From 68b0d5834de05952e85fc82f7254188d9259a889 Mon Sep 17 00:00:00 2001
From: marco <marco@skup.in>
Date: Tue, 28 Jan 2025 15:36:14 +0100
Subject: [PATCH] refactored overlay loading indicator code

---
 lib/pages/landing_page.dart       | 153 +++++++++++++++---------------
 lib/services/overlay_service.dart |  47 +++++++++
 2 files changed, 121 insertions(+), 79 deletions(-)
 create mode 100644 lib/services/overlay_service.dart

diff --git a/lib/pages/landing_page.dart b/lib/pages/landing_page.dart
index da60de3..98780d1 100644
--- a/lib/pages/landing_page.dart
+++ b/lib/pages/landing_page.dart
@@ -1,6 +1,8 @@
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
+import '../model/flood_station.dart';
+import '../services/overlay_service.dart';
 import '../widgets/flood_station_list_view.dart';
 import '../services/flood_station_provider.dart';
 import '../widgets/loading_notifier.dart';
@@ -14,10 +16,14 @@ class LandingPage extends StatefulWidget {
   State<LandingPage> createState() => _LandingPageState();
 }
 
-class _LandingPageState extends State<LandingPage> {
+class _LandingPageState extends State<LandingPage> with OverlayService {
   late FloodStationProvider floodStationProvider;
-  OverlayEntry? _overlayEntry;
-  int loadingTimes = 0;
+
+  @override
+  void dispose() {
+    super.dispose();
+    removeLoadingNotifier(); // Clean up overlay if needed
+  }
 
   @override
   Widget build(BuildContext context) {
@@ -25,91 +31,80 @@ class _LandingPageState extends State<LandingPage> {
     return Column(
       children: [
         StationFilter(
-          onChanged: (filterText) {
-            if (filterText.isEmpty) {
-              floodStationProvider.filtered = false;
-              setState(() {});
-              return;
-            }
-            showLoadingNotifier(context: context, message: 'Loading');
-            floodStationProvider.loadFilteredStations(filterText);
-            floodStationProvider.filteredStationsFuture
-                ?.then((_) => removeLoadingNotifier());
-            floodStationProvider.filtered = true;
-          },
+          onChanged: (filterText) => _handleFilterChange(filterText),
         ),
-        _shouldShowList()
-            ? Expanded(
-                child: FloodStationListView(
-                  stations: floodStationProvider.filtered
-                      ? floodStationProvider.filteredStations
-                      : floodStationProvider.allStations,
-                  onItemTapped: (station) {
-                    floodStationProvider.selectedStation = station;
-                    Navigator.of(context).pushNamed(FloodStationPage.routeName);
-                  },
-                ),
-              )
-            : Expanded(
-                child: Center(
-                  child: ElevatedButton(
-                    onPressed: () {
-                      showLoadingNotifier(context: context, message: 'Loading');
-                      floodStationProvider
-                          .loadAllStations()
-                          .whenComplete(() => removeLoadingNotifier());
-                    },
-                    child: Text('Load all Stations'),
-                  ),
-                ),
-              ),
+        _buildStationList(),
       ],
     );
   }
 
+  Widget _buildStationList() {
+    if (!_shouldShowList()) {
+      return Expanded(
+        child: Center(
+          child: ElevatedButton(
+            onPressed: _handleLoadAllStations,
+            child: const Text('Load all Stations'),
+          ),
+        ),
+      );
+    }
+
+    return Expanded(
+      child: FloodStationListView(
+        stations: floodStationProvider.filtered
+            ? floodStationProvider.filteredStations
+            : floodStationProvider.allStations,
+        onItemTapped: _navigateToStationDetail,
+      ),
+    );
+  }
+
+  void _handleFilterChange(String filterText) {
+    if (filterText.isEmpty) {
+      floodStationProvider.filtered = false;
+      setState(() {});
+      return;
+    }
+
+    showLoadingNotifier(
+      context: context,
+      message: 'Loading',
+      onDismiss: () {
+        floodStationProvider.cancelFilterLoading();
+      },
+    );
+
+    floodStationProvider.loadFilteredStations(filterText);
+    floodStationProvider.filteredStationsFuture
+        ?.then((_) => removeLoadingNotifier());
+    floodStationProvider.filtered = true;
+  }
+
+  void _handleLoadAllStations() {
+    showLoadingNotifier(
+      context: context,
+      message: 'Loading',
+      onDismiss: () {
+        floodStationProvider.cancelFilterLoading();
+      },
+    );
+
+    floodStationProvider
+        .loadAllStations()
+        .whenComplete(() => removeLoadingNotifier());
+  }
+
+  void _navigateToStationDetail(FloodStation station) {
+    floodStationProvider.selectedStation = station;
+    Navigator.of(context).pushNamed(FloodStationPage.routeName);
+  }
+
   bool _shouldShowList() {
     if (!floodStationProvider.filtered &&
         floodStationProvider.allStations.isNotEmpty) {
       return true;
     }
-    if (floodStationProvider.filtered) {
-      return true;
-    }
-    return false;
-  }
-
-  Future<void> showLoadingNotifier({
-    required BuildContext context,
-    required String message,
-  }) async {
-    if (_overlayEntry != null) return;
-    OverlayState? overlayState = Overlay.of(context);
-    _overlayEntry = OverlayEntry(
-      builder: (c) {
-        return Positioned(
-          bottom: 16,
-          left: 0,
-          right: 0,
-          child: Center(
-            child: LoadingNotifier(
-              message: 'Loading',
-              onDismissed: () {
-                floodStationProvider.cancelFilterLoading();
-                removeLoadingNotifier();
-              },
-            ),
-          ),
-        );
-      },
-    );
-    overlayState.insert(_overlayEntry!);
-    overlayState.setState(() {});
-  }
-
-  void removeLoadingNotifier() {
-    if (_overlayEntry != null) {
-      _overlayEntry?.remove();
-      _overlayEntry = null;
-    }
+    return floodStationProvider.filtered;
   }
 }
diff --git a/lib/services/overlay_service.dart b/lib/services/overlay_service.dart
new file mode 100644
index 0000000..492a0fc
--- /dev/null
+++ b/lib/services/overlay_service.dart
@@ -0,0 +1,47 @@
+import 'package:flutter/material.dart';
+
+import '../widgets/loading_notifier.dart';
+
+mixin OverlayService {
+  OverlayEntry? _overlayEntry;
+
+  Future<void> showLoadingNotifier({
+    required BuildContext context,
+    required String message,
+    required VoidCallback onDismiss,
+  }) async {
+    if (_overlayEntry != null) return;
+
+    final overlayState = Overlay.of(context);
+    _overlayEntry = OverlayEntry(
+      builder: (context) => Positioned(
+        bottom: 85,
+        left: 0,
+        right: 0,
+        child: Center(
+          child: LoadingNotifier(
+            message: message,
+            onDismissed: () {
+              onDismiss();
+              removeLoadingNotifier();
+            },
+          ),
+        ),
+      ),
+    );
+
+    overlayState.insert(_overlayEntry!);
+    // overlayState.setState(() {});
+  }
+
+  void removeLoadingNotifier() {
+    if (_overlayEntry != null) {
+      _overlayEntry?.remove();
+      _overlayEntry = null;
+    }
+  }
+
+  void dispose() {
+    removeLoadingNotifier();
+  }
+}