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

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:async';

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

 import 'time.dart';
 import 'typography.dart';

 /// Defines the localized resource values used by the Material widgets.
 ///
 /// See also:
 ///
 ///  * [DefaultMaterialLocalizations], the default, English-only, implementation
 ///    of this interface.
 ///  * [GlobalMaterialLocalizations], which provides material localizations for
 ///    many languages.
 abstract class MaterialLocalizations {
   /// The tooltip for the leading [AppBar] menu (a.k.a. 'hamburger') button.
   String get openAppDrawerTooltip;

   /// The [BackButton]'s tooltip.
   String get backButtonTooltip;

   /// The [CloseButton]'s tooltip.
   String get closeButtonTooltip;

   /// The tooltip for the [MonthPicker]'s "next month" button.
   String get nextMonthTooltip;

   /// The tooltip for the [MonthPicker]'s "previous month" button.
   String get previousMonthTooltip;

   /// The tooltip for the [PaginatedDataTable]'s "next page" button.
   String get nextPageTooltip;

   /// The tooltip for the [PaginatedDataTable]'s "previous page" button.
   String get previousPageTooltip;

   /// The default [PopupMenuButton] tooltip.
   String get showMenuTooltip;

   /// The default title for [AboutListTile].
   String aboutListTileTitle(String applicationName);

   /// Title for the [LicensePage] widget.
   String get licensesPageTitle;

   /// Title for the [PaginatedDataTable]'s row info footer.
   String pageRowsInfoTitle(int firstRow, int lastRow, int rowCount, bool rowCountIsApproximate);

   /// Title for the [PaginatedDataTable]'s "rows per page" footer.
   String get rowsPerPageTitle;

   /// Title for the [PaginatedDataTable]'s selected row count header.
   String selectedRowCountTitle(int selectedRowCount);

   /// Label for "cancel" buttons and menu items.
   String get cancelButtonLabel;

   /// Label for "close" buttons and menu items.
   String get closeButtonLabel;

   /// Label for "continue" buttons and menu items.
   String get continueButtonLabel;

   /// Label for "copy" edit buttons and menu items.
   String get copyButtonLabel;

   /// Label for "cut" edit buttons and menu items.
   String get cutButtonLabel;

   /// Label for OK buttons and menu items.
   String get okButtonLabel;

   /// Label for "paste" edit buttons and menu items.
   String get pasteButtonLabel;

   /// Label for "select all" edit buttons and menu items.
   String get selectAllButtonLabel;

   /// Label for the [AboutDialog] button that shows the [LicensePage].
   String get viewLicensesButtonLabel;

   /// The abbreviation for ante meridiem (before noon) shown in the time picker.
   String get anteMeridiemAbbreviation;

   /// The abbreviation for post meridiem (after noon) shown in the time picker.
   String get postMeridiemAbbreviation;

   /// The format used to lay out the time picker.
   ///
   /// The documentation for [TimeOfDayFormat] enum values provides details on
   /// each supported layout.
   TimeOfDayFormat timeOfDayFormat({ bool alwaysUse24HourFormat: false });

   /// Provides geometric text preferences for the current locale.
   ///
   /// This text theme is incomplete. For example, it lacks text color
   /// information. This theme must be merged with another text theme that
   /// provides the missing values.
   ///
   /// Typically a complete theme is obtained via [Theme.of], which can be
   /// localized using the [Localizations] widget.
   ///
   /// The text styles provided by this theme are expected to have their
   /// [TextStyle.inherit] property set to false, so that the [ThemeData]
   /// obtained from [Theme.of] no longer inherits text style properties and
   /// contains a complete set of properties needed to style a [Text] widget.
   ///
   /// See also: https://material.io/guidelines/style/typography.html
   TextTheme get localTextGeometry;

   /// Formats [number] as a decimal, inserting locale-appropriate thousands
   /// separators as necessary.
   String formatDecimal(int number);

   /// Formats [TimeOfDay.hour] in the given time of day according to the value
   /// of [timeOfDayFormat].
   ///
   /// If [alwaysUse24HourFormat] is true, formats hour using [HourFormat.HH]
   /// rather than the default for the current locale.
   String formatHour(TimeOfDay timeOfDay, { bool alwaysUse24HourFormat: false });

   /// Formats [TimeOfDay.minute] in the given time of day according to the value
   /// of [timeOfDayFormat].
   String formatMinute(TimeOfDay timeOfDay);

   /// Formats [timeOfDay] according to the value of [timeOfDayFormat].
   ///
   /// If [alwaysUse24HourFormat] is true, formats hour using [HourFormat.HH]
   /// rather than the default for the current locale. This value is usually
   /// passed from [MediaQueryData.alwaysUse24HourFormat], which has platform-
   /// specific behavior.
   String formatTimeOfDay(TimeOfDay timeOfDay, { bool alwaysUse24HourFormat: false });

   /// Full unabbreviated year format, e.g. 2017 rather than 17.
   String formatYear(DateTime date);

   /// Formats the date using a medium-width format.
   ///
   /// Abbreviates month and days of week. This appears in the header of the date
   /// picker invoked using [showDatePicker].
   ///
   /// Examples:
   ///
   /// - US English: Wed, Sep 27
   /// - Russian: ср, сент. 27
   String formatMediumDate(DateTime date);

   /// Formats the month and the year of the given [date].
   ///
   /// The returned string does not contain the day of the month. This appears
   /// in the date picker invoked using [showDatePicker].
   String formatMonthYear(DateTime date);

   /// List of week day names in narrow format, usually 1- or 2-letter
   /// abbreviations of full names.
   ///
   /// The list begins with the value corresponding to Sunday and ends with
   /// Saturday. Use [firstDayOfWeekIndex] to find the first day of week in this
   /// list.
   ///
   /// Examples:
   ///
   /// - US English: S, M, T, W, T, F, S
   /// - Russian: вс, пн, вт, ср, чт, пт, сб - notice that the list begins with
   ///   вс (Sunday) even though the first day of week for Russian is Monday.
   List<String> get narrowWeekdays;

   /// Index of the first day of week, where 0 points to Sunday, and 6 points to
   /// Saturday.
   ///
   /// This getter is compatible with [narrowWeekdays]. For example:
   ///
   /// ```dart
   /// var localizations = MaterialLocalizations.of(context);
   /// // The name of the first day of week for the current locale.
   /// var firstDayOfWeek = localizations.narrowWeekdays[localizations.firstDayOfWeekIndex];
   /// ```
   int get firstDayOfWeekIndex;

   /// The `MaterialLocalizations` from the closest [Localizations] instance
   /// that encloses the given context.
   ///
   /// This method is just a convenient shorthand for:
   /// `Localizations.of<MaterialLocalizations>(context, MaterialLocalizations)`.
   ///
   /// References to the localized resources defined by this class are typically
   /// written in terms of this method. For example:
   ///
   /// ```dart
   /// tooltip: MaterialLocalizations.of(context).backButtonTooltip,
   /// ```
   static MaterialLocalizations of(BuildContext context) {
     return Localizations.of<MaterialLocalizations>(context, MaterialLocalizations);
   }
 }

 class _MaterialLocalizationsDelegate extends LocalizationsDelegate<MaterialLocalizations> {
   const _MaterialLocalizationsDelegate();

   @override
   bool isSupported(Locale locale) => locale.languageCode == 'en';

   @override
   Future<MaterialLocalizations> load(Locale locale) => DefaultMaterialLocalizations.load(locale);

   @override
   bool shouldReload(_MaterialLocalizationsDelegate old) => false;
 }

 /// US English strings for the material widgets.
 ///
 /// See also:
 ///
 ///  * [GlobalMaterialLocalizations], which provides material localizations for
 ///    many languages.
 ///  * [MaterialApp.delegates], which automatically includes
 ///    [DefaultMaterialLocalizations.delegate] by default.
 class DefaultMaterialLocalizations implements MaterialLocalizations {
   /// Constructs an object that defines the material widgets' localized strings
   /// for US English (only).
   ///
   /// [LocalizationsDelegate] implementations typically call the static [load]
   /// function, rather than constructing this class directly.
   const DefaultMaterialLocalizations();


   // Ordered to match DateTime.MONDAY=1, DateTime.SUNDAY=6
   static const List<String>_shortWeekdays = const <String>[
     'Mon',
     'Tue',
     'Wed',
     'Thu',
     'Fri',
     'Sat',
     'Sun',
   ];

   static const List<String> _narrowWeekdays = const <String>[
     'S',
     'M',
     'T',
     'W',
     'T',
     'F',
     'S',
   ];

   static const List<String> _shortMonths = const <String>[
     'Jan',
     'Feb',
     'Mar',
     'Apr',
     'May',
     'Jun',
     'Jul',
     'Aug',
     'Sep',
     'Oct',
     'Nov',
     'Dec',
   ];

   static const List<String> _months = const <String>[
     'January',
     'February',
     'March',
     'April',
     'May',
     'June',
     'July',
     'August',
     'September',
     'October',
     'November',
     'December',
   ];

   @override
   String formatHour(TimeOfDay timeOfDay, { bool alwaysUse24HourFormat: false }) {
     final TimeOfDayFormat format = timeOfDayFormat(alwaysUse24HourFormat: alwaysUse24HourFormat);
     switch (format) {
       case TimeOfDayFormat.h_colon_mm_space_a:
         return formatDecimal(timeOfDay.hourOfPeriod == 0 ? 12 : timeOfDay.hourOfPeriod);
       case TimeOfDayFormat.HH_colon_mm:
         return _formatTwoDigitZeroPad(timeOfDay.hour);
       default:
         throw new AssertionError('$runtimeType does not support $format.');
     }
   }

   /// Formats [number] using two digits, assuming it's in the 0-99 inclusive
   /// range. Not designed to format values outside this range.
   String _formatTwoDigitZeroPad(int number) {
     assert(0 <= number && number < 100);

     if (number < 10)
       return '0$number';

     return '$number';
   }

   @override
   String formatMinute(TimeOfDay timeOfDay) {
     final int minute = timeOfDay.minute;
     return minute < 10 ? '0$minute' : minute.toString();
   }

   @override
   String formatYear(DateTime date) => date.year.toString();

   @override
   String formatMediumDate(DateTime date) {
     final String day = _shortWeekdays[date.weekday - DateTime.MONDAY];
     final String month = _shortMonths[date.month - DateTime.JANUARY];
     return '$day, $month ${date.day}';
   }

   @override
   String formatMonthYear(DateTime date) {
     final String year = formatYear(date);
     final String month = _months[date.month - DateTime.JANUARY];
     return '$month $year';
   }

   @override
   List<String> get narrowWeekdays => _narrowWeekdays;

   @override
   int get firstDayOfWeekIndex => 0; // narrowWeekdays[0] is 'S' for Sunday

   String _formatDayPeriod(TimeOfDay timeOfDay) {
     switch (timeOfDay.period) {
       case DayPeriod.am:
         return anteMeridiemAbbreviation;
       case DayPeriod.pm:
         return postMeridiemAbbreviation;
     }
     return null;
   }

   @override
   String formatDecimal(int number) {
     if (number > -1000 && number < 1000)
       return number.toString();

     final String digits = number.abs().toString();
     final StringBuffer result = new StringBuffer(number < 0 ? '-' : '');
     final int maxDigitIndex = digits.length - 1;
     for (int i = 0; i <= maxDigitIndex; i += 1) {
       result.write(digits[i]);
       if (i < maxDigitIndex && (maxDigitIndex - i) % 3 == 0)
         result.write(',');
     }
     return result.toString();
   }

   @override
   String formatTimeOfDay(TimeOfDay timeOfDay, { bool alwaysUse24HourFormat: false }) {
     // Not using intl.DateFormat for two reasons:
     //
     // - DateFormat supports more formats than our material time picker does,
     //   and we want to be consistent across time picker format and the string
     //   formatting of the time of day.
     // - DateFormat operates on DateTime, which is sensitive to time eras and
     //   time zones, while here we want to format hour and minute within one day
     //   no matter what date the day falls on.
     final StringBuffer buffer = new StringBuffer();

     // Add hour:minute.
     buffer
       ..write(formatHour(timeOfDay, alwaysUse24HourFormat: alwaysUse24HourFormat))
       ..write(':')
       ..write(formatMinute(timeOfDay));

     if (alwaysUse24HourFormat) {
       // There's no AM/PM indicator in 24-hour format.
       return '$buffer';
     }

     // Add AM/PM indicator.
     buffer
       ..write(' ')
       ..write(_formatDayPeriod(timeOfDay));
     return '$buffer';
   }

   @override
   String get openAppDrawerTooltip => 'Open navigation menu';

   @override
   String get backButtonTooltip => 'Back';

   @override
   String get closeButtonTooltip => 'Close';

   @override
   String get nextMonthTooltip => 'Next month';

   @override
   String get previousMonthTooltip => 'Previous month';

   @override
   String get nextPageTooltip => 'Next page';

   @override
   String get previousPageTooltip => 'Previous page';

   @override
   String get showMenuTooltip => 'Show menu';

   @override
   String aboutListTileTitle(String applicationName) => 'About $applicationName';

   @override
   String get licensesPageTitle => 'Licenses';

   @override
   String pageRowsInfoTitle(int firstRow, int lastRow, int rowCount, bool rowCountIsApproximate) {
     return rowCountIsApproximate
       ? '$firstRow–$lastRow of about $rowCount'
       : '$firstRow–$lastRow of $rowCount';
   }

   @override
   String get rowsPerPageTitle => 'Rows per page';

   @override
   String selectedRowCountTitle(int selectedRowCount) {
     switch (selectedRowCount) {
       case 0:
         return 'No items selected';
       case 1:
         return '1 item selected';
       default:
         return '$selectedRowCount items selected';
     }
   }

   @override
   String get cancelButtonLabel => 'CANCEL';

   @override
   String get closeButtonLabel => 'CLOSE';

   @override
   String get continueButtonLabel => 'CONTINUE';

   @override
   String get copyButtonLabel => 'COPY';

   @override
   String get cutButtonLabel => 'CUT';

   @override
   String get okButtonLabel => 'OK';

   @override
   String get pasteButtonLabel => 'PASTE';

   @override
   String get selectAllButtonLabel => 'SELECT ALL';

   @override
   String get viewLicensesButtonLabel => 'VIEW LICENSES';

   @override
   String get anteMeridiemAbbreviation => 'AM';

   @override
   String get postMeridiemAbbreviation => 'PM';

   @override
   TimeOfDayFormat timeOfDayFormat({ bool alwaysUse24HourFormat: false }) {
     return alwaysUse24HourFormat
       ? TimeOfDayFormat.HH_colon_mm
       : TimeOfDayFormat.h_colon_mm_space_a;
   }

   /// Looks up text geometry defined in [MaterialTextGeometry].
   @override
   TextTheme get localTextGeometry => MaterialTextGeometry.englishLike;

   /// Creates an object that provides US English resource values for the material
   /// library widgets.
   ///
   /// The [locale] parameter is ignored.
   ///
   /// This method is typically used to create a [LocalizationsDelegate].
   /// The [MaterialApp] does so by default.
   static Future<MaterialLocalizations> load(Locale locale) {
     return new SynchronousFuture<MaterialLocalizations>(const DefaultMaterialLocalizations());
   }

   /// A [LocalizationsDelegate] that uses [DefaultMaterialLocalizations.load]
   /// to create an instance of this class.
   ///
   /// [MaterialApp] automatically adds this value to [MaterialApp.localizationsDelegates].
   static const LocalizationsDelegate<MaterialLocalizations> delegate = const _MaterialLocalizationsDelegate();
 }
	// Copyright 2017 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:async';

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

	import 'time.dart';
	import 'typography.dart';

	/// Defines the localized resource values used by the Material widgets.
	///
	/// See also:
	///
	/// * [DefaultMaterialLocalizations], the default, English-only, implementation
	/// of this interface.
	/// * [GlobalMaterialLocalizations], which provides material localizations for
	/// many languages.
	abstract class MaterialLocalizations {
	/// The tooltip for the leading [AppBar] menu (a.k.a. 'hamburger') button.
	String get openAppDrawerTooltip;

	/// The [BackButton]'s tooltip.
	String get backButtonTooltip;

	/// The [CloseButton]'s tooltip.
	String get closeButtonTooltip;

	/// The tooltip for the [MonthPicker]'s "next month" button.
	String get nextMonthTooltip;

	/// The tooltip for the [MonthPicker]'s "previous month" button.
	String get previousMonthTooltip;

	/// The tooltip for the [PaginatedDataTable]'s "next page" button.
	String get nextPageTooltip;

	/// The tooltip for the [PaginatedDataTable]'s "previous page" button.
	String get previousPageTooltip;

	/// The default [PopupMenuButton] tooltip.
	String get showMenuTooltip;

	/// The default title for [AboutListTile].
	String aboutListTileTitle(String applicationName);

	/// Title for the [LicensePage] widget.
	String get licensesPageTitle;

	/// Title for the [PaginatedDataTable]'s row info footer.
	String pageRowsInfoTitle(int firstRow, int lastRow, int rowCount, bool rowCountIsApproximate);

	/// Title for the [PaginatedDataTable]'s "rows per page" footer.
	String get rowsPerPageTitle;

	/// Title for the [PaginatedDataTable]'s selected row count header.
	String selectedRowCountTitle(int selectedRowCount);

	/// Label for "cancel" buttons and menu items.
	String get cancelButtonLabel;

	/// Label for "close" buttons and menu items.
	String get closeButtonLabel;

	/// Label for "continue" buttons and menu items.
	String get continueButtonLabel;

	/// Label for "copy" edit buttons and menu items.
	String get copyButtonLabel;

	/// Label for "cut" edit buttons and menu items.
	String get cutButtonLabel;

	/// Label for OK buttons and menu items.
	String get okButtonLabel;

	/// Label for "paste" edit buttons and menu items.
	String get pasteButtonLabel;

	/// Label for "select all" edit buttons and menu items.
	String get selectAllButtonLabel;

	/// Label for the [AboutDialog] button that shows the [LicensePage].
	String get viewLicensesButtonLabel;

	/// The abbreviation for ante meridiem (before noon) shown in the time picker.
	String get anteMeridiemAbbreviation;

	/// The abbreviation for post meridiem (after noon) shown in the time picker.
	String get postMeridiemAbbreviation;

	/// The format used to lay out the time picker.
	///
	/// The documentation for [TimeOfDayFormat] enum values provides details on
	/// each supported layout.
	TimeOfDayFormat timeOfDayFormat({ bool alwaysUse24HourFormat: false });

	/// Provides geometric text preferences for the current locale.
	///
	/// This text theme is incomplete. For example, it lacks text color
	/// information. This theme must be merged with another text theme that
	/// provides the missing values.
	///
	/// Typically a complete theme is obtained via [Theme.of], which can be
	/// localized using the [Localizations] widget.
	///
	/// The text styles provided by this theme are expected to have their
	/// [TextStyle.inherit] property set to false, so that the [ThemeData]
	/// obtained from [Theme.of] no longer inherits text style properties and
	/// contains a complete set of properties needed to style a [Text] widget.
	///
	/// See also: https://material.io/guidelines/style/typography.html
	TextTheme get localTextGeometry;

	/// Formats [number] as a decimal, inserting locale-appropriate thousands
	/// separators as necessary.
	String formatDecimal(int number);

	/// Formats [TimeOfDay.hour] in the given time of day according to the value
	/// of [timeOfDayFormat].
	///
	/// If [alwaysUse24HourFormat] is true, formats hour using [HourFormat.HH]
	/// rather than the default for the current locale.
	String formatHour(TimeOfDay timeOfDay, { bool alwaysUse24HourFormat: false });

	/// Formats [TimeOfDay.minute] in the given time of day according to the value
	/// of [timeOfDayFormat].
	String formatMinute(TimeOfDay timeOfDay);

	/// Formats [timeOfDay] according to the value of [timeOfDayFormat].
	///
	/// If [alwaysUse24HourFormat] is true, formats hour using [HourFormat.HH]
	/// rather than the default for the current locale. This value is usually
	/// passed from [MediaQueryData.alwaysUse24HourFormat], which has platform-
	/// specific behavior.
	String formatTimeOfDay(TimeOfDay timeOfDay, { bool alwaysUse24HourFormat: false });

	/// Full unabbreviated year format, e.g. 2017 rather than 17.
	String formatYear(DateTime date);

	/// Formats the date using a medium-width format.
	///
	/// Abbreviates month and days of week. This appears in the header of the date
	/// picker invoked using [showDatePicker].
	///
	/// Examples:
	///
	/// - US English: Wed, Sep 27
	/// - Russian: ср, сент. 27
	String formatMediumDate(DateTime date);

	/// Formats the month and the year of the given [date].
	///
	/// The returned string does not contain the day of the month. This appears
	/// in the date picker invoked using [showDatePicker].
	String formatMonthYear(DateTime date);

	/// List of week day names in narrow format, usually 1- or 2-letter
	/// abbreviations of full names.
	///
	/// The list begins with the value corresponding to Sunday and ends with
	/// Saturday. Use [firstDayOfWeekIndex] to find the first day of week in this
	/// list.
	///
	/// Examples:
	///
	/// - US English: S, M, T, W, T, F, S
	/// - Russian: вс, пн, вт, ср, чт, пт, сб - notice that the list begins with
	/// вс (Sunday) even though the first day of week for Russian is Monday.
	List<String> get narrowWeekdays;

	/// Index of the first day of week, where 0 points to Sunday, and 6 points to
	/// Saturday.
	///
	/// This getter is compatible with [narrowWeekdays]. For example:
	///
	/// ```dart
	/// var localizations = MaterialLocalizations.of(context);
	/// // The name of the first day of week for the current locale.
	/// var firstDayOfWeek = localizations.narrowWeekdays[localizations.firstDayOfWeekIndex];
	/// ```
	int get firstDayOfWeekIndex;

	/// The `MaterialLocalizations` from the closest [Localizations] instance
	/// that encloses the given context.
	///
	/// This method is just a convenient shorthand for:
	/// `Localizations.of<MaterialLocalizations>(context, MaterialLocalizations)`.
	///
	/// References to the localized resources defined by this class are typically
	/// written in terms of this method. For example:
	///
	/// ```dart
	/// tooltip: MaterialLocalizations.of(context).backButtonTooltip,
	/// ```
	static MaterialLocalizations of(BuildContext context) {
	return Localizations.of<MaterialLocalizations>(context, MaterialLocalizations);
	}
	}

	class _MaterialLocalizationsDelegate extends LocalizationsDelegate<MaterialLocalizations> {
	const _MaterialLocalizationsDelegate();

	@override
	bool isSupported(Locale locale) => locale.languageCode == 'en';

	@override
	Future<MaterialLocalizations> load(Locale locale) => DefaultMaterialLocalizations.load(locale);

	@override
	bool shouldReload(_MaterialLocalizationsDelegate old) => false;
	}

	/// US English strings for the material widgets.
	///
	/// See also:
	///
	/// * [GlobalMaterialLocalizations], which provides material localizations for
	/// many languages.
	/// * [MaterialApp.delegates], which automatically includes
	/// [DefaultMaterialLocalizations.delegate] by default.
	class DefaultMaterialLocalizations implements MaterialLocalizations {
	/// Constructs an object that defines the material widgets' localized strings
	/// for US English (only).
	///
	/// [LocalizationsDelegate] implementations typically call the static [load]
	/// function, rather than constructing this class directly.
	const DefaultMaterialLocalizations();


	// Ordered to match DateTime.MONDAY=1, DateTime.SUNDAY=6
	static const List<String>_shortWeekdays = const <String>[
	'Mon',
	'Tue',
	'Wed',
	'Thu',
	'Fri',
	'Sat',
	'Sun',
	];

	static const List<String> _narrowWeekdays = const <String>[
	'S',
	'M',
	'T',
	'W',
	'T',
	'F',
	'S',
	];

	static const List<String> _shortMonths = const <String>[
	'Jan',
	'Feb',
	'Mar',
	'Apr',
	'May',
	'Jun',
	'Jul',
	'Aug',
	'Sep',
	'Oct',
	'Nov',
	'Dec',
	];

	static const List<String> _months = const <String>[
	'January',
	'February',
	'March',
	'April',
	'May',
	'June',
	'July',
	'August',
	'September',
	'October',
	'November',
	'December',
	];

	@override
	String formatHour(TimeOfDay timeOfDay, { bool alwaysUse24HourFormat: false }) {
	final TimeOfDayFormat format = timeOfDayFormat(alwaysUse24HourFormat: alwaysUse24HourFormat);
	switch (format) {
	case TimeOfDayFormat.h_colon_mm_space_a:
	return formatDecimal(timeOfDay.hourOfPeriod == 0 ? 12 : timeOfDay.hourOfPeriod);
	case TimeOfDayFormat.HH_colon_mm:
	return _formatTwoDigitZeroPad(timeOfDay.hour);
	default:
	throw new AssertionError('$runtimeType does not support $format.');
	}
	}

	/// Formats [number] using two digits, assuming it's in the 0-99 inclusive
	/// range. Not designed to format values outside this range.
	String _formatTwoDigitZeroPad(int number) {
	assert(0 <= number && number < 100);

	if (number < 10)
	return '0$number';

	return '$number';
	}

	@override
	String formatMinute(TimeOfDay timeOfDay) {
	final int minute = timeOfDay.minute;
	return minute < 10 ? '0$minute' : minute.toString();
	}

	@override
	String formatYear(DateTime date) => date.year.toString();

	@override
	String formatMediumDate(DateTime date) {
	final String day = _shortWeekdays[date.weekday - DateTime.MONDAY];
	final String month = _shortMonths[date.month - DateTime.JANUARY];
	return '$day, $month ${date.day}';
	}

	@override
	String formatMonthYear(DateTime date) {
	final String year = formatYear(date);
	final String month = _months[date.month - DateTime.JANUARY];
	return '$month $year';
	}

	@override
	List<String> get narrowWeekdays => _narrowWeekdays;

	@override
	int get firstDayOfWeekIndex => 0; // narrowWeekdays[0] is 'S' for Sunday

	String _formatDayPeriod(TimeOfDay timeOfDay) {
	switch (timeOfDay.period) {
	case DayPeriod.am:
	return anteMeridiemAbbreviation;
	case DayPeriod.pm:
	return postMeridiemAbbreviation;
	}
	return null;
	}

	@override
	String formatDecimal(int number) {
	if (number > -1000 && number < 1000)
	return number.toString();

	final String digits = number.abs().toString();
	final StringBuffer result = new StringBuffer(number < 0 ? '-' : '');
	final int maxDigitIndex = digits.length - 1;
	for (int i = 0; i <= maxDigitIndex; i += 1) {
	result.write(digits[i]);
	if (i < maxDigitIndex && (maxDigitIndex - i) % 3 == 0)
	result.write(',');
	}
	return result.toString();
	}

	@override
	String formatTimeOfDay(TimeOfDay timeOfDay, { bool alwaysUse24HourFormat: false }) {
	// Not using intl.DateFormat for two reasons:
	//
	// - DateFormat supports more formats than our material time picker does,
	// and we want to be consistent across time picker format and the string
	// formatting of the time of day.
	// - DateFormat operates on DateTime, which is sensitive to time eras and
	// time zones, while here we want to format hour and minute within one day
	// no matter what date the day falls on.
	final StringBuffer buffer = new StringBuffer();

	// Add hour:minute.
	buffer
	..write(formatHour(timeOfDay, alwaysUse24HourFormat: alwaysUse24HourFormat))
	..write(':')
	..write(formatMinute(timeOfDay));

	if (alwaysUse24HourFormat) {
	// There's no AM/PM indicator in 24-hour format.
	return '$buffer';
	}

	// Add AM/PM indicator.
	buffer
	..write(' ')
	..write(_formatDayPeriod(timeOfDay));
	return '$buffer';
	}

	@override
	String get openAppDrawerTooltip => 'Open navigation menu';

	@override
	String get backButtonTooltip => 'Back';

	@override
	String get closeButtonTooltip => 'Close';

	@override
	String get nextMonthTooltip => 'Next month';

	@override
	String get previousMonthTooltip => 'Previous month';

	@override
	String get nextPageTooltip => 'Next page';

	@override
	String get previousPageTooltip => 'Previous page';

	@override
	String get showMenuTooltip => 'Show menu';

	@override
	String aboutListTileTitle(String applicationName) => 'About $applicationName';

	@override
	String get licensesPageTitle => 'Licenses';

	@override
	String pageRowsInfoTitle(int firstRow, int lastRow, int rowCount, bool rowCountIsApproximate) {
	return rowCountIsApproximate
	? '$firstRow–$lastRow of about $rowCount'
	: '$firstRow–$lastRow of $rowCount';
	}

	@override
	String get rowsPerPageTitle => 'Rows per page';

	@override
	String selectedRowCountTitle(int selectedRowCount) {
	switch (selectedRowCount) {
	case 0:
	return 'No items selected';
	case 1:
	return '1 item selected';
	default:
	return '$selectedRowCount items selected';
	}
	}

	@override
	String get cancelButtonLabel => 'CANCEL';

	@override
	String get closeButtonLabel => 'CLOSE';

	@override
	String get continueButtonLabel => 'CONTINUE';

	@override
	String get copyButtonLabel => 'COPY';

	@override
	String get cutButtonLabel => 'CUT';

	@override
	String get okButtonLabel => 'OK';

	@override
	String get pasteButtonLabel => 'PASTE';

	@override
	String get selectAllButtonLabel => 'SELECT ALL';

	@override
	String get viewLicensesButtonLabel => 'VIEW LICENSES';

	@override
	String get anteMeridiemAbbreviation => 'AM';

	@override
	String get postMeridiemAbbreviation => 'PM';

	@override
	TimeOfDayFormat timeOfDayFormat({ bool alwaysUse24HourFormat: false }) {
	return alwaysUse24HourFormat
	? TimeOfDayFormat.HH_colon_mm
	: TimeOfDayFormat.h_colon_mm_space_a;
	}

	/// Looks up text geometry defined in [MaterialTextGeometry].
	@override
	TextTheme get localTextGeometry => MaterialTextGeometry.englishLike;

	/// Creates an object that provides US English resource values for the material
	/// library widgets.
	///
	/// The [locale] parameter is ignored.
	///
	/// This method is typically used to create a [LocalizationsDelegate].
	/// The [MaterialApp] does so by default.
	static Future<MaterialLocalizations> load(Locale locale) {
	return new SynchronousFuture<MaterialLocalizations>(const DefaultMaterialLocalizations());
	}

	/// A [LocalizationsDelegate] that uses [DefaultMaterialLocalizations.load]
	/// to create an instance of this class.
	///
	/// [MaterialApp] automatically adds this value to [MaterialApp.localizationsDelegates].
	static const LocalizationsDelegate<MaterialLocalizations> delegate = const _MaterialLocalizationsDelegate();
	}