feat: Added a new toast

at_common_flutter/lib/at_common_flutter.dart

@@ -5,3 +5,4 @@ export './widgets/custom_app_bar.dart';
 export './services/size_config.dart';
 export './widgets/custom_button.dart';
 export './widgets/custom_input_field.dart';
+export './widgets/custom_toast.dart';

at_common_flutter/lib/widgets/custom_toast.dart

@@ -0,0 +1,49 @@
+
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+
+class CustomToast {
+  /// pass [isError] true to have a red bg, [isSuccess] true to have a green bg.
+  static void show(String message, BuildContext context,
+          {Color? bgColor,
+          Color? textColor,
+          double? toastWidth,
+          double fontSize = 12,
+          int duration = 3,
+          double gravity = 10.0,
+          bool isError = false,
+          bool isSuccess = false}) {
+            assert(!(isError && isSuccess), 'Both isError and isSuccess cannot be true');
+            assert(gravity >= 0, 'gravity cannot be less than 0');            
+              ScaffoldMessenger.of(context).showSnackBar(
+                  SnackBar(
+          content: Text(
+            message,
+            textAlign: TextAlign.center,
+            style: TextStyle(
+              fontSize: fontSize,
+              color: textColor ?? Colors.white,
+            ),
+          ),
+          duration: const Duration(milliseconds: 3000),
+          elevation: 0,
+          margin: toastWidth != null
+              ? null
+              : EdgeInsets.symmetric(
+                  horizontal: MediaQuery.of(context).size.width * 0.2, vertical: gravity),
+          backgroundColor: isError
+              ? Colors.red
+              : (isSuccess
+                  ? Colors.green
+                  : (bgColor ?? const Color(0xA9FFFFFF))),
+          padding: const EdgeInsets.all(10),
+          width: toastWidth,
+          behavior: SnackBarBehavior.floating,
+          shape: RoundedRectangleBorder(
+              borderRadius:
+                  BorderRadius.circular(Platform.isAndroid ? 50 : 10)),
+                  ),
+                );
+            }
+}