vertical method
Implementation
@override
Widget vertical(double aniValue, int index, double page, Widget child) {
if (page == index) {
return child;
} else if (page > index) {
return super.vertical(aniValue, index, page, child);
} else {
return ClipRect(
child: Align(
widthFactor: aniValue,
child: super.vertical(aniValue, index, page, child),
),
);
}
}