printer_info library Null safety

Classes

ABrotherPrinter
Align
AModel
BatteryInfo
BatteryTernary
BLEPrinter
BluetoothPrinter
CheckPrintEnd
CustomPaperInfo
ErrorCode
Halftone
HealthStatus
LabelParam
Margin
Model
Msg
NetPrinter
Orientation
Paper
PaperKind
PaperSize
PjFeedMode
PjPaperKind
PjRollCase
Port
Printer
PrinterInfo
PrinterSeries
PrinterSettingItem
PrinterSpec
PrinterStatus
PrintMode
PrintQuality
TemplateInfo
TimeoutSetting
Unit
VAlign