ScrollableLazyList({Key key, double initialScrollOffset, Axis scrollDirection: Axis.vertical, ViewportAnchor scrollAnchor: ViewportAnchor.start, ScrollListener onScrollStart, ScrollListener onScroll, ScrollListener onScrollEnd, SnapOffsetCallback snapOffsetCallback, Key scrollableKey, @required double itemExtent, int itemCount, @required ItemListBuilder itemBuilder, EdgeInsets padding })

Creates an infinite scrollable list of children that have equal size.

The scrollDirection, scrollAnchor, itemExtent, and itemBuilder arguments must not be null. The itemCount argument must not be null unless the scrollAnchor argument is ViewportAnchor.start.

Source 

ScrollableLazyList({
  Key key,
  this.initialScrollOffset,
  this.scrollDirection: Axis.vertical,
  this.scrollAnchor: ViewportAnchor.start,
  this.onScrollStart,
  this.onScroll,
  this.onScrollEnd,
  this.snapOffsetCallback,
  this.scrollableKey,
  @required this.itemExtent,
  this.itemCount,
  @required this.itemBuilder,
  this.padding
}) : super(key: key) {
  assert(itemExtent != null);
  assert(itemBuilder != null);
  assert(itemCount != null || scrollAnchor == ViewportAnchor.start);
}