ListItemScope
The receiver of the composable cell body a ListCellRenderer stamps a row through: the three values the widget hands a ListCellRenderer for the row being stamped, exposed as read-only composition state so the cell can lay itself out by index, selection, and focus. A ListBox or ComboBox item cell is one such body, as is one a caller writes over their own JList or JComboBox with rememberListItemRenderer.
Mirrors the arguments of javax.swing.ListCellRenderer.getListCellRendererComponent: index is the row, isSelected whether that row is selected, cellHasFocus whether it currently draws the focus decoration.