#!/usr/bin/perl -w

use Gtk;
use strict;

set_locale Gtk;
init Gtk;

unless ( $ARGV[0] )
  {
    print( "usage: packbox num, where num is 1, 2, or 3.\n" );
    Gtk->exit( 1 );
    exit( 1 );
  }

my $false = 0;
my $true = 1;
my $which = $ARGV[0];

my $window;
my $box1;
my $box2;
my $label;
my $separator;
my $quitbox;
my $button;

# You should always remember to connect the delete_event signal
# to the main window. This is very important for proper intuitive
# behavior
$window = new Gtk::Window( "toplevel" );
$window->signal_connect( "delete_event", sub { Gtk->exit( 0 ); } );
$window->border_width( 10 );

# We create a vertical box (vbox) to pack the horizontal boxes
# into. This allows us to stack the horizontal boxes filled with
# buttons one on top of the other in this vbox.
$box1 = new Gtk::VBox( $false, 0 );

# which example to show. These correspond to the pictures above.
if ( $which == 1 )
  {
    # create a new label.
    $label = new Gtk::Label( 'new Gtk::HBox( $false, 0 );' );
    
    # Align the label to the left side.  We'll discuss this function
    # and others in the section on Widget Attributes.
    $label->set_alignment( 0, 0 );
    
    # Pack the label into the vertical box (vbox box1).  Remember
    # that widgets added to a vbox will be packed one on top of the
    # other in order.
    $box1->pack_start( $label, $false, $false, 0 );
    
    # Show the label
    $label->show();
    
    # Call our make box function - homogeneous = FALSE, spacing = 0, 
    # expand = FALSE, fill = FALSE, padding = 0
    $box2 = make_box( $false, 0, $false, $false, 0 );
    $box1->pack_start( $box2, $false, $false, 0 );
    $box2->show();
    
    # Call our make box function - homogeneous = FALSE, spacing = 0,
    # expand = TRUE, fill = FALSE, padding = 0
    $box2 = make_box( $false, 0, $true, $false, 0 );
    $box1->pack_start( $box2, $false, $false, 0 );
    $box2->show();
    
    # Args are: homogeneous, spacing, expand, fill, padding
    $box2 = make_box( $false, 0, $true, $true, 0 );
    $box1->pack_start( $box2, $false, $false, 0 );
    $box2->show();
    
    # Creates a separator, we'll learn more about these later, but
    # they are quite simple. 
    $separator = new Gtk::HSeparator();
    
    # Pack the separator into the vbox. Remember each of these
    # widgets is being packed into a vbox, so they'll be stacked 
    # vertically.
    $box1->pack_start( $separator, $false, $true, 5 );
    $separator->show();
    
    # Create another new label, and show it.
    $label = new Gtk::Label( 'new Gtk::HBox( $true, 0 );' );
    $label->set_alignment( 0, 0 );
    $box1->pack_start( $label, $false, $false, 0 );
    $label->show();
    
    # Args are: homogeneous, spacing, expand, fill, padding
    $box2 = make_box( $true, 0, $true, $false, 0 );
    $box1->pack_start( $box2, $false, $false, 0 );
    $box2->show();
    
    # Args are: homogeneous, spacing, expand, fill, padding
    $box2 = make_box( $true, 0, $true, $true, 0 );
    $box1->pack_start( $box2, $false, $false, 0 );
    $box2->show();
    
    # Another new separator.
    $separator = new Gtk::HSeparator();
    
    # The last 3 arguments to gtk_box_pack_start are:
    # expand, fill, padding.
    $box1->pack_start( $separator, $false, $true, 5 );
    $separator->show();
  }
elsif ( $which == 2 )
  {
    # Create a new label, remember box1 is a vbox as created  near
    # the beginning of main()
    $label = new Gtk::Label( 'new Gtk::HBox( $false, 10 );' );
    $label->set_alignment( 0, 0 );
    $box1->pack_start( $label, $false, $false, 0 );
    $label->show();
    
    # Args are: homogeneous, spacing, expand, fill, padding
    $box2 = make_box( $false, 10, $true, $false, 0 );
    $box1->pack_start( $box2, $false, $false, 0 );
    $box2->show();
    
    # Args are: homogeneous, spacing, expand, fill, padding
    $box2 = make_box( $false, 10, $true, $true, 0 );
    $box1->pack_start( $box2, $false, $false, 0 );
    $box2->show();
    
    $separator = new Gtk::HSeparator();
    # The last 3 arguments to gtk_box_pack_start are: expand, fill,
    # and padding.
    $box1->pack_start( $separator, $false, $true, 5 );
    $separator->show();
    
    $label = new Gtk::Label( 'new Gtk::HBox( $false, 0 );' );
    $label->set_alignment( 0, 0 );
    $box1->pack_start( $label, $false, $false, 0 );
    $label->show();
    
    # Args are: homogeneous, spacing, expand, fill, padding
    $box2 = make_box( $false, 0, $true, $false, 10 );
    $box1->pack_start( $box2, $false, $false, 0 );
    $box2->show();
    
    # Args are: homogeneous, spacing, expand, fill, padding
    $box2 = make_box( $false, 0, $true, $true, 10 );
    $box1->pack_start( $box2, $false, $false, 0 );
    $box2->show();
    
    $separator = new Gtk::HSeparator();
    # The last 3 arguments to pack_start are: expand, fill,
    # and padding.
    $box1->pack_start( $separator, $false, $true, 5);
    $separator->show();
  }
elsif ( $which == 3 )
  {
    # This demonstrates the ability to use pack_end() to right
    # justify widgets. First, we create a new box as before.
    $box2 = make_box( $false, 0, $false, $false, 0);
    
    # Create the label that will be put at the end.
    $label = new Gtk::Label( "end" );
    # Pack it using gtk_box_pack_end(), so it is put on the right
    # side of the hbox created in the make_box() call.
    $box2->pack_end( $label, $false, $false, 0 );
    # Show the label.
    $label->show();
    
    # Pack box2 into box1 (the vbox remember ? :)
    $box1->pack_start( $box2, $false, $false, 0 );
    $box2->show();
    
    # A separator for the bottom.
    $separator = new Gtk::HSeparator();
    # This explicitly sets the separator to 400 pixels wide by 5
    # pixels high. This is so the hbox we created will also be 400
    # pixels wide, and the "end" label will be separated from the
    # other labels in the hbox. Otherwise, all the widgets in the
    # hbox would be packed as close together as possible.
    $separator->set_usize( 400, 5 );
    # pack the separator into the vbox (box1) created near the start 
    # of main()
    $box1->pack_start( $separator, $false, $true, 5 );
    $separator->show();    
  }

# Create another new hbox.. remember we can use as many as we need!
$quitbox = new Gtk::HBox( $false, 0 );

# Our quit button.
$button = new Gtk::Button( "Quit" );

# Setup the signal to terminate the program when the button is
# clicked
$button->signal_connect( "clicked", sub { Gtk->exit( 0 ); } );
# Pack the button into the quitbox.
# The last 3 arguments to gtk_box_pack_start are:
# expand, fill, padding.
$quitbox->pack_start( $button, $true, $false, 0 );
# pack the quitbox into the vbox (box1)
$box1->pack_start( $quitbox, $false, $false, 0 );

# Pack the vbox (box1) which now contains all our widgets, into the
# main window.
$window->add( $box1 );

# And show everything left
$button->show();
$quitbox->show();

$box1->show();
# Showing the window last so everything pops up at once.
$window->show();

# And of course, our main function.
main Gtk;
exit( 0 );



### Subroutines

# Make a new hbox filled with button-labels. Arguments for the
# variables we're interested are passed in to this function. 
# We do not show the box, but do show everything inside.
sub make_box
  {
    my ( $homogeneous, $spacing, $expand, $fill, $padding ) = @_;
    
    # Create a new hbox with the appropriate homogeneous
    # and spacing settings
    my $box = new Gtk::HBox( $homogeneous, $spacing );
    
    $button = new Gtk::Button( '$box->' );
    $box->pack_start( $button, $expand, $fill, $padding );
    $button->show();
    
    # Create a series of buttons with the appropriate settings
    $button = new Gtk::Button( "pack" );
    $box->pack_start( $button, $expand, $fill, $padding );
    $button->show();
    
    $button = new Gtk::Button( '( $button,' );
    $box->pack_start( $button, $expand, $fill, $padding );
    $button->show();
    
    # Create a button with the label depending on the value of
    # expand.
    if ( $expand )
      {
	$button = new Gtk::Button( '$true,' );
      }
    else
      {
	$button = new Gtk::Button( '$false,' );
      }
    
    $box->pack_start( $button, $expand, $fill, $padding );
    $button->show();
    
    # This is the same as the button creation for "expand"
    if ( $fill )
      {
	$button = new Gtk::Button( '$true,' );
      }
    else
      {
	$button = new Gtk::Button( '$false,' );
      }
    
    $box->pack_start( $button, $expand, $fill, $padding );
    $button->show();
    
    $button = new Gtk::Button( "$padding );" );
    $box->pack_start( $button, $expand, $fill, $padding );
    $button->show();
    
    return ( $box );
  }


# END EXAMPLE PROGRAM