android_number_keyboard_fail.dart

import 'package:flutter/material.dart';

void main() {
  runApp(MaterialApp(home: MyHomePage()));
}

final TextEditingController controller = TextEditingController();

// It's possible to see the problem without using an EditableText subclass,
// by just adding a print statement to _TextInputClientHandler in
// packages/flutter/lib/src/services/text_input.dart under
// case 'TextInputClient.updateEditingState'.

class MyEditableText extends EditableText {
  MyEditableText() : super(
    // Commenting out this line causes updateEditingValue to be
    // called once per character, as expected.
    keyboardType: TextInputType.number,

    focusNode: FocusNode(),
    style: TextStyle(),
    cursorColor: Colors.red,
    backgroundCursorColor: Colors.green,
    controller: controller,
  );

  @override
  MyEditableTextState createState() => MyEditableTextState();
}

class MyEditableTextState extends EditableTextState {
  @override
  // When keyboardType is TextInputType.number this method
  // is called twice per input character.
  void updateEditingValue(TextEditingValue value) {
    print('updateEditingValue("${value.text}")');
    super.updateEditingValue(value);
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Padding(
        padding: EdgeInsets.all(32),
        child: Container(
          color: Colors.blue.withOpacity(0.15),
          child: MyEditableText(),
        ),
      ),
    );
  }
}