;©2007 Daniel Altamura

;OFF - Turns off (hides) the display of selected objects
;ON - Turns on (unhides) the display of selected or all objects
;TOGGLE - Turns off (hides) the display of objects that are on, and turns on (unhides) the display of objects that are off
;ISOLATE - Turns off (hides) the display of all objects, except for selected objects

(defun OFF (OL / OBJNUM SSOBJ OBJECT OBJLIST)
  (setq OBJNUM 0)
  (repeat (sslength OL)
    (setq SSOBJ (entget (ssname OL OBJNUM))
          OBJNUM (+ OBJNUM 1)
          OBJECT (append SSOBJ (list (cons 60 1)))
    )
    (if (= (cdr (assoc 0 SSOBJ)) "VIEWPORT")
      (princ "\nViewports cannot be turned off.")
      (entmod OBJECT)
    )
  )
)

(defun ON (OL / OBJNUM SSOBJ OBJECT)
  (setq OBJNUM 0)
  (repeat (sslength OL)
    (setq SSOBJ (entget (ssname OL OBJNUM))
          OBJNUM (+ OBJNUM 1)
          OBJECT (subst (cons 60 0) (assoc 60 SSOBJ) SSOBJ)
    )
    (entmod OBJECT)
  )
)

(defun C:OFF (/ OBJLIST)
  (if (setq OBJLIST (ssget))
    (OFF OBJLIST)
    (princ "\nNo objects selected to turn off.")
  )
)

(defun C:ON (/ OBJLIST OBJON OBJLISTLEN)
  (if (setq OBJLIST (ssget "x" (list (cons 60 1))))
    (progn
      (ON OBJLIST)
      (progn
 (princ "\nSelect objects to turn on, or <Enter> for all on.")
        (setq OBJON (ssget))
        (OFF OBJLIST)
        (if OBJON
   (ON OBJON)
   (ON OBJLIST)
 )
      )
    )
    (princ "\nNo objects found to turn on.")
  ) 
)

(defun C:TOGGLE (/ OBJLISTOFF OBJLISTON)
  (setq OBJLISTOFF (ssget "x" (list (cons 60 1)))
        OBJLISTON (ssget "x" (list (cons 60 0)))
  )
  (if OBJLISTOFF
    (ON OBJLISTOFF)
    (princ "\nNo objects found to toggle on.")
  )
  (if OBJLISTON
    (OFF OBJLISTON)
    (princ "\nNo objects found to toggle off.")
  )  
)

(defun C:ISOLATE (/ OBJLISTISO)
  (if (setq OBJLISTISO (ssget))
    (progn
      (OFF (ssget "x"))
      (ON OBJLISTISO)
    )
    (princ "\nNo objects selected to isolate.")
  )
)