| Re: global variables in IDL [message #28649 is a reply to message #28648] |
Wed, 26 December 2001 17:02   |
Gert
Messages: 11
Registered: December 2001
|
Junior Member |
|
|
David,
thanks for the tip - I could off course do it this way, but then i need to
pass the pointer around to anyone who might need it. What i wanted to is
pro Widgetpro,
widgetID = getIDofGlobalswidget
WIDGET_CONTROL, widgetID , GET_UVALUE=sGlobals, /NO_COPY
print, sGlobal.threshold
...
end
is this possible? How can I do the 'getIDofGlobalswidget'?
Gert
"David Fanning" <david@dfanning.com> wrote in message
news:MPG.16926460c37f95ec9897bb@news.frii.com...
> Gert (gert.van.de.wouwer@NO_SPAMpandora.be) writes:
>
>> I want to keep some global variables in an IDL program containing
different
>> widgets without having to pass the variables each time a new base widget
is
>> created. It can be done with common blocks, but then you can have only 1
>> instance of the program running.
>> I was thinking of creating a widget (called Globals) and copy the
variables
>> in a struct to its uvalue. If another widget then wants these variables,
I
>> need to get a widget identifier to Globals and retrieve the struct. But
how
>> can I get this widget identifier?
>
> It's odd, isn't it, how good ideas keep being rediscovered
> over and over again. :-)
>
> It sounds like what you need is, uh, a pointer!
>
> IDL> info = Ptr_New({all_your_stuff_in_here}, /No_Copy)
>
> Then, when you create your widgets, you simply
> pass the pointer to each program that needs it:
>
> IDL> widget_program_1, info
> IDL> widget_program_2, info
> IDL> widget_program_3, info
>
> The syntax of using pointers to structures is a little
> weird until you get used to it:
>
> TV, (*info).image, Order=(*info).order
>
> Alternatively, you can create your pointer in the first
> widget program, and pass it to the other programs that
> are called from the first, etc. There are lots of ways
> to do it, but all rely on a pointer of some sort.
>
> Cheers,
>
> David
>
> --
> David W. Fanning, Ph.D.
> Fanning Software Consulting
> Phone: 970-221-0438, E-mail: david@dfanning.com
> Coyote's Guide to IDL Programming: http://www.dfanning.com/
> Toll-Free IDL Book Orders: 1-888-461-0155
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
