in reply to Re: Tk hidden binding
in thread Tk hidden binding

Many thanks for your concerned handling of this case and for the time spent. My version of Perl is v5.10.1 (*) built for x86_64-linux-gnu-thread-multi (with 53 registered patches) and Tk installed (by Cpan I think) under /usr/local/lib/perl/5.10.1/Tk.pm seems to be Tk804.029 (as displayed by 'man Tk').

I've run your tests and the results reported below are quite puzzling to me. I won't create another mini example because I think yours is perfectly demonstrative of my problem. Apart from the fact that I still don't know how to solve it I find some ease in not having disturbed you for mere carelessness.

My results for the keypress of <control-s>:

test 4 (the original behaviour of your program):
"main control s\n" is printed to the console when the focus is $mw.
"\t\tfoo\n" is printed in the in the console and "\x{13}" in the text widget when the insertion point is in.

test 3 uncommented (other tests commented out):
"main control s\n" is printed to the console when the focus is $mw.
"\t\tfoo\n" is printed in the in the console and "\x{13}" in the text widget when the insertion point is in.
Behaves as test 4.

test 2 uncommented (other tests commented out):
"main control s\n" is printed to the console when the focus is $mw.
"\ttext control s\nmain control s\n" is printed in the in the console and "\x{13}" in the text widget when the insertion point is in.

test 1 (each test commented out):
"main control s\n" is printed to the console when the focus is $mw.
"main control s\n" is printed in the in the console and "\x{13}" in the text widget when the insertion point is in.

Comment:
If it wouldn't be for test4 which differs deeply, I would think that your newline is replaced by \x{13} in my Tk version. But why should a newline be printed anyway?

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Re^3: Tk hidden binding
by zentara (Cardinal) on Jul 24, 2011 at 11:12 UTC
    I would think that your newline is replaced by \x{13} in my Tk version. But why should a newline be printed anyway?

    This brings up a good point, what do YOU expect to happen when you press a <control s> in the TextUndo widget? The normal behavior, on my Tk ( version Tk-804.029_500 ) , with no extra bindings associated with it, is to print what appears to be an underscore line segment, not a newline. It is not a dash or hyphen. Repeated presses of <control s> create a continuous line looking like an underscore (at the bottom of the font area).

    Do you want this behaviour?

    If you want to stop all text insertion, with a <control s>, try this and see what happens. I get NO insertion of any kind into the TextUndo widget. Notice I'm getting the REAL widget, not the Scrolled one. 

    #!/usr/bin/perl
use warnings;
use strict;
use Tk;
require Tk::TextUndo;

# a <control s> in the TextUndo widget produces
# nothing in the Text area, and a foo to the console

my $mw = tkinit;

# create a top bar for testing pure $mw focus
my $button = $mw->Button(-text=>'test')->pack();

$mw->bind('<Control-s>', sub { print "main control s \n" });

my $t = $mw->Scrolled ('TextUndo')->pack;
my $t1 = $t->Subwidget("scrolled"); # get real widget

$t1->bind('<Control-s>', sub { print "\t\tfoo\n"; $_[0]->break });
$t1->bindtags([($t1->bindtags)[1,0,2,3]]);

MainLoop;

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    To address the point that you saw no difference in binding to a Scrolled or standard TextUndo widget, notice the difference in behavior in this script, where I bind to the Scrolled widget. I get the foo to the console, plus the underscore line gets printed to the TextUndo. 

    #!/usr/bin/perl
use warnings;
use strict;
use Tk;
require Tk::TextUndo;

# when binding to the Scrolled widget, instead
# of the real widget, a line gets printed to the text area
# as well as the foo to the console

my $mw = tkinit;

# create a top bar for testing pure $mw focus
my $button = $mw->Button(-text=>'test')->pack();

$mw->bind('<Control-s>', sub { print "main control s \n" });

my $t1 = $mw->Scrolled ('TextUndo')->pack;

$t1->bind('<Control-s>', sub { print "\t\tfoo\n"; $_[0]->break });
$t1->bindtags([($t1->bindtags)[1,0,2,3]]);

MainLoop;

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      This is it. I still have to study your bindtags line to understand the syntax but the main point is that I can consider the problem solved and use your Subwidget trick from now on. Thank you again.

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