importFromJson method
Importa puntos desde JSON (lista de mapas)
Implementation
void importFromJson(List<dynamic> jsonList) {
_points.clear();
for (var json in jsonList) {
if (json == null) {
_points.add(null);
} else {
_points.add(SignaturePoint.fromJson(Map<String, dynamic>.from(json)));
}
}
notifyListeners();
}