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Conference bulova::decw_jan-89_to_nov-90

Title:DECWINDOWS 26-JAN-89 to 29-NOV-90
Notice:See 1639.0 for VMS V5.3 kit; 2043.0 for 5.4 IFT kit
Moderator:STAR::VATNE
Created:Mon Oct 30 1989
Last Modified:Mon Dec 31 1990
Last Successful Update:Fri Jun 06 1997
Number of topics:3726
Total number of notes:19516

3272.0. "XtWindowToWidget returns NULL widget" by BIGRED::DANIELS (Brad Daniels, Chevron's new DEC whipping boy) Tue Aug 28 1990 19:16

Are there any constraints on the window passed to the XtWindowToWidget
function?  I have a customer who is getting back the null widget from
his calls (the window works fine with other functions), and we are not
sure why it is failing.  A brief list of possibilities would be appreciated.
(This is on Ultrix V3.1.)

Thanks!
- Brad
T.RTitleUserPersonal
Name		DateLines
3272.1Every window does not have a widgetRTL::TREGGIARIWed Aug 29 1990 09:1110
> I have a customer who is getting back the null widget from
> his calls (the window works fine with other functions), and we are not
> sure why it is failing.  A brief list of possibilities would be appreciated.
    
    You will get back NULL if the window is not the window of a widget.
    Every widget (but not gadget) has a window, but the reverse is not
    true.  You can create windows that are not associated with any widget.
    The root window is a simple example.
    
    Leo
3272.2CLTMAX::dickSchoeller - Failed XperimentWed Aug 29 1990 09:526
Circumstances in which I hit this were during the destruction process.  The
windows would still exist and certain events would occur on them and get fielded
after the widget went away.  Of course, we are doing multi-thread programming
so the risks of this kind of problem are a little higher.

Dick
3272.3BIGRED::DANIELS... but let's pretend you didn't...Thu Aug 30 1990 11:533
Thanks!  I'll see if these comments help my customer.

- Brad