Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!zephyr.ens.tek.com!orca.wv.tek.com!crevasse!glennw
From: glennw@crevasse.WV.TEK.COM (Glenn Widener;;61-049;;orca)
Newsgroups: comp.windows.x
Subject: Re: Using the X Resource Manager in Non-X Applications
Summary: Xlib XrmGetDefault needed
Keywords: resource manager
Message-ID: <6337@orca.wv.tek.com>
Date: 5 Mar 90 23:39:09 GMT
References: <207@van-bc.UUCP>
Sender: nobody@orca.wv.tek.com
Reply-To: glennw@crevasse.WV.TEK.COM (Glenn Widener)
Organization: Tektronix, Inc., Wilsonville, OR
Lines: 83

J.T. Conklin writes: 

< I am writing a set of utilities, lets call it the "foo" toolkit,
< that, for reasons of end-user flexibility, I would like to have
< system-wide and per-user configuration files.

< I was thinking about a /usr/local/lib/foo/app-defaults/*, for
< the system configuration, and a ~/.foodefaults file for the
< per-user configuration.

< My thoughts are that I could write a set of wrapper functions that
< clean up the interface to the RM (perhaps like is done in Xt?) and
< use that.

< Should I do that, or should I be looking at a different approach?

I take it that you are asking for a simple XGetDefault-like interface to
the Xlib Xrm facility, that uses Xt-like database initialization, for
non-Xt Xlib clients.  My belief is that such a facility in Xlib is long
overdue, and I will be proposing it for R5.  In the meantime, I'd
recommend that you steal the Xt XtInitialize code and remove all the
widget-isms (which is basically what I will propose for Xlib.)  Your call
interface might be something like:

XrmCreateDefaultDatabase(dpy, res_name, res_class,
				options, num_options,
				argc, argv, argc_return, argv_return,
				database_return)
    Display dpy;
    char *res_name;
    char *res_class;
    XrmOptionDescRec *options;
    int num_options;
    char *argv[];
    int argc;
    char **argv_return[];
    int *argc_return;
    XrmDatabase *database_return;


XOpenInitializeDisplay configures a resource database for a display and
supplied command line and options description.

XOpenInitializeDisplay returns a resource database which has been loaded
from the conventional locations:

 - Application-specific class resource file on the local host or by
   XSetFallbackResources
 - Application-specific user resource file on the local host
 - Resource property on the server or user preference resource file on 
   the local host
 - Per-host user environment resource file on the local host
 - Application command line (argv)

...
Per Xt spec.


char *XrmGetDefault(display, database, resource, resource_class)
    Display *display;
    XrmDatabase database;	/* In: resource database */
    char *resource_name;	/* In: resource name specifier, in ASCII */
    char *resource_class;	/* In: resource class specifier, in ASCII */

display		   Specifies the connection to the X server.

resource_name	   Specifies the resource name.

resource_class	   Specifies the resource class.  If NULL, defaults to the
		   resource argument with the first letter of each
		   (dot-separated) component upper cased.

Resource_name and resource_class are prepended with the res_name and
res_class supplied by XOpenInitializeDisplay for the specified display.

XrmGetDefault returns the value NULL if the requested resource does not
exist.  Note that it is permissible for resource or resource_class to
contain a hierarchy of names, separated by ".", e.g.  or
resource="exitButton.font" resource_class="Myprog.Cae".  The number of
resource  and class names should always match.

Glenn Widener
Tektronix, Inc.