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Appendix C. Complete Program Listings


Robot Control Program complex.ptr

This appendix contains program listings that, for one reason or another, did not appear in the book proper. This is mostly because only a small portion of the code was applicable to the chapter in which it appeared. Nonetheless, seeing the program in its entirety is useful, so here's a chapter full of code. Enjoy!

C.1. Tk::CollapsableFrame

Use a CollapsableFrame to hide information until the widget is opened. This widget is used by the MacCopy widget, described next. Both Tk::CollapsableFrame and Tk::MacCopy are more examples of composite mega-widgets, described in Chapter 14, "Creating Custom Widgets in Pure Perl/Tk".

See Figure C-1 for a demonstration of a CollapsableFrame widget.

Figure C-1

Figure C-1. A CollapsableFrame, shown both hidden and displayed

$Tk::CollapsableFrame::VERSION = '1.0';

package Tk::CollapsableFrame;

use Carp;
use Tk::widgets qw/Frame/;
use vars qw/$cf_height_bias $im_Close $im_Open/;
use strict;

use base qw/Tk::Frame/;
Construct Tk::Widget 'CollapsableFrame';

sub ClassInit {

    # Define global variables and images for the class.

    my($class, $mw) = @_;

    $cf_height_bias = 22;

    $im_Close = $mw->Photo(-data =>

    $im_Open = $mw->Photo(-data =>

} # end ClassInit

sub Populate {

    # Create an instance of a CollapsableFrame.  Instance variables are:
    # {frame} = the ridged frame, which contains the open/close
    #           Label image, the id Label for the collapsable Frame,
    #           and the container Frame within which the user manages
    #           collapsable widgets.  It's ALMOST possible to forgo
    #           this extra internal frame, were it not for the -pady
    #           packer attribute we use to make the widget look pretty.
    # {opcl}  = the open/close image Label.
    # {ident} = the identifying Label.
    # {colf}  = the user's container Frame, advertised as "colf".

    my($self, $args) = @_;

    my $height = $args->{-height};
    croak "Tk::CollapsableFrame: -height must be >= $cf_height_bias" unless
        $height >= $cf_height_bias;

    $self->{frame} = $self->Frame(
        qw/-borderwidth 2 -height 16 -relief ridge/,
        qw/-anchor center -expand 1 -fill x -pady 7 -side left/,

    $self->{opcl} = $self->Label(
        qw/-borderwidth 0 -relief raised/, -text => $height,
    $self->{opcl}->bind('<Button-1>' => [sub {$_[1]->toggle}, $self]);
        qw/-x 5 -y -1 -width 21 -height 21 -anchor nw -bordermode ignore/,

    $self->{ident} = $self->Label(qw/-anchor w -borderwidth 1/);
        qw/-x 23 -y 3  -height 12 -anchor nw -bordermode ignore/,

    $self->{colf} = $self->{frame}->Frame;
    $self->{colf}->place(qw/-x 20 -y 15/);
    $self->Advertise('colf' => $self->{colf});

    if (not defined $args->{-width}) {
	$args->{-width} = $self->parent->cget(-width);

      -background  => [qw/SELF background Background/],
      -height      => [qw/METHOD height Height 47/],
      -image       => [$self->{opcl}, 'image', 'Image', $im_Open],
      -title       => '-text',
      -text        => [$self->{ident}, qw/text Text NoTitle/],
      -width       => [$self->{frame}, qw/width Width 250/],
} # end Populate

sub bias {return $cf_height_bias}

# Instance methods.

sub toggle {
    my($self) = @_;
    my $i = $self->{opcl}->cget(-image);
    my $op = ($i == $im_Open) ? 'open' : 'close';
    $self->$op( );

sub close {
    my($self) = @_;
    $self->{opcl}->configure(-image  => $im_Open);
    $self->{frame}->configure(-height => 16);

sub open  {
    my($self) = @_;
    $self->{opcl}->configure(-image  => $im_Close);
    $self->{frame}->configure(-height => $self->{opcl}->cget(-text));

sub height {
    my($self, $h) = @_;
    $self->{opcl}->configure(-text => $h);



=head1 NAME

Tk::CollapsableFrame - a Frame that opens and closes via a mouse click.


S<    >I<$cf> = I<$parent>-E<gt>B<CollapsableFrame>(I<-option> =E<gt> I<value>);


This widget provides a switchable open or closed Frame
that provides for the vertical arrangement of widget
controls. This is an alternative to Notebook style
tabbed widgets.

The following option/value pairs are supported:

=over 4

=item B<-title>

Title of the CollapsableFrame widget.

=item B<-height>

The maximun open height of the CollapsableFrame.


=head1 METHODS

=over 4

=item B<close>

Closes the CollapsableFrame.

=item B<open>

Opens the CollapsableFrame.

=item B<toggle>

Toggles the open/close state of the CollapsableFrame.



Component subwidgets can be accessed via the B<Subwidget> method.
Valid subwidget names are listed below.

=over 4

=item Name:  colf, Class:  Frame

  Widget reference of the internal Frame widget within which user
  widgets are managed.


=head1 EXAMPLE

 use Tk::widgets qw/CollapsableFrame Pane/;

 my $mw = MainWindow->new;

 my $pane = $mw->Scrolled(
      qw/Pane -width 250 -height 50 -scrollbars osow -sticky nw/,

 my $cf = $pane->CollapsableFrame(-title => 'Frame1 ', -height => 50);
 $cf->pack(qw/-fill x -expand 1/);

 my $colf = $cf->Subwidget('colf');
 my $but = $colf->Button(-text => 'Close Frame 1!');
 $but->bind('<Button-1>' => [sub {$_[1]->close}, $cf]);


Stephen.O.Lidie@Lehigh.EDU, 2000/11/27.

Copyright (C) 2000 - 2001, Stephen O. Lidie.

This program is free software, you can redistribute it and/or modify
it under the same terms as Perl itself.

Based on the Tck/Tk CollapsableFrame widget by William J Giddings.


CollapsableFrame, Frame, Pane


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