Changing between PSViewports Reactor

What is the sequence of events that happen when switching between paperspace
viewports?
I have a sysvar reactor to the "CVPORT" variable, but then I need to wait
for something else to get done to update the dimscale based on the vpscale.
I just don't know what that something is. ??

Any help is appreciated.
Matthew

 

Recently with the help of some guys in the forum I came with this reactor:

(vl-load-com)
(if (null db:svr)
(setq db:svr (vlr-sysvar-reactor '("CVPORT") '(vlr-sysvarchanged .
setscale)))
)
)

If fires every time you change the viewport or go to paperspace and don't
react when you go to Model Layout.
The callback function looks like this:

(defun setscale (r data)
(if (member (car data) (vlr-data r))
(cond
((> (getvar "cvport") 1)
(setq xpf (rtos (/ 1 (caddr (trans '(0 0 1) 2 3))) 2 0))
(setq setsc (strcat "mode" xpf))
(eval (list (read (strcat "c:" setsc))))
)
((= (getvar "cvport") 1)
(cond
((= (getvar "lunits") 4)
(c:apsmode)
)
((/= (getvar "lunits") 4)
(csmode)
)
)
)
)
)
)

You may simplify/replace this with your own. Keep in mind that some AutoLisp
commands doesn't work under reactor (like COMMAND, VL-CMDF, INSERT and
other command considered as INTERACTIVE).
The way my callback function is working is this:
I have separate functions for each scale - they are setting many parameters
based on the viewport scale - Current Text Style, Dimension Style, LTScale,
Units, ect.
Each of these functions has a name MODE with the scale factor at the end
(e.g. MODE50 for 1:50 or MODE24 for 1/2"=1'-0"), so the callback function is
assembling the name based on the scale of the viewport and then activating
this function. In case you are returning from viewport to PS it goes to
function PSMODE (if you were in decimal unit viewport) or APSMODE (if you
were in architectural units viewport).
This way the drafters don't have to think about setting dimension style or
linetype scale or text style - they just jumping from viewport to viewport
and drawing.
John

 

There must be something about making selection sets inside reactors also.
The selection set must be setting a sysvar because the reactor fires just
after creating it and I get a unhandled exception. ??

Seems to work ok after using ActiveX methods.

Thanks
Matthew