How to format text inside text field?-CodePudding

I want to format the text in the textfield according to the pattern: "х,ххх.хх", where every three orders a comma will be placed, and after the point there should be no more than two characters. For setting commas I have a controller:

    myController.addListener(() {
        String text = (myController.text).replaceAllMapped(RegExp(r'(\d{1,3})(?=(\d{3}) (?!\d))'), (Match m) => '${m[1]},');
  myController.value = myController.value.copyWith(
    text: text,
    selection:
        TextSelection(baseOffset: text.length, extentOffset: text.length),
    composing: TextRange.empty,
  );
});

To prevent entering two points in a row and more than two characters after the dot I have input formatters:

                         inputFormatters:[
  FilteringTextInputFormatter.allow(RegExp("[0-9.]")),
  FilteringTextInputFormatter.deny(RegExp(r"\.\.")),
  FilteringTextInputFormatter.deny(RegExp(r"\....")),

They certainly work, but not in the way I need. If the user enters two points in a row, then both will simply be deleted from him. And if you enter the third digit after the point, then the entire fractional part will be deleted altogether.

CodePudding user response：

You can use the NumberFormatter for formatting string.

Example :

import 'package:intl/intl.dart';

void main() {
  var formatter = NumberFormat('#,##,000');
  print(formatter.format(12345));
  print(formatter.format(67890));
  print(formatter.format(123456));
}

Output :

12,345
67,890
1,23,456

CodePudding user response：

I solved the problem with TextInputFormatter.withFunction:

                        inputFormatters: [
                      FilteringTextInputFormatter.allow(RegExp("[0-9.]")),
                      TextInputFormatter.withFunction((oldValue, newValue) {
                        RegExp reg1 = RegExp(r'\.\.');
                        RegExp reg2 = RegExp(r'\....');
                        RegExp reg3 = RegExp(r'\..\.');
                        if (reg1.hasMatch(newValue.text) ||
                            reg2.hasMatch(newValue.text) ||
                            reg3.hasMatch(newValue.text)) {
                            return oldValue;
                        }
                        else{
                            return newValue;
                        }
                      })
                    ],