backward method

void backward({
  1. bool align = true,
  2. bool? animate,
})

backward will move the scrollbar with a distance of one item in the top direction. If value of align is true, the first visible item will be aligned.

Implementation

void backward({bool align = true, bool? animate}) {
  if (align) {
    final firstIdx = (offset / scrollPerItem - 1).ceil();
    if (firstIdx < 0) {
      return;
    }
    scrollToItem(firstIdx, animate: animate);
  } else {
    _scrollToPos(offset - scrollPerItem, animate: animate);
  }
}