Question

I want to have an element B following element A when A is dragged. I use draggable from jQueryUI.

I made this:
http://jsfiddle.net/7KhSS/

It works, but isn’t really accurate. While B is following A, ther often is a 1px-3px gap either horizontally or vertically.

I can’t nest element B inside element A (which would solve the current problem), because in my case, element B has fixed positioning.

Answer 1

Instead of using $(this).position() using the offset property on the ui object that is passed in as the second parameter to the event:

$("#boxa").draggable({
    drag: function(e, ui) {
        $("#boxb").css({
            left: ui.offset.left - 100,
            top: ui.offset.top
        });
    }    
});​

http://jsfiddle.net/7KhSS/3/