AnsweredAssumed Answered


Question asked by VRFuser on Apr 23, 1998
Hi one and all

The Book "Building an Operator Interface with HP VEE" sounds to be
useful.  Can anyone tell me where I can purchase a copy please.

Even though we are down in New Zealand we can usually obtain most items.


> ----------
> From:      trgroleau@CCGATE.HAC.COM[SMTP:trgroleau@CCGATE.HAC.COM]
> Sent:      Thursday, 23 April 1998 23:00
> To:
> Subject:      Re: VRF-PopUps
>      Greg,
>         You had a good response to the pop up question for a single
> point
>      input used in multiple areas.  You can include "OK" buttons, if
> you
>      just want to get the input once for your program.   An "OK"
> button or
>      WAIT ON INPUT will not cause a User Object to become modal, which
> was
>      sort of implied in your answer.  In v4 the same applies to User
>      Functions.  The box will not become modal, so parallel threads
> will
>      continue, but the calling thread will of course be stalled till
> the
>      object completes.
>         In your example, what happens if the user is in the process of
>      typing in data when the function is polled?  Does partial data
> come
>      through, or does the "old" value still come through?  Or does the
> call
>      hang till the user is done typing?  In these multi-threaded
> scenarios,
>      sequencing can get to be a bear sometimes! 
>         As an aside to newer users:  The concepts around building
> these
>      kind of pop-ups are covered in "Building an Operator Interface
> with HP
>      VEE" which is a really good book to read through.  One of the
> most
>      powerful concepts presented there is that a User Object does not
> have
>      to satisfy all of its OUTPUT pins for the thread to continue.
> This is
>      powerful when one realizes that a User Object or Function can
> ping
>      different output pins depending on whether it completed
> successfully,
>      as opposed to say 'C', where there is only one return value that
> must
>      be tested by the caller each time the function is run.  If you
> make
>      the test internal to your User Function, you can eliminate a lot
> of
>      redundant code and simplify the look of your program greatly.
>      Thomas Groleau
>      Tucson, Arizona