packages/flutter/lib/src/material/pickers/input_date_range_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_field.dart';
 import '../theme.dart';

 import 'date_utils.dart' as utils;

 /// Provides a pair of text fields that allow the user to enter the start and
 /// end dates that represent a range of dates.
 //
 // This is not publicly exported (see pickers.dart), as it is just an
 // internal component used by [showDateRangePicker].
 class InputDateRangePicker extends StatefulWidget {
   /// Creates a row with two text fields configured to accept the start and end dates
   /// of a date range.
   InputDateRangePicker({
     Key key,
     DateTime initialStartDate,
     DateTime initialEndDate,
     @required DateTime firstDate,
     @required DateTime lastDate,
     @required this.onStartDateChanged,
     @required this.onEndDateChanged,
     this.helpText,
     this.errorFormatText,
     this.errorInvalidText,
     this.errorInvalidRangeText,
     this.fieldStartHintText,
     this.fieldEndHintText,
     this.fieldStartLabelText,
     this.fieldEndLabelText,
     this.autofocus = false,
     this.autovalidate = false,
   }) : initialStartDate = initialStartDate == null ? null : utils.dateOnly(initialStartDate),
         initialEndDate = initialEndDate == null ? null : utils.dateOnly(initialEndDate),
         assert(firstDate != null),
         firstDate = utils.dateOnly(firstDate),
         assert(lastDate != null),
         lastDate = utils.dateOnly(lastDate),
         assert(firstDate != null),
         assert(lastDate != null),
         assert(autofocus != null),
         assert(autovalidate != null),
         super(key: key);

   /// The [DateTime] that represents the start of the initial date range selection.
   final DateTime initialStartDate;

   /// The [DateTime] that represents the end of the initial date range selection.
   final DateTime initialEndDate;

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

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

   /// Called when the user changes the start date of the selected range.
   final ValueChanged<DateTime> onStartDateChanged;

   /// Called when the user changes the end date of the selected range.
   final ValueChanged<DateTime> onEndDateChanged;

   /// The text that is displayed at the top of the header.
   ///
   /// This is used to indicate to the user what they are selecting a date for.
   final String helpText;

   /// Error text used to indicate the text in a field is not a valid date.
   final String errorFormatText;

   /// Error text used to indicate the date in a field is not in the valid range
   /// of [firstDate] - [lastDate].
   final String errorInvalidText;

   /// Error text used to indicate the dates given don't form a valid date
   /// range (i.e. the start date is after the end date).
   final String errorInvalidRangeText;

   /// Hint text shown when the start date field is empty.
   final String fieldStartHintText;

   /// Hint text shown when the end date field is empty.
   final String fieldEndHintText;

   /// Label used for the start date field.
   final String fieldStartLabelText;

   /// Label used for the end date field.
   final String fieldEndLabelText;

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

   /// If true, this the date fields will validate and update their error text
   /// immediately after every change. Otherwise, you must call
   /// [InputDateRangePickerState.validate] to validate.
   final bool autovalidate;

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

 /// The current state of an [InputDateRangePicker]. Can be used to
 /// [validate] the date field entries.
 class InputDateRangePickerState extends State<InputDateRangePicker> {
   String _startInputText;
   String _endInputText;
   DateTime _startDate;
   DateTime _endDate;
   TextEditingController _startController;
   TextEditingController _endController;
   String _startErrorText;
   String _endErrorText;
   bool _autoSelected = false;

   @override
   void initState() {
     super.initState();
     _startDate = widget.initialStartDate;
     _startController = TextEditingController();
     _endDate = widget.initialEndDate;
     _endController = TextEditingController();
   }

   @override
   void dispose() {
     _startController.dispose();
     _endController.dispose();
     super.dispose();
   }

   @override
   void didChangeDependencies() {
     super.didChangeDependencies();
     final MaterialLocalizations localizations = MaterialLocalizations.of(context);
     if (_startDate != null) {
       _startInputText = localizations.formatCompactDate(_startDate);
       final bool selectText = widget.autofocus && !_autoSelected;
       _updateController(_startController, _startInputText, selectText);
       _autoSelected = selectText;
     }

     if (_endDate != null) {
       _endInputText = localizations.formatCompactDate(_endDate);
       _updateController(_endController, _endInputText, false);
     }
   }

   /// Validates that the text in the start and end fields represent a valid
   /// date range.
   ///
   /// Will return true if the range is valid. If not, it will
   /// return false and display an appropriate error message under one of the
   /// text fields.
   bool validate() {
     String startError = _validateDate(_startDate);
     final String endError = _validateDate(_endDate);
     if (startError == null && endError == null) {
       if (_startDate.isAfter(_endDate)) {
         startError = widget.errorInvalidRangeText ?? MaterialLocalizations.of(context).invalidDateRangeLabel;
       }
     }
     setState(() {
       _startErrorText = startError;
       _endErrorText = endError;
     });
     return startError == null && endError == null;
   }

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

   String _validateDate(DateTime date) {
     if (date == null) {
       return widget.errorFormatText ?? MaterialLocalizations.of(context).invalidDateFormatLabel;
     } else if (date.isBefore(widget.firstDate) || date.isAfter(widget.lastDate)) {
       return widget.errorInvalidText ?? MaterialLocalizations.of(context).dateOutOfRangeLabel;
     }
     return null;
   }

   void _updateController(TextEditingController controller, String text, bool selectText) {
     TextEditingValue textEditingValue = controller.value.copyWith(text: text);
     if (selectText) {
       textEditingValue = textEditingValue.copyWith(selection: TextSelection(
         baseOffset: 0,
         extentOffset: text.length,
       ));
     }
     controller.value = textEditingValue;
   }

   void _handleStartChanged(String text) {
     setState(() {
       _startInputText = text;
       _startDate = _parseDate(text);
       widget.onStartDateChanged?.call(_startDate);
     });
     if (widget.autovalidate) {
       validate();
     }
   }

   void _handleEndChanged(String text) {
     setState(() {
       _endInputText = text;
       _endDate = _parseDate(text);
       widget.onEndDateChanged?.call(_endDate);
     });
     if (widget.autovalidate) {
       validate();
     }
   }

   @override
   Widget build(BuildContext context) {
     final MaterialLocalizations localizations = MaterialLocalizations.of(context);
     final InputDecorationTheme inputTheme = Theme.of(context).inputDecorationTheme;
     return Row(
       crossAxisAlignment: CrossAxisAlignment.start,
       children: <Widget>[
         Expanded(
           child: TextField(
             controller: _startController,
             decoration: InputDecoration(
               border: inputTheme.border ?? const UnderlineInputBorder(),
               filled: inputTheme.filled ?? true,
               hintText: widget.fieldStartHintText ?? localizations.dateHelpText,
               labelText: widget.fieldStartLabelText ?? localizations.dateRangeStartLabel,
               errorText: _startErrorText,
             ),
             keyboardType: TextInputType.datetime,
             onChanged: _handleStartChanged,
             autofocus: widget.autofocus,
           ),
         ),
         const SizedBox(width: 8),
         Expanded(
           child: TextField(
             controller: _endController,
             decoration: InputDecoration(
               border: inputTheme.border ?? const UnderlineInputBorder(),
               filled: inputTheme.filled ?? true,
               hintText: widget.fieldEndHintText ?? localizations.dateHelpText,
               labelText: widget.fieldEndLabelText ?? localizations.dateRangeEndLabel,
               errorText: _endErrorText,
             ),
             keyboardType: TextInputType.datetime,
             onChanged: _handleEndChanged,
           ),
         ),
       ],
     );
   }
 }
	// 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_field.dart';
	import '../theme.dart';

	import 'date_utils.dart' as utils;

	/// Provides a pair of text fields that allow the user to enter the start and
	/// end dates that represent a range of dates.
	//
	// This is not publicly exported (see pickers.dart), as it is just an
	// internal component used by [showDateRangePicker].
	class InputDateRangePicker extends StatefulWidget {
	/// Creates a row with two text fields configured to accept the start and end dates
	/// of a date range.
	InputDateRangePicker({
	Key key,
	DateTime initialStartDate,
	DateTime initialEndDate,
	@required DateTime firstDate,
	@required DateTime lastDate,
	@required this.onStartDateChanged,
	@required this.onEndDateChanged,
	this.helpText,
	this.errorFormatText,
	this.errorInvalidText,
	this.errorInvalidRangeText,
	this.fieldStartHintText,
	this.fieldEndHintText,
	this.fieldStartLabelText,
	this.fieldEndLabelText,
	this.autofocus = false,
	this.autovalidate = false,
	}) : initialStartDate = initialStartDate == null ? null : utils.dateOnly(initialStartDate),
	initialEndDate = initialEndDate == null ? null : utils.dateOnly(initialEndDate),
	assert(firstDate != null),
	firstDate = utils.dateOnly(firstDate),
	assert(lastDate != null),
	lastDate = utils.dateOnly(lastDate),
	assert(firstDate != null),
	assert(lastDate != null),
	assert(autofocus != null),
	assert(autovalidate != null),
	super(key: key);

	/// The [DateTime] that represents the start of the initial date range selection.
	final DateTime initialStartDate;

	/// The [DateTime] that represents the end of the initial date range selection.
	final DateTime initialEndDate;

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

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

	/// Called when the user changes the start date of the selected range.
	final ValueChanged<DateTime> onStartDateChanged;

	/// Called when the user changes the end date of the selected range.
	final ValueChanged<DateTime> onEndDateChanged;

	/// The text that is displayed at the top of the header.
	///
	/// This is used to indicate to the user what they are selecting a date for.
	final String helpText;

	/// Error text used to indicate the text in a field is not a valid date.
	final String errorFormatText;

	/// Error text used to indicate the date in a field is not in the valid range
	/// of [firstDate] - [lastDate].
	final String errorInvalidText;

	/// Error text used to indicate the dates given don't form a valid date
	/// range (i.e. the start date is after the end date).
	final String errorInvalidRangeText;

	/// Hint text shown when the start date field is empty.
	final String fieldStartHintText;

	/// Hint text shown when the end date field is empty.
	final String fieldEndHintText;

	/// Label used for the start date field.
	final String fieldStartLabelText;

	/// Label used for the end date field.
	final String fieldEndLabelText;

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

	/// If true, this the date fields will validate and update their error text
	/// immediately after every change. Otherwise, you must call
	/// [InputDateRangePickerState.validate] to validate.
	final bool autovalidate;

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

	/// The current state of an [InputDateRangePicker]. Can be used to
	/// [validate] the date field entries.
	class InputDateRangePickerState extends State<InputDateRangePicker> {
	String _startInputText;
	String _endInputText;
	DateTime _startDate;
	DateTime _endDate;
	TextEditingController _startController;
	TextEditingController _endController;
	String _startErrorText;
	String _endErrorText;
	bool _autoSelected = false;

	@override
	void initState() {
	super.initState();
	_startDate = widget.initialStartDate;
	_startController = TextEditingController();
	_endDate = widget.initialEndDate;
	_endController = TextEditingController();
	}

	@override
	void dispose() {
	_startController.dispose();
	_endController.dispose();
	super.dispose();
	}

	@override
	void didChangeDependencies() {
	super.didChangeDependencies();
	final MaterialLocalizations localizations = MaterialLocalizations.of(context);
	if (_startDate != null) {
	_startInputText = localizations.formatCompactDate(_startDate);
	final bool selectText = widget.autofocus && !_autoSelected;
	_updateController(_startController, _startInputText, selectText);
	_autoSelected = selectText;
	}

	if (_endDate != null) {
	_endInputText = localizations.formatCompactDate(_endDate);
	_updateController(_endController, _endInputText, false);
	}
	}

	/// Validates that the text in the start and end fields represent a valid
	/// date range.
	///
	/// Will return true if the range is valid. If not, it will
	/// return false and display an appropriate error message under one of the
	/// text fields.
	bool validate() {
	String startError = _validateDate(_startDate);
	final String endError = _validateDate(_endDate);
	if (startError == null && endError == null) {
	if (_startDate.isAfter(_endDate)) {
	startError = widget.errorInvalidRangeText ?? MaterialLocalizations.of(context).invalidDateRangeLabel;
	}
	}
	setState(() {
	_startErrorText = startError;
	_endErrorText = endError;
	});
	return startError == null && endError == null;
	}

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

	String _validateDate(DateTime date) {
	if (date == null) {
	return widget.errorFormatText ?? MaterialLocalizations.of(context).invalidDateFormatLabel;
	} else if (date.isBefore(widget.firstDate) \|\| date.isAfter(widget.lastDate)) {
	return widget.errorInvalidText ?? MaterialLocalizations.of(context).dateOutOfRangeLabel;
	}
	return null;
	}

	void _updateController(TextEditingController controller, String text, bool selectText) {
	TextEditingValue textEditingValue = controller.value.copyWith(text: text);
	if (selectText) {
	textEditingValue = textEditingValue.copyWith(selection: TextSelection(
	baseOffset: 0,
	extentOffset: text.length,
	));
	}
	controller.value = textEditingValue;
	}

	void _handleStartChanged(String text) {
	setState(() {
	_startInputText = text;
	_startDate = _parseDate(text);
	widget.onStartDateChanged?.call(_startDate);
	});
	if (widget.autovalidate) {
	validate();
	}
	}

	void _handleEndChanged(String text) {
	setState(() {
	_endInputText = text;
	_endDate = _parseDate(text);
	widget.onEndDateChanged?.call(_endDate);
	});
	if (widget.autovalidate) {
	validate();
	}
	}

	@override
	Widget build(BuildContext context) {
	final MaterialLocalizations localizations = MaterialLocalizations.of(context);
	final InputDecorationTheme inputTheme = Theme.of(context).inputDecorationTheme;
	return Row(
	crossAxisAlignment: CrossAxisAlignment.start,
	children: <Widget>[
	Expanded(
	child: TextField(
	controller: _startController,
	decoration: InputDecoration(
	border: inputTheme.border ?? const UnderlineInputBorder(),
	filled: inputTheme.filled ?? true,
	hintText: widget.fieldStartHintText ?? localizations.dateHelpText,
	labelText: widget.fieldStartLabelText ?? localizations.dateRangeStartLabel,
	errorText: _startErrorText,
	),
	keyboardType: TextInputType.datetime,
	onChanged: _handleStartChanged,
	autofocus: widget.autofocus,
	),
	),
	const SizedBox(width: 8),
	Expanded(
	child: TextField(
	controller: _endController,
	decoration: InputDecoration(
	border: inputTheme.border ?? const UnderlineInputBorder(),
	filled: inputTheme.filled ?? true,
	hintText: widget.fieldEndHintText ?? localizations.dateHelpText,
	labelText: widget.fieldEndLabelText ?? localizations.dateRangeEndLabel,
	errorText: _endErrorText,
	),
	keyboardType: TextInputType.datetime,
	onChanged: _handleEndChanged,
	),
	),
	],
	);
	}
	}