Conference bulova::decw_jan-89_to_nov-90

739.0. "Example of multiple shells?" by TOTALY::ROSSI () Mon May 08 1989 17:37

Even after reading note 201, multiple hierarchies are still not clear to me.
In my application I attempt to open several shells. I continually get a 
stack dump when the code enters XtMainLoop. The code looks something like this...

    XtToolkitInitialize();
    ApplicationContext = XtCreateApplicationContext();
    syncdpy = XtOpenDisplay(ApplicationContext,NULL,"ROOT","XXX_UI",NULL,0,&argc,&argv);
    root_widget = XtAppCreateShell("Primary_Shell","xxxShell",applicationShellWidgetClass,syncdpy,0,
    toplevel_widget = XtCreatePopupShell("SHELL1",topLevelShellWidgetClass,root_widget,0,0);
                 
    etc. etc...
                      
    XtRealizeWidget(toplevel_widget);
    XtMainLoop();

The error reported is...

X Toolkit Error: Error in XMultiplexInput
%DWT-F-DWTABORT, xtoolkit fatal error
%TRACE-F-TRACEBACK, symbolic stack dump follows
module name     routine name                     line       rel PC    abs PC
    etc. etc...
XXX_MAIN        main                            19198      0000019C  0000308D

I was hoping that for each new shell I could just keep calling 
XtCreatePopupShell with root_widget as the parent. If someone could post 
an example starting with toolkit initialization through the realizing of 
a new shell it would be helpfull.

Using the code above, if I swap XtAppMainLoop for XtMainLoop, I'll get an access
violation and stack dump when I enter MainLoop with no mention of 
XMultiplexInput. What is the difference between XtMainLoop and XtAppMainLoop?

    If you use XtOpenDisplay and XtAppCreateShell, you must use
    XtAppMainLoop and not XtMainLoop.
    
    XtAppMainLoop takes an application context as an argument.  If you omit
    it you'd get an access violation.

    Thanks, I'll try it.