indicatorPadding property
The horizontal padding for the line that appears below the selected tab.
For isScrollable tab bars, specifying kTabLabelPadding will align the indicator with the tab's text for Tab widgets and all but the shortest Tab.text values.
The EdgeInsets.top and EdgeInsets.bottom values of the indicatorPadding are ignored.
The default value of indicatorPadding is EdgeInsets.zero.
If indicator is specified, this property is ignored.
Implementation
final EdgeInsetsGeometry indicatorPadding;