Replace SnackBars with custom iOS-style top alerts with icons

flutter_app/lib/route_transitions.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'package:flutter/material.dart';
 
 class FadeSlidePageRoute<T> extends PageRouteBuilder<T> {
@@ -34,3 +35,154 @@ class FadeSlidePageRoute<T> extends PageRouteBuilder<T> {
           reverseTransitionDuration: const Duration(milliseconds: 200),
         );
 }
+
+void showTopAlert(
+  BuildContext context,
+  String message, {
+  bool isError = false,
+  IconData? icon,
+}) {
+  final overlayState = Overlay.of(context);
+  late OverlayEntry overlayEntry;
+
+  overlayEntry = OverlayEntry(
+    builder: (context) => _TopAlertWidget(
+      message: message,
+      isError: isError,
+      icon: icon,
+      onDismiss: () {
+        overlayEntry.remove();
+      },
+    ),
+  );
+
+  overlayState.insert(overlayEntry);
+}
+
+class _TopAlertWidget extends StatefulWidget {
+  final String message;
+  final bool isError;
+  final IconData? icon;
+  final VoidCallback onDismiss;
+
+  const _TopAlertWidget({
+    required this.message,
+    required this.isError,
+    this.icon,
+    required this.onDismiss,
+  });
+
+  @override
+  State<_TopAlertWidget> createState() => _TopAlertWidgetState();
+}
+
+class _TopAlertWidgetState extends State<_TopAlertWidget> with SingleTickerProviderStateMixin {
+  late AnimationController _controller;
+  late Animation<double> _slideAnimation;
+  late Animation<double> _opacityAnimation;
+  Timer? _dismissTimer;
+
+  @override
+  void initState() {
+    super.initState();
+    _controller = AnimationController(
+      vsync: this,
+      duration: const Duration(milliseconds: 400),
+    );
+
+    _slideAnimation = CurvedAnimation(
+      parent: _controller,
+      curve: Curves.easeOutBack,
+    );
+
+    _opacityAnimation = CurvedAnimation(
+      parent: _controller,
+      curve: Curves.easeIn,
+    );
+
+    _controller.forward();
+
+    _dismissTimer = Timer(const Duration(milliseconds: 2800), () {
+      if (mounted) {
+        _controller.reverse().then((_) {
+          widget.onDismiss();
+        });
+      }
+    });
+  }
+
+  @override
+  void dispose() {
+    _dismissTimer?.cancel();
+    _controller.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final mediaQuery = MediaQuery.of(context);
+    final topPadding = mediaQuery.padding.top + 16.0;
+
+    IconData alertIcon = widget.icon ?? 
+        (widget.isError ? Icons.error_outline : Icons.check_circle_outline);
+    Color backgroundColor = widget.isError ? const Color(0xFFBA1A20) : const Color(0xFF2E7D32);
+    
+    return AnimatedBuilder(
+      animation: _controller,
+      builder: (context, child) {
+        return Positioned(
+          top: topPadding * _slideAnimation.value - 80.0 * (1.0 - _slideAnimation.value),
+          left: 16.0,
+          right: 16.0,
+          child: Opacity(
+            opacity: _opacityAnimation.value,
+            child: Material(
+              color: Colors.transparent,
+              child: Align(
+                alignment: Alignment.topCenter,
+                child: ConstrainedBox(
+                  constraints: const BoxConstraints(maxWidth: 450),
+                  child: Container(
+                    padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 12.0),
+                    decoration: BoxDecoration(
+                      color: backgroundColor,
+                      borderRadius: BorderRadius.circular(20),
+                      boxShadow: [
+                        BoxShadow(
+                          color: Colors.black.withOpacity(0.12),
+                          blurRadius: 16,
+                          offset: const Offset(0, 6),
+                        ),
+                      ],
+                    ),
+                    child: Row(
+                      mainAxisSize: MainAxisSize.min,
+                      children: [
+                        Icon(
+                          alertIcon,
+                          color: Colors.white,
+                          size: 20,
+                        ),
+                        const SizedBox(width: 12),
+                        Expanded(
+                          child: Text(
+                            widget.message,
+                            style: const TextStyle(
+                              color: Colors.white,
+                              fontSize: 14,
+                              fontWeight: FontWeight.w600,
+                            ),
+                          ),
+                        ),
+                      ],
+                    ),
+                  ),
+                ),
+              ),
+            ),
+          ),
+        );
+      },
+    );
+  }
+}

flutter_app/lib/screens/billing_dashboard_screen.dart

@@ -1,5 +1,6 @@
 import 'dart:math';
 import 'package:flutter/material.dart';
+import '../route_transitions.dart';
 
 class ProductItem {
   final String id;
@@ -160,13 +161,7 @@ class _BillingDashboardScreenState extends State<BillingDashboardScreen> {
   }
 
   void _showErrorSnackBar(String message) {
-    ScaffoldMessenger.of(context).showSnackBar(
+    showTopAlert(context, message, isError: true);
-      SnackBar(
-        content: Text(message),
-        backgroundColor: Colors.red[800],
-        behavior: SnackBarBehavior.floating,
-      ),
-    );
   }
 
   double get _subtotal {
@@ -944,12 +939,10 @@ class _BillingDashboardScreenState extends State<BillingDashboardScreen> {
                 const SizedBox(height: 16),
                 ElevatedButton.icon(
                   onPressed: () {
-                    ScaffoldMessenger.of(context).showSnackBar(
+                    showTopAlert(
-                      SnackBar(
+                      context,
-                        content: Text('🧾 Thermal Printed: $_invoiceNumber successfully!'),
+                      'Thermal Printed: $_invoiceNumber successfully!',
-                        backgroundColor: const Color(0xFF10B981),
+                      icon: Icons.print,
-                        behavior: SnackBarBehavior.floating,
-                      ),
                     );
                   },
                   icon: const Icon(Icons.print, size: 16),

flutter_app/lib/screens/business_setup_screen.dart

@@ -90,29 +90,25 @@ class _BusinessSetupScreenState extends State<BusinessSetupScreen> {
           setState(() {
             _uploadedDocs[docName] = file.name;
           });
-          ScaffoldMessenger.of(context).showSnackBar(
+          showTopAlert(
-            SnackBar(
+            context,
-              content: Text('✅ Successfully loaded $docName!'),
+            'Successfully loaded $docName!',
-              backgroundColor: Colors.green,
+            icon: Icons.check_circle_outline,
-              behavior: SnackBarBehavior.floating,
-            ),
           );
         }
       } catch (e) {
         if (!mounted) return;
-        ScaffoldMessenger.of(context).showSnackBar(
+        showTopAlert(
-          SnackBar(
+          context,
-            content: Text('Failed to pick image: $e'),
+          'Failed to pick image: $e',
-            behavior: SnackBarBehavior.floating,
+          isError: true,
-          ),
         );
       }
     } else {
-      ScaffoldMessenger.of(context).showSnackBar(
+      showTopAlert(
-        const SnackBar(
+        context,
-          content: Text('Permission denied. Cannot load document image.'),
+        'Permission denied. Cannot load document image.',
-          behavior: SnackBarBehavior.floating,
+        isError: true,
-        ),
       );
     }
   }
@@ -298,11 +294,10 @@ class _BusinessSetupScreenState extends State<BusinessSetupScreen> {
                         setState(() {
                           _uploadedDocs.remove(docName);
                         });
-                        ScaffoldMessenger.of(context).showSnackBar(
+                        showTopAlert(
-                          SnackBar(
+                          context,
-                            content: Text('$docName attachment removed.'),
+                          '$docName attachment removed.',
-                            behavior: SnackBarBehavior.floating,
+                          icon: Icons.delete_outline,
-                          ),
                         );
                       },
                     ),
@@ -590,12 +585,10 @@ class _BusinessSetupScreenState extends State<BusinessSetupScreen> {
                               const SizedBox(width: 12),
                               ElevatedButton(
                                 onPressed: () {
-                                  ScaffoldMessenger.of(context).showSnackBar(
+                                  showTopAlert(
-                                    const SnackBar(
+                                    context,
-                                      content: Text('GSTIN Verified Successfully!'),
+                                    'GSTIN Verified Successfully!',
-                                      backgroundColor: Colors.green,
+                                    icon: Icons.verified_outlined,
-                                      behavior: SnackBarBehavior.floating,
-                                    ),
                                   );
                                 },
                                 style: ElevatedButton.styleFrom(
@@ -628,12 +621,10 @@ class _BusinessSetupScreenState extends State<BusinessSetupScreen> {
                           const SizedBox(height: 8),
                           InkWell(
                             onTap: () {
-                              ScaffoldMessenger.of(context).showSnackBar(
+                              showTopAlert(
-                                const SnackBar(
+                                context,
-                                  content: Text('📍 Location detected: Sector 62, Noida, UP'),
+                                'Location detected: Sector 62, Noida, UP',
-                                  backgroundColor: Colors.green,
+                                icon: Icons.my_location_outlined,
-                                  behavior: SnackBarBehavior.floating,
-                                ),
                               );
                             },
                             borderRadius: BorderRadius.circular(16),

flutter_app/lib/screens/mobile_login_screen.dart

@@ -84,11 +84,10 @@ class _MobileLoginScreenState extends State<MobileLoginScreen> {
     if (status.isGranted || kIsWeb) {
       _showContactPicker();
     } else {
-      ScaffoldMessenger.of(context).showSnackBar(
+      showTopAlert(
-        const SnackBar(
+        context,
-          content: Text('Contacts permission was denied. Please enter the number manually or enable it in Settings.'),
+        'Contacts permission was denied. Please enter the number manually or enable it in Settings.',
-          behavior: SnackBarBehavior.floating,
+        isError: true,
-        ),
       );
     }
   }
@@ -402,12 +401,10 @@ class _MobileLoginScreenState extends State<MobileLoginScreen> {
                                     setState(() {
                                       _isValid = true;
                                     });
-                                    ScaffoldMessenger.of(context).showSnackBar(
+                                    showTopAlert(
-                                      const SnackBar(
+                                      context,
-                                        content: Text('⚡ Phone verified automatically with Truecaller! Joining PozoApp...'),
+                                      'Phone verified automatically with Truecaller! Joining PozoApp...',
-                                        backgroundColor: Color(0xFF005FAF),
+                                      icon: Icons.verified_user_outlined,
-                                        behavior: SnackBarBehavior.floating,
-                                      ),
                                     );
                                     Navigator.push(
                                       context,
@@ -610,11 +607,10 @@ class _MobileLoginScreenState extends State<MobileLoginScreen> {
                       SizedBox(height: gap / 2),
                       OutlinedButton(
                         onPressed: () {
-                          ScaffoldMessenger.of(context).showSnackBar(
+                          showTopAlert(
-                            const SnackBar(
+                            context,
-                              content: Text('💬 Connecting with Pozo Support... Please wait.'),
+                            'Connecting with Pozo Support... Please wait.',
-                              behavior: SnackBarBehavior.floating,
+                            icon: Icons.support_agent_outlined,
-                            ),
                           );
                         },
                         style: OutlinedButton.styleFrom(

flutter_app/lib/screens/setup_complete_screen.dart

@@ -293,13 +293,10 @@ class SetupCompleteScreen extends StatelessWidget {
                   // Primary Launcher CTA
                   ElevatedButton(
                     onPressed: () {
-                      ScaffoldMessenger.of(context).showSnackBar(
+                      showTopAlert(
-                        const SnackBar(
+                        context,
-                          content: Text('⚡ Launching Register Dashboard... Enjoy billing!'),
+                        'Launching Register Dashboard... Enjoy billing!',
-                          behavior: SnackBarBehavior.floating,
+                        icon: Icons.rocket_launch_outlined,
-                          backgroundColor: Colors.green,
-                          duration: Duration(milliseconds: 1500),
-                        ),
                       );
                       Navigator.push(
                         context,