Creates a flex render object.
By default, the flex layout is horizontal and children are aligned to the start of the main axis and the center of the cross axis.
Source
RenderFlex({
List<RenderBox> children,
Axis direction: Axis.horizontal,
MainAxisSize mainAxisSize: MainAxisSize.max,
MainAxisAlignment mainAxisAlignment: MainAxisAlignment.start,
CrossAxisAlignment crossAxisAlignment: CrossAxisAlignment.center,
TextBaseline textBaseline
}) : _direction = direction,
_mainAxisAlignment = mainAxisAlignment,
_mainAxisSize = mainAxisSize,
_crossAxisAlignment = crossAxisAlignment,
_textBaseline = textBaseline {
addAll(children);
}