<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 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="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="The position of items that are at least partially visible in the viewport."/>