own_window.signal_button_press_event().connect (mem_fun (*this, &TearOff::window_button_press));
own_window.signal_button_release_event().connect (mem_fun (*this, &TearOff::window_button_release));
own_window.signal_motion_notify_event().connect (mem_fun (*this, &TearOff::window_motion));
own_window.signal_button_press_event().connect (mem_fun (*this, &TearOff::window_button_press));
own_window.signal_button_release_event().connect (mem_fun (*this, &TearOff::window_button_release));
own_window.signal_motion_notify_event().connect (mem_fun (*this, &TearOff::window_motion));