@Override
public int compare(GraphObject t0, GraphObject t1) {
long x0 = t1.getReturnTime(t0);
long x1 = t0.getReturnTime(t1);
if (x0 == x1) { // either same or == 0
long d = t0.getStartTime() - t1.getStartTime();
if (d < 0) return -1;
else if (d > 0) return 1;
else if (t0.getName() == null) return -1;
else if (t1.getName() == null) return 1;
else return t0.getName().compareTo(t1.getName());
} else if (x0 == 0) return -1;
else if (x1 == 0) return 1;
else if (x0 < x1) return 1;
else return -1;
}
long getReturnTime(GraphObject to) {
for (GraphLink lnk : out_links) {
if (lnk.getType() == LinkType.RETURN) {
GraphObject go = lnk.getToObject();
if (go == to) return lnk.getTime();
else {
long rt = go.getReturnTime(to);
if (rt != 0) return Math.min(lnk.getTime(), rt);
}
}
}
return 0;
}