initial commit: push everything

lib/controllers/connectivity_mixin.dart

@@ -0,0 +1,55 @@
+import 'dart:async';
+import 'dart:io';
+import 'package:get/get.dart';
+import 'package:flutter/foundation.dart';
+
+mixin ConnectivityControllerMixin on GetxController {
+  final RxBool isOnline = true.obs;
+  Timer? _tick;
+
+  @protected
+  Future<bool> checkInternet() async {
+    try {
+      final result = await InternetAddress.lookup('example.com');
+      return result.isNotEmpty && result.first.rawAddress.isNotEmpty;
+    } catch (_) {
+      return false;
+    }
+  }
+
+  @protected
+  void onConnectivityOnline() {}
+
+  @protected
+  void onConnectivityOffline() {}
+
+  void _startWatcher() {
+    _tick?.cancel();
+    _tick = Timer.periodic(const Duration(seconds: 5), (_) async {
+      final ok = await checkInternet();
+      final prev = isOnline.value;
+      if (ok != prev) {
+        isOnline.value = ok;
+        if (ok) {
+          onConnectivityOnline();
+        } else {
+          onConnectivityOffline();
+        }
+      } else {
+        isOnline.value = ok;
+      }
+    });
+  }
+
+  @override
+  void onInit() {
+    super.onInit();
+    _startWatcher();
+  }
+
+  @override
+  void onClose() {
+    _tick?.cancel();
+    super.onClose();
+  }
+}