question

Here an example that may show you, how to do it:

/**Custom Code - change Location of loaded items to three in a row*/
Object item = param(1);
Object current = ownerobject(c);
Object station = param(2);
//*** New Code *** 
int loadedItems = current.subnodes.length;
if(loadedItems> 1){   
  int level = (loadedItems-1)/3;    
   // integer division to get the level in z direction    
  int place = ((2+loadedItems)%3);   
   // I need the series 0, 1, 2 dependency of the amount of loaded items    
   // (1+2)%3 = 0; (2+2)%3 = 1; (3+2)%3 = 2; (4+2)%3 = 0;...   
  treenode loaded1st = current.subnodes[1];   
   // root item to place the other    
  double locX = loaded1st.as(Object).location.x 
                + loaded1st.as(Object).size.x*place;    
   // I assume the size is constant   
  double locY = item.location.y;    
   // y location does not change   
  double locZ = loaded1st.as(Object).location.z
                +(item.size.z*level);    
  item.setLocation(locX, locY, locZ);}