; Funktion zum Setzen des Reaktors
(defun add-cmd-reactors( / )
  (vl-load-com)
  (vlr-command-reactor nil
    '( (:vlr-commandWillStart . cmd-start-callback))
  )
  (vlr-command-reactor nil
    '( (:vlr-commandEnded . cmd-end-callback))
  )
)

; 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 / )
  (cond
    ( (member(car argslist)'("DIMLINEAR""DIMALIGNED"
                             "DIMRADIUS""DIMANGULAR"
                             "DIMBASELINE""DIMDIAMETER"
                             "DIMCONTINUE""QLEADER" "DIMORDINATE"))
      (dim-start-callback reactor argslist)
    )    
  )
)

; allgemeine Cmd-Callback-Funktion
; (nach der Befehlsausführung)
(defun cmd-end-callback(reactor argslist / )
  (cond
    ( (member(car argslist)'("DIMLINEAR""DIMALIGNED"
                             "DIMRADIUS""DIMANGULAR"
                             "DIMBASELINE""DIMDIAMETER"
                             "DIMCONTINUE""QLEADER" "DIMORDINATE"))
      (dim-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 Bemassungen
(defun dim-start-callback(reactor argslist /
                            scale str layer)
  (setq scale(getvar"dimscale"))
  (setq str
    (cond
      ( (>= scale 200.0 )  "1-200")
      ( (>= scale 150.0 )  "1-150")
      ( (>= scale 100.0 )  "1-100")
      ( (>= scale  75.0 )   "1-75")
      ( (>= scale  50.0 )   "1-50")
      ( (>= scale  25.0 )   "1-25")
      ( (>= scale  20.0 )   "1-20")
      ( (>= scale  15.0 )   "1-15")
      ( (>= scale  10.0 )   "1-10")
      ( (>= scale   5.0 )    "1-5")
      ( (>= scale   4.0 )    "1-4")
      ( (>= scale   3.0 )    "1-3")
      ( (>= scale   2.5 )  "1-2_5")
      ( (>= scale   2.0 )    "1-2")
      ( (>= scale   1.0 )    "1-1")
      ( (>= scale   0.5 )    "2-1")
      ( (>= scale   0.33)    "3-1")
      ( (>= scale   0.25)    "4-1")
      ( (>= scale   0.20)    "5-1")
      ( (>= scale   0.10)   "10-1")
      ( 1 "1~XX")
    )
  )
  (setq layer(strcat "GS_DIM_M" str))
  (if(not(layer-object layer))
    (create-layer layer '((Color . 12)))
  )
  (setq *previous-layer*(get-current-layer))
  (set-layer layer)
)

; Nachher-Callback für Bemassungen
(defun dim-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)