Scrolling Lists

@ How do I set the font of individual Scrolling List items?
    PANEL_LIST_FONT takes an int row_number and an Xv_opaque font_handle.
    PANEL_LIST_FONTS take a NULL terminated list of Xv_opaque font_handles.
    There is no easy way to make an entire list fixed width font.
    You have to make sure that you always specify PANEL_LIST_FONT when you
    insert a new row into that list, or write a convenience function
    insert_row(list, row, string) that hides the nasty bits.
    The most efficient way to do this involves creating an Xv_attr array
    to do lots of insertions at once, complete with PANEL_LIST_FONTs.

    If you give both PANEL_LIST_STRING and PANEL_LIST_FONT in the same
    xv_set() call, PANEL_LIST_STRING must be given first, or the default
    font will be used.

@ How do I set the selected item of an exclusive list with required choice?
    If you have a PANEL_LIST with a required choice, and the list is
    exclusive, you must de-select the old item and select the new one in
    a single xv_set() call, for example:

	xv_create(owner, PANEL_LIST,
	    ....
	    PANEL_CHOOSE_ONE, TRUE,    /* only one entry can be selected */
	    PANEL_CHOOSE_NONE, FALSE,  /* one entry must be selected	  */
	    NULL
	);

	xv_set(List,
	    PANEL_CHOOSE_NONE, TRUE,
	    PANEL_LIST_SELECT, xv_get(List, PANEL_LIST_FIRST_SELECTED), FALSE,
	    PANEL_LIST_SELECT, row, TRUE,
	    PANEL_CHOOSE_NONE, FALSE,
	    NULL
	);

    Note: you may find it useful to start with PANEL_CHOOSE_NONE true so that
    the list comes up with no selection; and then on the first selection set
    PANEL_CHOOSE_NONE to FALSE so that a selection is required.