
              height: double.infinity,
              width: double.infinity,
              fit: BoxFit.cover,
            ),
          SafeArea(
            child: Column(
              children: <Widget>[
                ConnectionStatusHeader(),
                Expanded(
                  child: FutureBuilder<bool>(
                    future: getTimeline(context),
                    builder: (BuildContext context, snapshot) {
                      if (!snapshot.hasData) {
                        return Center(
                          child: CircularProgressIndicator(),
                        );
                      }

                      if (room.notificationCount != null &&
                          room.notificationCount > 0 &&
                          timeline != null &&
                          timeline.events.isNotEmpty &&
                          Matrix.of(context).webHasFocus) {
                        room.sendReadMarker(timeline.events.first.eventId);
                      }

                      final filteredEvents = getFilteredEvents();

                      // create a map of eventId --> index to greatly improve performance of
                      // ListView's findChildIndexCallback
                      final thisEventsKeyMap = <String, int>{};
                      for (var i = 0; i < filteredEvents.length; i++) {
                        thisEventsKeyMap[filteredEvents[i].eventId] = i;
                      }

                      return ListView.custom(
                        padding: EdgeInsets.symmetric(
                          horizontal: max(
                              0,
                              (MediaQuery.of(context).size.width -
                                      AdaptivePageLayout.defaultMinWidth *
                                          3.5) /
                                  2),
                        ),
                        reverse: true,
                        controller: _scrollController,
                        childrenDelegate: SliverChildBuilderDelegate(
                          (BuildContext context, int i) {
                            return i == filteredEvents.length + 1
                                ? _loadingHistory
                                    ? Container(
                                        height: 50,
                                        alignment: Alignment.center,
                                        padding: EdgeInsets.all(8),
                                        child: CircularProgressIndicator(),
                                      )
                                    : _canLoadMore
                                        ? FlatButton(
                                            child: Text(
                                              L10n.of(context).loadMore,
                                              style: TextStyle(
                                                color: Theme.of(context)
                                                    .primaryColor,
                                                fontWeight: FontWeight.bold,
                                                decoration:
                                                    TextDecoration.underline,
                                              ),
                                            ),
                                            onPressed: requestHistory,
                                          )
                                        : Container()
                                : i == 0
                                    ? AnimatedContainer(
                                        height: seenByText.isEmpty ? 0 : 24,
                                        duration: seenByText.isEmpty
                                            ? Duration(milliseconds: 0)
                                            : Duration(milliseconds: 300),
                                        alignment:
                                            filteredEvents.first.senderId ==
                                                    client.userID
                                                ? Alignment.topRight
                                                : Alignment.topLeft,
                                        child: Container(
                                          padding: EdgeInsets.symmetric(
                                              horizontal: 4),
                                          decoration: BoxDecoration(
                                            color: Theme.of(context)
                                                .scaffoldBackgroundColor
                                                .withOpacity(0.8),
                                            borderRadius:
                                                BorderRadius.circular(4),
                                          ),
                                          child: Text(
                                            seenByText,
                                            maxLines: 1,
                                            overflow: TextOverflow.ellipsis,
                                            style: TextStyle(
                                              color: Theme.of(context)
                                                  .primaryColor,
                                            ),
                                          ),
                                        ),
                                        padding: EdgeInsets.only(
                                          left: 8,
                                          right: 8,
                                          bottom: 8,
                                        ),
                                      )
                                    : AutoScrollTag(
                                        key: ValueKey(
                                            filteredEvents[i - 1].eventId),
                                        index: i - 1,
                                        controller: _scrollController,
                                        child: Swipeable(
                                          key: ValueKey(
                                              filteredEvents[i - 1].eventId),
                                          background: Padding(
                                            padding: EdgeInsets.symmetric(
                                                horizontal: 12.0),
                                            child: Center(
                                              child: Icon(Icons.reply_outlined),
                                            ),
                                          ),
                                          direction: SwipeDirection.endToStart,
                                          onSwipe: (direction) => replyAction(
                                              replyTo: filteredEvents[i - 1]),
                                          child: Message(filteredEvents[i - 1],
                                              onAvatarTab: (Event event) =>
                                                  showModalBottomSheet(
                                                    context: context,
                                                    builder: (context) =>
                                                        UserBottomSheet(
                                                      user: event.sender,
                                                      onMention: () =>
                                                          sendController.text +=
                                                              ' ${event.senderId}',
                                                    ),
                                                  ),
                                              onSelect: (Event event) {
                                                if (event.type ==
                                                    EventTypes.RoomCreate) {
                                                  return setState(() =>
                                                      _collapseRoomCreate =
                                                          false);
                                                }
                                                if (!event.redacted) {
                                                  if (selectedEvents
                                                      .contains(event)) {
                                                    setState(
                                                      () => selectedEvents
                                                          .remove(event),
                                                    );
                                                  } else {
                                                    setState(
                                                      () => selectedEvents
                                                          .add(event),
                                                    );
                                                  }
                                                  selectedEvents.sort(
                                                    (a, b) => a.originServerTs
                                                        .compareTo(
                                                            b.originServerTs),
                                                  );
                                                }
                                              },
                                              scrollToEventId:
                                                  (String eventId) =>
                                                      _scrollToEventId(eventId,
                                                          context: context),
                                              longPressSelect:
                                                  selectedEvents.isEmpty,
                                              selected: selectedEvents.contains(
                                                  filteredEvents[i - 1]),
                                              timeline: timeline,
                                              nextEvent: i >= 2
                                                  ? filteredEvents[i - 2]
                                                  : null),
                                        ),
                                      );
                          },
                          childCount: filteredEvents.length + 2,
                          findChildIndexCallback: (Key key) {
                            // this method is called very often. As such, it has to be optimized for speed.
                            if (!(key is ValueKey)) {
                              return null;
                            }
                            final eventId = (key as ValueKey).value;
                            if (!(eventId is String)) {
                              return null;
                            }
                            // first fetch the last index the event was at
                            final index = thisEventsKeyMap[eventId];
                            if (index == null) {
                              return null;
                            }
                            // we need to +1 as 0 is the typing thing at the bottom
                            return index + 1;
                          },
                        ),
                      );
                    },
                  ),
                ),
                AnimatedContainer(
                  duration: Duration(milliseconds: 300),
                  height: (editEvent == null &&
                          replyEvent == null &&
                          selectedEvents.length == 1)
                      ? 56
                      : 0,
                  child: Material(
                    color: Theme.of(context).secondaryHeaderColor,
                    child: Builder(builder: (context) {
                      if (!(editEvent == null &&
                          replyEvent == null &&
                          selectedEvents.length == 1)) {
                        return Container();
                      }
                      var emojis = List<String>.from(AppEmojis.emojis);
                      final allReactionEvents = selectedEvents.first
                          .aggregatedEvents(
                              timeline, RelationshipTypes.Reaction)
                          ?.where((event) =>
                              event.senderId == event.room.client.userID &&
                              event.type == 'm.reaction');

                      allReactionEvents.forEach((event) {
                        try {
                          emojis.remove(event.content['m.relates_to']['key']);
                        } catch (_) {}
                      });
                      return ListView.builder(
                        scrollDirection: Axis.horizontal,
                        itemCount: emojis.length + 1,
                        itemBuilder: (c, i) => i == emojis.length
                            ? InkWell(
                                borderRadius: BorderRadius.circular(8),
                                child: Container(
                                  width: 56,
                                  height: 56,
                                  alignment: Alignment.center,
                                  child: Icon(Icons.add_outlined),
                                ),
                                onTap: () => _pickEmojiAction(
                                    context, allReactionEvents),
                              )
                            : InkWell(
                                borderRadius: BorderRadius.circular(8),
                                onTap: () =>
                                    _sendEmojiAction(context, emojis[i]),
                                child: Container(
                                  width: 56,
                                  height: 56,
                                  alignment: Alignment.center,
                                  child: Text(
                                    emojis[i],
                                    style: TextStyle(fontSize: 30),
                                  ),
                                ),
                              ),
                      );
                    }),
                  ),
                ),
                AnimatedContainer(
                  duration: Duration(milliseconds: 300),
                  height: editEvent != null || replyEvent != null ? 56 : 0,
                  child: Material(
                    color: Theme.of(context).secondaryHeaderColor,
                    child: Row(
                      children: <Widget>[
                        IconButton(
                          icon: Icon(Icons.close),
                          onPressed: () => setState(() {
                            if (editEvent != null) {
                              inputText = sendController.text = pendingText;
                              pendingText = '';
                            }
                            replyEvent = null;
                            editEvent = null;
                          }),
                        ),
                        Expanded(
                          child: replyEvent != null
                              ? ReplyContent(replyEvent, timeline: timeline)
                              : _EditContent(
                                  editEvent?.getDisplayEvent(timeline)),
                        ),
                      ],
                    ),
                  ),
                ),
                Divider(
                  height: 1,
                  color: Theme.of(context).secondaryHeaderColor,
                  thickness: 1,
                ),
                room.canSendDefaultMessages &&
                        room.membership == Membership.join
                    ? Container(
                        decoration: BoxDecoration(
                          color: Theme.of(context).backgroundColor,
                        ),
                        child: Row(
                          crossAxisAlignment: CrossAxisAlignment.end,
                          mainAxisAlignment: MainAxisAlignment.spaceBetween,
                          children: selectMode
                              ? <Widget>[
                                  Container(
                                    height: 56,
                                    child: FlatButton(
                                      onPressed: () =>
                                          forwardEventsAction(context),
                                      child: Row(
                                        children: <Widget>[
                                          Icon(Icons
                                              .keyboard_arrow_left_outlined),
                                          Text(L10n.of(context).forward),
                                        ],
                                      ),
                                    ),
                                  ),
                                  selectedEvents.length == 1
                                      ? selectedEvents.first
                                                  .getDisplayEvent(timeline)
                                                  .status >
                                              0
                                          ? Container(
                                              height: 56,
                                              child: FlatButton(
                                                onPressed: () => replyAction(),
                                                child: Row(
                                                  children: <Widget>[
                                                    Text(
                                                        L10n.of(context).reply),
                                                    Icon(Icons
                                                        .keyboard_arrow_right),
                                                  ],
                                                ),
                                              ),
                                            )
                                          : Container(
                                              height: 56,
                                              child: FlatButton(
                                                onPressed: () =>
                                                    sendAgainAction(timeline),
                                                child: Row(
                                                  children: <Widget>[
                                                    Text(L10n.of(context)
                                                        .tryToSendAgain),
                                                    SizedBox(width: 4),
                                                    Icon(Icons.send_outlined,
                                                        size: 16),
                                                  ],
                                                ),
                                              ),
                                            )
                                      : Container(),
                                ]
                              : <Widget>[
                                  if (inputText.isEmpty)
                                    Container(
                                      height: 56,
                                      alignment: Alignment.center,
                                      child: PopupMenuButton<String>(
                                        icon: Icon(Icons.add_outlined),
                                        onSelected: (String choice) async {
                                          if (choice == 'file') {
                                            sendFileAction(context);
                                          } else if (choice == 'image') {
                                            sendImageAction(context);
                                          }
                                          if (choice == 'camera') {
                                            openCameraAction(context);
                                          }
                                          if (choice == 'voice') {
                                            voiceMessageAction(context);
                                          }
                                        },
                                        itemBuilder: (BuildContext context) =>
                                            <PopupMenuEntry<String>>[
                                          PopupMenuItem<String>(
                                            value: 'file',
                                            child: ListTile(
                                              leading: CircleAvatar(
                                                backgroundColor: Colors.green,
                                                foregroundColor: Colors.white,
                                                child: Icon(
                                                    Icons.attachment_outlined),
                                              ),
                                              title: Text(
                                                  L10n.of(context).sendFile),
                                              contentPadding: EdgeInsets.all(0),
                                            ),
                                          ),
                                          PopupMenuItem<String>(
                                            value: 'image',
                                            child: ListTile(
                                              leading: CircleAvatar(
                                                backgroundColor: Colors.blue,
                                                foregroundColor: Colors.white,
                                                child:
                                                    Icon(Icons.image_outlined),
                                              ),
                                              title: Text(
                                                  L10n.of(context).sendImage),
                                              contentPadding: EdgeInsets.all(0),
                                            ),
                                          ),
                                          if (PlatformInfos.isMobile)
                                            PopupMenuItem<String>(
                                              value: 'camera',
                                              child: ListTile(
                                                leading: CircleAvatar(
                                                  backgroundColor:
                                                      Colors.purple,
                                                  foregroundColor: Colors.white,
                                                  child: Icon(Icons
                                                      .camera_alt_outlined),
                                                ),
                                                title: Text(L10n.of(context)
                                                    .openCamera),
                                                contentPadding:
                                                    EdgeInsets.all(0),
                                              ),
                                            ),
                                          if (PlatformInfos.isMobile)
                                            PopupMenuItem<String>(
                                              value: 'voice',
                                              child: ListTile(
                                                leading: CircleAvatar(
                                                  backgroundColor: Colors.red,
                                                  foregroundColor: Colors.white,
                                                  child: Icon(
                                                      Icons.mic_none_outlined),
                                                ),
                                                title: Text(L10n.of(context)
                                                    .voiceMessage),
                                                contentPadding:
                                                    EdgeInsets.all(0),
                                              ),
                                            ),
                                        ],
                                      ),
                                    ),
                                  Container(
                                    height: 56,
                                    alignment: Alignment.center,
                                    child: EncryptionButton(room),
                                  ),
                                  Expanded(
                                    child: Padding(
                                      padding: const EdgeInsets.symmetric(
                                          vertical: 4.0),
                                      child: InputBar(
                                        room: room,
                                        minLines: 1,
                                        maxLines: kIsWeb ? 1 : 8,
                                        autofocus: !PlatformInfos.isMobile,
                                        keyboardType: !PlatformInfos.isMobile
                                            ? TextInputType.text
                                            : TextInputType.multiline,
                                        onSubmitted: (String text) {
                                          send();
                                          FocusScope.of(context)
                                              .requestFocus(inputFocus);
                                        },
                                        focusNode: inputFocus,
                                        controller: sendController,
                                        decoration: InputDecoration(
                                          hintText:
                                              L10n.of(context).writeAMessage,
                                          hintMaxLines: 1,
                                          border: InputBorder.none,
                                        ),
                                        onChanged: (String text) {
                                          typingCoolDown?.cancel();
                                          typingCoolDown =
                                              Timer(Duration(seconds: 2), () {
                                            typingCoolDown = null;
                                            currentlyTyping = false;
                                            room.sendTypingInfo(false);
                                          });
                                          typingTimeout ??=
                                              Timer(Duration(seconds: 30), () {
                                            typingTimeout = null;
                                            currentlyTyping = false;
                                          });
                                          if (!currentlyTyping) {
                                            currentlyTyping = true;
                                            room.sendTypingInfo(true,
                                                timeout: Duration(seconds: 30)
                                                    .inMilliseconds);
                                          }
                                          // Workaround for a current desktop bug
                                          if (!PlatformInfos.isBetaDesktop) {
                                            setState(() => inputText = text);
                                          }
                                        },
                                      ),
                                    ),
                                  ),
                                  if (PlatformInfos.isMobile &&
                                      inputText.isEmpty)
                                    Container(
                                      height: 56,
                                      alignment: Alignment.center,
                                      child: IconButton(
                                        icon: Icon(Icons.mic_none_outlined),
                                        onPressed: () =>
                                            voiceMessageAction(context),
                                      ),
                                    ),
                                  if (!PlatformInfos.isMobile ||
                                      inputText.isNotEmpty)
                                    Container(
                                      height: 56,
                                      alignment: Alignment.center,
                                      child: IconButton(
                                        icon: Icon(Icons.send_outlined),
                                        onPressed: () => send(),
                                      ),
                                    ),
                                ],
                        ),
                      )
                    : Container(),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

class _EditContent extends StatelessWidget {
  final Event event;

  _EditContent(this.event);

  @override
  Widget build(BuildContext context) {
    if (event == null) {
      return Container();
    }
    return Row(
      children: <Widget>[
        Icon(
          Icons.edit,
          color: Theme.of(context).primaryColor,
        ),
        Container(width: 15.0),
        Text(
          event?.getLocalizedBody(
                MatrixLocals(L10n.of(context)),
                withSenderNamePrefix: false,
                hideReply: true,
              ) ??
              '',
          overflow: TextOverflow.ellipsis,
          maxLines: 1,
          style: TextStyle(
            color: Theme.of(context).textTheme.bodyText2.color,
          ),
        ),
      ],
    );
  }
}