LinearGradientSpec.fromJson constructor

Implementation

factory LinearGradientSpec.fromJson(Map<String, dynamic> json) {
  _requireExactKeys(json, const <String>{
    'start',
    'end',
    'stops',
  }, 'LinearGradientSpec');

  final stops = json['stops'];
  if (stops is! List) {
    throw const FormatException('LinearGradientSpec.stops must be a list.');
  }

  return LinearGradientSpec(
    start: _gradientPoint(json['start'], 'LinearGradientSpec.start'),
    end: _gradientPoint(json['end'], 'LinearGradientSpec.end'),
    stops: stops.map((raw) {
      if (raw is! Map || raw.keys.any((key) => key is! String)) {
        throw const FormatException(
          'LinearGradientSpec.stops must contain objects with string keys.',
        );
      }
      return GradientStop.fromJson(Map<String, dynamic>.from(raw));
    }),
  );
}