dev/tools/update_icons.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

 // Regenerates the material icons file.
 // See https://github.com/flutter/flutter/wiki/Updating-Material-Design-Fonts-&-Icons

 import 'dart:convert' show LineSplitter;
 import 'dart:io';

 import 'package:args/args.dart';
 import 'package:path/path.dart' as path;

 const String _newCodepointsPathOption = 'new-codepoints';
 const String _oldCodepointsPathOption = 'old-codepoints';
 const String _iconsClassPathOption = 'icons';
 const String _dryRunOption = 'dry-run';

 const String _defaultNewCodepointsPath = 'codepoints';
 const String _defaultOldCodepointsPath = 'bin/cache/artifacts/material_fonts/codepoints';
 const String _defaultIconsPath = 'packages/flutter/lib/src/material/icons.dart';

 const String _beginGeneratedMark = '// BEGIN GENERATED ICONS';
 const String _endGeneratedMark = '// END GENERATED ICONS';
 const String _beginPlatformAdaptiveGeneratedMark = '// BEGIN GENERATED PLATFORM ADAPTIVE ICONS';
 const String _endPlatformAdaptiveGeneratedMark = '// END GENERATED PLATFORM ADAPTIVE ICONS';

 const Map<String, List<String>> _platformAdaptiveIdentifiers = <String, List<String>>{
   // Mapping of Flutter IDs to an Android/agnostic ID and an iOS ID.
   // Flutter IDs can be anything, but should be chosen to be agnostic.
   'arrow_back': <String>['arrow_back', 'arrow_back_ios'],
   'arrow_forward': <String>['arrow_forward', 'arrow_forward_ios'],
   'flip_camera': <String>['flip_camera_android', 'flip_camera_ios'],
   'more': <String>['more_vert', 'more_horiz'],
   'share': <String>['share', 'ios_share'],
 };

 // Rewrite certain Flutter IDs (reserved keywords, numbers) using prefix matching.
 const Map<String, String> identifierRewrites = <String, String>{
   '1x': 'one_x',
   '360': 'threesixty',
   '2d': 'twod',
   '3d': 'threed',
   '3p': 'three_p',
   '6_ft': 'six_ft',
   '3g': 'three_g',
   '4g': 'four_g',
   '5g': 'five_g',
   '30fps': 'thirty_fps',
   '60fps': 'sixty_fps',
   '1k': 'one_k',
   '2k': 'two_k',
   '3k': 'three_k',
   '4k': 'four_k',
   '5k': 'five_k',
   '6k': 'six_k',
   '7k': 'seven_k',
   '8k': 'eight_k',
   '9k': 'nine_k',
   '10k': 'ten_k',
   '1mp': 'one_mp',
   '2mp': 'two_mp',
   '3mp': 'three_mp',
   '4mp': 'four_mp',
   '5mp': 'five_mp',
   '6mp': 'six_mp',
   '7mp': 'seven_mp',
   '8mp': 'eight_mp',
   '9mp': 'nine_mp',
   '10mp': 'ten_mp',
   '11mp': 'eleven_mp',
   '12mp': 'twelve_mp',
   '13mp': 'thirteen_mp',
   '14mp': 'fourteen_mp',
   '15mp': 'fifteen_mp',
   '16mp': 'sixteen_mp',
   '17mp': 'seventeen_mp',
   '18mp': 'eighteen_mp',
   '19mp': 'nineteen_mp',
   '20mp': 'twenty_mp',
   '21mp': 'twenty_one_mp',
   '22mp': 'twenty_two_mp',
   '23mp': 'twenty_three_mp',
   '24mp': 'twenty_four_mp',
   'class': 'class_',
   'try': 'try_sms_star',
 };

 const Set<String> _iconsMirroredWhenRTL = <String>{
   // This list is obtained from:
   // http://google.github.io/material-design-icons/#icons-in-rtl
   'arrow_back',
   'arrow_back_ios',
   'arrow_forward',
   'arrow_forward_ios',
   'arrow_left',
   'arrow_right',
   'assignment',
   'assignment_return',
   'backspace',
   'battery_unknown',
   'call_made',
   'call_merge',
   'call_missed',
   'call_missed_outgoing',
   'call_received',
   'call_split',
   'chevron_left',
   'chevron_right',
   'chrome_reader_mode',
   'device_unknown',
   'dvr',
   'event_note',
   'featured_play_list',
   'featured_video',
   'first_page',
   'flight_land',
   'flight_takeoff',
   'format_indent_decrease',
   'format_indent_increase',
   'format_list_bulleted',
   'forward',
   'functions',
   'help',
   'help_outline',
   'input',
   'keyboard_backspace',
   'keyboard_tab',
   'label',
   'label_important',
   'label_outline',
   'last_page',
   'launch',
   'list',
   'live_help',
   'mobile_screen_share',
   'multiline_chart',
   'navigate_before',
   'navigate_next',
   'next_week',
   'note',
   'open_in_new',
   'playlist_add',
   'queue_music',
   'redo',
   'reply',
   'reply_all',
   'screen_share',
   'send',
   'short_text',
   'show_chart',
   'sort',
   'star_half',
   'subject',
   'trending_flat',
   'toc',
   'trending_down',
   'trending_up',
   'undo',
   'view_list',
   'view_quilt',
   'wrap_text',
 };

 void main(List<String> args) {
   // If we're run from the `tools` dir, set the cwd to the repo root.
   if (path.basename(Directory.current.path) == 'tools')
     Directory.current = Directory.current.parent.parent;

   final ArgResults argResults = _handleArguments(args);

   final File iconClassFile = File(path.normalize(path.absolute(argResults[_iconsClassPathOption] as String)));
   if (!iconClassFile.existsSync()) {
     stderr.writeln('Error: Icons file not found: ${iconClassFile.path}');
     exit(1);
   }
   final File newCodepointsFile = File(argResults[_newCodepointsPathOption] as String);
   if (!newCodepointsFile.existsSync()) {
     stderr.writeln('Error: New codepoints file not found: ${newCodepointsFile.path}');
     exit(1);
   }
   final File oldCodepointsFile = File(argResults[_oldCodepointsPathOption] as String);
   if (!oldCodepointsFile.existsSync()) {
     stderr.writeln('Error: Old codepoints file not found: ${oldCodepointsFile.path}');
     exit(1);
   }

   final String newCodepointsString = newCodepointsFile.readAsStringSync();
   final Map<String, String> newTokenPairMap = stringToTokenPairMap(newCodepointsString);

   final String oldCodepointsString = oldCodepointsFile.readAsStringSync();
   final Map<String, String> oldTokenPairMap = stringToTokenPairMap(oldCodepointsString);

   _testIsMapSuperset(newTokenPairMap, oldTokenPairMap);

   final String iconClassFileData = iconClassFile.readAsStringSync();

   stderr.writeln('Generating icons file...');
   final String newIconData = regenerateIconsFile(iconClassFileData, newTokenPairMap);

   if (argResults[_dryRunOption] as bool) {
     stdout.write(newIconData);
   } else {
     stderr.writeln('\nWriting to ${iconClassFile.path}.');
     iconClassFile.writeAsStringSync(newIconData);
     _overwriteOldCodepoints(newCodepointsFile, oldCodepointsFile);
   }
 }

 ArgResults _handleArguments(List<String> args) {
   final ArgParser argParser = ArgParser()
     ..addOption(_newCodepointsPathOption, defaultsTo: _defaultNewCodepointsPath, help: 'Location of the new codepoints directory')
     ..addOption(_oldCodepointsPathOption, defaultsTo: _defaultOldCodepointsPath, help: 'Location of the existing codepoints directory')
     ..addOption(_iconsClassPathOption, defaultsTo: _defaultIconsPath, help: 'Location of the material icons file')
     ..addFlag(_dryRunOption, defaultsTo: false);
   argParser.addFlag('help', abbr: 'h', negatable: false, callback: (bool help) {
     if (help) {
       print(argParser.usage);
       exit(1);
     }
   });
   return argParser.parse(args);
 }

 Map<String, String> stringToTokenPairMap(String codepointData) {
   final Iterable<String> cleanData = LineSplitter.split(codepointData)
       .map((String line) => line.trim())
       .where((String line) => line.isNotEmpty);

   final Map<String, String> pairs = <String, String>{};

   for (final String line in cleanData) {
     final List<String> tokens = line.split(' ');
     if (tokens.length != 2) {
       throw FormatException('Unexpected codepoint data: $line');
     }
     pairs.putIfAbsent(tokens[0], () => tokens[1]);
   }

   return pairs;
 }

 String regenerateIconsFile(String iconData, Map<String, String> tokenPairMap) {
   final List<_Icon> newIcons = tokenPairMap.entries.map((MapEntry<String, String> entry) => _Icon(entry)).toList();
   newIcons.sort((_Icon a, _Icon b) => a._compareTo(b));

   final StringBuffer buf = StringBuffer();
   bool generating = false;

   for (final String line in LineSplitter.split(iconData)) {
     if (!generating) {
       buf.writeln(line);
     }

     // Generate for _PlatformAdaptiveIcons
     if (line.contains(_beginPlatformAdaptiveGeneratedMark)) {
       generating = true;
       final List<String> platformAdaptiveDeclarations = <String>[];
       _platformAdaptiveIdentifiers.forEach((String flutterId, List<String> ids) {
         // Automatically finds and generates styled icon declarations.
         for (final String style in _Icon.styleSuffixes) {
           try {
             final _Icon agnosticIcon = newIcons.firstWhere(
                 (_Icon icon) => icon.id == '${ids[0]}$style',
                 orElse: () => throw ids[0]);
             final _Icon iOSIcon = newIcons.firstWhere(
                 (_Icon icon) => icon.id == '${ids[1]}$style',
                 orElse: () => throw ids[1]);

             platformAdaptiveDeclarations.add(_Icon.platformAdaptiveDeclaration('$flutterId$style', agnosticIcon, iOSIcon));
           } catch (e) {
             if (style == '') {
               // Throw an error for regular (unstyled) icons.
               stderr.writeln("Error while generating platformAdaptiveDeclarations: Icon '$e' not found.");
               exit(1);
             } else {
               // Ignore errors for styled icons since some don't exist.
             }
           }
         }
       });
       buf.write(platformAdaptiveDeclarations.join());
     } else if (line.contains(_endPlatformAdaptiveGeneratedMark)) {
       generating = false;
       buf.writeln(line);
     }

     // Generate for Icons
     if (line.contains(_beginGeneratedMark)) {
       generating = true;
       final String iconDeclarationsString = newIcons.map((_Icon icon) => icon.fullDeclaration).join('');
       buf.write(iconDeclarationsString);
     } else if (line.contains(_endGeneratedMark)) {
       generating = false;
       buf.writeln(line);
     }
   }
   return buf.toString();
 }

 void _testIsMapSuperset(Map<String, String> newCodepoints, Map<String, String> oldCodepoints) {
   final Set<String> newCodepointsSet = newCodepoints.keys.toSet();
   final Set<String> oldCodepointsSet = oldCodepoints.keys.toSet();

   if (!newCodepointsSet.containsAll(oldCodepointsSet)) {
     stderr.writeln('''
 Error: New codepoints file does not contain all the existing codepoints.\n
         Missing: ${oldCodepointsSet.difference(newCodepointsSet)}
         ''',
     );
     exit(1);
   } else {
     final int diff = newCodepointsSet.length - oldCodepointsSet.length;
     stderr.writeln('New codepoints file contains all ${oldCodepointsSet.length} existing codepoints.');
     if (diff > 0) {
       stderr.writeln('It also contains $diff new codepoints: ${newCodepointsSet.difference(oldCodepointsSet)}');
     }
   }
 }

 // Replace the old codepoints file with the new.
 void _overwriteOldCodepoints(File newCodepointsFile, File oldCodepointsFile) {
   stderr.writeln('Copying new codepoints file to ${oldCodepointsFile.path}.\n');
   newCodepointsFile.copySync(oldCodepointsFile.path);
 }

 class _Icon {
   // Parse tokenPair (e.g. {"6_ft_apart_outlined": "e004"}).
   _Icon(MapEntry<String, String> tokenPair) {
     id = tokenPair.key;
     hexCodepoint = tokenPair.value;

     if (id.endsWith('_outlined') && id!='insert_chart_outlined') {
       shortId = _replaceLast(id, '_outlined');
       htmlSuffix = '-outlined';
     } else if (id.endsWith('_rounded')) {
       shortId = _replaceLast(id, '_rounded');
       htmlSuffix = '-round';
     } else if (id.endsWith('_sharp')) {
       shortId = _replaceLast(id, '_sharp');
       htmlSuffix = '-sharp';
     } else {
       shortId = id;
       htmlSuffix = '';
     }

     flutterId = id;
     for (final MapEntry<String, String> rewritePair in identifierRewrites.entries) {
       if (id.startsWith(rewritePair.key)) {
         flutterId = id.replaceFirst(rewritePair.key, identifierRewrites[rewritePair.key]);
       }
     }

     name = id.replaceAll('_', ' ');
   }

   static const List<String> styleSuffixes = <String>['', '_outlined', '_rounded', '_sharp'];

   String id;            // e.g. 5g, 5g_outlined, 5g_rounded, 5g_sharp
   String shortId;       // e.g. 5g
   String flutterId;     // e.g. five_g, five_g_outlined, five_g_rounded, five_g_sharp
   String name;          // e.g. five g, five g outlined, five g rounded, five g sharp
   String hexCodepoint;  // e.g. e547

   // The suffix for the 'material-icons' HTML class.
   String htmlSuffix;

   String get mirroredInRTL => _iconsMirroredWhenRTL.contains(shortId) ? ', matchTextDirection: true' : '';

   String get dartDoc => '<i class="material-icons$htmlSuffix md-36">$shortId</i> &#x2014; material icon named "$name"';

   String get declaration =>
       "static const IconData $flutterId = IconData(0x$hexCodepoint, fontFamily: 'MaterialIcons'$mirroredInRTL);";

   String get fullDeclaration => '''

   /// $dartDoc.
   $declaration
 ''';

   static String platformAdaptiveDeclaration(String fullFlutterId, _Icon agnosticIcon, _Icon iOSIcon) => '''

   /// Platform-adaptive icon for ${agnosticIcon.dartDoc} and ${iOSIcon.dartDoc}.;
   IconData get $fullFlutterId => !_isCupertino() ? Icons.${agnosticIcon.flutterId} : Icons.${iOSIcon.flutterId};
 ''';

   @override
   String toString() => id;

   /// Analogous to [String.compareTo]
   int _compareTo(_Icon b) {
     // Sort a regular icon before its variants.
     if (shortId == b.shortId) {
       return id.length - b.id.length;
     } else {
       return flutterId.compareTo(b.flutterId);
     }
   }

   String _replaceLast(String string, String toReplace) {
     return string.replaceAll(RegExp('$toReplace\$'), '');
   }
 }
	// 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

	// Regenerates the material icons file.
	// See https://github.com/flutter/flutter/wiki/Updating-Material-Design-Fonts-&-Icons

	import 'dart:convert' show LineSplitter;
	import 'dart:io';

	import 'package:args/args.dart';
	import 'package:path/path.dart' as path;

	const String _newCodepointsPathOption = 'new-codepoints';
	const String _oldCodepointsPathOption = 'old-codepoints';
	const String _iconsClassPathOption = 'icons';
	const String _dryRunOption = 'dry-run';

	const String _defaultNewCodepointsPath = 'codepoints';
	const String _defaultOldCodepointsPath = 'bin/cache/artifacts/material_fonts/codepoints';
	const String _defaultIconsPath = 'packages/flutter/lib/src/material/icons.dart';

	const String _beginGeneratedMark = '// BEGIN GENERATED ICONS';
	const String _endGeneratedMark = '// END GENERATED ICONS';
	const String _beginPlatformAdaptiveGeneratedMark = '// BEGIN GENERATED PLATFORM ADAPTIVE ICONS';
	const String _endPlatformAdaptiveGeneratedMark = '// END GENERATED PLATFORM ADAPTIVE ICONS';

	const Map<String, List<String>> _platformAdaptiveIdentifiers = <String, List<String>>{
	// Mapping of Flutter IDs to an Android/agnostic ID and an iOS ID.
	// Flutter IDs can be anything, but should be chosen to be agnostic.
	'arrow_back': <String>['arrow_back', 'arrow_back_ios'],
	'arrow_forward': <String>['arrow_forward', 'arrow_forward_ios'],
	'flip_camera': <String>['flip_camera_android', 'flip_camera_ios'],
	'more': <String>['more_vert', 'more_horiz'],
	'share': <String>['share', 'ios_share'],
	};

	// Rewrite certain Flutter IDs (reserved keywords, numbers) using prefix matching.
	const Map<String, String> identifierRewrites = <String, String>{
	'1x': 'one_x',
	'360': 'threesixty',
	'2d': 'twod',
	'3d': 'threed',
	'3p': 'three_p',
	'6_ft': 'six_ft',
	'3g': 'three_g',
	'4g': 'four_g',
	'5g': 'five_g',
	'30fps': 'thirty_fps',
	'60fps': 'sixty_fps',
	'1k': 'one_k',
	'2k': 'two_k',
	'3k': 'three_k',
	'4k': 'four_k',
	'5k': 'five_k',
	'6k': 'six_k',
	'7k': 'seven_k',
	'8k': 'eight_k',
	'9k': 'nine_k',
	'10k': 'ten_k',
	'1mp': 'one_mp',
	'2mp': 'two_mp',
	'3mp': 'three_mp',
	'4mp': 'four_mp',
	'5mp': 'five_mp',
	'6mp': 'six_mp',
	'7mp': 'seven_mp',
	'8mp': 'eight_mp',
	'9mp': 'nine_mp',
	'10mp': 'ten_mp',
	'11mp': 'eleven_mp',
	'12mp': 'twelve_mp',
	'13mp': 'thirteen_mp',
	'14mp': 'fourteen_mp',
	'15mp': 'fifteen_mp',
	'16mp': 'sixteen_mp',
	'17mp': 'seventeen_mp',
	'18mp': 'eighteen_mp',
	'19mp': 'nineteen_mp',
	'20mp': 'twenty_mp',
	'21mp': 'twenty_one_mp',
	'22mp': 'twenty_two_mp',
	'23mp': 'twenty_three_mp',
	'24mp': 'twenty_four_mp',
	'class': 'class_',
	'try': 'try_sms_star',
	};

	const Set<String> _iconsMirroredWhenRTL = <String>{
	// This list is obtained from:
	// http://google.github.io/material-design-icons/#icons-in-rtl
	'arrow_back',
	'arrow_back_ios',
	'arrow_forward',
	'arrow_forward_ios',
	'arrow_left',
	'arrow_right',
	'assignment',
	'assignment_return',
	'backspace',
	'battery_unknown',
	'call_made',
	'call_merge',
	'call_missed',
	'call_missed_outgoing',
	'call_received',
	'call_split',
	'chevron_left',
	'chevron_right',
	'chrome_reader_mode',
	'device_unknown',
	'dvr',
	'event_note',
	'featured_play_list',
	'featured_video',
	'first_page',
	'flight_land',
	'flight_takeoff',
	'format_indent_decrease',
	'format_indent_increase',
	'format_list_bulleted',
	'forward',
	'functions',
	'help',
	'help_outline',
	'input',
	'keyboard_backspace',
	'keyboard_tab',
	'label',
	'label_important',
	'label_outline',
	'last_page',
	'launch',
	'list',
	'live_help',
	'mobile_screen_share',
	'multiline_chart',
	'navigate_before',
	'navigate_next',
	'next_week',
	'note',
	'open_in_new',
	'playlist_add',
	'queue_music',
	'redo',
	'reply',
	'reply_all',
	'screen_share',
	'send',
	'short_text',
	'show_chart',
	'sort',
	'star_half',
	'subject',
	'trending_flat',
	'toc',
	'trending_down',
	'trending_up',
	'undo',
	'view_list',
	'view_quilt',
	'wrap_text',
	};

	void main(List<String> args) {
	// If we're run from the `tools` dir, set the cwd to the repo root.
	if (path.basename(Directory.current.path) == 'tools')
	Directory.current = Directory.current.parent.parent;

	final ArgResults argResults = _handleArguments(args);

	final File iconClassFile = File(path.normalize(path.absolute(argResults[_iconsClassPathOption] as String)));
	if (!iconClassFile.existsSync()) {
	stderr.writeln('Error: Icons file not found: ${iconClassFile.path}');
	exit(1);
	}
	final File newCodepointsFile = File(argResults[_newCodepointsPathOption] as String);
	if (!newCodepointsFile.existsSync()) {
	stderr.writeln('Error: New codepoints file not found: ${newCodepointsFile.path}');
	exit(1);
	}
	final File oldCodepointsFile = File(argResults[_oldCodepointsPathOption] as String);
	if (!oldCodepointsFile.existsSync()) {
	stderr.writeln('Error: Old codepoints file not found: ${oldCodepointsFile.path}');
	exit(1);
	}

	final String newCodepointsString = newCodepointsFile.readAsStringSync();
	final Map<String, String> newTokenPairMap = stringToTokenPairMap(newCodepointsString);

	final String oldCodepointsString = oldCodepointsFile.readAsStringSync();
	final Map<String, String> oldTokenPairMap = stringToTokenPairMap(oldCodepointsString);

	_testIsMapSuperset(newTokenPairMap, oldTokenPairMap);

	final String iconClassFileData = iconClassFile.readAsStringSync();

	stderr.writeln('Generating icons file...');
	final String newIconData = regenerateIconsFile(iconClassFileData, newTokenPairMap);

	if (argResults[_dryRunOption] as bool) {
	stdout.write(newIconData);
	} else {
	stderr.writeln('\nWriting to ${iconClassFile.path}.');
	iconClassFile.writeAsStringSync(newIconData);
	_overwriteOldCodepoints(newCodepointsFile, oldCodepointsFile);
	}
	}

	ArgResults _handleArguments(List<String> args) {
	final ArgParser argParser = ArgParser()
	..addOption(_newCodepointsPathOption, defaultsTo: _defaultNewCodepointsPath, help: 'Location of the new codepoints directory')
	..addOption(_oldCodepointsPathOption, defaultsTo: _defaultOldCodepointsPath, help: 'Location of the existing codepoints directory')
	..addOption(_iconsClassPathOption, defaultsTo: _defaultIconsPath, help: 'Location of the material icons file')
	..addFlag(_dryRunOption, defaultsTo: false);
	argParser.addFlag('help', abbr: 'h', negatable: false, callback: (bool help) {
	if (help) {
	print(argParser.usage);
	exit(1);
	}
	});
	return argParser.parse(args);
	}

	Map<String, String> stringToTokenPairMap(String codepointData) {
	final Iterable<String> cleanData = LineSplitter.split(codepointData)
	.map((String line) => line.trim())
	.where((String line) => line.isNotEmpty);

	final Map<String, String> pairs = <String, String>{};

	for (final String line in cleanData) {
	final List<String> tokens = line.split(' ');
	if (tokens.length != 2) {
	throw FormatException('Unexpected codepoint data: $line');
	}
	pairs.putIfAbsent(tokens[0], () => tokens[1]);
	}

	return pairs;
	}

	String regenerateIconsFile(String iconData, Map<String, String> tokenPairMap) {
	final List<_Icon> newIcons = tokenPairMap.entries.map((MapEntry<String, String> entry) => _Icon(entry)).toList();
	newIcons.sort((_Icon a, _Icon b) => a._compareTo(b));

	final StringBuffer buf = StringBuffer();
	bool generating = false;

	for (final String line in LineSplitter.split(iconData)) {
	if (!generating) {
	buf.writeln(line);
	}

	// Generate for _PlatformAdaptiveIcons
	if (line.contains(_beginPlatformAdaptiveGeneratedMark)) {
	generating = true;
	final List<String> platformAdaptiveDeclarations = <String>[];
	_platformAdaptiveIdentifiers.forEach((String flutterId, List<String> ids) {
	// Automatically finds and generates styled icon declarations.
	for (final String style in _Icon.styleSuffixes) {
	try {
	final _Icon agnosticIcon = newIcons.firstWhere(
	(_Icon icon) => icon.id == '${ids[0]}$style',
	orElse: () => throw ids[0]);
	final _Icon iOSIcon = newIcons.firstWhere(
	(_Icon icon) => icon.id == '${ids[1]}$style',
	orElse: () => throw ids[1]);

	platformAdaptiveDeclarations.add(_Icon.platformAdaptiveDeclaration('$flutterId$style', agnosticIcon, iOSIcon));
	} catch (e) {
	if (style == '') {
	// Throw an error for regular (unstyled) icons.
	stderr.writeln("Error while generating platformAdaptiveDeclarations: Icon '$e' not found.");
	exit(1);
	} else {
	// Ignore errors for styled icons since some don't exist.
	}
	}
	}
	});
	buf.write(platformAdaptiveDeclarations.join());
	} else if (line.contains(_endPlatformAdaptiveGeneratedMark)) {
	generating = false;
	buf.writeln(line);
	}

	// Generate for Icons
	if (line.contains(_beginGeneratedMark)) {
	generating = true;
	final String iconDeclarationsString = newIcons.map((_Icon icon) => icon.fullDeclaration).join('');
	buf.write(iconDeclarationsString);
	} else if (line.contains(_endGeneratedMark)) {
	generating = false;
	buf.writeln(line);
	}
	}
	return buf.toString();
	}

	void _testIsMapSuperset(Map<String, String> newCodepoints, Map<String, String> oldCodepoints) {
	final Set<String> newCodepointsSet = newCodepoints.keys.toSet();
	final Set<String> oldCodepointsSet = oldCodepoints.keys.toSet();

	if (!newCodepointsSet.containsAll(oldCodepointsSet)) {
	stderr.writeln('''
	Error: New codepoints file does not contain all the existing codepoints.\n
	Missing: ${oldCodepointsSet.difference(newCodepointsSet)}
	''',
	);
	exit(1);
	} else {
	final int diff = newCodepointsSet.length - oldCodepointsSet.length;
	stderr.writeln('New codepoints file contains all ${oldCodepointsSet.length} existing codepoints.');
	if (diff > 0) {
	stderr.writeln('It also contains $diff new codepoints: ${newCodepointsSet.difference(oldCodepointsSet)}');
	}
	}
	}

	// Replace the old codepoints file with the new.
	void _overwriteOldCodepoints(File newCodepointsFile, File oldCodepointsFile) {
	stderr.writeln('Copying new codepoints file to ${oldCodepointsFile.path}.\n');
	newCodepointsFile.copySync(oldCodepointsFile.path);
	}

	class _Icon {
	// Parse tokenPair (e.g. {"6_ft_apart_outlined": "e004"}).
	_Icon(MapEntry<String, String> tokenPair) {
	id = tokenPair.key;
	hexCodepoint = tokenPair.value;

	if (id.endsWith('_outlined') && id!='insert_chart_outlined') {
	shortId = _replaceLast(id, '_outlined');
	htmlSuffix = '-outlined';
	} else if (id.endsWith('_rounded')) {
	shortId = _replaceLast(id, '_rounded');
	htmlSuffix = '-round';
	} else if (id.endsWith('_sharp')) {
	shortId = _replaceLast(id, '_sharp');
	htmlSuffix = '-sharp';
	} else {
	shortId = id;
	htmlSuffix = '';
	}

	flutterId = id;
	for (final MapEntry<String, String> rewritePair in identifierRewrites.entries) {
	if (id.startsWith(rewritePair.key)) {
	flutterId = id.replaceFirst(rewritePair.key, identifierRewrites[rewritePair.key]);
	}
	}

	name = id.replaceAll('_', ' ');
	}

	static const List<String> styleSuffixes = <String>['', '_outlined', '_rounded', '_sharp'];

	String id; // e.g. 5g, 5g_outlined, 5g_rounded, 5g_sharp
	String shortId; // e.g. 5g
	String flutterId; // e.g. five_g, five_g_outlined, five_g_rounded, five_g_sharp
	String name; // e.g. five g, five g outlined, five g rounded, five g sharp
	String hexCodepoint; // e.g. e547

	// The suffix for the 'material-icons' HTML class.
	String htmlSuffix;

	String get mirroredInRTL => _iconsMirroredWhenRTL.contains(shortId) ? ', matchTextDirection: true' : '';

	String get dartDoc => '<i class="material-icons$htmlSuffix md-36">$shortId</i> — material icon named "$name"';

	String get declaration =>
	"static const IconData $flutterId = IconData(0x$hexCodepoint, fontFamily: 'MaterialIcons'$mirroredInRTL);";

	String get fullDeclaration => '''

	/// $dartDoc.
	$declaration
	''';

	static String platformAdaptiveDeclaration(String fullFlutterId, _Icon agnosticIcon, _Icon iOSIcon) => '''

	/// Platform-adaptive icon for ${agnosticIcon.dartDoc} and ${iOSIcon.dartDoc}.;
	IconData get $fullFlutterId => !_isCupertino() ? Icons.${agnosticIcon.flutterId} : Icons.${iOSIcon.flutterId};
	''';

	@override
	String toString() => id;

	/// Analogous to [String.compareTo]
	int _compareTo(_Icon b) {
	// Sort a regular icon before its variants.
	if (shortId == b.shortId) {
	return id.length - b.id.length;
	} else {
	return flutterId.compareTo(b.flutterId);
	}
	}

	String _replaceLast(String string, String toReplace) {
	return string.replaceAll(RegExp('$toReplace\$'), '');
	}
	}