A horizontal scrollbar appears when the total width of all columns exceeds the TreeList component's width. The component allows users to fix individual columns at the right or left border so that they are always visible. To enable this feature, set the columnFixing.enabled property to true.
To fix or unfix a column, users should right-click the column's header and select the corresponding operation in the context menu. To prevent users from fixing or unfixing a column, set its allowFixing property to false.
To fix a column programmatically, set its fixed property to true. The default position is the TreeList's left, but you can set the column's fixedPosition property to "right".