font_feature.dart

// Copyright 2013 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.

import 'dart:async';

import 'package:flutter/material.dart';

import 'diagram_step.dart';

// When adding a new font here, add it to:
//    /packages/diagram_generator/pubspec.yaml
// ...and put the binary and license file in:
//    /packages/diagram_generator/fonts

const double _margin = 5.0;
const double _gap = _margin * 5;

abstract class FontFeatureDiagram<T> extends StatelessWidget
    with DiagramMetadata {
  const FontFeatureDiagram({super.key});

  Iterable<T> get entries;
  Widget buildEntry(BuildContext context, T entry);
  String describe(T entry);

  TextStyle get textStyle =>
      const TextStyle(color: Colors.black, fontSize: 32.0);

  Widget buildRow(BuildContext context, T entry) {
    return Stack(
      children: <Widget>[
        Positioned.fill(
          top: _margin,
          left: _margin,
          child: buildEntry(context, entry),
        ),
        Positioned(
          left: 0.0,
          top: 0.0,
          child: buildDescription(context, entry),
        ),
      ],
    );
  }

  Widget buildDescription(BuildContext context, T entry) {
    return Text(describe(entry), style: const TextStyle(fontSize: 10.0));
  }

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      key: UniqueKey(),
      width: 600.0,
      height:
          (textStyle.fontSize! * 1.2 + _margin + _gap) * entries.length +
          _margin * 3.0 -
          _gap,
      child: Container(
        padding: const EdgeInsets.all(_margin),
        color: Colors.white,
        child: OverflowBox(
          alignment: Alignment.topLeft,
          minWidth: 600.0,
          maxWidth: 600.0,
          minHeight: 0.0,
          maxHeight: double.infinity,
          child: Column(
            children:
                entries
                    .map(
                      (T entry) => SizedBox(
                        height: _margin + textStyle.fontSize! * 1.2 + _gap,
                        child: buildRow(context, entry),
                      ),
                    )
                    .toList(),
          ),
        ),
      ),
    );
  }
}

class FontFeatureValueDiagram extends FontFeatureDiagram<int> {
  const FontFeatureValueDiagram(
    this.feature,
    this.values,
    this.font, {
    this.sampleText = 'The infamous Tuna Torture.', // from s03e09, of course
    this.style,
    this.additionalFontFeatures,
    super.key,
  });

  @override
  String get name => 'font_feature_$feature';

  final String feature;
  final List<int> values;
  final String font;
  final String sampleText;
  final TextStyle? style;
  final List<FontFeature>? additionalFontFeatures;

  @override
  Iterable<int> get entries => values;

  @override
  Widget buildEntry(BuildContext context, int entry) => Text(
    sampleText,
    style: textStyle
        .copyWith(
          fontFamily: font,
          package: 'diagrams',
          fontFeatures: <FontFeature>[
            FontFeature(feature, entry),
            ...?additionalFontFeatures,
          ],
        )
        .merge(style),
    textAlign: TextAlign.left,
  );

  @override
  String describe(int entry) => '$feature $entry';
}

class HistoricalFontFeatureDiagram
    extends FontFeatureDiagram<List<FontFeature>> {
  const HistoricalFontFeatureDiagram(
    this.font, {
    required this.sampleText,
    super.key,
  });

  @override
  String get name => 'font_feature_historical';

  final String font;
  final String sampleText;

  @override
  Iterable<List<FontFeature>> get entries => const <List<FontFeature>>[
    <FontFeature>[FontFeature('hist', 0), FontFeature('hlig', 0)],
    <FontFeature>[FontFeature('hist'), FontFeature('hlig', 0)],
    <FontFeature>[FontFeature('hist', 0), FontFeature('hlig')],
    <FontFeature>[FontFeature('hist'), FontFeature('hlig')],
  ];

  @override
  Widget buildEntry(BuildContext context, List<FontFeature> entry) => Text(
    sampleText,
    style: textStyle.copyWith(
      fontFamily: font,
      package: 'diagrams',
      fontFeatures: entry,
    ),
    textAlign: TextAlign.left,
  );

  @override
  String describe(List<FontFeature> entry) => entry
      .map<String>(
        (FontFeature feature) => '${feature.feature} ${feature.value}',
      )
      .join(', ');
}

class LocalizedFontFeatureDiagram extends FontFeatureDiagram<Locale> {
  const LocalizedFontFeatureDiagram({super.key});

  @override
  String get name => 'font_feature_locl';

  @override
  Iterable<Locale> get entries => const <Locale>[
    Locale('ja'),
    Locale('ko'),
    Locale('zh', 'CN'),
    Locale('zh', 'TW'),
  ]; // alphabetical order

  @override
  Widget buildEntry(BuildContext context, Locale entry) => Text(
    '次 化 刃 直 入 令',
    style: textStyle.copyWith(
      fontFamily: 'Noto Sans',
      package: 'diagrams',
      fontFeatures: <FontFeature>[
        const FontFeature('locl'), // redundant, this is the default anyway
      ],
    ),
    textAlign: TextAlign.left,
    locale: entry,
  );

  @override
  String describe(Locale entry) => 'Locale: ${entry.toLanguageTag()}';
}

abstract class SideBySideFontFeatureDiagram<T> extends FontFeatureDiagram<T> {
  const SideBySideFontFeatureDiagram({super.key});

  String get font;

  @override
  Widget buildRow(BuildContext context, T entry) {
    return Row(
      children: <Widget>[
        buildSubEntry(context, entry, enable: false),
        buildSubEntry(context, entry),
      ],
    );
  }

  Widget buildSubEntry(BuildContext context, T entry, {bool enable = true}) =>
      Expanded(
        child: Stack(
          children: <Widget>[
            Positioned.fill(
              top: _margin,
              left: _margin,
              child: buildEntry(context, entry, enable: enable),
            ),
            Positioned(
              left: 0.0,
              top: 0.0,
              child: buildDescription(context, entry, enable: enable),
            ),
          ],
        ),
      );

  @override
  Widget buildDescription(BuildContext context, T entry, {bool enable = true}) {
    return Text(
      describe(entry, enable: enable),
      style: const TextStyle(fontSize: 10.0),
    );
  }

  @override
  Widget buildEntry(BuildContext context, T entry, {bool enable = true}) {
    return Text(
      describe(entry, enable: enable),
      style: const TextStyle(fontSize: 10.0),
    );
  }

  @override
  String describe(T entry, {bool enable = true});
}

class CharacterVariantsFontFeatureDiagram
    extends SideBySideFontFeatureDiagram<String> {
  const CharacterVariantsFontFeatureDiagram({super.key});

  @override
  String get name => 'font_feature_cvXX';

  @override
  String get font => 'Source Code Pro';

  @override
  Iterable<String> get entries => const <String>['cv01', 'cv02', 'cv04'];

  static const Map<String, String> demos = <String, String>{
    'cv01': 'aáâ β',
    'cv02': 'gǵĝ θб',
    'cv04': 'Iiíî Ll',
    'cv06': 'Ŋ',
    'cv07': 'β',
    'cv08': 'θ',
    'cv09': 'φ',
    'cv10': 'б',
    'cv12': '0',
    'cv17': '1',
    'cv16': r'$',
    'cv15': '*',
  };

  @override
  Widget buildEntry(BuildContext context, String entry, {bool enable = true}) =>
      Text(
        demos[entry]!,
        style: textStyle.copyWith(
          fontFamily: font,
          package: 'diagrams',
          fontFeatures: enable ? <FontFeature>[FontFeature(entry)] : null,
        ),
        textAlign: TextAlign.left,
      );

  @override
  String describe(String entry, {bool enable = true}) {
    return 'with $entry ${enable ? "enabled" : "disabled"}';
  }
}

class StylisticSetsFontFeatureDiagram1
    extends SideBySideFontFeatureDiagram<String> {
  const StylisticSetsFontFeatureDiagram1({super.key});

  @override
  String get name => 'font_feature_ssXX_1';

  @override
  String get font => 'Source Code Pro';

  @override
  Iterable<String> get entries => const <String>['ss02', 'ss03', 'ss04'];

  static const Map<String, String> demos = <String, String>{
    'ss02': 'aáâ β',
    'ss03': 'gǵĝ θб',
    'ss04': 'Iiíî Ll',
  };

  @override
  Widget buildEntry(BuildContext context, String entry, {bool enable = true}) =>
      Text(
        demos[entry]!,
        style: textStyle.copyWith(
          fontFamily: font,
          package: 'diagrams',
          fontFeatures: enable ? <FontFeature>[FontFeature(entry)] : null,
        ),
        textAlign: TextAlign.left,
      );

  @override
  String describe(String entry, {bool enable = true}) {
    return 'with $entry ${enable ? "enabled" : "disabled"}';
  }
}

class StylisticSetsFontFeatureDiagram2 extends FontFeatureDiagram<int> {
  const StylisticSetsFontFeatureDiagram2({super.key});

  @override
  String get name => 'font_feature_ssXX_2';

  @override
  Iterable<int> get entries => const <int>[0x00, 0x01, 0x02, 0x03];

  String get font => 'Piazzolla';

  @override
  Widget buildEntry(BuildContext context, int entry) => Text(
    '-> MCMXCVII <-', // the year SG-1 started
    style: textStyle.copyWith(
      fontFamily: font,
      package: 'diagrams',
      fontFeatures: <FontFeature>[
        if (0x01 & entry > 0) const FontFeature('ss01'),
        if (0x02 & entry > 0) const FontFeature('ss02', 2),
      ],
    ),
    textAlign: TextAlign.left,
  );

  @override
  String describe(int entry) {
    switch (entry) {
      case 0x00:
        return 'no stylistic sets enabled';
      case 0x01:
        return 'only ss01 enabled';
      case 0x02:
        return 'only ss02 enabled';
      case 0x03:
        return 'ss01 and ss02 enabled';
    }
    throw UnsupportedError('$entry not recognized');
  }
}

class FontFeatureDiagramStep extends DiagramStep {
  @override
  final String category = 'dart-ui';

  @override
  Future<List<FontFeatureDiagram<Object>>>
  get diagrams async => <FontFeatureDiagram<Object>>[
    const FontFeatureValueDiagram('aalt', <int>[0, 1, 2], 'Raleway'),
    const FontFeatureValueDiagram(
      'afrc',
      <int>[0, 1],
      'Ubuntu Mono',
      sampleText: 'Fractions: 1/2 2/3 3/4 4/5',
    ),
    const FontFeatureValueDiagram(
      'calt',
      <int>[0, 1],
      'Barriecito',
      sampleText: "Ooohh, we weren't going to tell him that.",
    ),
    const FontFeatureValueDiagram(
      'case',
      <int>[0, 1],
      'Piazzolla',
      sampleText: '(A) [A] {A} «A» A/B A•B',
    ),
    const CharacterVariantsFontFeatureDiagram(), // cvXX, uses 'Source Code Pro'
    const FontFeatureValueDiagram(
      'dnom',
      <int>[0, 1],
      'Piazzolla',
      sampleText: 'Fractions: 1/2 2/3 3/4 4/5',
    ),
    const FontFeatureValueDiagram(
      'frac',
      <int>[0, 1],
      'Ubuntu Mono',
      sampleText: 'Fractions: 1/2 2/3 3/4 4/5',
    ),
    const HistoricalFontFeatureDiagram(
      'Cardo',
      sampleText: 'VIBRANT fish assisted his business.',
    ),
    const FontFeatureValueDiagram(
      'lnum',
      <int>[0, 1],
      'Sorts Mill Goudy',
      sampleText: 'CALL 311-555-2368 NOW!',
    ),
    const LocalizedFontFeatureDiagram(), // locl, uses 'Noto Sans'
    const FontFeatureValueDiagram(
      'nalt',
      <int>[0, 1, 2, 3, 4, 5, 7],
      'Gothic A1',
      sampleText: 'abc 123',
    ),
    const FontFeatureValueDiagram(
      'numr',
      <int>[0, 1],
      'Piazzolla',
      sampleText: 'Fractions: 1/2 2/3 3/4 4/5',
    ),
    const FontFeatureValueDiagram(
      'onum',
      <int>[0, 1],
      'Piazzolla',
      sampleText: 'Call 311-555-2368 now!',
    ),
    const FontFeatureValueDiagram(
      'ordn',
      <int>[0, 1],
      'Piazzolla',
      sampleText: '1st, 2nd, 3rd, 4th...',
    ),
    const FontFeatureValueDiagram(
      'pnum',
      <int>[0, 1],
      'Kufam',
      sampleText: 'Call 311-555-2368 now!',
    ),
    const FontFeatureValueDiagram(
      'salt',
      <int>[0, 1],
      'Source Code Pro',
      sampleText: r'Agile Game - $100 initial bet',
    ),
    const FontFeatureValueDiagram(
      'sinf',
      <int>[0, 1],
      'Piazzolla',
      sampleText: 'C8H10N4O2',
    ),
    const StylisticSetsFontFeatureDiagram1(), // ssXX, uses 'Source Code Pro'
    const StylisticSetsFontFeatureDiagram2(), // ssXX, uses 'Piazzolla'
    const FontFeatureValueDiagram(
      'subs',
      <int>[0, 1],
      'Piazzolla',
      sampleText: 'Line from x1,y1 to x2,y2',
    ),
    const FontFeatureValueDiagram(
      'sups',
      <int>[0, 1],
      'Sorts Mill Goudy',
      sampleText: 'The isotope 238U decays to 206Pb',
    ),
    const FontFeatureValueDiagram(
      'swsh',
      <int>[0, 1],
      'BioRhyme Expanded',
      sampleText: 'Queer & Romantic',
    ),
    const FontFeatureValueDiagram(
      'tnum',
      <int>[0, 1],
      'Piazzolla',
      sampleText: 'Call 311-555-2368 now!',
    ),
    const FontFeatureValueDiagram(
      'zero',
      <int>[0, 1],
      'Source Code Pro',
      sampleText: 'One million is: 1,000,000.00',
    ),
  ];
}