Positioned.fill constructor
Positioned.fill({})
Creates a Positioned object with left, top, right, and bottom set to 0.0 unless a value for them is passed.
Implementation
Positioned.fill({
this.left = 0.0,
this.top = 0.0,
this.right = 0.0,
this.bottom = 0.0,
required Widget child,
}) : super(child: child);