Reactor advice please

[madcadder]

Disclaimer: I am asking before I even try, so be nice.

I have this code to make sure MLeader, QLeader, and Leader are on the Dimensions layer.

;;;
;;; Leaders on "Dimensions" layer reactor
;;;

(IF (NOT |leader_reactor|)
  (SETQ	|leader_reactor|
	 (VLR-COMMAND-REACTOR
	   nil
	   '((:VLR-COMMANDWILLSTART . startleadercommand)
	     (:VLR-COMMANDENDED . endleadercommand)
	     (:VLR-COMMANDCANCELLED . cancelleadercommand)
	    )
	 ) ;_ end of VLR-COMMAND-REACTOR
  ) ;_ end of SETQ
) ;_ end of IF

(DEFUN startleadercommand
			  (calling-reactor startcommandinfo / |commandstart|)
  (SETQ |leader_clayer| (GETVAR "clayer"))
  (SETQ |commandstart| (CAR startcommandinfo))
  (IF (OR (= |commandstart| "LEADER")
	  (= |commandstart| "MLEADER")
	  (= |commandstart| "QLEADER")
      ) ;_ end of OR
      (SETVAR "clayer" "DIMENSIONS")
  ) ;_ end of IF
  (PRINC)
) ;_ end of DEFUN

(DEFUN endleadercommand	(calling-reactor endcommandinfo / |commandend|)
  (SETQ |commandend| (CAR endcommandinfo))
  (IF (OR (= |commandend| "LEADER")
	  (= |commandend| "MLEADER")
	  (= |commandend| "QLEADER")
      ) ;_ end of OR
    (SETVAR "clayer" |leader_clayer|)
  ) ;_ end of IF
  (PRINC)
) ;_ end of DEFUN

(DEFUN cancelleadercommand
			   (calling-reactor cancelcommandinfo / |commandcancel|)
  (SETQ |commandcancel| (CAR cancelcommandinfo))
  (IF (OR (= |commandcancel| "LEADER")
	  (= |commandcancel| "MLEADER")
	  (= |commandcancel| "QLEADER")
      ) ;_ end of OR
    (SETVAR "clayer" |leader_clayer|)
  ) ;_ end of IF
  (PRINC)
) ;_ end of DEFUN

I would like to make another one for XLines.

1. Can I have multiple reactors defined?
2. Will a reactor still work to force the XLine on a specific layer if the command is called from inside a LISP? I have a LISP that does XLH and XLV. And another one that puts an H and a V at 0,0.

So please, if you would, just drop some help, advice, or insight on reactors and making them play pretty.

Thanks,
MC

[Opie]

Why not change those IF functions to COND functions to cycle through the possible different commands? Also, if you can probably combine the end and cancelled reactor functions to the same if you are doing the same steps.

[Tom Beauford]

Lee Mac's Command Reactor code to automatically set the current layer when a command is called, proceeding to reset to the previous current layer when the command is completed should be just what you're looking for: http://www.lee-mac.com/layerdirector.html

It will even add the layers, descriptions and properties as needed and comes with commands to turn it off and on.

[madcadder]

Sorry I'm just now getting back to this. We just went through 4 months of 50+ hour weeks and I had zero time.

I was under the impression that the start, end, and cancel had to all be separate definitions. Can they be combined?

[BlackBox]

I was under the impression that the start, end, and cancel had to all be separate definitions. Can they be combined?

Each Event's handler is defined by you (in the list of grouped pairs provided to VLR-COMMAND-REACTOR), so you can tell each which Defun to use.

I typically use one for CommandStarted, and another for CommanCancelled, CommanEnded and CommanFailed.

[madcadder]

So for safety and completeness I should really add a command failed.