getting started with gtk-builder

[Damon Register <damon w register lmco com>]

Just when I finally am making some progress with learning gtkmm and
libglademm, along comes gtk-builder.  Since gtk-builder is the future,
I would like to start learning that before I get too far down the
libglademm road.

So far I don't find much help on learning gtk-builder.  The only
tutorial I could find is
http://www.micahcarrick.com/05-30-2008/gtk-builder-libglade-faq.html
which covers C but I don't know how to do that in C++.

If I could just get started with a simple hello world example, I
could probably make some progress with gtk-builder.  Using the gtkmm
documentation, I have made guess-work changes to a simple libglademm
example I have.  It compiles and runs but does not display as I
expect.  It only shows a small window.

In the hello.cpp I have commented the libglademm items and replaced
them with what I think are the appropriate gtk-builder items.
Can anyone please tell me what I am doing wrong?

Damon Register

----------------- hello.xml ----------------------------------------

<?xml version="1.0"?>
<!--*- mode: xml -*-->
<interface>
  <object class="GtkWindow" id="hello_main_window">
    <child>
      <object class="GtkLayout" id="layout1">
        <property name="width_request">450</property>
        <property name="height_request">450</property>
        <property name="visible">True</property>
        <property name="width">450</property>
        <property name="height">450</property>
        <child>
          <object class="GtkButton" id="button2">
            <property name="width_request">100</property>
            <property name="height_request">25</property>
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="receives_default">True</property>
            <property name="label" translatable="yes">quit</property>
          </object>
          <packing>
            <property name="x">21</property>
            <property name="y">403</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>

-------------------------- hello.cpp ---------------------------

#include <iomanip>
#include <sstream>
#include <iostream>

#include <locale.h>
#include <sigc++/retype_return.h>
#include <gtkmm.h>

class hello : public Gtk::Window
{
public:
  hello();
  virtual ~hello();

protected:
  // The widgets that are manipulated.
  Gtk::Button* quit_button;

  // Glade interface description.
  //Glib::RefPtr<Gnome::Glade::Xml> xml_interface;
  Glib::RefPtr<Gtk::Builder>  xml_interface;

};

using namespace std;

hello::hello()
{
  int k;
  double heading;

  std::cout << "hello()" << std::endl;
  set_title("gtk-builder demo");
  set_resizable(false);

  // Get the Glade user interface and add it to this window.
  //xml_interface = Gnome::Glade::Xml::create("hello.glade", "layout1");
  xml_interface = Gtk::Builder::create_from_file("hello.xml");

  Gtk::Layout *main_vbox;
  xml_interface->get_widget("layout1", main_vbox);
  //add(*main_vbox);
// if this line is uncommented I get a runtime warning about
// layout1 already being inside a window

  xml_interface->get_widget("button2", quit_button);

  // Set up signal handers for buttons.
  quit_button->signal_clicked().connect ( sigc::mem_fun(*this, &hello::hide) );

}

hello::~hello()
{
    std::cout << "~hello()" << std::endl;
}

int main (int argc, char *argv[])
{
  Gtk::Main kit(argc, argv);
  hello window;
  kit.run(window);
  return 0;
}