Improve default scrollbar

lib/ui/app/forms/app_form.dart

@@ -29,6 +29,7 @@ class AppForm extends StatelessWidget {
         key: formKey,
         child: child ??
             ScrollableListView(
+              primary: true,
               children: children,
             ),
       ),

lib/ui/app/scrollable_listview.dart

@@ -69,6 +69,7 @@ class ScrollableListViewBuilder extends StatefulWidget {
     this.separatorBuilder,
     this.scrollController,
     this.padding,
+    this.primary = false,
   }) : super(key: key);
 
   final IndexedWidgetBuilder itemBuilder;
@@ -76,6 +77,7 @@ class ScrollableListViewBuilder extends StatefulWidget {
   final int itemCount;
   final ScrollController scrollController;
   final EdgeInsetsGeometry padding;
+  final bool primary;
 
   @override
   _ScrollableListViewBuilderState createState() =>
@@ -101,18 +103,24 @@ class _ScrollableListViewBuilderState extends State<ScrollableListViewBuilder> {
   Widget build(BuildContext context) {
     return widget.separatorBuilder != null
         ? ListView.separated(
+            primary: widget.primary,
             separatorBuilder: widget.separatorBuilder,
             padding: widget.padding,
             itemBuilder: widget.itemBuilder,
             itemCount: widget.itemCount,
-            controller: widget.scrollController ?? _scrollController,
+            controller: widget.primary
+                ? null
+                : widget.scrollController ?? _scrollController,
             shrinkWrap: true,
           )
         : ListView.builder(
+            primary: widget.primary,
             padding: widget.padding,
             itemBuilder: widget.itemBuilder,
             itemCount: widget.itemCount,
-            controller: widget.scrollController ?? _scrollController,
+            controller: widget.primary
+                ? null
+                : widget.scrollController ?? _scrollController,
             shrinkWrap: true,
           );
   }

lib/ui/app/tables/entity_list.dart

@@ -64,14 +64,11 @@ class _EntityListState extends State<EntityList> {
   EntityDataTableSource dataTableSource;
 
   int _firstRowIndex = 0;
-  ScrollController _controller;
 
   @override
   void initState() {
     super.initState();
 
-    _controller = ScrollController();
-
     final entityType = widget.entityType;
     final state = widget.state;
     final entityList = widget.entityList;
@@ -113,12 +110,6 @@ class _EntityListState extends State<EntityList> {
     dataTableSource.notifyListeners();
   }
 
-  @override
-  void dispose() {
-    _controller.dispose();
-    super.dispose();
-  }
-
   @override
   Widget build(BuildContext context) {
     final store = StoreProvider.of<AppState>(context);
@@ -238,7 +229,7 @@ class _EntityListState extends State<EntityList> {
               ),
             Expanded(
               child: SingleChildScrollView(
-                controller: _controller,
+                primary: true,
                 child: Padding(
                   padding: const EdgeInsets.symmetric(vertical: 16),
                   child: AppPaginatedDataTable(

lib/ui/dashboard/dashboard_panels.dart

@@ -445,6 +445,7 @@ class DashboardPanels extends StatelessWidget {
         Padding(
           padding: const EdgeInsets.only(top: kTopBottomBarHeight),
           child: ScrollableListViewBuilder(
+            primary: true,
             scrollController: scrollController,
             itemCount: sections.length + 1,
             itemBuilder: (context, index) {

lib/ui/reports/reports_screen.dart

@@ -436,6 +436,7 @@ class ReportsScreen extends StatelessWidget {
                 ),
               )
             : ScrollableListView(
+                primary: true,
                 key: ValueKey(
                     '${viewModel.state.company.id}_${viewModel.state.isSaving}_${reportsState.report}_${reportsState.group}'),
                 children: <Widget>[

lib/ui/settings/account_management.dart

@@ -188,6 +188,7 @@ class _AccountManagementState extends State<AccountManagement>
         children: <Widget>[
           _AccountOverview(viewModel: viewModel),
           ScrollableListView(
+            primary: true,
             children: <Widget>[
               FormCard(
                   children: kModules.keys.map((module) {
@@ -210,7 +211,7 @@ class _AccountManagementState extends State<AccountManagement>
               }).toList()),
             ],
           ),
-          ScrollableListView(children: [
+          ScrollableListView(primary: true, children: [
             FormCard(
               children: [
                 LearnMoreUrl(
@@ -225,6 +226,7 @@ class _AccountManagementState extends State<AccountManagement>
             )
           ]),
           ScrollableListView(
+            primary: true,
             children: [
               FormCard(
                 children: [
@@ -315,6 +317,7 @@ class _AccountOverview extends StatelessWidget {
     }
 
     return ScrollableListView(
+      primary: true,
       children: <Widget>[
         AppHeader(
           label: localization.plan,

lib/ui/settings/company_details.dart

@@ -261,6 +261,7 @@ class _CompanyDetailsState extends State<CompanyDetails>
         tabController: _controller,
         children: <Widget>[
           ScrollableListView(
+            primary: true,
             children: <Widget>[
               FormCard(
                 children: <Widget>[
@@ -385,6 +386,7 @@ class _CompanyDetailsState extends State<CompanyDetails>
           ),
           AutofillGroup(
             child: ScrollableListView(
+              primary: true,
               children: <Widget>[
                 FormCard(
                   isLast: true,
@@ -442,6 +444,7 @@ class _CompanyDetailsState extends State<CompanyDetails>
           Padding(
             padding: const EdgeInsets.symmetric(horizontal: 20),
             child: ScrollableListView(
+              primary: true,
               children: <Widget>[
                 Builder(
                   builder: (context) {
@@ -496,6 +499,7 @@ class _CompanyDetailsState extends State<CompanyDetails>
             ),
           ),
           ScrollableListView(
+            primary: true,
             children: <Widget>[
               FormCard(
                 crossAxisAlignment: CrossAxisAlignment.stretch,

lib/ui/settings/device_settings.dart

@@ -109,6 +109,7 @@ class _DeviceSettingsState extends State<DeviceSettings>
         focusNode: _focusNode,
         children: [
           ScrollableListView(
+            primary: true,
             children: <Widget>[
               FormCard(
                 children: <Widget>[
@@ -364,6 +365,7 @@ class _DeviceSettingsState extends State<DeviceSettings>
             ],
           ),
           ScrollableListView(
+            primary: true,
             children: [
               FormCard(children: [
                 SwitchListTile(

lib/ui/settings/import_export.dart

@@ -85,6 +85,7 @@ class _ImportExportState extends State<ImportExport> {
         formKey: _formKey,
         focusNode: _focusNode,
         child: ScrollableListView(
+          primary: true,
           children: [
             if (_response == null)
               _FileImport(

lib/ui/settings/invoice_design.dart

@@ -153,6 +153,7 @@ class _InvoiceDesignState extends State<InvoiceDesign>
         focusNode: _focusNode,
         children: <Widget>[
           ScrollableListView(
+            primary: true,
             children: <Widget>[
               Padding(
                 padding: const EdgeInsets.only(right: 16, bottom: 10, left: 16),

lib/ui/settings/localization_settings.dart

@@ -137,6 +137,7 @@ class _LocalizationSettingsState extends State<LocalizationSettings>
         tabController: _controller,
         children: <Widget>[
           ScrollableListView(
+            primary: true,
             children: [
               FormCard(
                 children: <Widget>[
@@ -266,6 +267,7 @@ class _LocalizationSettingsState extends State<LocalizationSettings>
             ],
           ),
           ScrollableListView(
+            primary: true,
             children: [
               FormCard(
                 isLast: true,

lib/ui/settings/templates_and_reminders.dart

@@ -343,6 +343,7 @@ class _TemplatesAndRemindersState extends State<TemplatesAndReminders>
         focusNode: _focusNode,
         children: <Widget>[
           ScrollableListView(
+            primary: true,
             children: <Widget>[
               FormCard(children: <Widget>[
                 AppDropdownButton<EmailTemplate>(

lib/ui/settings/user_details.dart

@@ -308,6 +308,7 @@ class _UserDetailsState extends State<UserDetails>
         tabController: _controller,
         children: <Widget>[
           ScrollableListView(
+            primary: true,
             children: <Widget>[
               FormCard(children: <Widget>[
                 DecoratedFormField(
@@ -482,6 +483,7 @@ class _UserDetailsState extends State<UserDetails>
             ],
           ),
           ScrollableListView(
+            primary: true,
             children: <Widget>[
               NotificationSettings(
                 user: user,

lib/ui/settings/workflow_settings.dart

@@ -92,6 +92,7 @@ class _WorkflowSettingsState extends State<WorkflowSettings>
           focusNode: _focusNode,
           children: <Widget>[
             ScrollableListView(
+              primary: true,
               children: <Widget>[
                 FormCard(children: <Widget>[
                   BoolDropdownButton(
@@ -155,6 +156,7 @@ class _WorkflowSettingsState extends State<WorkflowSettings>
               ],
             ),
             ScrollableListView(
+              primary: true,
               children: <Widget>[
                 FormCard(
                   isLast: true,