LimeJS detection for overlapping

Question

I have recently started using LimeJS for my game development, and I have run into a bit of a hault.

I am making a RTS type of game. I have functions which let you chose buildings, and then click on the map to add chosen building to the map. I do not want the player to be able to place a building if it overlaps with one that is already there. How would I check this? The buildings are Sprites which in turn are added as children to a map sprite. I was thinking of using hitTest but I can't quite figure out how that function works. Example of the event handler:

goog.events.listen(field,['mousedown'],function build(e){


    if(selected_ == 1){
     var house = new rh.house().setPosition(e.position.x, e.position.y);
     field.appendChild(house);
     selected_ = -1;
     houselbl.setFill('assets/storage.png');
    }  
    if(selected_ == 2){
     var blacksmith = new rh.blacksmith().setPosition(e.position.x, e.position.y);
     field.appendChild(blacksmith);
     selected_ = -1;
     blacksmithlbl.setFill('assets/blacksmith.png');
    }      
    if(selected_ == 3){
     var lumbermill = new rh.lumbermill().setPosition(e.position.x, e.position.y);
     field.appendChild(lumbermill);
     selected_ = -1;
     lumbermilllbl.setFill('assets/lumbermill.png');
   }  
});

Answer 1

I got it working. I used getBoundingBox on all of the children, and checked if it was safe. Example below:

goog.events.listen(field,['mousedown'],function build(e){ 

    if(selected_ == 1){
        var house = new rh.house().setPosition(e.position.x, e.position.y);
        var safe=true;
        for (var i=0;i<field.getNumberOfChildren();i++)
        { 
           var box = field.getChildAt(i).getBoundingBox();
           if (goog.math.Box.intersects(box,house.getBoundingBox())){
           safe=false;
       }
    }
        if (safe){
            field.appendChild(house);
            selected_ = -1;
            houselbl.setFill('assets/storage.png');
        }
    }  
}