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From: pasturel@sctc.com (Pierre Pasturel)
Newsgroups: comp.windows.x.motif
Subject: Re: Determining children widget IDs (Summary)
Message-ID: <1991Jan3.181945.26911@sctc.com>
Date: 3 Jan 91 18:19:45 GMT
References: <20.277b089c@idicl1.idi.battelle.org> <21.277e1314@idicl1.idi.battelle.org> <1991Jan2.185621.20296@sctc.com>
Organization: Secure Computing Technology Corporation
Lines: 56

>As an observation, I thought that one should never include both
>IntrinsicP.h and Intrinisic.h (and the same goes with Composite include
>files).

I set up the includes like I did based on some example code in Douglas A.
Young's book "The X WINDOW SYSTEM Programming and Applications with Xt"
OSF/MOTIF edition.  It seems to work fine for me. Looking into it further, my
X11/IntrinsicP.h header file includes X11/Intrinsic.h anyhow so I don't
see a problem.  I am on VMS though and this may make a difference.

--
* Roger Grywalski - Software Developer  |   GRYWALSKI@IDICL1.IDI.BATTELLE.ORG
* Information Dimensions Inc.           |
* 655 Metro Place South                 |
* Dublin, Ohio 43017                    |

****************************************************************************
Ok, I remember, the problem was not the order in which the include files
are included (as you  pointed out, IntrinsicP.h includes Intrinsic.h), but
the problem I had was that some functions were being redefined by 
IntrinsicP.h which always returns a value of 0 which was used by another
function, resulting in a core dump.

For example, Intrinsic.h had the following fucnction prototypes:

extern Display *XtDisplay();
    /*	Widget widget;		*/

extern Screen *XtScreen();
    /*	Widget widget;		*/

extern Window XtWindow();
    /*	Widget widget;		*/



which are then redefined by IntrinsicP.h as follows:

#define XtDisplay(widget)	((widget)->core.screen->display)
#define XtScreen(widget)	((widget)->core.screen)
#define XtWindow(widget)	((widget)->core.window)

The three macros were returning a value of 0 (I guess those core fields
were not initialized).  I don't know why they are zero, but when I did
not include IntrinsicP.h, the function protocols in Intrinsic.h worked
fine (they returned legitimate display, screen, and window numbers).

So, what I don't know is why I have zero screen->display, screen, and window
widget fields.

Any ideas on that??

I am running OSF/Motif 1.0 with X11R4 on a 3/60 with SUN OS 4.0.3 

Pierre
pasturel@sctc.com