Dropdowns in windows version keep auto scrolling back to top #391

lib/ui/task/edit/task_edit.dart

@@ -10,6 +10,7 @@ import 'package:flutter_redux/flutter_redux.dart';
 // Project imports:
 import 'package:invoiceninja_flutter/constants.dart';
 import 'package:invoiceninja_flutter/data/models/entities.dart';
+import 'package:invoiceninja_flutter/data/models/task_model.dart';
 import 'package:invoiceninja_flutter/redux/app/app_actions.dart';
 import 'package:invoiceninja_flutter/redux/app/app_state.dart';
 import 'package:invoiceninja_flutter/ui/app/app_border.dart';
@@ -36,7 +37,6 @@ class TaskEdit extends StatefulWidget {
 
 class _TaskEditState extends State<TaskEdit>
     with SingleTickerProviderStateMixin {
-  Timer _timer;
   TabController _controller;
   int _updatedAt = 0;
 
@@ -50,9 +50,6 @@ class _TaskEditState extends State<TaskEdit>
   void initState() {
     super.initState();
 
-    _timer = Timer.periodic(Duration(seconds: 1),
-        (Timer t) => mounted ? setState(() => false) : false);
-
     final index =
         widget.viewModel.taskTimeIndex != null ? kTimesScreen : kDetailsScreen;
 
@@ -70,8 +67,6 @@ class _TaskEditState extends State<TaskEdit>
 
   @override
   void dispose() {
-    _timer.cancel();
-    _timer = null;
     _controller.dispose();
     super.dispose();
   }
@@ -81,11 +76,7 @@ class _TaskEditState extends State<TaskEdit>
     final localization = AppLocalization.of(context);
     final viewModel = widget.viewModel;
     final task = viewModel.task;
-
     final state = viewModel.state;
-    final useSidebarEditor =
-        state.prefState.useSidebarEditor[EntityType.task] ?? false;
-    final store = StoreProvider.of<AppState>(context);
     final isFullscreen = state.prefState.isEditorFullScreen(EntityType.task);
 
     return EditScaffold(
@@ -134,7 +125,69 @@ class _TaskEditState extends State<TaskEdit>
                 ],
               ),
       ),
-      bottomNavigationBar: BottomAppBar(
+      bottomNavigationBar: _BottomBar(
+        task: task,
+      ),
+      floatingActionButton: task.isInvoiced || task.isDeleted
+          ? SizedBox()
+          : FloatingActionButton(
+              heroTag: 'task_edit_fab',
+              backgroundColor: Theme.of(context).primaryColorDark,
+              onPressed: () {
+                viewModel.onFabPressed();
+                setState(() {
+                  _updatedAt = DateTime.now().millisecondsSinceEpoch;
+                });
+              },
+              child: Icon(
+                task.isRunning ? Icons.stop : Icons.play_arrow,
+                color: Colors.white,
+              ),
+              tooltip: task.isRunning ? localization.stop : localization.start,
+            ),
+    );
+  }
+}
+
+class _BottomBar extends StatefulWidget {
+  const _BottomBar({
+    Key key,
+    @required this.task,
+  }) : super(key: key);
+
+  final TaskEntity task;
+
+  @override
+  State<_BottomBar> createState() => _BottomBarState();
+}
+
+class _BottomBarState extends State<_BottomBar> {
+  Timer _timer;
+
+  @override
+  void initState() {
+    super.initState();
+
+    _timer = Timer.periodic(Duration(seconds: 1),
+        (Timer t) => mounted ? setState(() => false) : false);
+  }
+
+  @override
+  void dispose() {
+    _timer.cancel();
+    _timer = null;
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final localization = AppLocalization.of(context);
+    final store = StoreProvider.of<AppState>(context);
+    final state = store.state;
+    final useSidebarEditor =
+        state.prefState.useSidebarEditor[EntityType.task] ?? false;
+
+    return BottomAppBar(
       elevation: 0,
       color: Theme.of(context).cardColor,
       shape: CircularNotchedRectangle(),
@@ -171,16 +224,16 @@ class _TaskEditState extends State<TaskEdit>
                       return localization.duration +
                           ' ' +
                           formatNumber(
-                                task
+                              widget.task
                                   .calculateDuration(
-                                        includeRunning: task.showAsRunning)
+                                      includeRunning: widget.task.showAsRunning)
                                   .inSeconds
                                   .toDouble(),
                               context,
                               formatNumberType: FormatNumberType.duration);
                     },
                         style: TextStyle(
-                            color: viewModel.state.prefState.enableDarkMode
+                          color: state.prefState.enableDarkMode
                               ? Colors.white
                               : Colors.black,
                           fontSize: 20.0,
@@ -192,24 +245,6 @@ class _TaskEditState extends State<TaskEdit>
           ),
         ),
       ),
-      ),
-      floatingActionButton: task.isInvoiced || task.isDeleted
-          ? SizedBox()
-          : FloatingActionButton(
-              heroTag: 'task_edit_fab',
-              backgroundColor: Theme.of(context).primaryColorDark,
-              onPressed: () {
-                viewModel.onFabPressed();
-                setState(() {
-                  _updatedAt = DateTime.now().millisecondsSinceEpoch;
-                });
-              },
-              child: Icon(
-                task.isRunning ? Icons.stop : Icons.play_arrow,
-                color: Colors.white,
-              ),
-              tooltip: task.isRunning ? localization.stop : localization.start,
-            ),
     );
   }
 }