ModelGraphAxisSpec class

Describes metadata for a simple 2D chart axis.

Holds a human-readable title and an inclusive numeric range defined by min and max. The model is immutable and supports JSON (de)serialization and value-based equality.

Contracts

• fromJson is lenient and never throws:
  • title is stringified via Utils.getStringFromDynamic.
  • min and max are parsed via Utils.getDouble, which may return double.nan for invalid inputs.
• No invariant checks are enforced here:
  • min may be greater than max.
  • Non-finite values (NaN, ±Infinity) may be accepted. Validate these in higher layers if required.

Example

void main() {
  // Construction
  const GraphAxisSpec x = GraphAxisSpec(title: 'Month', min: 1.0, max: 12.0);
  const GraphAxisSpec y = GraphAxisSpec(title: 'Price', min: 55000.0, max: 65000.0);
  print(x.toJson()); // { "title": "Month", "min": 1.0, "max": 12.0 }

  // JSON round-trip
  final Map<String, dynamic> j = <String, dynamic>{
    'title': 'Units',
    'min': 0,
    'max': 100,
  };
  final GraphAxisSpec a = GraphAxisSpec.fromJson(j);
  print('${a.title} [${a.min}, ${a.max}]'); // Units [0.0, 100.0]
}