szn-options.js
function scrollToSelection(instance, selectionStartIndex, selectionEndIndex) {
    const lastSelectionIndexes = instance._lastSelectionIndexes
    if (
      selectionStartIndex !== -1 &&
      (selectionStartIndex !== lastSelectionIndexes.start || selectionEndIndex !== lastSelectionIndexes.end)
    ) {
      const changedIndex = selectionStartIndex !== lastSelectionIndexes.start ? selectionStartIndex : selectionEndIndex
      scrollToOption(instance, changedIndex)
    }

    lastSelectionIndexes.start = selectionStartIndex
    lastSelectionIndexes.end = selectionEndIndex
  }
function scrollToSelection(instance, selectionStartIndex, selectionEndIndex) {
    const lastSelectionIndexes = instance._lastSelectionIndexes
    if (
      selectionStartIndex !== -1 &&
      (selectionStartIndex !== lastSelectionIndexes.start || selectionEndIndex !== lastSelectionIndexes.end)
    ) {
      const changedIndex = selectionStartIndex !== lastSelectionIndexes.start ? selectionStartIndex : selectionEndIndex
      scrollToOption(instance, changedIndex)
    }

    lastSelectionIndexes.start = selectionStartIndex
    lastSelectionIndexes.end = selectionEndIndex
  }
function scrollToSelection ( instance , selectionStartIndex , selectionEndIndex ) { const lastSelectionIndexes = instance . _lastSelectionIndexes if ( selectionStartIndex !== - 1 && ( selectionStartIndex !== lastSelectionIndexes . start || selectionEndIndex !== lastSelectionIndexes . end ) ) { const changedIndex = selectionStartIndex !== lastSelectionIndexes . start ? selectionStartIndex : selectionEndIndex scrollToOption ( instance , changedIndex ) } lastSelectionIndexes . start = selectionStartIndex lastSelectionIndexes . end = selectionEndIndex }
Scrolls, only if necessary, the UI of the provided szn-options element to make the last selected option visible.
Which option is the last selected one is determined by comparing the provided index with the indexes passed to the
previous call of this function.

@param {SznElements.SznOptions} instance The szn-options element instance.
@param {number} selectionStartIndex The index of the first selected option. The index must be a non-negative
integer and cannot be greater that the total number of options; or set to <code>-1</code> if there is no
option currently selected.
@param {number} selectionEndIndex The index of the last selected option. The index must be a non-negative integer,
cannot be greater than the total number of options and must not be lower than the
<code>selectionStartIndex</code>; or set to <code>-1</code> if there is no option currently selected.
Scrolls only if necessary the UI of the provided szn - options element to make the last selected option visible . Which option is the last selected one is determined by comparing the provided index with the indexes passed to the previous call of this function .