Introduced auto refresh for API Data

ac_web/lib/Pages/AgentDetails.dart

@@ -4,6 +4,7 @@ import 'package:ac_web/Api/Dtos/AgentTaskDto.dart';
 import 'package:ac_web/Widgets/AgentStatusIndicator.dart';
 import 'package:ac_web/Widgets/AgentTaskCard.dart';
 import 'package:ac_web/Widgets/AgentTypeIcons.dart';
+import 'package:ac_web/Widgets/AutoRefreshState.dart';
 import 'package:flutter/material.dart';
 
 /// Page that shows every detail of a single agent, including all of its tasks
@@ -18,7 +19,8 @@ class AgentDetails extends StatefulWidget {
   State<AgentDetails> createState() => _AgentDetailsState();
 }
 
-class _AgentDetailsState extends State<AgentDetails> {
+class _AgentDetailsState extends State<AgentDetails>
+    with AutoRefreshState<AgentDetails> {
 
   late AgentDto mAgent;
 
@@ -30,17 +32,29 @@ class _AgentDetailsState extends State<AgentDetails> {
     mAgent = widget.agent;
   }
 
+  /// Reload triggered by the user through the app bar or by pulling the page
+  /// down. Reports what happened, even when nothing changed.
+  Future<void> ReloadAgent() => _reloadAgent(silent: false);
+
+  /// Automatic reload. It runs without the user asking for it, so it neither
+  /// disables the reload button nor pops up a message - the page simply keeps
+  /// showing the agent it already has.
+  @override
+  Future<void> RefreshData() => _reloadAgent(silent: true);
+
   /// The api only offers the whole list of agents, so the agent this page
   /// shows is looked up by its name again.
-  Future<void> ReloadAgent() async {
+  Future<void> _reloadAgent({required bool silent}) async {
 
     if (mIsReloading) {
       return;
     }
 
-    setState(() {
-      mIsReloading = true;
-    });
+    mIsReloading = true;
+
+    if (!silent) {
+      setState(() {});
+    }
 
     try {
       final List<AgentDto> agents = await AcApi.instance.agents.getAgents();
@@ -60,7 +74,7 @@ class _AgentDetailsState extends State<AgentDetails> {
         }
       });
 
-      if (updated == null) {
+      if (updated == null && !silent) {
         _showMessage("This agent is no longer reported by the api.");
       }
     } catch (error) {
@@ -73,7 +87,9 @@ class _AgentDetailsState extends State<AgentDetails> {
         mIsReloading = false;
       });
 
-      _showMessage("Could not reload the agent: $error");
+      if (!silent) {
+        _showMessage("Could not reload the agent: $error");
+      }
     }
   }