Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!snorkelwacker!bloom-beacon!MAPS.CS.CMU.EDU!Matthew.Diamond
From: Matthew.Diamond@MAPS.CS.CMU.EDU
Newsgroups: comp.windows.x
Subject: XtCreateManagedWidget blues
Message-ID: <9003051747.AA03308@ATHENA.MIT.EDU>
Date: 5 Mar 90 17:44:31 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 35


Here is what could be a simple problem (but I'm not sure).

I have a piece of code which creates a unique name, then creates a
form widget with that name.
  ...
  n = 0;
  XtSetArg(args[n], XtNheight, 10); n++;
  XtSetArg(args[n], XtNwidth, 10); n++;
  varWidget = XtCreateManagedWidget(uniquename, formWidgetClass, myboxwidget,
                                    args, n);
  ...

The first time I do this everything works, I add some child widgets later
and things are great.  Then I unmanage varWidget and go back to create a new
form widget, calling the same code (but the unique name is different).
Once I've called XtCreateManagedWidget this second time, and not before,
I'll get the following error when I enter an event loop:

X Protocol error:  not a valid window ID
  Major opcode of failed request: 8 (X_MapWindow)
  Minor opcode of failed request: 0
  Resource id in failed request:  0x0
  Serial number of failed request:  409
  Current serial number in output stream:  411

The only difference I can think of between the first and second time this
code is called is that the parent widget (myboxwidget) is not yet mapped
the first time, but is the second time.  That shouldn't make a difference...
should it?

This is running in R3, on a microVax with a 4-bit (monochrome) display.
I welcome any suggestions, no matter how stupid they make me feel.
Matthew Diamond
matt@maps.cs.cmu.edu