Add room tag support

lib/matrix_api/model/tag.dart

@@ -20,7 +20,7 @@ class Tag {
   double order;
 
   Tag.fromJson(Map<String, dynamic> json) {
-    order = json['order'];
+    order = json['order']?.toDouble();
   }
 
   Map<String, dynamic> toJson() {
@@ -31,3 +31,12 @@ class Tag {
     return data;
   }
 }
+
+abstract class TagType {
+  static const String Favourite = 'm.favourite';
+  static const String LowPriority = 'm.lowpriority';
+  static const String ServerNotice = 'm.server_notice';
+  static bool isValid(String tag) => tag.startsWith('m.')
+      ? [Favourite, LowPriority, ServerNotice].contains(tag)
+      : true;
+}

lib/src/client.dart

@@ -1074,8 +1074,10 @@ class Client {
   /// The compare function how the rooms should be sorted internally. By default
   /// rooms are sorted by timestamp of the last m.room.message event or the last
   /// event if there is no known message.
-  RoomSorter sortRoomsBy = (a, b) => b.timeCreated.millisecondsSinceEpoch
-      .compareTo(a.timeCreated.millisecondsSinceEpoch);
+  RoomSorter sortRoomsBy = (a, b) => (a.isFavourite != b.isFavourite)
+      ? (a.isFavourite ? -1 : 1)
+      : b.timeCreated.millisecondsSinceEpoch
+          .compareTo(a.timeCreated.millisecondsSinceEpoch);
 
   void _sortRooms() {
     if (prevBatch == null || _sortLock || rooms.length < 2) return;

lib/src/room.dart

@@ -361,6 +361,40 @@ class Room {
         {'topic': newName},
       );
 
+  /// Add a tag to the room.
+  Future<void> addTag(String tag, {double order}) => client.api.addRoomTag(
+        client.userID,
+        id,
+        tag,
+        order: order,
+      );
+
+  /// Removes a tag from the room.
+  Future<void> removeTag(String tag) => client.api.removeRoomTag(
+        client.userID,
+        id,
+        tag,
+      );
+
+  /// Returns all tags for this room.
+  Map<String, Tag> get tags {
+    if (roomAccountData['m.tag'] == null ||
+        !(roomAccountData['m.tag'].content['tags'] is Map)) {
+      return {};
+    }
+    final tags = (roomAccountData['m.tag'].content['tags'] as Map)
+        .map((k, v) => MapEntry<String, Tag>(k, Tag.fromJson(v)));
+    tags.removeWhere((k, v) => !TagType.isValid(k));
+    return tags;
+  }
+
+  /// Returns true if this room has a m.favourite tag.
+  bool get isFavourite => tags[TagType.Favourite] != null;
+
+  /// Sets the m.favourite tag for this room.
+  Future<void> setFavourite(bool favourite) =>
+      favourite ? addTag(TagType.Favourite) : removeTag(TagType.Favourite);
+
   /// Call the Matrix API to change the pinned events of this room.
   Future<String> setPinnedEvents(List<String> pinnedEventIds) =>
       client.api.sendState(

test/fake_matrix_api.dart

@@ -1791,6 +1791,8 @@ class FakeMatrixApi extends MockClient {
           (var reqI) => {
                 'event_id': '\$event${FakeMatrixApi.eventCounter++}',
               },
+      '/client/r0/user/%40test%3AfakeServer.notExisting/rooms/%21localpart%3Aserver.abc/tags/m.favourite':
+          (var req) => {},
       '/client/r0/user/%40alice%3Aexample.com/rooms/%21localpart%3Aexample.com/tags/testtag':
           (var req) => {},
       '/client/r0/user/%40alice%3Aexample.com/account_data/test.account.data':
@@ -1839,6 +1841,8 @@ class FakeMatrixApi extends MockClient {
       '/client/r0/pushrules/global/content/nocake': (var req) => {},
       '/client/r0/pushrules/global/override/!localpart%3Aserver.abc':
           (var req) => {},
+      '/client/r0/user/%40test%3AfakeServer.notExisting/rooms/%21localpart%3Aserver.abc/tags/m.favourite':
+          (var req) => {},
       '/client/r0/user/%40alice%3Aexample.com/rooms/%21localpart%3Aexample.com/tags/testtag':
           (var req) => {},
     },

test/room_test.dart

@@ -409,6 +409,25 @@ void main() {
       await room.sendCallCandidates('1234', [], txid: '1234');
     });
 
+    test('Test tag methods', () async {
+      await room.addTag(TagType.Favourite, order: 0.1);
+      await room.removeTag(TagType.Favourite);
+      expect(room.isFavourite, false);
+      room.roomAccountData['m.tag'] = BasicRoomEvent.fromJson({
+        'content': {
+          'tags': {
+            'm.favourite': {'order': 0.1},
+            'm.wrong': {'order': 0.2},
+          }
+        },
+        'type': 'm.tag'
+      });
+      expect(room.tags.length, 1);
+      expect(room.tags[TagType.Favourite].order, 0.1);
+      expect(room.isFavourite, true);
+      await room.setFavourite(false);
+    });
+
     test('joinRules', () async {
       expect(room.canChangeJoinRules, false);
       expect(room.joinRules, JoinRules.public);