Signal handler problem while linking

["Tomek Lorek" <tlorek gmail com>]

Hi there,
I've got another thing that I can't go through: my sources are
compiling properly but the final linking fails with:
addtask.o: In function `AddTask::AddTask(Glib::RefPtr<Gnome::Glade::Xml>)':
addtask.cpp:(.text+0x490): undefined reference to `AddTask::on_ok_clicked()'
addtask.cpp:(.text+0x54a): undefined reference to `AddTask::on_cancel_clicked()'
addtask.cpp:(.text+0x604): undefined reference to
`AddTask::on_open_calendar_clicked()'

My sources are:

addtask.h
=======
#include <libglademm/xml.h>
#include <gtkmm.h>

class AddTask
{
  Gtk::Window* m_wWindow;
  Gtk::Button* m_wOk;
  Gtk::Button* m_wCancel;
  Gtk::Button* m_wOpenCalendar;
  Gtk::Entry* m_wDate;
  Gtk::ComboBoxEntry* m_wTaskTime;
public:
  AddTask(Glib::RefPtr<Gnome::Glade::Xml> refXml);
  ~AddTask();

  /* signal handlers */
  static void on_ok_clicked();
  static void on_cancel_clicked();
  static void on_open_calendar_clicked();
};

addtask.cpp
=========
#include <libglademm/xml.h>
#include <sigc++/slot.h>
#include "addtask.h"

AddTask::AddTask(Glib::RefPtr<Gnome::Glade::Xml> refXml)
{
  refXml->get_widget("wndMain", m_wWindow);
  refXml->get_widget("wOk", m_wOk);
  refXml->get_widget("wCancel", m_wCancel);
  refXml->get_widget("wOpenCalendar", m_wOpenCalendar);
  refXml->get_widget("wDate", m_wDate);
  refXml->get_widget("wTaskTime", m_wTaskTime);

  if (m_wOk) {
     m_wOk->signal_clicked().connect(SigC::slot(&on_ok_clicked));
  }
  if (m_wCancel) {
     m_wCancel->signal_clicked().connect(SigC::slot(&on_cancel_clicked));
  }
  if (m_wOpenCalendar) {
     m_wOpenCalendar->signal_clicked().connect(SigC::slot(&on_open_calendar_clicked));
  }
}

I had to make my signal handlers static, because it was impossible to
make a reference to a non-static member.

Can anyone please take a look at it?

Best regards
teel