=head1 NAME

Tk::TextUndo - perl/tk text widget with bindings to undo changes.

=for pm Tk/TextUndo.pm

=for category Derived Widgets

=head1 SYNOPSIS

S<    >B<use Tk::TextUndo;>

S<    >I<$testundo> = I<$parent>-E<gt>B<TextUndo>(?I<-option>=E<gt>I<value>, ...?);

=head1 DESCRIPTION

This IS-A text widget with an unlimited 'undo' history but without
a re'undo' capability.

=head2 Bindings

The C<TextUndo> widget has the same bindings as the L<Text|Tk::Text> widget.
In addition there are the following bindings:

=over 4

=item Event <L4> <<Undo>>

undo the last change.  Pressing <L4> several times undo
step by step the changes made to the text widget.

=back

=head2 Methods

The C<TextUndo> widget has the same methods as C<Text> widget.
Additional methods for the C<TextUndo> widget are:

=over 4

=item $text->Load($filename);

Loads the contents of the $filename into the text widget. Load()
delete the previous contents of the text widget as well as it's
undo history of the previous file.

=item $text->Save(?$otherfilename?)

Save contents of the text widget to a file. If the
$otherfilename is not specified, the text widget contents
writes the file of $filename used in the last Load()
call.  If no file was previously Load()'ed an error message
pops up.  The default filename of the last Load() call
is not overwriten by $otherfilename.

=item $text->FileName(?$otherfilename?)

If passed an argument sets the file name associated with the loaded
document. Returns the current file name associated with the document.

=back

=head1 KEYS

widget, text, undo

=head1 SEE ALSO

L<Tk::Text>, L<Tk::ROText>

=cut