date_picker.dart

import 'package:flutter/material.dart';

class DatePicker extends StatefulWidget {
  final TextEditingController dateCtr;
  DatePicker({required this.dateCtr});
  @override
  _DatePickerState createState() => _DatePickerState();
}

class _DatePickerState extends State<DatePicker> {
  FocusNode _node = FocusNode();
  Color _iocnColor = Colors.purple;
  @override
  void initState() {
    super.initState();
    _node.addListener(() {
      if (_node.hasFocus) {
        _iocnColor = Colors.purple;
      } else {
        _iocnColor = Colors.grey;
      }
      setState(() {});
    });
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      height: 50,
      decoration: BoxDecoration(border: Border.all(color: Colors.grey), borderRadius: BorderRadius.circular(5)),
      child: GestureDetector(
        onTap: _datePicker,
        child: Row(
          children: [
            Expanded(
                child: TextFormField(
              enabled: false,
              focusNode: _node,
              controller: widget.dateCtr,
              decoration: InputDecoration(
                hintText: "dd/mm/yyyy",
                border: InputBorder.none,
              ),
            )),
            Container(
              padding: const EdgeInsets.all(10),
              height: double.infinity,
              color: Colors.grey[300],
              child: Center(
                child: Icon(
                  Icons.calendar_today_outlined,
                  color: _iocnColor,
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  void _datePicker() async {
    var date = await showDatePicker(context: context, initialDate: DateTime.now(), firstDate: DateTime.parse("1900-01-10"), lastDate: DateTime.parse("2030-01-10"));
    if (date != null) {
      widget.dateCtr.text = "${date.day}/${date.month}/${date.year}";
    }
  }
}