Updating the C:GPath Function
Update the C:GPath function by adding reactor creation logic.
To add reactor creation logic to C:GPath
(defun C:GPath (/
gp_PathData
gp_dialogResults
PolylineName
tileList
)
(setvar "OSMODE" 0) ;; Turn off object snaps
;|
;; Lesson 6 adds a stubbed-out command reactor to AutoCAD
;; However, it would be undesirable to react to every
;; drawing of a circle should the COMMAND tile creation
;; method be chosen by the user. So, disable the
;; *commandReactor* in case it exists.
|;
(if *commandReactor*
(progn
(setq *commandReactor* nil)
(vlr-remove-all :VLR-Command-Reactor)
)
)
;; Ask the user for input: first for path location and
;; direction, then for path parameters. Continue only if you
;; have valid input. Store the data in gp_PathData.
(if (setq gp_PathData (gp:getPointInput))
(if (setq gp_dialogResults
(gp:getDialogInput
(cdr (assoc 40 gp_PathData))
) ;_ end of gp:getDialogInput
) ;_ end of setq
(progn
;; Now take the results of gp:getPointInput and append this to
;; the added information supplied by gp:getDialogInput
(setq gp_PathData (append gp_PathData gp_DialogResults))
;; At this point, you have all the input from the user
;; Draw the outline, storing the resulting polyline "pointer"
;; in the variable called PolylineName
(setq PolylineName (gp:drawOutline gp_PathData))
;; Next, it is time to draw the tiles within the boundary.
;; The gp_tileList contains a list of the object pointers for
;; the tiles. By counting up the number of points (using the
;; length function), we can print out the results of how many
;; tiles were drawn.
(princ "\nThe path required ")
(princ
(length
(setq tileList (gp:Calculate-and-Draw-Tiles gp_PathData))
) ;_ end of length
) ;_ end of princ
(princ " tiles.")
;; Add the list of pointers to the tiles (returned by
;; gp:Calculate-and-Draw-Tiles) to gp_PathData. This will
;; be stored in the reactor data for the reactor attached
;; to the boundary polyline. With this data, the polyline
;; "knows" what tiles (circles) belong to it.
(setq gp_PathData
(append (list (cons 100 tileList))
; all the tiles
gp_PathData
) ;_ end of append
) ;_ end of setq
;; Before we attach reactor data to an object, let's look at
;; the function vlr-object-reactor
;; vlr-object-reactor has the following arguments:
;; (vlr-object-reactor owner's data callbacks)
;; The callbacks Argument is a list comprised
;; '(event_name . callback_function)
;;
;; For this exercise we will use all arguments
;; associated with vlr-object-reactor
;; These reactor functions will execute only if
;; the polyline in PolylineName is modified or erased
(vlr-object-reactor
;; The first argument for vlr-object-reactor is
;; the "Owner's List" argument. This is where to
;; place the object to be associated with the
;; reactor. In this case, it is the vlaObject
;; stored in PolylineName.
(list PolylineName)
;; The second argument contains the data for the path
gp_PathData
;; The third argument is the list of specific reactor
;; types that we are interested in using
'
(
;; reactor that is called upon modification of the object
(:vlr-modified . gp:outline-changed)
;; reactor that is called upon erasure of the object
(:vlr-erased . gp:outline-erased)
)
) ;_ end of vlr-object-reactor
;; Next, register a command reactor to adjust the polyline
;; when the changing command is finished
(if (not *commandReactor*)
(setq *commandReactor*
(VLR-Command-Reactor
nil ; No data is associated with the command reactor
'(
(:vlr-commandWillStart . gp:command-will-start)
(:vlr-commandEnded . gp:command-ended)
)
) ;_ end of vlr-command-reactor
)
)
;; The following code removes all reactors when the drawing is
;; closed. This is extremely important!!!!!!!!!
;; Without this notification, AutoCAD may crash upon exiting!
(if (not *DrawingReactor*)
(setq *DrawingReactor*
(VLR-DWG-Reactor
nil ; No data is associated with the drawing reactor
'((:vlr-beginClose . gp:clean-all-reactors)
)
) ;_ end of vlr-DWG-reactor
)
)
) ;_ end of progn
(princ "\nFunction cancelled.")
) ;_ end of if
(princ "\nIncomplete information to draw a boundary.")
) ;_ end of if
(princ) ; exit quietly
) ;_ end of defun
;;; Display a message to let the user know the command name.
(princ "\nType GPATH to draw a garden path.")
(princ)