feat: Add support for restricted join rule

lib/l10n/intl_en.arb

@@ -3392,5 +3392,23 @@
         "type": "int"
       }
     }
+  },
+  "spaceMemberOf": "Space member of {spaces}",
+  "@spaceMemberOf": {
+    "type": "String",
+    "placeholders": {
+      "spaces": {
+        "type": "String"
+      }
+    }
+  },
+  "spaceMemberOfCanKnock": "Space member of {spaces} can knock",
+  "@spaceMemberOfCanKnock": {
+    "type": "String",
+    "placeholders": {
+      "spaces": {
+        "type": "String"
+      }
+    }
   }
 }

lib/pages/chat_access_settings/chat_access_settings_controller.dart

@@ -26,6 +26,16 @@ class ChatAccessSettingsController extends State<ChatAccessSettings> {
   bool historyVisibilityLoading = false;
   bool guestAccessLoading = false;
   Room get room => Matrix.of(context).client.getRoomById(widget.roomId)!;
+  Set<Room> get knownSpaceParents => {
+        ...room.client.rooms.where(
+          (space) =>
+              space.isSpace &&
+              space.spaceChildren.any((child) => child.roomId == room.id),
+        ),
+        ...room.spaceParents
+            .map((parent) => room.client.getRoomById(parent.roomId ?? ''))
+            .whereType<Room>(),
+      };
 
   String get roomVersion =>
       room
@@ -46,9 +56,12 @@ class ChatAccessSettingsController extends State<ChatAccessSettings> {
       joinRules.remove(JoinRules.knock);
     }
 
-    // Not yet supported in FluffyChat:
+    if (knownSpaceParents.isEmpty) {
-    joinRules.remove(JoinRules.restricted);
+      joinRules.remove(JoinRules.restricted);
-    joinRules.remove(JoinRules.knockRestricted);
+      if (roomVersionInt != null && roomVersionInt <= 6) {
+        joinRules.remove(JoinRules.knockRestricted);
+      }
+    }
 
     // If an unsupported join rule is the current join rule, display it:
     final currentJoinRule = room.joinRules;
@@ -64,7 +77,13 @@ class ChatAccessSettingsController extends State<ChatAccessSettings> {
     });
 
     try {
-      await room.setJoinRules(newJoinRules);
+      await room.setJoinRules(
+        newJoinRules,
+        allowConditionRoomId: {JoinRules.restricted, JoinRules.knockRestricted}
+                .contains(newJoinRules)
+            ? knownSpaceParents.first.id
+            : null,
+      );
     } catch (e, s) {
       Logs().w('Unable to change join rules', e, s);
       if (mounted) {

lib/pages/chat_access_settings/chat_access_settings_page.dart

@@ -88,7 +88,10 @@ class ChatAccessSettingsPageView extends StatelessWidget {
                             enabled: !controller.joinRulesLoading &&
                                 room.canChangeJoinRules,
                             title: Text(
-                              joinRule.localizedString(L10n.of(context)),
+                              joinRule.localizedString(
+                                L10n.of(context),
+                                controller.knownSpaceParents,
+                              ),
                             ),
                             value: joinRule,
                           ),
@@ -280,7 +283,7 @@ class _AliasListTile extends StatelessWidget {
 }
 
 extension JoinRulesDisplayString on JoinRules {
-  String localizedString(L10n l10n) {
+  String localizedString(L10n l10n, Set<Room> spaceParents) {
     switch (this) {
       case JoinRules.public:
         return l10n.anyoneCanJoin;
@@ -291,9 +294,17 @@ extension JoinRulesDisplayString on JoinRules {
       case JoinRules.private:
         return l10n.noOneCanJoin;
       case JoinRules.restricted:
-        return l10n.restricted;
+        return l10n.spaceMemberOf(
+          spaceParents
+              .map((space) => space.getLocalizedDisplayname(MatrixLocals(l10n)))
+              .join(', '),
+        );
       case JoinRules.knockRestricted:
-        return l10n.knockRestricted;
+        return l10n.spaceMemberOfCanKnock(
+          spaceParents
+              .map((space) => space.getLocalizedDisplayname(MatrixLocals(l10n)))
+              .join(', '),
+        );
     }
   }
 }