class IoniaTip { const IoniaTip({ required this.originalAmount, required this.percentage, this.isCustom = false}); final double originalAmount; final double percentage; final bool isCustom; double get additionalAmount => double.parse((originalAmount * percentage / 100).toStringAsFixed(2)); static const tipList = [ IoniaTip(originalAmount: 0, percentage: 0), IoniaTip(originalAmount: 10, percentage: 10), IoniaTip(originalAmount: 20, percentage: 20) ]; }