flutter_wordle/lib/validated_number_input.dart

import 'package:flutter/material.dart';

class ValidatedNumberInput extends StatefulWidget {
  final int? minValue;
  final int? maxValue;
  final ValueChanged<int>? onValueChanged;
  final int? defaultValue;
  final ValueChanged<bool>? onValidityChanged;

  const ValidatedNumberInput({
    super.key,
    this.minValue,
    this.maxValue,
    this.onValueChanged,
    this.defaultValue,
    this.onValidityChanged,
  });

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

class _ValidatedNumberInputState extends State<ValidatedNumberInput> {
  late int currentValue;
  late TextEditingController _controller;
  bool isValid = true;

  @override
  void initState() {
    super.initState();
    currentValue = widget.defaultValue ?? 0;
    _controller = TextEditingController(text: currentValue.toString());
    _validateInput(currentValue);
  }

  @override
  void didUpdateWidget(covariant ValidatedNumberInput oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (widget.defaultValue != null && widget.defaultValue != currentValue) {
      setState(() {
        currentValue = widget.defaultValue!;
        _controller.text = currentValue.toString();
        _validateInput(currentValue);
      });
    }
  }

  void _incrementValue() {
    setState(() {
      currentValue++;
      _controller.text = currentValue.toString();
      _validateInput(currentValue);
      widget.onValueChanged?.call(currentValue);
    });
  }

  void _decrementValue() {
    setState(() {
      currentValue--;
      _controller.text = currentValue.toString();
      _validateInput(currentValue);
      widget.onValueChanged?.call(currentValue);
    });
  }

  void _updateValueFromText(String value) {
    String sanitizedValue = value.replaceAll(RegExp(r'[^0-9]'), '');
    int? newValue = int.tryParse(sanitizedValue);
    if (newValue != null) {
      setState(() {
        currentValue = newValue;
        _controller.text = currentValue.toString();
        _controller.selection = TextSelection.fromPosition(
          TextPosition(offset: _controller.text.length),
        );
        _validateInput(currentValue);
        widget.onValueChanged?.call(currentValue);
      });
    } else {
      _controller.text = currentValue.toString();
      _controller.selection = TextSelection.fromPosition(
        TextPosition(offset: _controller.text.length),
      );
    }
  }

  void _validateInput(int value) {
    int minValue = widget.minValue ?? double.negativeInfinity.toInt();
    int maxValue = widget.maxValue ?? double.maxFinite.toInt();
    bool newIsValid = value >= minValue && value <= maxValue;

    if (newIsValid != isValid) {
      isValid = newIsValid;

      WidgetsBinding.instance.addPostFrameCallback((_) {
        widget.onValidityChanged?.call(isValid);
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 8.0),
      decoration: BoxDecoration(
        color: Colors.grey[800],
        borderRadius: BorderRadius.circular(30),
        border: Border.all(
          color: isValid ? Colors.grey : Colors.red,
          width: 2.0,
        ),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          IconButton(
            icon: const Icon(Icons.remove),
            onPressed: _decrementValue,
            constraints: const BoxConstraints(),
            padding: EdgeInsets.zero,
          ),
          SizedBox(
            width: 60,
            child: TextFormField(
              controller: _controller,
              textAlign: TextAlign.center,
              keyboardType: TextInputType.number,
              decoration: const InputDecoration(
                border: InputBorder.none,
                contentPadding: EdgeInsets.symmetric(vertical: 8.0),
              ),
              onChanged: (value) {
                _updateValueFromText(value);
              },
            ),
          ),
          IconButton(
            icon: const Icon(Icons.add),
            onPressed: _incrementValue,
            constraints: const BoxConstraints(),
            padding: EdgeInsets.zero,
          ),
        ],
      ),
    );
  }
}