Ah, you are right. I feel so stupid:)
So, for those, who will have the same problem, theres corected code:
import com.greensock.loading.LoaderMax;
import com.greensock.loading.ImageLoader;
import com.greensock.loading.core.LoaderCore;
import com.greensock.events.LoaderEvent;
var loader1:ImageLoader = new ImageLoader("1.jpg", {name: "loader1"})
var loader2:ImageLoader = new ImageLoader("2.jpg", {name: "loader2"})
var queue:LoaderMax = new LoaderMax({maxConnections:1, onChildComplete: childComplete});
queue.append(loader1);
queue.append(loader2);
queue.load();
function childComplete(e:LoaderEvent){
var i:int = queue.getChildIndex(e.target as LoaderCore);
trace("index: " + i + " | url: " + e.target.url);
}
And here are 3 ways to prioritize loader2:
loader2.prioritize(true);
LoaderMax.prioritize("loader2");
LoaderMax.getLoader("loader2").prioritize();