(vlr-remove-all)
(setq *cmd-reactor-added* nil)

; Funktion zum Setzen der Reaktoren
(defun add-cmd-reactors( / )
  (vl-load-com)
  (if(not *cmd-reactor-added*)
    (progn
      (vlr-command-reactor nil
       '( (:vlr-commandWillStart . cmd-start-callback))
      )
      (vlr-command-reactor nil
       '( (:vlr-commandEnded . cmd-end-callback))
      )
      (setq *cmd-reactor-added* 'T)
    )
  )
)

; allgemeine Cmd-Callback-Funktion
; (vor der Befehlsausführung)
(defun cmd-start-callback(reactor argslist / )
  (if(=(type(car argslist))'STR)
    (cond
      ((member(strcase(car argslist))
             '("QLEADER"  "LEADER")
       )   
       (LAYER-start-callback  "LEADER")
      )
      ((member(strcase(car argslist))
             '("XLINE" )
       )               
       (LAYER-start-callback  "XLINE")
      )
      ((member(strcase(car argslist))
             '("LINE" "CIRCLE" "ARC" "PLINE")
       )                  
       (LAYER-start-callback  "LINIENLAYER")
      )
      ((member(strcase(car argslist))
             '("TEXT""MTEXT")
       )                  
       (LAYER-start-callback  "TEXTLAYER")
      )      
    )    
  )
)

; allgemeine Cmd-Callback-Funktion
; (nach der Befehlsausführung)
(defun cmd-end-callback(reactor argslist / )
  (LAYER-end-callback)  
)

; Macht einen Layer aktuell
(defun set-layer(name / )
  (vla-put-ActiveLayer
    (current-document)
    (vla-item(document-layers)name)
  )
)

; gibt das Vla-Object zu einem
; Layernamen zurück
(defun layer-object(name / result)
  (vlax-for layer(document-layers)
    (if
      (=(strcase name)
        (strcase(vla-get-name layer))
      )
      (setq result layer)
    )
  )
  result
)

; Erzeugt einen neuen Layer
(defun create-layer(name props / newlayer)
  (setq newlayer
    (vla-add (document-layers) name)
  )
  (foreach prop props
    (vlax-put-property
      newlayer (car prop)(cdr prop)
    )
  )
  newlayer
)

; Ermittelt den aktuellen Layer
(defun get-current-layer( / )
  (vla-get-activelayer
    (current-document)
  )
)

; Gibt die Layer-Collection zurück
(defun document-layers( / )
  (vla-get-layers
    (current-document)
  )
)

; gibt die aktuelle Zeichnung zurück
(defun current-document( / )
  (vla-get-activedocument
    (vlax-get-acad-object)
  )
)

; Vorher-Callback für Schraffuren
(defun LAYER-start-callback( layer)    
  (if(not(layer-object layer))
    (create-layer layer '((Color . 4)))
  )
  (setq *previous-layer* (get-current-layer))
  (set-layer layer)
)

; Nachher-Callback für Schraffuren
(defun LAYER-end-callback( / )
  (if *previous-layer*
    (progn
      (vla-put-activelayer
        (current-document)
        *previous-layer*
      )
      (setq *previous-layer* nil)
    )
  )
)


; Sicherstellen, dass die ActiveX-
; Funktionen geladen sind
(vl-load-com)
; Reaktoren beim Laden starten
(add-cmd-reactors)
; Ende Datei