Am trying to develop my first (maybe 1st.5) GUI in Tk. I had program working in non-object oriented mode and have been converting to object oriented (only 2.3x in size (751 lines ->1776 lines), so far; :-) ).

I seem to be running into an "oddity".

There are "handler" functions, in Tk, that can be called when events happen like keyboard or timer input.

I'm running into a "unique" problem from the object oriented structure I'm converting to. When my classes are being called from a Tk event handler, calls are not finding "base" or ancestor "methods" in handler routines. Sample error messages: 

Tk::Error: Undefined subroutine &Entry_Display_In_Wins::next_rand_or_r
+ecorded_file called at shown.pl line 1403.
 <Key>
 (command bound to event)
 at blib/lib/Tk.pm (autosplit into blib/lib/auto/Tk/Error.al) line 488
    Tk::Error('MainWindow=HASH(0x667084)', 'Undefined subroutine &Entr
+y_Display_In_Wins::next_rand_or_rec...', '<Key>', '(command bound to 
+event)') called at /usr/lib/perl5/vendor_perl/5.8/cygwin/Tk.pm line 4
+06
    eval {...} called at /usr/lib/perl5/vendor_perl/5.8/cygwin/Tk.pm l
+ine 406
    Tk::MainLoop called at shown.pl line 1720
    main::main() called at shown.pl line 1727
----
and
----

Tk::Error: Undefined subroutine &Entry_Display_In_Wins::write_db calle
+d at shown.pl line 1392.
 <Key>
 (command bound to event)
 at blib/lib/Tk.pm (autosplit into blib/lib/auto/Tk/Error.al) line 488
    Tk::Error('MainWindow=HASH(0x667084)', 'Undefined subroutine &Entr
+y_Display_In_Wins::write_db cal...', '<Key>', '(command bound to even
+t)') called at /usr/lib/perl5/vendor_perl/5.8/cygwin/Tk.pm line 406
    eval {...} called at /usr/lib/perl5/vendor_perl/5.8/cygwin/Tk.pm l
+ine 406
    Tk::MainLoop called at shown.pl line 1720
    main::main() called at shown.pl line 1727

[download]
Both "write_filedb" and "next_rand_or_recorded_file" are in Base classes of the handler routines.

Relevant packages are like this 

   package File_Rating_DB;                 #pckg ONE
      sub write_db(){}...

   package Entry_Ordering;                 #pckg TWO
    our @ISA = qw(File_Rating_DB);
      sub next_rand_or_recorded_file() {}...

   package Entry_Display_In_Wins;          #pckg THREE
    our @ISA = qw(Entry_Ordering);
      sub __hk_space(){ call next_rand_or_recorded_file}...
      sub __hk_quit(){ ...calls write_db on exit }
      sub handle_key($tkcontext,$dbhandle,$key_event, $key_code) {}

   package Timed_Display_In_Wins;          #pckg FOUR
    our @ISA = qw(Entry_Display_In_Wins);
      sub _handle_timer(){}

[download]
I've disabled timer ticks for now, so only events coming in are from keyboard, but got similar error:
"Tk::Error: Undefined subroutine Timed_Display_In_Wins::write_db not found..."
when it was enabled.

As may or may not be evident, the handler routines are located in pckg's THREE and FOUR, and try to call routines in pckg's TWO and ONE.

Any special "magic" I was supposed to use to get my handling routine's "base" classes to be searched?

It is, as if is "losing" my "Base" classes as it enters into my "handler(s)" from Tk.

Focusing on the keyboard, I bind it with: 

$main_win->bind('<Any-KeyPress>'=>[\&handle_key, $s,Ev('A'), Ev('K')])
+;

[download]
so the routines are called like "$main_win->handle_key($s, Ev('A'), Ev('K'))", where "$s" is the main "self" data structure/pointer.

Subroutines in the same "package" seem to be called correctly, like "handle_key->calls->hk_space, but hk_space can't find "next_rand_or_recorded" from its parent.

What am I missing? :-?
Thanks!
Linda

In reply to Missing base classes when called from Tk by perl-diddler

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