jQuery get the location of an element relative to window

Question

Initially, Grab the .offset position of the element and calculate its relative position with respect to window

Refer :
1. offset
2. scroll
3. scrollTop

You can give it a try at this fiddle

Following few lines of code explains how this can be solved

when .scroll event is performed, we calculate the relative position of the element with respect to window object

$(window).scroll(function () {
    console.log(eTop - $(window).scrollTop());
});

when scroll is performed in browser, we call the above event handler function

code snippet

---

function log(txt) {
  $("#log").html("location : <b>" + txt + "</b> px")
}

$(function() {
  var eTop = $('#element').offset().top; //get the offset top of the element
  log(eTop - $(window).scrollTop()); //position of the ele w.r.t window

  $(window).scroll(function() { //when window is scrolled
    log(eTop - $(window).scrollTop());
  });
});

#element {
  margin: 140px;
  text-align: center;
  padding: 5px;
  width: 200px;
  height: 200px;
  border: 1px solid #0099f9;
  border-radius: 3px;
  background: #444;
  color: #0099d9;
  opacity: 0.6;
}
#log {
  position: fixed;
  top: 40px;
  left: 40px;
  color: #333;
}
#scroll {
  position: fixed;
  bottom: 10px;
  right: 10px;
  border: 1px solid #000;
  border-radius: 2px;
  padding: 5px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="log"></div>

<div id="element">Hello
  <hr>World</div>
<div id="scroll">Scroll Down</div>

Try the bounding box. It's simple:

var leftPos  = $("#element")[0].getBoundingClientRect().left   + $(window)['scrollLeft']();
var rightPos = $("#element")[0].getBoundingClientRect().right  + $(window)['scrollLeft']();
var topPos   = $("#element")[0].getBoundingClientRect().top    + $(window)['scrollTop']();
var bottomPos= $("#element")[0].getBoundingClientRect().bottom + $(window)['scrollTop']();

function getWindowRelativeOffset(parentWindow, elem) {
    var offset = {
        left : 0,
        top : 0
    };

    // relative to the target field's document
    offset.left = elem.getBoundingClientRect().left;
    offset.top = elem.getBoundingClientRect().top;

    // now we will calculate according to the current document, this current
    // document might be same as the document of target field or it may be
    // parent of the document of the target field
    var childWindow = elem.document.frames.window;
    while (childWindow != parentWindow) {
        offset.left = offset.left + childWindow.frameElement.getBoundingClientRect().left;
        offset.top = offset.top + childWindow.frameElement.getBoundingClientRect().top;
        childWindow = childWindow.parent;
    }

    return offset;
};

you can call it like this

getWindowRelativeOffset(top, inputElement);

I focus for IE only as per my requirement but similar can be done for other browsers

TL;DR

headroom_by_jQuery = $('#id').offset().top - $(window).scrollTop();

headroom_by_DOM = $('#id')[0].getBoundingClientRect().top;   // if no iframe

.getBoundingClientRect() appears to be universal. .offset() and .scrollTop() have been supported since jQuery 1.2. Thanks @user372551 and @prograhammer. To use DOM in an iframe see @ImranAnsari's solution.

This sounds more like you want a tooltip for the link selected. There are many jQuery tooltips, try out jQuery qTip. It has a lot of options and is easy to change the styles.

Otherwise if you want to do this yourself you can use the jQuery .position(). More info about .position() is on http://api.jquery.com/position/

$("#element").position(); will return the current position of an element relative to the offset parent.

There is also the jQuery .offset(); which will return the position relative to the document.