tearoff_event_box.set_events (BUTTON_PRESS_MASK|BUTTON_RELEASE_MASK);
tearoff_event_box.signal_button_release_event().connect (mem_fun (*this, &TearOff::tearoff_click));
tearoff_event_box.set_events (BUTTON_PRESS_MASK|BUTTON_RELEASE_MASK);
tearoff_event_box.signal_button_release_event().connect (mem_fun (*this, &TearOff::tearoff_click));