wip Integrate ComposeBox for testing.

Signed-off-by: Zixuan James Li <[email protected]>

Author: PIG208

lib/widgets/compose_box.dart

@@ -9,6 +9,7 @@ import 'package:mime/mime.dart';
 import '../api/exception.dart';
 import '../api/model/model.dart';
 import '../api/route/messages.dart';
+import '../log.dart';
 import '../model/binding.dart';
 import '../model/compose.dart';
 import '../model/narrow.dart';
@@ -1064,6 +1065,31 @@ class _FixedDestinationComposeBoxState extends State<_FixedDestinationComposeBox
   @override FocusNode get contentFocusNode => _contentFocusNode;
   final _contentFocusNode = FocusNode();
 
+  @override
+  void initState() {
+    super.initState();
+    _contentController.addListener(_contentChanged);
+  }
+
+  void _contentChanged() {
+    final store = PerAccountStoreWidget.of(context);
+    final curNarrow = widget.narrow;
+    assert(debugLog('${widget.narrow} content changed'));
+    if (curNarrow is TopicNarrow) {
+      if (_contentController.text.isNotEmpty) {
+        store.typingNotifier.handleTyping(
+          store,
+          StreamDestination(curNarrow.streamId, curNarrow.topic)
+        );
+      } else {
+        store.typingNotifier.handleTypingStop(
+          store,
+          StreamDestination(curNarrow.streamId, curNarrow.topic)
+        );
+      }
+    }
+  }
+
   @override
   void dispose() {
     _contentController.dispose();