Third decimal for Frequency

lib/utils/frequency_input_formatter.dart

@@ -1,29 +1,55 @@
 import 'package:flutter/services.dart';
 
 class FrequencyInputFormatter extends TextInputFormatter {
-  static const int maxDigits = 5;
-
   @override
   TextEditingValue formatEditUpdate(
-      TextEditingValue oldValue, TextEditingValue newValue) {
-    String digitsOnly = newValue.text.replaceAll(RegExp(r'[^0-9]'), '');
+    TextEditingValue oldValue,
+    TextEditingValue newValue,
+  ) {
+    // Skip formatting if deleting
+    if (oldValue.text.length > newValue.text.length) {
+      return newValue;
+    }
 
-    if (digitsOnly.length > maxDigits) {
+    // Allow only numbers and decimal point
+    String filteredText = newValue.text.replaceAll(RegExp(r'[^\d.]'), '');
+
+    // Only allow one decimal point
+    if (filteredText.split('.').length > 2) {
       return oldValue;
     }
 
-    String formatted = digitsOnly;
-    if (digitsOnly.length > 3) {
-      formatted = '${digitsOnly.substring(0, 3)}.${digitsOnly.substring(3)}';
+    // Format for three decimal places and auto-insert decimal point
+    if (filteredText.contains('.')) {
+      List<String> parts = filteredText.split('.');
+      String whole = parts[0];
+      String fraction = parts[1];
+
+      // Limit to three decimal places
+      if (fraction.length > 3) {
+        fraction = fraction.substring(0, 3);
       }
       
-    if (formatted.endsWith('.') && digitsOnly.length <= 3) {
-      formatted = formatted.substring(0, formatted.length - 1);
+      // Reconstruct the text
+      filteredText = "$whole.$fraction";
+    } else {
+      // Auto-insert decimal point after the third digit
+      if (filteredText.length > 3) {
+        String whole = filteredText.substring(0, 3);
+        String fraction = filteredText.substring(3);
+        
+        // Limit fraction to three digits
+        if (fraction.length > 3) {
+          fraction = fraction.substring(0, 3);
+        }
+        
+        filteredText = "$whole.$fraction";
+      }
     }
 
     return TextEditingValue(
-      text: formatted,
-      selection: TextSelection.collapsed(offset: formatted.length),
+      text: filteredText,
+      selection: TextSelection.collapsed(offset: filteredText.length),
     );
   }
 }