[TypeDef] Place all typedefs on the top

lib/src/Client.dart

@@ -37,6 +37,9 @@ import 'requests/SetPushersRequest.dart';
 import 'responses/ErrorResponse.dart';
 import 'responses/PushrulesResponse.dart';
 
+typedef AccountDataEventCB = void Function(AccountData accountData);
+typedef PresenceCB = void Function(Presence presence);
+
 /// Represents a Matrix client to communicate with a
 /// [Matrix](https://matrix.org) homeserver and is the entry point for this
 /// SDK.
@@ -338,6 +341,3 @@ class Client {
     return resp;
   }
 }
-
-typedef AccountDataEventCB = void Function(AccountData accountData);
-typedef PresenceCB = void Function(Presence presence);

lib/src/Connection.dart

@@ -473,6 +473,8 @@ class Connection {
   }
 }
 
+typedef _FutureVoidCallback = Future<void> Function();
+
 class _LifecycleEventHandler extends WidgetsBindingObserver {
   _LifecycleEventHandler({this.resumeCallBack, this.suspendingCallBack});
 
@@ -494,6 +496,4 @@ class _LifecycleEventHandler extends WidgetsBindingObserver {
   }
 }
 
-typedef _FutureVoidCallback = Future<void> Function();
-
 enum LoginState { logged, loggedOut }

lib/src/RoomList.dart

@@ -32,6 +32,10 @@ import 'User.dart';
 import 'sync/EventUpdate.dart';
 import 'sync/RoomUpdate.dart';
 
+typedef onRoomListUpdateCallback = void Function();
+typedef onRoomListInsertCallback = void Function(int insertID);
+typedef onRoomListRemoveCallback = void Function(int insertID);
+
 /// Represents a list of rooms for this client, which will automatically update
 /// itself and call the [onUpdate], [onInsert] and [onDelete] callbacks. To get
 /// the initial room list, use the store or create a RoomList instance by using
@@ -167,7 +171,3 @@ class RoomList {
     if (onUpdate != null) onUpdate();
   }
 }
-
-typedef onRoomListUpdateCallback = void Function();
-typedef onRoomListInsertCallback = void Function(int insertID);
-typedef onRoomListRemoveCallback = void Function(int insertID);

lib/src/Timeline.dart

@@ -28,6 +28,9 @@ import 'Room.dart';
 import 'User.dart';
 import 'sync/EventUpdate.dart';
 
+typedef onTimelineUpdateCallback = void Function();
+typedef onTimelineInsertCallback = void Function(int insertID);
+
 /// Represents the timeline of a room. The callbacks [onUpdate], [onDelete],
 /// [onInsert] and [onResort] will be triggered automatically. The initial
 /// event list will be retreived when created by the [room.getTimeline] method.
@@ -102,6 +105,3 @@ class Timeline {
     if (onUpdate != null) onUpdate();
   }
 }
-
-typedef onTimelineUpdateCallback = void Function();
-typedef onTimelineInsertCallback = void Function(int insertID);