
   LessTif logo
   
                                LessTif FAQ
                                      
   This article contains the answers to some Frequently Asked Questions
   (FAQ) often seen in the LessTif mailing list and posted to the
   newsgroup comp.windows.x.motif. It is posted to help reduce volume in
   the LessTif mailing list and to provide hard-to-find information of
   general interest.
   
                     Please redistribute this article! 
     _________________________________________________________________
   
                                  Contents
                                      
   TOPIC: LessTif General Information
     * What is LessTif?
     * Where can I get LessTif?
     * Who is developing LessTif?
     * Can I use LessTif in my applications?
     * Will LessTif be Motif1.2 Compliant?
     * Will LessTif be Motif2.0 Compliant?
     * Will LessTif be Motif2.1 Compliant?
     * What about CDE?
     * Is UIL (User Interface Language) supported?
     * Is there a LessTif newsgroup?
     * Is there a LessTif mailing list?
     * Is there a LessTif mailing list digest?
     * Is a LessTif mailing list archive available on FTP or WWW?
     * What is LessDox?
     * How can I obtain LessDox?
       
   TOPIC: LessTif Installation
     * What Platforms is LessTif on?
     * Is there a pre-built library available for My Platform?
     * Do I have to have Imake/xmkmf?
     * Can I build a Shared Library?
     * Can I build a Static Library?
     * How do I build the makefiles?
     * Why does it say I have X11r5 when I have r6 ?
     * The build fails with undefined symbols
       
   TOPIC: Running applications with LessTif
     * Application fails to start
     * Application can't load Shared Libraries
     * Application doesn't work as expected
       
   TOPIC: LessTif Development Progress
     * How complete is LessTif ?
     * Is there any Documentation for LessTif ?
     * How often is a release made ?
     * What if I find a Bug ?
     * What currently Works?
     * Will Motif _Xm functions be implemented?
     * Does LessTif support I18N?
     * How to submit a bugfix/patch?
     * What about memory leaks ?
       
   TOPIC: Compiling Applications With LessTif
     * I installed LessTif but I can't compile apps with it. Help !
     * My application doesn't build. What do I do ?
     * This app uses Imake but it won't build right.
     * Can I use LessTif with C++ ?
     _________________________________________________________________
   
                     TOPIC: LessTif General Information
                                      
     * What is LessTif?
       LessTif is a clone of the Motif® toolkit. Currently LessTif is
       partially implemented with most of the API in place. Saying this a
       lot of the internal functionality is still missing.
       Compatibility can have several degrees, the ultimate one being
       binary compatibility. This is the one we're aiming for. This can
       be tested even today on most platforms on which shared libraries
       are supported : if you also have Motif® shared libraries, you can
       choose which library to use by setting an environment variable
       such as LD_LIBRARY_PATH prior to executing an application.
       The primary objectives have been to develop the widget code of the
       LessTif Toolkit. Intermittently, the window manager (mwm) and the
       combination of UIL compiler and libMrm are being worked on.
       Volunteers to advance one or more parts of LessTif development, or
       for writing documentation without an OSF, X/Open or The Open Group
       copyright on it, are always welcome.
     * Where can I get LessTif?
       You can get it over the Internet at several locations. They're
       listed on our web site at http://www.lesstif.org, which is one of
       the places to get it.
       The same web pages can point you to quite a few CD-ROM
       manufacturers which put a version of LessTif on some of their
       products. Many free Unix (RedHat, Debian, SuSE, Walnut Creek
       FreeBSD, ...) are among them.
     * Who is developing LessTif?
       The hungry programmers and a few Internet based individuals. Look
       for an up to date list in the AUTHORS file in the LessTif
       distribution.
       Keeping a list of developers for each widget is not really
       possible mainly because the we're not fanatic about ownership of a
       widget. We do keep in touch enough to know who's messing with what
       so we don't overlap too much.
     * Can I use LessTif in my applications?
       The odds of your application running fairly well with LessTif are
       pretty good.
       You should be able to compile and run your code, how well it works
       is another matter... If it doesn't, then we're very interested in
       hearing about what doesn't work and why (we can't fix bugs that we
       don't know about), and we're even more interested in a fix.
       If your favourite application does work, please tell us so we add
       it to the list of apps known to work.
     * Will LessTif be Motif1.2 Compliant?
       Yes this is the first major step.
       Up to now we are very close, all interfaces are in place, we might
       only have to fight against some remaining bugs ...
       In early 1997 however, someone asked whether submissions for 2.0
       or CDE widgets would be accepted.
       Of course !
       Therefore, we expanded the source directory tree to make it easy
       to add new stuff, and to build several versions of the library
       (and the corresponding tools). So if anybody has a widget, or an
       application, to offer which can advance us in the 2.x or CDE
       areas, please E-mail us.
       Somewhere along 1997 we actually started building 2.0 compliant
       widgets. More of them are needed though.
     * Will LessTif be Motif2.0 Compliant?
       Probably not fully. Since 2.0 is now gone and has been replaced by
       the OpenGroup's Motif version 2.1 we will also no longer focus on
       a 2.0 compatible release. Especially WRT CSText and the C++
       extensions - unless someone will donate implementations of these
       we will probably never get this!
       See also in Will LessTif be Motif1.2 Compliant?.
     * Will LessTif be Motif2.1 Compliant?
       Yes, even though we're convinced that this might still take some
       time. Some of the new features in 2.x are not exactly easy stuff !
       Having some of the widgets implemented can make us get away with a
       lot of stuff : some applications just need one of the new widgets.
       If applications use some of the flashy new features such as
       renderings, ...
     * What about CDE?
       We've made room for CDE compatible widgets and applications, and
       we should probably talk to the people in the eXode project, who
       are working on this. Look up their stuff at
       http://www.simplicity.net/exode.
       We did talk to them. They basically don't want to use too much of
       the 2.* stuff (some of it is rather buggy in OSF releases); also
       they really want the core of eXode to run on top of LessTif.
       Meanhwile we also have to make a similar statement as in the
       asnwer for question Will LessTif be Motif2.0 Compliant?. Our main
       focus is and will be Motif 2.1 compliance.
     * Is UIL (User Interface Language) supported?
       Not really. Though there is some old code in place already it's
       unlikely you succeed with a project using it.
     * Is there a LessTif newsgroup?
       No.
       Regularly, questions about LessTif (or about any free Motif®)
       clone are asked in comp.windows.x or comp.windows.x.motif .
     * Is there a LessTif mailing list?
       Yes there is. How to get on it is described on this web page.
     * Is there a LessTif mailing list digest?
       Yes. How to get on it is described in the web pages.
     * Is a LessTif mailing list archive available on FTP or WWW?
       Yes!
       Please check out the mailinglists page on our website.
     * What is LessDox?
       LessDox is the shortened version of the LessTif Documentation
       Project. Any previous reference to "LDP" is now dropped because of
       the conflict with the "Linux Documentation Project".
     * How can I obtain LessDox?
       Currently you can obtain LessDox from the LessTif website.
       Nothing has happened to LessDox in a long time, we would love some
       people to write free documentation describing the LessTif widget
       set.
     _________________________________________________________________
   
                        TOPIC: LessTif Installation
                                      
     * What Platforms is LessTif on?
       A more accurate list is available in an extraneous file. Here's an
       excerpt, with version numbers stripped for brevity :
          + Linux
          + FreeBSD, NetBSD, OpenBSD, BSDi (BSD/OS)
          + Sun (SunOS, Solaris)
          + MkLinux
          + OS/2 (requires XFree86)
          + AIX
          + Digital UNIX/Compaq Tru64
          + HP/UX
          + CygWin 32 (Windows NT, Windows 95 with GNU development
            environment)
     * Is there a pre-built library available for My Platform?
       Might be, we started doing that as of early March, 1997. The core
       team (and some other brave guys) are providing compiled images.
       Currently we don't have a document describing how to install them,
       but they're there for Linux, FreeBSD, OS/2.
       Note we'll only refresh these binary distributions at release
       time, which is about once a month.
       The INSTALL file found in the source distribution and on the web
       explains how to install it.
       Make sure that you do get a binary version, if that's what you're
       interested in; not the source distribution.
       We also have a list of CD-ROMs which include LessTif
       distributions.
     * Do I need to have imake/xmkmf?
       No. LessTif used to work with those, but they became more of a
       problem than a solution, so we switched to GNU autoconf, which has
       the additional capability to find out many many things about the
       target platform while auto-configuring itself.
       Around December 1997 we also started to work with libtool and
       automake, two more free tools. They should solve the portability
       problems with building shared libraries on multiple platforms for
       us. You'll find this in distributions of LessTif starting with
       release 0.85.
     * Can I build a Shared Library?
       Yes, you can on many platforms. They include Linux, FreeBSD,
       HP-UX, SunOS, Solaris, ... .
       We use libtool for keeping the complexities of building and
       installing shared libraries out of LessTif. Therefore, if LessTif
       doesn't build a working shared library on some platform, you may
       want to check whether libtool already supports this platform.
       Contact the libtool mailing list if you're interested in details
       about the platforms supported by libtool. A link to libtool
       homepage is on our links page.
     * Can I build a Static Library?
       Even for this we use libtool; but yes, you can on all platforms we
       can think of.
       By default buiding these is disabled. Check out the INSTALL
       document how to actually build them (you have use a configure
       switch)
     * How do I build the makefiles?
       LessTif is now using the GNU configure system so all you need to
       do is type
   ./configure
   make
       That's all!
       For more information on this topic check out the INSTALL document.
     * Why does it say I need X11r5 or higher when I have r6 ?
       Several people have reported build problems; the configure script
       looks for an X distribution and then checks whether it is X11R5 or
       X11R6.
       On some systems the configure script stops, saying
configure: error: You must have X11 Revision 5 or higher to compile LessTif
       while the system actually has X11r6.
       Apparently this has to do with installations of Linux, in which
       the include files (under /usr/include) often contain symbolic
       links to the source directories (either on disk or on CD-ROM).
       In such a situation, if one either removes the CD-ROM, or cleans
       up /usr/src, the effect will be dangling symbolic links under
       /usr/include which confuse our configure script.
       The solution is obvious : make sure that your include files don't
       contain symbolic links to nonexistent files.
     * The build fails with undefined symbols
       We might have screwed up of course.
       On the other hand, please make sure that you've built the entire
       distribution with the same configuration.
       Not clear ? After running the "configure" command with its
       options, you should ideally run "make clean". Otherwise e.g.
       clients/Motif-1.2/mwm/Makefile may be configured such that it
       looks for stuff that isn't there in lib/Xm/* .
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                  TOPIC: Running applications with LessTif
                                      
     * Application fails to start
       Your application fails to start and a "sophisticated" error
       message like the following is given:
Error: PANIC: no realize procedure specified for this widget.
       or
Error: attempt to add non-widget child "DropSiteManager" to parent
       "xmfoo" which supports only widgets
       We've seen this happen when the order of libraries upon linking
       was incorrect. The correct order is :
-lXm -lXt -lX11
       (see also Question 5.1)
       If you built this application please link it again, otherwise
       notify the maintainer.
       Check out _LtCheckClassOfVendorShell() in lib/Xm/Vendor.c. A
       related message should be in the mailinglist archive.
     * Application can't load Shared Libraries
       If you get a message like
foo: error in loading shared libraries
libXm.so.1: cannot open shared object file: No such file or directory
       then you did not tell your system where to look for the shared
       libraries you have (hopefully) installed. The INSTALL file
       describes how to this.
     * Application doesn't work as expected
       If you build the application make sure you followed the
       instructions in section TOPIC: Compiling Applications With
       LessTif. Also you may have discovered a remaining bug or missing
       feature in LessTif. See section 4.3 What if I find a Bug ?
     _________________________________________________________________
   
                    TOPIC: LessTif Development Progress
                                      
     * How complete is LessTif ?
       Hard to say really. Depends on how much credit you give us.
       Actually most LessTif widgets work somewhat. Many work fairly
       well. Things like traversal and focus handling have been worked
       on, but probably aren't really all that functional yet.
       The menu system is quickly losing its child diseases (occasionally
       freezing the X server with grabs). If you're not in a rush when
       working the menus, the odds are low that you'll get in much
       trouble. Also dragging in the menus will get you in trouble faster
       than clicking.
       In short, if something does not work quite right, tell us at
       lesstif@hungry.com and we'll try to help you as soon as we
       possibly can. In fact telling us about your problem is the fastest
       way to get your app to work with LessTif. Recommended !
     * Is there any documentation for LessTif ?
       Yes the LessTif Documentation Project (Lessox) check out the
       LessDox home page at: http://www.lesstif.org/Lessdox/lesstif.html
     * How often is a release made ?
       Starting December 1996 we plan to make intermediary releases every
       month or so, and "real" releases every three months or so. The
       0.75 release was made available around December 11, 1996. In April
       2000 0.90 was released. See versions.html for a list of all
       released versions.
       release-policy.html has more on this topic.
       In between releases, you can always grab get our latest
       development sources from our CVS repository.
     * What if I find a Bug ?
       Bug reports are very welcome, and we'll do our best to get the
       fixes out as quick as possible.
       The web site and all distributions contain a write-up on how to
       submit bug fixes or reports.
     * What currently runs ?
       DDD, Mosaic-2.7, NEdit, ...
       Look at the web site for a more accurate and timely list.
     * Will Motif _Xm functions be implemented?
       Sure they will. Many of them are implemented already.
       This was not easy though. The _Xm* functions seem to be
       undocumented in Motif 1.2 therefore we will make every effort to
       implement the functions as best we can.
       One of our sources of information was "Writing Your Own OSF/MOTIF
       Widgets" by McMinds and Whitty, kindly donated to us by Linux
       International.
       Many of the _Xm* functions are exposed in OSF/Motif® 2.0/2.1 where
       they changed names into Xme*.
     * Does LessTif support I18N?
       Two widgets that accept text input (namely XmText and XmTextField)
       do support it, but they don't feature multibyte support.
       This means you can use sequences such as Multi_key+c+o to get ©,
       Multi_key+n+~ to get the ñ, etc.. These work because they're part
       of the ISO Latin 1 character set, which is based on one-byte
       representations.
       The XmText and XmTextField widgets can handle input methods, as
       described above, but they don't have multibyte support. This means
       that Asian input methods which work with a multi-byte
       representation of a character will not work (yet).
       The XmIm*() API is work in progress, this is probably not a
       problem for you as we have yet to discover an application that
       uses it.
     * How to submit a bugfix/patch?
       This topic is covered in an extraneous document which is also
       distributed in plain ASCII format (BUG-REPORTING).
     * What about memory leaks ?
       Obviously we don't like memory leaks in LessTif. A couple of tests
       have been done with commercial memory analysis tools, some of the
       apps in the tests/ tree help tracking some leaks as well.
       We believe we're not doing really bad. In fact we did run some
       simple comparisons with official Motif 1.2.4 implementations which
       showed LessTif was even leaking less memory!
       One package which can help you (and us) in tracking memory
       problems both in your application and in LessTif, is dmalloc, a
       library which can be obtained from www.dmalloc.com .
       You can compile LessTif itself with dmalloc by using the
       --with-dmalloc option to the "configure" command.
       Dmalloc is freely available software, but please note the license
       which is different from most other free software licenses.
     _________________________________________________________________
   
                 TOPIC: Compiling Applications With LessTif
                                      
     * I installed LessTif but I can't compile apps with it. What's wrong
       ? 
       This probably has to do with your compiler options. If it's indeed
       that, there are several possibilities.
       In the examples we'll give now, we'll be using some installation
       directories that may differ from your installation. Please adjust
       your compilation parameters accordingly, don't try to fix your
       installation so it matches our examples. In our examples, X has
       been installed in /usr/X11R6 and LessTif has been installed in
       /usr/lesstif.
       Compilation of applications is really a two-step process :
         1. compiling all sources
         2. linking them together
       The compilation phase needs to know where to find include files.
       These are files that are referenced in the C (or C++) sources of
       your programs as
#include <Xm/Xm.h>
       and you should find them on your system in a couple of directories
       under /usr/lesstif/Motif1.2/include or
       /usr/lesstif/Motif2.0/include. Specifically the file mentioned
       above should show up as /usr/lesstif/Motif1.2/include/Xm/Xm.h or
       /usr/lesstif/Motif2.0/include/Xm/Xm.h .
       For your compiler to find these files, it needs to be told where
       to look. Using the examples above, the flag needed would be
       -I/usr/lesstif/include . Note that you need to tell the compiler
       the same thing about the X Window System include files, you need
       to do that by using the -I/usr/X11R6/include flag. So together
       this gives
  -I/usr/X11R6/include -I/usr/lesstif/include
       The second step, linking all the source files together, requires
       similar flags. The linker needs to know where the libraries are,
       and additionally you need to tell it which libraries to include in
       the link process.
       Again, using the example outlined above, we'd need to use the
       flags
  -L/usr/X11R6/lib -L/usr/lesstif/lib
       for the linker to know where to look, and
  -lMrm -lXm -lXt -lXext -lX11 -lSM -lICE
       to know which libraries to use. Note that the -lMrm library, as
       well as the -lXext library, aren't always needed, so you might get
       away with using flags like
  -L/usr/X11R6/lib -L/usr/lesstif/lib -lXm -lXt -lX11 -lSM -lICE
       Note that the order of the libraries is important on some systems,
       and less important on others. This means that an application
       writer better uses the right order, or his application won't build
       on some systems.
     * My application doesn't build. What do I do ?
       If your application doesn't build, this could have several
       reasons. If it fails in the compilation process, you probably have
       an application that's not error-free; or (more likely) one which
       needs configuration for your site, computer platform, etc.
       It would be a good idea to consult the compilation and
       installation guidelines for that application.
       If the linking process fails, this probably means you didn't
       specify some library, or the required libraries aren't present on
       your system. Error messages indicating this are a long list of
       undefined symbols most of which have a name with an identical
       prefix, such as Xm.
       In the following we list some prefixes and the related library.
       
   prefix linker command
   Xt -lXt
   Xmu -lXmu
   Sm -lSM
   Ice -lICE
   Xp -lXp
   Xdbe, Xext, XShape -lXext
   Xm -lXm
   Mrm -lMrm
   
       The order in which you should specify these options is
-lMrm -lXm -lXt -lXmu -lXp -lXext -lX11 -lSM -lICE
       Of course not all of these libraries are always necessary, but in
       some cases more libraries may be required (-lsocket is another
       candidate here). Also make sure the linker is able to find the
       libs, e.g. it may be necessary to add an -L/usr/lesstif/lib or
       similar.
       Once more, the compilation and installation guidelines for the
       application probably tell you which libraries to link with.
       Finally, please make sure that you have the X development packages
       installed on your system, not only the X user stuff. Forgetting to
       install the development system could result in messages like
       Xm/Xm.h : cannot open file, or -lXt: library not found.
     * This app uses Imake but it won't build right.
       Imake is a tool which is included in the X Window System
       distributions. It is an extra layer above Makefiles (processed by
       the make program) which attempts to make the build process more
       system independent.
       Nowadays more and more applications use GNU autoconf and GNU
       automake for the same purpose.
       The imake program process an Imakefile and turns it into a
       Makefile. Often the Imakefile uses some template file that comes
       with the application, to specify additional options.
       If you use imake directly to create the Makefile, then this will
       probably not work right, because you need to tell imake to read
       the LessTif configuration files. The mxmkmf program calls imake
       with the right parameters, so just using this should help.
       It is also possible that the Imakefile file or some file used by
       it overrides some of LessTif's parameters. Please check whether
       EXTRA_INCLUDES, XMLIB, or XmClientLibs are overruled in these
       files. If they are, then this is probably the cause of the
       problem.
     * Can I use LessTif with C++ ?
       You sure can. There really are two ways. You can use it directly,
       or through one of the C++ wrappers for Motif. Much of this is
       discussed in the Motif FAQ which can be found at Ken Lee's website
       at http://www.rahul.net/~kenton . We're copying a tiny bit of
       information from one of the FAQ issues here.
       Using LessTif directly with C++ prompts the question on how to use
       class member functions as callbacks. Here's part of Ken's answer :
       There are three common user problems with C++ callbacks.
          + First, make sure you use the correct function prototype for
            the function declarations.
          + Second, the callback function must be declared as a static
            member of the class.
          + Third, when registering it with XtAddCallback(), you must use
            its full signature.
       Here's an example :
    class MyClass {
      void createWidgets();
      static void myButtonCB(Widget, XtPointer, XtPointer);
    };

    void MyClass::createWidgets() {
      w = XtCreatePushButton(...);
      XtAddCallback(w, XmNactivateCallback, &MyClass::myButtonCB, (XtPointer) t
his);
    }

    void myButtonCB(Widget w, XtPointer clientData, XtPointer callData) {
      MyClass *myclass = (MyClass *) clientData;
    }
       Note that the "this" pointer is used as the client data. This
       technique is popular, but not required.
       Motif++ has a nice tutorial summarizing mechanisms.
       Motif++ is one of the C++ wrappers for Motif/LessTif.
     _________________________________________________________________
   
   
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