initialized Application theme

lib/utils/helpers/phone_number_formatter.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/services.dart';
+
+class PhoneNumberTextInputFormatter extends TextInputFormatter {
+  final String mask;
+  final String separator;
+  PhoneNumberTextInputFormatter({
+    required this.mask,
+    required this.separator,
+  });
+  @override
+  TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
+    if (newValue.text.isNotEmpty) {
+      if (newValue.text.length > oldValue.text.length) {
+        if (newValue.text.length > mask.length) return oldValue;
+        if (newValue.text.length < mask.length && mask[newValue.text.length - 1] == separator) {
+          return TextEditingValue(
+            text: '${oldValue.text}$separator${newValue.text.substring(newValue.text.length - 1)}',
+            selection: TextSelection.collapsed(
+              offset: newValue.selection.end + 1,
+            ),
+          );
+        }
+      }
+    }
+    return newValue;
+  }
+}