LinearProgressIndicator constructor Null safety

const LinearProgressIndicator(
  1. {Key? key,
  2. double? value,
  3. Color? backgroundColor,
  4. Animation<Color?>? valueColor,
  5. double? minHeight,
  6. String? semanticsLabel,
  7. String? semanticsValue}

Creates a linear progress indicator.

The value argument can either be null for an indeterminate progress indicator, or non-null for a determinate progress indicator.


The semanticsLabel can be used to identify the purpose of this progress bar for screen reading software. The semanticsValue property may be used for determinate progress indicators to indicate how much progress has been made.


const LinearProgressIndicator({
  Key? key,
  double? value,
  Color? backgroundColor,
  Animation<Color?>? valueColor,
  String? semanticsLabel,
  String? semanticsValue,
}) : assert(minHeight == null || minHeight > 0),
      key: key,
      value: value,
      backgroundColor: backgroundColor,
      valueColor: valueColor,
      semanticsLabel: semanticsLabel,
      semanticsValue: semanticsValue,