<itemvalue="Distance in proportion of the viewport's main axis length from the leading edge of the viewport to the trailing edge of the item. May be greater than one if the item is partially visible."/>
<itemvalue="Distance in proportion of the viewport's main axis length from the leading edge of the viewport to the leading edge of the item. May be negative if the item is partially visible."/>
<itemvalue="The position of items that are at least partially visible in the viewport."/>
<itemvalue="Immediately, without animation, reconfigure the list so that the item at [index]'s leading edge is at the given [alignment]. The [alignment] specifies the desired position for the leading edge of the item. The [alignment] is expected to be a value in the range \[0.0, 1.0\] and represents a proportion along the main axis of the viewport. For a vertically scrolling view that is not reversed: 0 aligns the top edge of the item with the top edge of the view. 1 aligns the top edge of the item with the bottom of the view. 0.5 aligns the top edge of the item with the center of the view. For a horizontally scrolling view that is not reversed: 0 aligns the left edge of the item with the left edge of the view 1 aligns the left edge of the item with the right edge of the view. 0.5 aligns the left edge of the item with the center of the view."/>
<itemvalue="Animate the list over [duration] using the given [curve] such that the item at [index] ends up with its leading edge at the given [alignment]. See [jumpTo] for an explanation of alignment."/>
<itemvalue="The [opacityAnimationWeights] can be used to apply custom weights to these three stages of this animation. The default weights, `[40, 20, 40]`, are good with default [Curves.linear]. Different weights might be better for other cases. For example, if you use [Curves.easeOut], consider setting [opacityAnimationWeights] to `[20, 20, 60]`."/>