stable_sort(traces.begin(), traces.end(),
[](const shared_ptr<Trace> &a, const shared_ptr<Trace> &b) {
stable_sort(traces.begin(), traces.end(),
[](const shared_ptr<Trace> &a, const shared_ptr<Trace> &b) {
const int delta = -min(v_min, 0);
for (shared_ptr<Trace> t : traces)
const int delta = -min(v_min, 0);
for (shared_ptr<Trace> t : traces)
verticalScrollBar()->setSliderPosition(_v_offset + delta);
v_scroll_value_changed(verticalScrollBar()->sliderPosition());
verticalScrollBar()->setSliderPosition(_v_offset + delta);
v_scroll_value_changed(verticalScrollBar()->sliderPosition());