use Glib qw/TRUE FALSE/;
use Gtk2 '-init';

sub delete_event
{
	Gtk2->main_quit;
	return FALSE;
}

# 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
	$box = Gtk2::HBox->new($homogenous, $spacing);

	# Create a series of buttons with the appropriate settings
	$button = Gtk2::Button->new("Gtk2::HBox::pack");
	$box->pack_start($button, $expand, $fill, $padding);
	$button->show;

	$button = Gtk2::Button->new("(box,");
	$box->pack_start($button, $expand, $fill, $padding);
	$button->show;

	$button = Gtk2::Button->new("button,");
	$box->pack_start($button, $expand, $fill, $padding);
	$button->show;
	
	# Create a button with the label depending on the value of $expand.
	if ($expand == TRUE)
	{
		$button = Gtk2::Button->new("TRUE,");
	}
	else
	{
		$button = Gtk2::Button->new("FALSE,");
	}

	$box->pack_start($button, $expand, $fill, $padding);
	$button->show;
	
	# This is the same as the button creation for "expand"
	# above, but uses the shorthand form.
	$button = Gtk2::Button->new($fill ? "TRUE," : "FALSE,");
	$box->pack_start($button, $expand, $fill, $padding);
	$button->show;

	$button = Gtk2::Button->new("$padding");
	$box->pack_start($button, $expand, $fill, $padding);
	$button->show;

	return $box;
}

die "usage: packbox.pl num, where num is 1, 2, or 3.\n"
	unless defined $ARGV[0];

# Create our window
$window = Gtk2::Window->new('toplevel');

# You should always remember to connect the delete_event signal
# to the main window. This is very important for proper intuitive
# behavior
$window->signal_connect(delete_event => \&delete_event);
$window->set_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 = Gtk2::VBox->new(FALSE, 0);
$which = $ARGV[0];

# which example to show. These correspond to the pictures above.
if (1 == $which)
{
	# create a new label.
	$label = Gtk2::Label->new("Gtk2::HBox->new (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, 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 = Gtk2::HSeparator->new;

	# 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 = Gtk2::Label->new("Gtk2::HBox->new (TRUE, 0);");
	$label->set_alignment(0.0, 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 = Gtk2::HSeparator->new;
	# The last 3 arguments to gtk_box_pack_start are:
	# expand, fill, padding.
	$box1->pack_start($separator, FALSE, TRUE, 5);
	$separator->show;
}
elsif (2 == $which)
{
	# Create a new label, remember box1 is a vbox as created
	# near the beginning
	$label = Gtk2::Label->new("Gtk2::HBox->new (FALSE, 10);");
	$label->set_alignment(0.0, 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 = Gtk2::HSeparator->new;
	# The last 3 arguments to gtk_box_pack_start are:
	# expand, fill, padding.
	$box1->pack_start($separator, FALSE, TRUE, 5);
	$separator->show;

	$label = Gtk2::Label->new("Gtk2::HBox->new (FALSE, 0);");
	$label->set_alignment(0.0, 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 = Gtk2::HSeparator->new;
	# The last 3 arguments to gtk_box_pack_start are:
	# expand, fill, padding.
	$box1->pack_start($separator, FALSE, TRUE, 5);
	$separator->show;
}
elsif (3 == $which)
{
	# This demonstrates the ability to use gtk_box_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 = Gtk2::Label->new("end");
	# Pack it using Gtk2::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 = Gtk2::HSeparator->new;
	# 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_size_request(400, 5);
	# pack the separator into the vbox (box1) created near the start
	$box1->pack_start($separator, FALSE, TRUE, 5);
	$separator->show;
}

# Create another new hbox.. remember we can use as many as we need!
$quitbox = Gtk2::HBox->new(FALSE, 0);

# Our quit button.
$button = Gtk2::Button->new("Quit");

# Setup the signal to terminate the program when the button is clicked
$button->signal_connect(clicked => sub { Gtk2->main_quit; });

# 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.
Gtk2->main;

# Control returns here when gtk_main_quit() is called, but not when
# exit() is used.
0;