packages/flutter/lib/src/material/pickers/input_date_picker.dart - mirrors/flutter - Git at Google

 // Copyright 2014 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 // @dart = 2.8

 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';

 import '../input_border.dart';
 import '../input_decorator.dart';
 import '../material_localizations.dart';
 import '../text_form_field.dart';
 import '../theme.dart';

 import 'date_picker_common.dart';
 import 'date_utils.dart' as utils;

 /// A [TextFormField] configured to accept and validate a date entered by the user.
 ///
 /// The text entered into this field will be constrained to only allow digits
 /// and separators. When saved or submitted, the text will be parsed into a
 /// [DateTime] according to the ambient locale. If the input text doesn't parse
 /// into a date, the [errorFormatText] message will be displayed under the field.
 ///
 /// [firstDate], [lastDate], and [selectableDayPredicate] provide constraints on
 /// what days are valid. If the input date isn't in the date range or doesn't pass
 /// the given predicate, then the [errorInvalidText] message will be displayed
 /// under the field.
 ///
 /// See also:
 ///
 ///  * [showDatePicker], which shows a dialog that contains a material design
 ///    date picker which includes support for text entry of dates.
 ///  * [MaterialLocalizations.parseCompactDate], which is used to parse the text
 ///    input into a [DateTime].
 ///
 class InputDatePickerFormField extends StatefulWidget {
   /// Creates a [TextFormField] configured to accept and validate a date.
   ///
   /// If the optional [initialDate] is provided, then it will be used to populate
   /// the text field. If the [fieldHintText] is provided, it will be shown.
   ///
   /// If [initialDate] is provided, it must not be before [firstDate] or after
   /// [lastDate]. If [selectableDayPredicate] is provided, it must return `true`
   /// for [initialDate].
   ///
   /// [firstDate] must be on or before [lastDate].
   ///
   /// [firstDate], [lastDate], and [autofocus] must be non-null.
   ///
   InputDatePickerFormField({
     Key key,
     DateTime initialDate,
     @required DateTime firstDate,
     @required DateTime lastDate,
     this.onDateSubmitted,
     this.onDateSaved,
     this.selectableDayPredicate,
     this.errorFormatText,
     this.errorInvalidText,
     this.fieldHintText,
     this.fieldLabelText,
     this.autofocus = false,
   }) : assert(firstDate != null),
        assert(lastDate != null),
        assert(autofocus != null),
        initialDate = initialDate != null ? utils.dateOnly(initialDate) : null,
        firstDate = utils.dateOnly(firstDate),
        lastDate = utils.dateOnly(lastDate),
        super(key: key) {
     assert(
       !this.lastDate.isBefore(this.firstDate),
       'lastDate ${this.lastDate} must be on or after firstDate ${this.firstDate}.'
     );
     assert(
       initialDate == null || !this.initialDate.isBefore(this.firstDate),
       'initialDate ${this.initialDate} must be on or after firstDate ${this.firstDate}.'
     );
     assert(
       initialDate == null || !this.initialDate.isAfter(this.lastDate),
       'initialDate ${this.initialDate} must be on or before lastDate ${this.lastDate}.'
     );
     assert(
       selectableDayPredicate == null || initialDate == null || selectableDayPredicate(this.initialDate),
       'Provided initialDate ${this.initialDate} must satisfy provided selectableDayPredicate.'
     );
   }

   /// If provided, it will be used as the default value of the field.
   final DateTime initialDate;

   /// The earliest allowable [DateTime] that the user can input.
   final DateTime firstDate;

   /// The latest allowable [DateTime] that the user can input.
   final DateTime lastDate;

   /// An optional method to call when the user indicates they are done editing
   /// the text in the field. Will only be called if the input represents a valid
   /// [DateTime].
   final ValueChanged<DateTime> onDateSubmitted;

   /// An optional method to call with the final date when the form is
   /// saved via [FormState.save]. Will only be called if the input represents
   /// a valid [DateTime].
   final ValueChanged<DateTime> onDateSaved;

   /// Function to provide full control over which [DateTime] can be selected.
   final SelectableDayPredicate selectableDayPredicate;

   /// The error text displayed if the entered date is not in the correct format.
   final String errorFormatText;

   /// The error text displayed if the date is not valid.
   ///
   /// A date is not valid if it is earlier than [firstDate], later than
   /// [lastDate], or doesn't pass the [selectableDayPredicate].
   final String errorInvalidText;

   /// The hint text displayed in the [TextField].
   ///
   /// If this is null, it will default to the date format string. For example,
   /// 'mm/dd/yyyy' for en_US.
   final String fieldHintText;

   /// The label text displayed in the [TextField].
   ///
   /// If this is null, it will default to the words representing the date format
   /// string. For example, 'Month, Day, Year' for en_US.
   final String fieldLabelText;

   /// {@macro flutter.widgets.editableText.autofocus}
   final bool autofocus;

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

 class _InputDatePickerFormFieldState extends State<InputDatePickerFormField> {
   final TextEditingController _controller = TextEditingController();
   DateTime _selectedDate;
   String _inputText;
   bool _autoSelected = false;

   @override
   void initState() {
     super.initState();
     _selectedDate = widget.initialDate;
   }

   @override
   void dispose() {
     _controller.dispose();
     super.dispose();
   }

   @override
   void didChangeDependencies() {
     super.didChangeDependencies();
     if (_selectedDate != null) {
       final MaterialLocalizations localizations = MaterialLocalizations.of(context);
       _inputText = localizations.formatCompactDate(_selectedDate);
       TextEditingValue textEditingValue = _controller.value.copyWith(text: _inputText);
       // Select the new text if we are auto focused and haven't selected the text before.
       if (widget.autofocus && !_autoSelected) {
         textEditingValue = textEditingValue.copyWith(selection: TextSelection(
           baseOffset: 0,
           extentOffset: _inputText.length,
         ));
         _autoSelected = true;
       }
       _controller.value = textEditingValue;
     }
   }

   DateTime _parseDate(String text) {
     final MaterialLocalizations localizations = MaterialLocalizations.of(context);
     return localizations.parseCompactDate(text);
   }

   bool _isValidAcceptableDate(DateTime date) {
     return
       date != null &&
       !date.isBefore(widget.firstDate) &&
       !date.isAfter(widget.lastDate) &&
       (widget.selectableDayPredicate == null || widget.selectableDayPredicate(date));
   }

   String _validateDate(String text) {
     final DateTime date = _parseDate(text);
     if (date == null) {
       return widget.errorFormatText ?? MaterialLocalizations.of(context).invalidDateFormatLabel;
     } else if (!_isValidAcceptableDate(date)) {
       return widget.errorInvalidText ?? MaterialLocalizations.of(context).dateOutOfRangeLabel;
     }
     return null;
   }

   void _handleSaved(String text) {
     if (widget.onDateSaved != null) {
       final DateTime date = _parseDate(text);
       if (_isValidAcceptableDate(date)) {
         _selectedDate = date;
         _inputText = text;
         widget.onDateSaved(date);
       }
     }
   }

   void _handleSubmitted(String text) {
     if (widget.onDateSubmitted != null) {
       final DateTime date = _parseDate(text);
       if (_isValidAcceptableDate(date)) {
         _selectedDate = date;
         _inputText = text;
         widget.onDateSubmitted(date);
       }
     }
   }

   @override
   Widget build(BuildContext context) {
     final MaterialLocalizations localizations = MaterialLocalizations.of(context);
     final InputDecorationTheme inputTheme = Theme.of(context).inputDecorationTheme;
     return TextFormField(
       decoration: InputDecoration(
         border: inputTheme.border ?? const UnderlineInputBorder(),
         filled: inputTheme.filled ?? true,
         hintText: widget.fieldHintText ?? localizations.dateHelpText,
         labelText: widget.fieldLabelText ?? localizations.dateInputLabel,
       ),
       validator: _validateDate,
       inputFormatters: <TextInputFormatter>[
         DateTextInputFormatter(localizations.dateSeparator),
       ],
       keyboardType: TextInputType.datetime,
       onSaved: _handleSaved,
       onFieldSubmitted: _handleSubmitted,
       autofocus: widget.autofocus,
       controller: _controller,
     );
   }
 }

 /// A `TextInputFormatter` set up to format dates.
 //
 // This is not publicly exported (see pickers.dart), as it is
 // just meant for internal use by `InputDatePickerFormField` and
 // `InputDateRangePicker`.
 class DateTextInputFormatter extends TextInputFormatter {

   /// Creates a date formatter with the given separator.
   DateTextInputFormatter(
     this.separator
   ) : _filterFormatter = FilteringTextInputFormatter.allow(RegExp('[\\d$_commonSeparators\\$separator]+'));

   /// List of common separators that are used in dates. This is used to make
   /// sure that if given platform's [TextInputType.datetime] keyboard doesn't
   /// provide the given locale's separator character, they can still enter the
   /// separator using one of these characters (slash, period, comma, dash, or
   /// space).
   static const String _commonSeparators = r'\/\.,-\s';

   /// The date separator for the current locale.
   final String separator;

   // Formatter that will filter out all characters except digits and date
   // separators.
   final TextInputFormatter _filterFormatter;

   @override
   TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
     final TextEditingValue filteredValue = _filterFormatter.formatEditUpdate(oldValue, newValue);
     return filteredValue.copyWith(
       // Replace any non-digits with the given separator
       text: filteredValue.text.replaceAll(RegExp(r'[\D]'), separator),
     );
   }
 }
	// Copyright 2014 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	// @dart = 2.8

	import 'package:flutter/services.dart';
	import 'package:flutter/widgets.dart';

	import '../input_border.dart';
	import '../input_decorator.dart';
	import '../material_localizations.dart';
	import '../text_form_field.dart';
	import '../theme.dart';

	import 'date_picker_common.dart';
	import 'date_utils.dart' as utils;

	/// A [TextFormField] configured to accept and validate a date entered by the user.
	///
	/// The text entered into this field will be constrained to only allow digits
	/// and separators. When saved or submitted, the text will be parsed into a
	/// [DateTime] according to the ambient locale. If the input text doesn't parse
	/// into a date, the [errorFormatText] message will be displayed under the field.
	///
	/// [firstDate], [lastDate], and [selectableDayPredicate] provide constraints on
	/// what days are valid. If the input date isn't in the date range or doesn't pass
	/// the given predicate, then the [errorInvalidText] message will be displayed
	/// under the field.
	///
	/// See also:
	///
	/// * [showDatePicker], which shows a dialog that contains a material design
	/// date picker which includes support for text entry of dates.
	/// * [MaterialLocalizations.parseCompactDate], which is used to parse the text
	/// input into a [DateTime].
	///
	class InputDatePickerFormField extends StatefulWidget {
	/// Creates a [TextFormField] configured to accept and validate a date.
	///
	/// If the optional [initialDate] is provided, then it will be used to populate
	/// the text field. If the [fieldHintText] is provided, it will be shown.
	///
	/// If [initialDate] is provided, it must not be before [firstDate] or after
	/// [lastDate]. If [selectableDayPredicate] is provided, it must return `true`
	/// for [initialDate].
	///
	/// [firstDate] must be on or before [lastDate].
	///
	/// [firstDate], [lastDate], and [autofocus] must be non-null.
	///
	InputDatePickerFormField({
	Key key,
	DateTime initialDate,
	@required DateTime firstDate,
	@required DateTime lastDate,
	this.onDateSubmitted,
	this.onDateSaved,
	this.selectableDayPredicate,
	this.errorFormatText,
	this.errorInvalidText,
	this.fieldHintText,
	this.fieldLabelText,
	this.autofocus = false,
	}) : assert(firstDate != null),
	assert(lastDate != null),
	assert(autofocus != null),
	initialDate = initialDate != null ? utils.dateOnly(initialDate) : null,
	firstDate = utils.dateOnly(firstDate),
	lastDate = utils.dateOnly(lastDate),
	super(key: key) {
	assert(
	!this.lastDate.isBefore(this.firstDate),
	'lastDate ${this.lastDate} must be on or after firstDate ${this.firstDate}.'
	);
	assert(
	initialDate == null \|\| !this.initialDate.isBefore(this.firstDate),
	'initialDate ${this.initialDate} must be on or after firstDate ${this.firstDate}.'
	);
	assert(
	initialDate == null \|\| !this.initialDate.isAfter(this.lastDate),
	'initialDate ${this.initialDate} must be on or before lastDate ${this.lastDate}.'
	);
	assert(
	selectableDayPredicate == null \|\| initialDate == null \|\| selectableDayPredicate(this.initialDate),
	'Provided initialDate ${this.initialDate} must satisfy provided selectableDayPredicate.'
	);
	}

	/// If provided, it will be used as the default value of the field.
	final DateTime initialDate;

	/// The earliest allowable [DateTime] that the user can input.
	final DateTime firstDate;

	/// The latest allowable [DateTime] that the user can input.
	final DateTime lastDate;

	/// An optional method to call when the user indicates they are done editing
	/// the text in the field. Will only be called if the input represents a valid
	/// [DateTime].
	final ValueChanged<DateTime> onDateSubmitted;

	/// An optional method to call with the final date when the form is
	/// saved via [FormState.save]. Will only be called if the input represents
	/// a valid [DateTime].
	final ValueChanged<DateTime> onDateSaved;

	/// Function to provide full control over which [DateTime] can be selected.
	final SelectableDayPredicate selectableDayPredicate;

	/// The error text displayed if the entered date is not in the correct format.
	final String errorFormatText;

	/// The error text displayed if the date is not valid.
	///
	/// A date is not valid if it is earlier than [firstDate], later than
	/// [lastDate], or doesn't pass the [selectableDayPredicate].
	final String errorInvalidText;

	/// The hint text displayed in the [TextField].
	///
	/// If this is null, it will default to the date format string. For example,
	/// 'mm/dd/yyyy' for en_US.
	final String fieldHintText;

	/// The label text displayed in the [TextField].
	///
	/// If this is null, it will default to the words representing the date format
	/// string. For example, 'Month, Day, Year' for en_US.
	final String fieldLabelText;

	/// {@macro flutter.widgets.editableText.autofocus}
	final bool autofocus;

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

	class _InputDatePickerFormFieldState extends State<InputDatePickerFormField> {
	final TextEditingController _controller = TextEditingController();
	DateTime _selectedDate;
	String _inputText;
	bool _autoSelected = false;

	@override
	void initState() {
	super.initState();
	_selectedDate = widget.initialDate;
	}

	@override
	void dispose() {
	_controller.dispose();
	super.dispose();
	}

	@override
	void didChangeDependencies() {
	super.didChangeDependencies();
	if (_selectedDate != null) {
	final MaterialLocalizations localizations = MaterialLocalizations.of(context);
	_inputText = localizations.formatCompactDate(_selectedDate);
	TextEditingValue textEditingValue = _controller.value.copyWith(text: _inputText);
	// Select the new text if we are auto focused and haven't selected the text before.
	if (widget.autofocus && !_autoSelected) {
	textEditingValue = textEditingValue.copyWith(selection: TextSelection(
	baseOffset: 0,
	extentOffset: _inputText.length,
	));
	_autoSelected = true;
	}
	_controller.value = textEditingValue;
	}
	}

	DateTime _parseDate(String text) {
	final MaterialLocalizations localizations = MaterialLocalizations.of(context);
	return localizations.parseCompactDate(text);
	}

	bool _isValidAcceptableDate(DateTime date) {
	return
	date != null &&
	!date.isBefore(widget.firstDate) &&
	!date.isAfter(widget.lastDate) &&
	(widget.selectableDayPredicate == null \|\| widget.selectableDayPredicate(date));
	}

	String _validateDate(String text) {
	final DateTime date = _parseDate(text);
	if (date == null) {
	return widget.errorFormatText ?? MaterialLocalizations.of(context).invalidDateFormatLabel;
	} else if (!_isValidAcceptableDate(date)) {
	return widget.errorInvalidText ?? MaterialLocalizations.of(context).dateOutOfRangeLabel;
	}
	return null;
	}

	void _handleSaved(String text) {
	if (widget.onDateSaved != null) {
	final DateTime date = _parseDate(text);
	if (_isValidAcceptableDate(date)) {
	_selectedDate = date;
	_inputText = text;
	widget.onDateSaved(date);
	}
	}
	}

	void _handleSubmitted(String text) {
	if (widget.onDateSubmitted != null) {
	final DateTime date = _parseDate(text);
	if (_isValidAcceptableDate(date)) {
	_selectedDate = date;
	_inputText = text;
	widget.onDateSubmitted(date);
	}
	}
	}

	@override
	Widget build(BuildContext context) {
	final MaterialLocalizations localizations = MaterialLocalizations.of(context);
	final InputDecorationTheme inputTheme = Theme.of(context).inputDecorationTheme;
	return TextFormField(
	decoration: InputDecoration(
	border: inputTheme.border ?? const UnderlineInputBorder(),
	filled: inputTheme.filled ?? true,
	hintText: widget.fieldHintText ?? localizations.dateHelpText,
	labelText: widget.fieldLabelText ?? localizations.dateInputLabel,
	),
	validator: _validateDate,
	inputFormatters: <TextInputFormatter>[
	DateTextInputFormatter(localizations.dateSeparator),
	],
	keyboardType: TextInputType.datetime,
	onSaved: _handleSaved,
	onFieldSubmitted: _handleSubmitted,
	autofocus: widget.autofocus,
	controller: _controller,
	);
	}
	}

	/// A `TextInputFormatter` set up to format dates.
	//
	// This is not publicly exported (see pickers.dart), as it is
	// just meant for internal use by `InputDatePickerFormField` and
	// `InputDateRangePicker`.
	class DateTextInputFormatter extends TextInputFormatter {

	/// Creates a date formatter with the given separator.
	DateTextInputFormatter(
	this.separator
	) : _filterFormatter = FilteringTextInputFormatter.allow(RegExp('[\\d$_commonSeparators\\$separator]+'));

	/// List of common separators that are used in dates. This is used to make
	/// sure that if given platform's [TextInputType.datetime] keyboard doesn't
	/// provide the given locale's separator character, they can still enter the
	/// separator using one of these characters (slash, period, comma, dash, or
	/// space).
	static const String _commonSeparators = r'\/\.,-\s';

	/// The date separator for the current locale.
	final String separator;

	// Formatter that will filter out all characters except digits and date
	// separators.
	final TextInputFormatter _filterFormatter;

	@override
	TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
	final TextEditingValue filteredValue = _filterFormatter.formatEditUpdate(oldValue, newValue);
	return filteredValue.copyWith(
	// Replace any non-digits with the given separator
	text: filteredValue.text.replaceAll(RegExp(r'[\D]'), separator),
	);
	}
	}