#include <gtk/gtk.h>

#define XSIZE  600
#define YSIZE  400

/* This routine gets control when the close button is clicked */
gint close_application( GtkWidget *widget,
                        GdkEvent  *event,
                        gpointer   data )
{
	gtk_main_quit ();
	return FALSE;
}

/* The main routine */
int main( int argc, char *argv[] )
{
	GtkWidget	*window, *drawing_area;
	GdkColor	*color;
	GdkGC	*gc;
	guint16 red = 100, green = 0, blue = 0;

	/* Initialize GTK and create the main window */
	gtk_init (&argc, &argv);

	window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
	g_signal_connect (G_OBJECT (window), "delete_event",
	                  G_CALLBACK (close_application), NULL);

	drawing_area = gtk_drawing_area_new ();
	gtk_container_add (GTK_CONTAINER (window), drawing_area);
	gtk_widget_set_size_request (GTK_WIDGET (drawing_area), XSIZE, YSIZE);

	gtk_widget_realize(drawing_area);
	/* first, create a GC to draw on */
	gc = gdk_gc_new(drawing_area->window);

	/* the color we want to use */
	color = (GdkColor *) g_malloc(sizeof(GdkColor));
	color->red = red * (65535/255);
	color->green = green * (65535/255);
	color->blue = blue * (65535/255);
	color->pixel = (gulong)(red*65536 + green*256 + blue);
	gdk_color_alloc(gtk_widget_get_colormap(drawing_area), color);
	gdk_gc_set_foreground(gc, color);
	g_free(color);
	gdk_gc_set_line_attributes(gc, 8, GDK_LINE_SOLID, GDK_CAP_NOT_LAST,
	                           GDK_JOIN_MITER);
	gdk_draw_line(drawing_area->window, gc, 0, 0, 300, 300);

	/* Now show everything */
	gtk_widget_show (drawing_area);
	gtk_widget_show (window);
	gtk_main ();

	return 0;
}