SpecPerl 0.2  

This package contains two scripts for producing perl/Tk output from
specTcl. 

This should be considered a beta release; I have created and tested
the scripts using perl 5.003 and Tk400.202 on a DEC Alpha running
Digital Unix 4.0a. I am skeptical that it would run on a much earlier
version of Tk, as the grid geometry manager used here is relatively
new and experimental. In particular, don't expect this to be useful on
a Mac or PC, as the perl/Tk is broken or nonexistent there. Your
mileage may vary.


Changes: 

0.1 to 0.2

        - better handling of variables and textvariables entered via
          the widget configuration dialog
        - better handling of attached scrollbars and other widget
          containing commands
        - now works correctly with files in other directories. This
          is still a bug in specTcl, but is now fixed in specPerl :)
          (Achim Bohnet and Stephen O. Lidie)
        - encapsulated MainWindow object $top in wrapper code;
          perl -w -Mstrict hello.ui.pl now passes
          (Larry Virden)
        - a number of less significant changes

I would like to thank Achim Bohnet, Stephen O. Lidie, and Larry Virden
for their comments on and testing of specPerl 0.1. Unbeknownst to me,
Achim and Stephen were also working a specPerl project and graciously
allowed me to peruse their code. In doing so, I discovered the third
bug above and also made several improvements to my perl code
generation. With their code folded into mine, this specPerl will
become the "official" version.


Installation:

0) get the SpecTcl distribution from

        http://www.sunlabs.com/research/tcl/spectcl/
   
   and thank Stephen Uhler and Ken Corey for making the source
   available. Unpacking it yields the directories

        SpecTcl1.0/
        SpecTcl1.0/SpecTcl/
        SpecTcl1.0/bin

1) move the script SpecTcl1.0/SpecTcl/perl_init.tk  
                to SpecTcl1.0/SpecTcl/perl_init.tk.old
   
   copy the script perl_init.tk to SpecTcl1.0/SpecTcl/perl_init.tk 
   copy the script specPerl to SpecTcl1.0/bin/specPerl

2) edit the file specPerl and change the line

      DIR=/home/kvale/tcltk/SpecTcl1.0/SpecTcl
  
   to the corresponding directory on your machine.



Running specPerl:

specPerl runs in pretty much the same way as specTcl does, so the online
help is applicable for specPerl as well. When saving project foo,
specPerl produces two files: foo.ui and foo.ui.pl. One can test the Tk
perl script by pressing the execute button or "Build Perl" in the
Commands menu. One kills the running script by pressing the Stop
button or the "Kill Perl" entry in the Commands menu. Note that
in addition to "Save" and "Save As", "Build Perl" also saves the
project. 

Once the 


Two projects are included in the package:

    hello.ui, hello.ui.pl - the canonical Tk project
    trip.ui, trip.ui.pl - a nonsensical, but gnarly trip test for specPerl 

In fact, trip.ui is gnarly enough to pick out three bugs:
   1) when executing specTcl trip.ui, one cannot modify the text of
      the "exit" button. (This is a intermittent problem.)
   2) run specPerl trip.ui and build a perl test. When you press on
      either menu button, you get the message

Tk::Error: Can't locate object method "Unpost" via package "Tk::Menu"
at /home/kvale/lib/perl5/site_perl/auto/Tk/Menubutton/ButtonUp.al line 14.
(command bound to event) at
/home/kvale/lib/perl5/site_perl/auto/Tk/Error.al line 13. 

****late breaking news: 10/9/97 - I added require Tk::Menu; to the
wrapper, so that this warning no longer occurs. *****

The perl/Tk code looks ok, and the corresponding tcl code gives no error.

Another bug, courtesy of Larry Virden <lvirden@cas.org>:
   3) if one executes perl -w trip.ui.pl, one gets the following
      message on startup:        

Use of uninitialized value at /home/kvale/lib/perl5/site_perl/Tk/Widget.pm line 183.
Use of uninitialized value at /home/kvale/lib/perl5/site_perl/Tk/Widget.pm line 183.

If one then runs the cursor through either of the scale widgets, one
gets many

Use of uninitialized value at /home/kvale/lib/perl5/site_perl/auto/Tk/Scale/Activate.al line 19.


perl/Tk notes: 

In general, the perl code produced by specPerl is a close counterpart
to the tcl code produced by specTcl. The main difference lies in two
places: 
        - the wrapper around the subroutine. The Tk400.202 distribution
          has a bug in the grid geometry manager: the gridRowconfigure and
          gridColumnconfigure methods do not work with the MainWindow
          object, so I put all the widgets in a Frame in the
          MainWindow object. I'll change this when the grid manager
          gets fixed. 

        - the widget commands. When, e.g., attaching scrollbars to a
          text widget in Tcl/Tk, one can create -commands involving
          undefined widgets with impunity, as long as those widgets
          are defined by the time the -command gets executed. In
          perl/Tk by contrast, the widgets need to be defined before
          they are used in a -command. In specPerl, this is handled by
          creating all the widgets first, and then further configuring
          all the widgets with -command type options.



I would enjoy hearing your comments, what you are building with
specPerl, bug reports and fixes, etc. My address is kvale@phy.ucsf.edu

Enjoy!
                                -Mark