} else if (Keyboard::modifier_state_equals (ev->state, Keyboard::ScrollZoomVerticalModifier)) {
if (!current_stepping_trackview) {
step_timeout = Glib::signal_timeout().connect (sigc::mem_fun(*this, &Editor::track_height_step_timeout), 500);
} else if (Keyboard::modifier_state_equals (ev->state, Keyboard::ScrollZoomVerticalModifier)) {
if (!current_stepping_trackview) {
step_timeout = Glib::signal_timeout().connect (sigc::mem_fun(*this, &Editor::track_height_step_timeout), 500);