------------------------------------------------------------------------
                      [incr Tcl] - version 2.1
------------------------------------------------------------------------
  This version includes tcl7.5 / tk4.1 upgraded to support
  namespaces, along with [incr Tk] and [incr Widgets].  It also
  includes the "plus" and "dash" patches by Jan Nijtmans, which
  offer improvements in dynamic loading and in the canvas widget.
  See "README.PLUS" and "README.DASH" for details.

  Many different people have contributed code for this release,
  and I thank them for their contributions.  Please read the
  acknowledgements section below.

  Send comments or suggestions to the [incr Tcl] mailing list
  (itcl@fuentez.com) or directly to me (michael.mclennan@att.com).
  If you want to subscribe to the mailing list, send a message
  with the subject "subscribe" to "itcl-request@fuentez.com".

  Visit our web site:  http://www.tcltk.com/itcl/

========================================================================
           Copyright (c) 1993-1996   AT&T Bell Laboratories
========================================================================
 Permission to use, copy, modify, and distribute this software and its
 documentation for any purpose and without fee is hereby granted,
 provided that the above copyright notice appear in all copies and that
 both that the copyright notice and warranty disclaimer appear in
 supporting documentation, and that the names of AT&T Bell Laboratories
 any of their entities not be used in advertising or publicity
 pertaining to distribution of the software without specific, written
 prior permission.

 AT&T disclaims all warranties with regard to this software, including
 all implied warranties of merchantability and fitness.  In no event
 shall AT&T be liable for any special, indirect or consequential
 damages or any damages whatsoever resulting from loss of use, data or
 profits, whether in an action of contract, negligence or other
 tortuous action, arising out of or in connection with the use or
 performance of this software.
========================================================================

 OVERVIEW
------------------------------------------------------------------------
 - What is [incr Tcl]?
 - Getting started
 - Installation
 - Integrating [incr Tcl] with other extensions
 - Acknowledgements
------------------------------------------------------------------------


 What is [incr Tcl]?
------------------------------------------------------------------------
 [incr Tcl] started as a small, object-oriented extension of the
 Tcl language.  It was created to support more structured programming
 in Tcl.  Tcl scripts that grow beyond a few thousand lines become
 extremely difficult to maintain.  This is because the building blocks
 of vanilla Tcl are procedures and global variables, and all of these
 building blocks must reside in a single global namespace.  There is
 no support for protection or encapsulation.

 [incr Tcl] introduces the notion of objects.  Each object is a bag
 of data with a set of procedures or "methods" that are used to
 manipulate it.  Objects are organized into "classes" with identical
 characteristics, and classes can inherit functionality from one
 another.  This object-oriented paradigm adds another level of
 organization on top of the basic variable/procedure elements, and
 the resulting code is easier to understand and maintain.

 Among other things, [incr Tcl] can be used to create new widgets that
 look and work like the usual Tk widgets, but are written entirely at
 the Tcl language level (C code is optional).  These "mega-widgets"
 can be created using [incr Tk], a set of base classes which provide
 the core mega-widget functionality.  [incr Widgets] is a set of
 high-level mega-widgets built using [incr Tk].  It has more than
 30 widget classes, and can be used right out of the box to create:

   - fileselectiondialog
   - tabnotebook
   - panedwindow
   - scrolledhtml
   - combobox
   - optionmenu
   - scrolledlistbox
   - scrolledframe
   - messagedialog
   - and many others...
 
 Classes and/or related procedures can also be encapsulated in their
 own "namespace".  A namespace is a collection of commands, variables,
 classes and other namespaces that is set apart from the usual global
 scope.  Elements within a namespace can be "private" or "protected",
 so that access to them is restricted.  An "import" command allows all
 of the elements from one namespace to be integrated into another.

 Extension writers will immediately see the benefit of namespaces.
 With vanilla Tcl, each extension must add its commands and variables
 at the global scope.  Extension writers are encouraged to add a unique
 prefix to all of the names in their package, to avoid naming collisions.
 Extensions can now sit in their own namespace of commands and variables,
 and sensitive elements can be protected from accidental access.  For
 example, the current release of [incr Tcl] has a namespace "itcl"
 for object-oriented support, a namespace "itk" for mega-widget
 support, and a namespace "iwidgets" for the [incr Widgets] package.
 Each of these namespaces has its own collection of commands and
 variables.  Developers can then pick and choose among the extensions,
 and integrate the parts that they need for their application by
 importing various namespaces at the global scope.


 Getting started
------------------------------------------------------------------------
 Read the first part of the CHANGES file for a brief overview of
 new commands, and a summary of important changes.  Consult the
 man pages for detailed information on particular commands.

 Check out our web site on WebNet for extra doc and the latest
 news:

     http://www.tcltk.com/itcl/

 Build and install the package as described below, then check
 out the "catalog" demo in the "iwidgets2.1.0/demos" directory.
 This shows off all of the mega-widgets available in the
 [incr Widgets] package.  The file "iwidgets2.1.0/doc/iwidgets.ps"
 contains a tutorial introduction to the [incr Widgets] package.

 The mega-widget classes in the "iwidgets2.1.0" directory show off
 most of the functionality in this release.  They are excellent
 code examples for creating new widget classes.


 Installation on Unix Systems
------------------------------------------------------------------------
  1)  Obtain this distribution from an archive site like this:

        ftp ftp.neosoft.com
        cd pub/tcl/alcatel/NEW
        binary
        get itcl2.1.tar.gz
        quit


  2)  Uncompress and untar the distribution:

        gunzip itcl2.1.tar.gz
        tar xvf itcl2.1.tar


  3)  Run the configuration script:

        cd itcl2.1
        ./configure

      or, for systems that don't recognize "#!" in shell scripts:

        cd itcl2.1
        /bin/sh ./configure

      The "configure" script finds the appropriate compiler flags and
      generates new Makefiles from template files (Makefile.in).

      By default, the configuration script will set things up so
      that everything is installed in "/usr/local".  You can change
      this by specifying a different "prefix" in the "configure" command:

        ./configure --prefix=/your/install/path

      By default, everything will be build with non-shared libraries.
      You can request shared libraries and dynamic loading like this:

        ./configure --enable-shared


  4)  Build the libraries and the executables.  From the toplevel
      directory type:

        make all


  5)  Install the libraries, executables, man pages and script files.
      From the toplevel directory type:

        make install


  6)  Use the final product.  This distribution creates and installs
      four executables:
      
        ish ........... [incr Tcl] sh  (tclsh + namespaces)
        iwish ......... [incr Tcl] wish  (wish + namespaces)
        itclsh ........ tclsh + namespaces + classes
        itkwish ....... wish + namespaces + classes + megawidgets

      If you configured this distribution with "--enabled-shared" to
      request dynamic loading, you can use "ish" as the core program
      and load everything else as needed.  For example, you can start
      up "ish" and load the [incr Widgets] package like this:

        unix$ ish
        % package require Iwidgets

      This single command is enough to load Tk4.1, Itcl2.1, Itk2.1
      and Iwidgets2.1.0 dynamically.  The main window "." will appear,
      and the interpreter will have all the commands needed to use
      the [incr Widgets] package.

      On some systems, you may get an error like:

          ish: can't load library 'libtcl7.5i.so'

      If you get this, it means that you need to include the "lib"
      directory containing the [incr Tcl] libraries in your
      LD_LIBRARY_PATH environment variable.  You might add some
      lines like this to your ".cshrc" or ".profile" file:

          csh users: add something this to .cshrc
            setenv LD_LIBRARY_PATH "/usr/local/lib/itcl:$LD_LIBRARY_PATH"

          ksh users: add something this to .profile
            LD_LIBRARY_PATH="/usr/local/lib/itcl:$LD_LIBRARY_PATH"
            export LD_LIBRARY_PATH

      This assumes that the libraries were installed in the
      directory "/usr/local/lib/itcl".


      If you did not configure for dynamic loading, you will probably
      want to use the "itkwish" program instead.  This includes
      everything you need to use [incr Widgets], and you won't have
      to worry about LD_LIBRARY_PATH at all.


 Installation on Macintosh Systems
------------------------------------------------------------------------
 This release should now work on MacOS.  MacOS users should use
 stuffit expander to expand the 'MacItcl.sit.hqx' archive and follow
 instructions in there.

 -- MacOS changes by:

      Vince Darley, 
      Harvard University, 
      <mailto:vince@das.harvard.edu>
      <http://www.fas.harvard.edu/~darley/>


 Integrating [incr Tcl] with other extensions
------------------------------------------------------------------------
 [incr Tcl] now requires its own version of Tcl/Tk with support for
 namespaces.  Therefore, you must use the version of Tcl/Tk that
 comes in this distribution as a basis for other applications.
 Hopefully, the namespace support will become a part of the standard
 distribution some day.

 You can add other extensions into the [incr Tcl] package by
 following the usual instructions for Tcl/Tk:

  1) Put the source code for the extension in the directory
     "itcl2.1", at the same level as the directories "tcl7.5"
     and "tk4.1".

  2) Copy "tclAppInit.c" or "tkAppInit.c" from the standard
     distribution.  Choose the appropriate version according to
     your needs:

       tcl7.5/tclAppInit.c .... Tcl with namespaces
       tk4.1/tkAppInit.c ...... Tcl/Tk with namespaces
       itcl/tclAppInit.c ...... Tcl with namespaces and [incr Tcl]
       itk/tkAppInit.c ........ Tcl/Tk with namespaces and [incr Tcl]/[incr Tk]

  3) Each extension should have an initialization function with a
     name like "XXX_Init()".  The BLT package, for example, has a
     function "Blt_Init()".

     a) Include the declarations for any initialization routines
        at the top of the tclAppInit.c or tkAppInit.c file.

     b) Within the body of Tcl_AppInit(), add a call to the
        initialization routine.  It should look something like this:

          if (Itcl_Init(interp) == TCL_ERROR) {
              return TCL_ERROR;
          }
          if (Itk_Init(interp) == TCL_ERROR) {
              return TCL_ERROR;
          }
          if (Blt_Init(interp) == TCL_ERROR) {
              return TCL_ERROR;
          }

        In this example we have integrated BLT in with [incr Tcl] and
        [incr Tk].

  4) Link your application with the appropriate libraries:

       libtcl.a ............ Tcl with namespaces
       libtk.a ............. Tk with namespaces
       libitcl.a ........... [incr Tcl]
       libitk.a ............ [incr Tk]
       -lX11 ............... X11 library

     Make sure to use the versions of "libtcl.a" and "libtk.a" that
     are sitting with "libitcl.a" and "libitk.a" in the "lib/itcl"
     directory.


 Acknowledgements
------------------------------------------------------------------------
 Thanks to Karel Zuiderveld, Jan Nijtmans and Vince Darley for making
 the integration with tcl7.5/tk4.1 a reality.  They did an enormous
 amount of work to make sure that things build cleanly and work smoothly.
 They even added functionality to the core Tcl/Tk distribution.

 Thanks to Jim Ingham, Christopher Hylands, Jan Nijtmans and Vince
 Darley for doing a quick beta test for the itcl2.1 release.

 Thanks to Mark Ulferts, Sue Yockey, John Sigler, Bill Scott, Alfredo
 Jahn, Tako Schotanus and Kris Raney for building the [incr Widgets]
 package.  With a sketchy overview and a crappy prototype of [incr Tk],
 they managed to build a nice set of mega-widgets.  Their initial
 designs helped me smooth out the rough spots in [incr Tk].

 Thanks to George Howlett for donating the tiling code from his BLT
 toolkit.  This adds a "-tile" option which allows widgets to have a
 pixmap background instead of a solid color.

 Thanks to Forest Rouse and ICEM CFD Engineering for integrating
 [incr Tcl] into their Tcl/Tk compiler.  This is a large undertaking,
 and they have done an excellent job.

 Thanks to Alfredo Jahn and Bret Schuhmacher at WebNet for helping
 to create the [incr Tcl] web site.

 Thanks to Joe Hildebrand for maintaining the [incr Tcl] mailing list.

 Thanks to extension writers like Mark Diekhans (tclX) and Ioi Lam (Tix)
 for making their packages compatible with [incr Tcl].

 Thanks to George Howlett for teaching me how namespaces should really
 work.  He has been a constant source of inspiration, and has kept
 a careful watch against many bad ideas.  Jim Ingham fleshed out the
 notion of explicit scoping, and added many nice features to [incr Tk].
 Bill Scott, with a steady stream of bug reports, helped me understand
 the questions that a typical user might have.  He forced me to reinvent
 the paradigm on more than one occasion.

 Thanks to more than 100 beta-testers that helped me polish the itcl2.0
 release.

 Thanks to Mark Harrison for his enthusiasm and support.  Due in
 large part to his evangelism, I have been able to make [incr Tcl]
 development a mainstream activity.

 And many thanks to my wife Maria and my son Maxwell for putting up
 with all of this.

--Michael

    =--===   ///////////////////////////////////////////////////////////
  =-----====   Michael J. McLennan 2C-226    michael.mclennan@att.com 
 =------=====  AT&T Bell Laboratories
 ==----======  1247 S Cedar Crest Blvd        Phone: (610) 712-2842
  ==========   Allentown, PA  18103             FAX: (610) 712-2773
    ======   ///////////////////////////////////////////////////////////
