void generateDart()

in packages/pigeon/lib/dart_generator.dart [395:564]

• 160 lines of code
• 23 McCabe index (conditional complexity)

void generateDart(DartOptions opt, Root root, StringSink sink) {
  final String nullTag = opt.isNullSafe ? '?' : '';
  final String unwrapOperator = opt.isNullSafe ? '!' : '';
  final List<String> customClassNames =
      root.classes.map((Class x) => x.name).toList();
  final List<String> customEnumNames =
      root.enums.map((Enum x) => x.name).toList();
  final Indent indent = Indent(sink);

  void writeHeader() {
    if (opt.copyrightHeader != null) {
      addLines(indent, opt.copyrightHeader!, linePrefix: '// ');
    }
    indent.writeln('// $generatedCodeWarning');
    indent.writeln('// $seeAlsoWarning');
    indent.writeln(
      '// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name',
    );
    indent.writeln('// @dart = ${opt.isNullSafe ? '2.12' : '2.8'}');
  }

  void writeEnums() {
    for (final Enum anEnum in root.enums) {
      indent.writeln('');
      indent.write('enum ${anEnum.name} ');
      indent.scoped('{', '}', () {
        for (final String member in anEnum.members) {
          indent.writeln('$member,');
        }
      });
    }
  }

  void writeImports() {
    indent.writeln('import \'dart:async\';');
    indent.writeln(
      'import \'dart:typed_data\' show Uint8List, Int32List, Int64List, Float64List;',
    );
    indent.addln('');
    indent.writeln(
        'import \'package:flutter/foundation.dart\' show WriteBuffer, ReadBuffer;');
    indent.writeln('import \'package:flutter/services.dart\';');
  }

  void writeDataClass(Class klass) {
    void writeConstructor() {
      indent.write(klass.name);
      indent.scoped('({', '});', () {
        for (final NamedType field in klass.fields) {
          final String required = field.type.isNullable ? '' : 'required ';
          indent.writeln('${required}this.${field.name},');
        }
      });
    }

    void writeEncode() {
      indent.write('Object encode() ');
      indent.scoped('{', '}', () {
        indent.writeln(
          'final Map<Object$nullTag, Object$nullTag> pigeonMap = <Object$nullTag, Object$nullTag>{};',
        );
        for (final NamedType field in klass.fields) {
          indent.write('pigeonMap[\'${field.name}\'] = ');
          if (customClassNames.contains(field.type.baseName)) {
            indent.addln(
              '${field.name} == null ? null : ${field.name}$unwrapOperator.encode();',
            );
          } else if (customEnumNames.contains(field.type.baseName)) {
            indent.addln(
              '${field.name} == null ? null : ${field.name}$unwrapOperator.index;',
            );
          } else {
            indent.addln('${field.name};');
          }
        }
        indent.writeln('return pigeonMap;');
      });
    }

    void writeDecode() {
      void writeValueDecode(NamedType field) {
        if (customClassNames.contains(field.type.baseName)) {
          indent.format('''
pigeonMap['${field.name}'] != null
\t\t? ${field.type.baseName}.decode(pigeonMap['${field.name}']$unwrapOperator)
\t\t: null''', leadingSpace: false, trailingNewline: false);
        } else if (customEnumNames.contains(field.type.baseName)) {
          indent.format('''
pigeonMap['${field.name}'] != null
\t\t? ${field.type.baseName}.values[pigeonMap['${field.name}']$unwrapOperator as int]
\t\t: null''', leadingSpace: false, trailingNewline: false);
        } else if (field.type.typeArguments.isNotEmpty) {
          final String genericType =
              _makeGenericTypeArguments(field.type, nullTag);
          final String castCall = _makeGenericCastCall(field.type, nullTag);
          final String castCallPrefix =
              field.type.isNullable ? nullTag : unwrapOperator;
          indent.add(
            '(pigeonMap[\'${field.name}\'] as $genericType$nullTag)$castCallPrefix$castCall',
          );
        } else {
          final String genericdType = _addGenericTypesNullable(field, nullTag);
          if (field.type.isNullable) {
            indent.add(
              'pigeonMap[\'${field.name}\'] as $genericdType',
            );
          } else {
            indent.add(
              'pigeonMap[\'${field.name}\']$unwrapOperator as $genericdType',
            );
          }
        }
      }

      indent.write(
        'static ${klass.name} decode(Object message) ',
      );
      indent.scoped('{', '}', () {
        indent.writeln(
          'final Map<Object$nullTag, Object$nullTag> pigeonMap = message as Map<Object$nullTag, Object$nullTag>;',
        );
        indent.write('return ${klass.name}');
        indent.scoped('(', ');', () {
          for (int index = 0; index < klass.fields.length; index += 1) {
            final NamedType field = klass.fields[index];
            indent.write('${field.name}: ');
            writeValueDecode(field);
            indent.addln(',');
          }
        });
      });
    }

    indent.write('class ${klass.name} ');
    indent.scoped('{', '}', () {
      writeConstructor();
      indent.addln('');
      for (final NamedType field in klass.fields) {
        final String datatype = _addGenericTypesNullable(field, nullTag);
        indent.writeln('$datatype ${field.name};');
      }
      if (klass.fields.isNotEmpty) {
        indent.writeln('');
      }
      writeEncode();
      indent.writeln('');
      writeDecode();
    });
  }

  void writeApi(Api api) {
    if (api.location == ApiLocation.host) {
      _writeHostApi(opt, indent, api, root);
    } else if (api.location == ApiLocation.flutter) {
      _writeFlutterApi(opt, indent, api, root);
    }
  }

  writeHeader();
  writeImports();
  writeEnums();
  for (final Class klass in root.classes) {
    indent.writeln('');
    writeDataClass(klass);
  }
  for (final Api api in root.apis) {
    indent.writeln('');
    writeApi(api);
  }
}