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 'dart:io';
import 'dart:ui' show FontFeature;

import 'package:diagram_capture/diagram_capture.dart';
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
    implements DiagramMetadata {
  const FontFeatureDiagram({Key? key}) : super(key: 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,
    Key? key,
  }) : super(key: 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,
          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, Key? key})
      : super(key: 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', 1), FontFeature('hlig', 0)],
        <FontFeature>[FontFeature('hist', 0), FontFeature('hlig', 1)],
        <FontFeature>[FontFeature('hist', 1), FontFeature('hlig', 1)],
      ];

  @override
  Widget buildEntry(BuildContext context, List<FontFeature> entry) => Text(
        sampleText,
        style: textStyle.copyWith(
          fontFamily: font,
          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({Key? key}) : super(key: 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',
          fontFeatures: <FontFeature>[
            const FontFeature(
                'locl', 1), // 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({Key? key}) : super(key: key);

  String get font;

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

  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({Key? key}) : super(key: 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,
          fontFeatures: enable
              ? <FontFeature>[
                  FontFeature(entry, 1),
                ]
              : 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({Key? key}) : super(key: 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,
          fontFeatures: enable
              ? <FontFeature>[
                  FontFeature(entry, 1),
                ]
              : 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({Key? key}) : super(key: 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,
          fontFeatures: <FontFeature>[
            if (0x01 & entry > 0) const FontFeature('ss01', 1),
            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<FontFeatureDiagram<Object>> {
  FontFeatureDiagramStep(DiagramController controller) : super(controller);

  @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'),
      ];

  @override
  Future<File> generateDiagram(FontFeatureDiagram<Object> diagram) async {
    controller.builder = (BuildContext context) => diagram;
    return controller.drawDiagramToFile(File('${diagram.name}.png'));
  }
}