Introduced auto refresh for API Data

ac_web/lib/Widgets/LatestReportColumn.dart

@@ -2,6 +2,7 @@ import 'package:ac_web/Api/AcApi.dart';
 import 'package:ac_web/Api/Dtos/EReportType.dart';
 import 'package:ac_web/Api/Dtos/ReportDto.dart';
 import 'package:ac_web/Pages/ReportDetails.dart';
+import 'package:ac_web/Widgets/AutoRefreshState.dart';
 import 'package:ac_web/Widgets/LatestReportEntry.dart';
 import 'package:ac_web/Widgets/LatestReportHeader.dart';
 import 'package:ac_web/Widgets/ReportTypeIcons.dart';
@@ -20,7 +21,8 @@ class LatestReportColumn extends StatefulWidget{
   State<LatestReportColumn> createState() => _LatestReportColumnState();
 }
 
-class _LatestReportColumnState extends State<LatestReportColumn>{
+class _LatestReportColumnState extends State<LatestReportColumn>
+    with AutoRefreshState<LatestReportColumn> {
 
   late Future<List<ReportDto>> mReportsFuture;
 
@@ -30,17 +32,36 @@ class _LatestReportColumnState extends State<LatestReportColumn>{
     mReportsFuture = AcApi.instance.reports.getReports();
   }
 
+  /// Automatic reload. The reports that are already on screen stay visible
+  /// while the request runs, the future is only replaced once it succeeded.
+  @override
+  Future<void> RefreshData() async {
+
+    final List<ReportDto> reports = await AcApi.instance.reports.getReports();
+
+    if (!mounted) {
+      return;
+    }
+
+    setState(() {
+      mReportsFuture = Future<List<ReportDto>>.value(reports);
+    });
+  }
+
   @override
   Widget build(BuildContext context) {
     return FutureBuilder<List<ReportDto>>(
       future: mReportsFuture,
       builder: (context, snapshot) {
 
-        if (snapshot.connectionState != ConnectionState.done) {
+        // Not `connectionState`: a refresh puts the builder back into the
+        // waiting state although the previous reports are still available, and
+        // those should stay on screen instead of flashing a spinner.
+        if (!snapshot.hasData && !snapshot.hasError) {
           return const Center(child: CircularProgressIndicator());
         }
 
-        if (snapshot.hasError) {
+        if (snapshot.hasError && !snapshot.hasData) {
           return Center(child: Text('Could not load reports: ${snapshot.error}'));
         }