Initial commit

lib/widgets/presence_builder.dart

@@ -0,0 +1,60 @@
+// SPDX-FileCopyrightText: 2019-Present Christian Kußowski
+// SPDX-FileCopyrightText: 2019-Present Contributors to FluffyChat
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import 'dart:async';
+
+import 'package:tatchat/widgets/matrix.dart';
+import 'package:material_ui/material_ui.dart';
+import 'package:matrix/matrix.dart';
+
+class PresenceBuilder extends StatefulWidget {
+  final Widget Function(BuildContext context, CachedPresence? presence) builder;
+  final String? userId;
+  final Client? client;
+
+  const PresenceBuilder({
+    required this.builder,
+    this.userId,
+    this.client,
+    super.key,
+  });
+
+  @override
+  State<PresenceBuilder> createState() => _PresenceBuilderState();
+}
+
+class _PresenceBuilderState extends State<PresenceBuilder> {
+  CachedPresence? _presence;
+  StreamSubscription<CachedPresence>? _sub;
+
+  void _updatePresence(CachedPresence? presence) {
+    if (!mounted) return;
+    setState(() {
+      _presence = presence;
+    });
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    final client = widget.client ?? Matrix.of(context).client;
+    final userId = widget.userId;
+    if (userId != null) {
+      client.fetchCurrentPresence(userId).then(_updatePresence);
+      _sub = client.onPresenceChanged.stream
+          .where((presence) => presence.userid == userId)
+          .listen(_updatePresence);
+    }
+  }
+
+  @override
+  void dispose() {
+    _sub?.cancel();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) => widget.builder(context, _presence);
+}