gtk:window-icon-name (object)

object -- a gtk:window widget
name -- a string with the name of the themed icon

Accessor of the icon-name slot of the gtk:window class. The gtk:window-icon-name function returns the name of the themed icon for the window. The (setf gtk:window-icon-name) function sets the icon for the window from a named themed icon. See the gtk:icon-theme documentation for more details.