Conference bulova::decw_jan-89_to_nov-90

3348.0. "fatal xlib error in XsendEvent" by TAV02::GAN () Sun Sep 16 1990 04:58

One of our customers is trying to use the XSendEvent routine.
He gets a FATAL XLIB ERROR when he uses it. He is probably
doing some programming error. As an example he added a few lines
to the HELLOWORLD.C to show the problem. I am posting here
the lines he added to that small application:

The following lines to be included in HELLOWORLD.C:


	.
	.
	.

static void helloworld_button_activate( widget, tag, callback_data )
	Widget	widget;
	char    *tag;
	DwtAnyCallbackStruct *callback_data;
{
    Arg arglist[2];

    static int call_count = 0;

/***************************************************/
/* Here starts the added lines to HELLOWORLD.C     */
/* The XsendEvent option entered here just to      */
/* demonstrate the Xlib error 			   */
/***************************************************/

	XClientMessageEvent ev;
	ev.type = ClientMessage;
	ev.display = XtDisplay(widget);
	ev.window = XtWindow(widget);
	ev.message_type = 0;
	ev.format = 0;
	XSendEvent(XtDisplay(widget), XtWindow(widget),
		False, NoEventMask, (XEvent *)&ev);

/***************************************************/
/*  End of added code to Helloworld.               */
/***************************************************/

    call_count += 1 ;
    switch ( call_count )
        {
        case 1:
            XtSetArg( arglist[0], DwtNlabel,
                DwtLatin1String("Goodbye\nWorld!") );
            XtSetArg( arglist[1], DwtNx, 11 );  
            XtSetValues( widget, arglist, 2 );
            break ;
        case 2:
            exit(1);
            break ;
        }
}

    ev.format = 0 is an invalid ClientMessage format.  The format must be
    8, 16, or 32.
    
    Ken