Overloading mouse events in a ProgressBar

[Phil Wolff <adiabat centurylink net>]

I'm deriving from Gtk::ProgressBar in order to track mouse events within 
the widget. The only callback that executes is on_map(). Can anyone tell 
me what vital (and likely obvious) operation I've failed to include?

// g++ -o test test.cc `pkg-config gtkmm-3.0 --cflags --libs`

#include <gtkmm.h>
#include <iostream>

class CProgressBar : public Gtk::ProgressBar
{
public:
    explicit        CProgressBar ();
protected:
    virtual bool    on_button_press_event ( GdkEventButton* pEvent );
    virtual bool    on_enter_notify_event ( GdkEventCrossing* pEvent );
    virtual bool    on_leave_notify_event ( GdkEventCrossing* pEvent );
    virtual void    on_map ();
    virtual bool    on_motion_notify_event ( GdkEventMotion* pEvent );
};

class CTest : public Gtk::ApplicationWindow
{
public:
    CTest();
protected:
    CProgressBar* m_pBar;
};

CTest::CTest ()
{
    m_pBar = Gtk::manage ( new CProgressBar () );
    add ( *m_pBar );
    set_position ( Gtk::WIN_POS_CENTER );
    show_all_children ();
}

CProgressBar::CProgressBar ()
{
    set_hexpand ();
    set_margin_bottom ( 30 );
    set_margin_end ( 30 );
    set_margin_top ( 30 );
    set_margin_start ( 30 );
    set_fraction ( 0.5 );
}

bool CProgressBar::on_button_press_event ( GdkEventButton* pEvent )
{
    Gtk::ProgressBar::on_button_press_event ( pEvent );
    std::cout << "Click @ " << pEvent->x << std::endl;
    return ( false );
}

bool CProgressBar::on_enter_notify_event ( GdkEventCrossing* pEvent )
{
    Gtk::ProgressBar::on_enter_notify_event ( pEvent );
    std::cout << "Enter @ " << pEvent->x << std::endl;
    return ( false );
}

bool CProgressBar::on_leave_notify_event ( GdkEventCrossing* pEvent )
{
    Gtk::ProgressBar::on_leave_notify_event ( pEvent );
    std::cout << "Leave @ " << pEvent->x << std::endl;
    return ( false );
}

void CProgressBar::on_map ()
{
    Gtk::ProgressBar::on_map ();
    Glib::RefPtr<Gdk::Window > refWindow = get_window ();
    Gdk::EventMask mask = refWindow->get_events ();
    mask |= Gdk::ENTER_NOTIFY_MASK | Gdk::LEAVE_NOTIFY_MASK | 
Gdk::POINTER_MOTION_MASK | Gdk::BUTTON_PRESS_MASK;
    refWindow->set_events ( mask );
}

bool CProgressBar::on_motion_notify_event ( GdkEventMotion* pEvent )
{
    Gtk::ProgressBar::on_motion_notify_event ( pEvent );
    std::cout << "Move to " << pEvent->x << std::endl;
    return ( false );
}

int main ( int argc, char *argv[] )
{
    Glib::RefPtr<Gtk::Application> app = Gtk::Application::create ( 
"org.gtkmm.example" );
    CTest test;
    return app->run ( test );
}