Some VBA toolbox questions (R. Robert Bell, are you out there?)

I have finally given up on doing a Vlisp based layer management tool. I just
can't get Mtext and Dimensions to work like I want. SO I am looking at
making layer management event driven with VBA, which I think is really a
better solution, at least conceptually.
In trying to emulate the system usually used in Lisp, I would use
BeginCommand and EndCommend events, and set layers and such accordingly.
However, I see some issues.
1: How do you handle canceled commands? There doesn't seem to be a
CommandCanceled event, without which you can't cleanup.
2: How do you handle commands in lisp? Events would fire for every (command
"XXX") in your lisp code as well. Do you handle this by flagging a lisp as
active and suspending your layer management code when the command comes from
inside lisp?
3: How do you make sure both command events bracket a single command, so
that you can reset clayer and such after the command ends? Or is the only
way to nest commands with transparent commands that you don't react to. I
guess you could set a variable to the command name you did manage layers on,
and then in the EndCommand event check to see that the ended command is the
one in question and cleanup if so. Again, pretty ugly if the user cancels
and you can't see that event.

Having looked at all of this, one thought is to use a single ObjectAdded
event, and change the layer of the object after the fact. This works until
the user changes the layer of an object for good reason, then copies it, and
the new object is forced back to the old layer. I guess you could use
BeginCommand to store what command was in effect, then if the user uses
Mtext, force the layer, but if using copy don't? Any thoughts?

Lastly, I only find TrueColor as a property. Now, I can use TrueColor to
create a layer of color 30, but it shows up in the layer list as the RGB
numbers, not 30. Long term this is not a huge deal, but right now I am
working my users into STBs and freaking them out with new color numbers is
not high on my list, not to mention the TrueColor RGB value just takes up
too much space. Is there a way to assign an indexed color # in VBA?

Has anyone gone down this road in VBA? Is there a spiffy website dealing
with how to do this? Mr. Bell, are you planning a VBA version of your
excellent Error Handling AUGI/AU class? Hint, hint

Best,
Gordon

 

Gordon, comments in-line. Others, please jump in where you see the need to.

| I have finally given up on doing a Vlisp based layer management tool. I
just
| can't get Mtext and Dimensions to work like I want. SO I am looking at
| making layer management event driven with VBA, which I think is really a
| better solution, at least conceptually.
| In trying to emulate the system usually used in Lisp, I would use
| BeginCommand and EndCommend events, and set layers and such accordingly.
| However, I see some issues.


EndCommand events can hose the Undo facility, so you need to be careful
there.


| 1: How do you handle canceled commands? There doesn't seem to be a
| CommandCanceled event, without which you can't cleanup.


There is no CommandCanceled event, curses. I haven't sweated it myself, but
I have seen some code that sets a flag during the prior command event, and a
new BeginCommand checks that flag to do a reset. I'm not thrilled with that
either. 8^(


| 2: How do you handle commands in lisp? Events would fire for every
(command
| "XXX") in your lisp code as well. Do you handle this by flagging a lisp as
| active and suspending your layer management code when the command comes
from
| inside lisp?


The Begin/EndLISP events help here.


| 3: How do you make sure both command events bracket a single command, so
| that you can reset clayer and such after the command ends? Or is the only
| way to nest commands with transparent commands that you don't react to. I
| guess you could set a variable to the command name you did manage layers
on,
| and then in the EndCommand event check to see that the ended command is
the
| one in question and cleanup if so. Again, pretty ugly if the user cancels
| and you can't see that event.


This is why I try to post-process. Too many problems can crop up.


| Having looked at all of this, one thought is to use a single ObjectAdded
| event, and change the layer of the object after the fact. This works until
| the user changes the layer of an object for good reason, then copies it,
and
| the new object is forced back to the old layer. I guess you could use
| BeginCommand to store what command was in effect, then if the user uses
| Mtext, force the layer, but if using copy don't? Any thoughts?


That is a sound approach. However, ObjectAdded can get very busy so you need
to account for performance issues too.


| Lastly, I only find TrueColor as a property. Now, I can use TrueColor to
| create a layer of color 30, but it shows up in the layer list as the RGB
| numbers, not 30. Long term this is not a huge deal, but right now I am
| working my users into STBs and freaking them out with new color numbers is
| not high on my list, not to mention the TrueColor RGB value just takes up
| too much space. Is there a way to assign an indexed color # in VBA?


Sub Test()
Dim aLayer As AcadLayer
Set aLayer = ThisDrawing.Layers.Add("Test")

Dim aColor As AcadAcCmColor
Set aColor = New AcadAcCmColor
aColor.ColorIndex = 30

aLayer.TrueColor = aColor
End Sub


| Has anyone gone down this road in VBA? Is there a spiffy website dealing
| with how to do this? Mr. Bell, are you planning a VBA version of your
| excellent Error Handling AUGI/AU class? Hint, hint


There aren't any errors possible in VBA, are there?! (I'm too stinking busy
to do any class coursework right now, sad to say.) But thanks for the kind
words.

 

That is a sound approach. However, ObjectAdded can get very busy so you
need

Hmm. Tried some big copy/pastes, with the ObjectAdded just counting, and it
was SLOW... So I wonder, can you 'disable' an event? In other words, could I
have an ObjectAdded event that normally doesn't do anything. Then I use the
BeginCommand event to toggle ObjectAdded 'on' for particular commands?
SOmehow I think I really should learn C#.net huh?

Gordon

 

Think flag...

--
R. Robert Bell, MCSE
www.AcadX.com


| > That is a sound approach. However, ObjectAdded can get very busy so you
| need
| > to account for performance issues too.
|
| Hmm. Tried some big copy/pastes, with the ObjectAdded just counting, and
it
| was SLOW... So I wonder, can you 'disable' an event? In other words, could
I
| have an ObjectAdded event that normally doesn't do anything. Then I use
the
| BeginCommand event to toggle ObjectAdded 'on' for particular commands?
| SOmehow I think I really should learn C#.net huh?
|
| Gordon
|
|

 

Gordon, I utilize the ObjectAdded event to autolayer text, dims, and such.
Of the nearly 100 users currently using the system, never has one of them
ever complained about it being slow. I'm willing to bet that the amount of
time saved in 15 or so minutes of drafting and not worrying about layering
anything more than makes up for any extra time that it may take to
copy/paste even large amounts of drawing objects.

<deleted paragraph that sounded way to preachy on second read thru>

TGIF!

 

You're back!


"Bobby C. Jones" <bobbyj (at) acadx (dot) com> wrote in message
|
| TGIF!

 

Hmm. I agree the pause is minor, certainly less than that which is saved.
However, I am running into new problems (see my other post about
ObjectAdded). Any chance you could jot down in pseudo-code how you are doing
this? You mention doing it with text and dims, perhaps you are not doing it
with blocks (where my current brain flatulance is happening)?

Thanks,
Gordon
(in frozen disfunctional, burried under SIX INCHES of snow, Portland. No
comments from those in the NE & MW please.)