store: Expose sendMessage for general destinations

Author: gnprice

lib/model/store.dart

@@ -248,19 +248,15 @@ class PerAccountStore extends ChangeNotifier {
     }
   }
 
-  Future<void> sendStreamMessage({required String topic, required String content}) {
+  Future<void> sendMessage({required MessageDestination destination, required String content}) {
     // TODO implement outbox; see design at
     //   https://chat.zulip.org/#narrow/stream/243-mobile-team/topic/.23M3881.20Sending.20outbox.20messages.20is.20fraught.20with.20issues/near/1405739
-
-    if (connection.realmUrl.origin != 'https://chat.zulip.org') {
-      throw Exception('This method can currently only be used on https://chat.zulip.org.');
-    }
-    final destination = StreamDestination(7, topic); // TODO parametrize; this is `#test here`
-
-    return sendMessage(connection, destination: destination, content: content);
+    return _apiSendMessage(connection, destination: destination, content: content);
   }
 }
 
+const _apiSendMessage = sendMessage; // Bit ugly; for alternatives, see: https://chat.zulip.org/#narrow/stream/243-mobile-team/topic/flutter.3A.20PerAccountStore.20methods/near/1545809
+
 /// A [GlobalStore] that uses a live server and live, persistent local database.
 ///
 /// The underlying data store is an [AppDatabase] corresponding to a SQLite

lib/widgets/compose_box.dart

@@ -517,10 +517,12 @@ class _StreamSendButtonState extends State<_StreamSendButton> {
     }
 
     final store = PerAccountStoreWidget.of(context);
-    store.sendStreamMessage(
-      topic: widget.topicController.textNormalized(),
-      content: widget.contentController.textNormalized(),
-    );
+    if (store.connection.realmUrl.origin != 'https://chat.zulip.org') {
+      throw Exception('This method can currently only be used on https://chat.zulip.org.');
+    }
+    final destination = StreamDestination(7, widget.topicController.textNormalized()); // TODO parametrize; this is `#test here`
+    final content = widget.contentController.textNormalized();
+    store.sendMessage(destination: destination, content: content);
 
     widget.contentController.clear();
   }