HyperPics: Beyond the UI

Creating Objects without the COMMAND Function in AutoCAD

The ENTMAKE and ENTMAKEX functions are often forgotten elements of the AutoLISP programming environment because the use of the COMMAND function to call a command line LINE and CIRCLE are so tempting and easy.  Why reinvent the wheel if you do not need to, or in this case the functionality.

Both ENTMAKE and ENTMAKEX allow you to create new graphical and non-graphical objects without using the COMMAND function. This allows you to create a line and assign it a specific layer without first changing the layer with the Layer command and then calling the Line command to create the line and then restore the previous layer.  Not bad, but if you think about it further you need to turn off command echoing (CMDECHO) to keep the command line clean, drawing off screen or outside the drawing limits at times, and worry about the current running object snaps.

So after writing a few articles on the SETPROPERTYVALUE and GETPROPERTYVALUE functions the last few days I decided to go one step further and show how to create some new objects without the COMMAND function and then update their properties.  The following sample shows how to create a line, circle, and layer prior to updating their properties.

NOTE: The helper function (AddObj) does all the object creation work.

;; Begin Code
;; Create a new layer and change its plowable state, then
;; create a new line and circle without using the command function
;; 8/20/11 - Lee Ambrosius
(defun c:newObjects ( / layEnt newObj)
  ;; Create a new Layer named Const if it does not exist
  (if (= (setq layEnt (tblobjname "layer" "Const")) nil)
    (progn
      (setq layEnt (addobj "Layer"))
      
      ;; Update the new layers name
      (setpropertyvalue layEnt "Name" "Const")

      ;; Set the color of the new layer
      ;; Color can be ACI (6), true color (125,125,125),
      ;; or color book (PANTONE+ CMYK Coated,PANTONE P 1-3 C)
      (setpropertyvalue layEnt "Color" "231,18,18")

      ;; Set the layer so it cannot be plotted
      (setpropertyvalue layEnt "IsPlottable" 0)
    )
  )

  ;; Create a new line
  (setq newObj (addObj "Line"))

  ;; Set the start and end point
  (setpropertyvalue newObj "StartPoint" '(0.0 0.0 0.0))
  (setpropertyvalue newObj "EndPoint" '(5.0 5.0 0.0))

  ;; Change the layer of the new line
  (setpropertyvalue newObj "LayerID" layEnt)

  ;; Create a new circle
  (setq newObj (addObj "Circle"))

  ;; Set the start and end point
  (setpropertyvalue newObj "Center" '(5.0 5.0 0.0))

  ;; Change the layer of the new line
  (setpropertyvalue newObj "LayerID" layEnt)

 (princ)
)

;; Helper function to create the initial object without using the commands
(defun addObj (objType / newObj)
  (setq newObj nil)

  (cond
    ((= (strcase objType) "LINE")
        (setq newObj (entmakex '((0 . "LINE")
                                               (10 0.0 0.0 0.0) ; Start point
                                               (11 1.0 1.0 1.0) ; End point
                             ))
        )
    )
    ((= (strcase objType) "CIRCLE")
        (setq newObj (entmakex '((0 . "CIRCLE")
                                               (10 0.0 0.0 0.0) ; Center point
                                               (40 . 1.0) ; Radius
                             ))
        )
    )
    ((= (strcase objType) "LAYER")
        (setq newObj (entmakex (list (cons 0 "LAYER")
                                                    (cons 100 "AcDbSymbolTableRecord")
                                                    (cons 100 "AcDbLayerTableRecord")
                                                    (cons 2 (strcat "TEMP-" (rtos (getvar "CDATE") 2 8))) ; Name
                                                    (cons 70 0) ; State
                                                    (cons 62 7) ; Color
                                                    (cons 6 "Continuous") ; Linetype
                             ))
         )
    )
  )

 ;; Return the new object
 newObj
)

(prompt "\nType NEWOBJECTS to create a new line, circle, and layer without the COMMAND function.") 
;; End Code

Sincerely,
  Lee 

Accessing Information About Layers in a Drawing with GETPROPERTYVALUE

AutoCAD 2012 and AutoCAD 2012 for Mac has four new functions that essentially allow you to access object properties without the use of the COM API (Windows only) or dig around for a DXF code.  I covered the basics of these functions in the article New AutoLISP Functions in AutoCAD 2012 for Mac, but a few questions have come up about accessing non-graphical information such as Layers and Blocks.

The following example shows how to access the Layers table and then step through each layer in a drawing and return some information about the layer.

;; Begin Code
;; Outputs some general information about all the layers in a drawing
;; 8/19/11 - Lee Ambrosius
(defun c:LayInfo ( / )
  ;; Get the first layer in the LAYER symbol table
  (setq layTblEntry (tblnext "LAYER" T))

  ;; Loop while there are still layers
  (while layTblEntry
    ;; Get the layer and entity name of the layer
    (setq layName (cdr (assoc 2 layTblEntry)))
    (setq layTblEnt (tblobjname "layer" layName))

    ;; Use (dumpallproperties layTblEnt) to see what layer properties are available

    ;; Output some general layer info
    (prompt "\n_")
    (outputProp "Name" "Name" layTblEnt)
    (outputProp "Color" "Color" layTblEnt)
    (outputProp "Frozen" "IsFrozen" layTblEnt)
    (outputProp "Locked" "IsLocked" layTblEnt)
    (outputProp "Plottable" "IsPlottable" layTblEnt)
    (outputProp "LineWeight" "LineWeight" layTblEnt)

    ;; Get the linetype name
    (setq linetypeTblEnt (getpropertyvalue layTblEnt "LinetypeObjectID"))
    (outputProp "Linetype" "Name" linetypeTblEnt)

    ;; Get the next layer in the symbol table
    (setq layTblEntry (tblnext "LAYER"))
  )
 (princ)
)

;; Function used to output property information to the Command Line
(defun outputProp (infoTag propName ent / )
  (prompt (strcat "\n" infoTag ": "))
  (princ (getpropertyvalue ent propName))
 (princ)
)

(prompt "\nType LAYINFO to output information about the layers in the drawing.")
;; End Code 

Sincerely,
  Lee 

New AutoLISP Functions in AutoCAD 2012 for Mac

If you are planning to upgrade to AutoCAD 2012 for Mac (or AutoCAD 2012 on Windows) and use AutoLISP, there is some exciting news. One of the best features of the new release is the ability to access and modify object properties with a set of 4 new functions. The functions can be used to access both graphical and non-graphical objects in a drawing. The functions are not available in earlier releases and are a nice alternative to using the VLAX functions that are only available in AutoCAD 2012 on Windows.

The 4 new functions are:

• dumpallproperties - Outputs all the properties and their current value for the specified entity.
• getpropertyvalue - Returns the current value of the specified property for an entity.
• ispropertyreadonly - Returns T or nil of the specified property for an entity is read-only or not.
• setpropertyvalue - Sets the specified property to a new value for an entity. 

Now that you have 4 new functions just burning a hole in your code, the following helps you to using these new functions to change the background mask color of a dimension or multiline text object. The code also outputs the current background mask color before asking you to turn the background mask on or off.

*NOTE: Much of the desired error handling is not present in the sample code.*

To get started, you use the DUMPALLPROPERTIES function with the type of object you want to work with. Properties like Layer, Color, and Linetype are consistent across all graphical objects.  Add the objects you want to work with your drawing, for this example I added a linear dimension and multiline text object. After the objects are in the drawing, enter the following at the Command prompt to see a list of all available properties for an object:

(setq ent (car (entsel "\nSelect a dimension or multiline text object: ")))
(dumpallproperties ent)

You should see a listing of properties, data types, and values. For a multiline text object, the background mask behavior is controlled by 5 properties:

• BackgroundFill - A background fill is used or not
• BackgroundFillColor - The color of the background fill
• BackgroundScaleFactor - The factor used to control how far out from the text the fill should go
• BackgroundTransparency - The transparency level of the background fill
• UseBackgroundColor - Background fill color uses the drawing background to get the color for the fill

If no background fill was applied to the multiline text object, you will see the values of 'Failed to get value' and that is normal because the property is not set yet. Turning on Background Mask for the text object and running DUMPALLPROPERTIES again will reflect the current values assigned to the multiline text object.

For dimensions, you use the following properties to control the use of background masking:

• Dimtfill - A background fill is used or not
• Dimtfillclr - The color of the background fill

The ISPROPERTYREADONLY is used to test if a property is read-only or not before trying to update its value using the SETPROPERTYVALUE function.

The following sample shows the use of the GETPROPERTYVALUE and SETPROPERTYVALUE functions.

;; Update the fill color for a dimension or multiline text object
(defun c:bfill ( / ent objType bFill bFillClr bFillScale bFillTrans bUseBackClr kWord)
  ;; Get the object
  (setq ent (car (entsel "\nSelect a dimension or multiline text object: ")))

  ;; Check to see if an object was selected
  (if (/= ent nil)
    (progn

      ;; Get the type of object
      (setq objType (cdr (assoc 0 (entget ent))))

      ;; Output current background property values
      (if (= objType "MTEXT")
        (progn
          (setq bFill (getpropertyvalue ent "BackgroundFill"))
          (outputPropValue "BackgroundFill" bFill)

          (setq bFillClr (getpropertyvalue ent "BackgroundFillColor"))
          (outputPropValue "BackgroundFill" bFillClr)

          (setq bFillScale (getpropertyvalue ent "BackgroundScaleFactor"))
          (outputPropValue "BackgroundFill" bFillScale)

          (setq bFillTrans (getpropertyvalue ent "BackgroundTransparency"))
          (outputPropValue "BackgroundFill" bFillTrans)

          (setq bUseBackClr (getpropertyvalue ent "UseBackgroundColor"))
          (outputPropValue "UseBackgroundColor" bUseBackClr)
        )
        (progn
          (setq bFill (getpropertyvalue ent "Dimtfill"))
          (outputPropValue "Dimtfill" bFill)

          (setq bFillClr (getpropertyvalue ent "Dimtfillclr"))
          (outputPropValue "Dimtfillclr" bFillClr)
        )
      )

      ;; Prompt the user to turn background masking on or off
      (initget 0 "ON OFF")
      (setq kWord (getkword "\nEnable Background masking [ON/OFF]: "))

      ;; Toggles background mask on or off, when turning it on set it to cyan 
      (if (= objType "MTEXT")
        (progn
          (if (= kWord "ON")
            (progn
              (setpropertyvalue ent "BackgroundFill" 1)
              (setpropertyvalue ent "BackgroundFillColor" 4)
              (setpropertyvalue ent "UseBackgroundColor" 0)
            )
            (setpropertyvalue ent "BackgroundFill" 0)
          )
        )
        (progn
          (if (= kWord "ON")
            (progn
              (setpropertyvalue ent "Dimtfill" 2)
              (setpropertyvalue ent "Dimtfillclr" 4)
            )
            (setpropertyvalue ent "Dimtfill" 0)
          )
        )
      )
    )
  )

 (princ)
)

;; Function used to output property name and value to the Command Line
(defun outputPropValue (propName propValue / )
  (terpri)
  (prompt (strcat propName ": "))
  (princ propValue)
 (princ)
)

(prompt "\nType BFILL to use the background fill command.")

Sincerely,
  Lee