Add a GtkBuilder section to the tutorial

examples/builder.c

@@ -0,0 +1,40 @@
+#include <gtk/gtk.h>
+
+static void
+print_hello (GtkWidget *widget,
+             gpointer   data)
+{
+  g_print ("Hello World\n");
+}
+
+int
+main (int   argc,
+      char *argv[])
+{
+  GtkBuilder *builder;
+  GObject *window;
+  GObject *button;
+
+  gtk_init (&argc, &argv);
+
+  /* Construct a GtkBuilder instance and load our UI description */
+  builder = gtk_builder_new ();
+  gtk_builder_add_from_file (builder, "builder.ui", NULL);
+
+  /* Connect signal handlers to the constructed widgets. */
+  window = gtk_builder_get_object (builder, "window");
+  g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
+
+  button = gtk_builder_get_object (builder, "button1");
+  g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
+
+  button = gtk_builder_get_object (builder, "button2");
+  g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
+
+  button = gtk_builder_get_object (builder, "quit");
+  g_signal_connect (button, "clicked", G_CALLBACK (gtk_main_quit), NULL);
+
+  gtk_main ();
+
+  return 0;
+}