acet-layerp-mark (AutoLISP)

Places beginning and ending marks for Layer Previous recording

Supported Platforms: Windows and Mac OS

Signature

(acet-layerp-mark [status])
status

Type: T or nil

T -- sets a begin mark

nil -- sets an end mark, clearing the begin mark

Return Values

Type: T or nil

T if a begin mark is in effect; otherwise nil.

If status is omitted, acet-layerp-mark returns the current mark status for layer settings.

Remarks

The acet-layerp-mark function allows you to group multiple layer commands into a single transaction so that they can be undone by issuing the AutoCAD LAYERP command a single time. The LAYERPMODE setting must be On in order to set marks.

Examples

The following code changes layer 0 to blue, and then makes several additional layer changes between a set of begin and end marks. If you issue the AutoCAD LAYERP command after running this code, layer 0 reverts to blue. 

(defun TestLayerP ()
  ;; Turn LAYERPMODE on, if it is not already
  (if (not (acet-layerp-mode))
    (acet-layerp-mode T)
  )

  ;; Set layer 0 to the color blue
  (command "._layer" "_color" "blue" "0" "")

  ;; Set a begin mark
  (acet-layerp-mark T)

  ;; Issue a series of layer commands, and then set an end mark
  (command "._layer" "_color" "green" "0" "")
  (command "._layer" "_thaw" "*" "")
  (command "._layer" "_unlock" "*" "")
  (command "._layer" "_ltype" "hidden" "0" "")
  (command "._layer" "_color" "red" "0" "")

  ;; Set an end mark
  (acet-layerp-mark nil)
 (princ)
)

Related Reference