gtk:list-box-row-header (row)

row -- a gtk:list-box-row widget
header -- a gtk:widget object

The gtk:list-box-row-header function returns the current header of the list box row. This can be used in a gtk:list-box-update-header-func callback function to see if there is a header set already, and if so to update the state of it.

The (setf gtk:list-box-row-header) function sets the current header. This is only allowed to be called from a gtk:list-box-update-header-func callback function. It will replace any existing header in the row, and be shown in front of the row in the list box.