import 'dart:math' show pow; import 'package:flutter/widgets.dart'; extension ImageExtension on num { int? cacheSize(BuildContext context) { if (this == 0) { return null; } return (this * MediaQuery.devicePixelRatioOf(context)).round(); } } extension IntExt on int? { int? operator +(int other) => this == null ? null : this! + other; int? operator -(int other) => this == null ? null : this! - other; } extension DoubleExt on double { double toPrecision(int fractionDigits) { final mod = pow(10, fractionDigits).toDouble(); return (this * mod).roundToDouble() / mod; } }