Retrieve the position (X,Y) of an HTML element

Retrieve the position (X,Y) of an HTML element - javascript

I want to know how to get the X and Y position of HTML elements such as img and div in JavaScript.

The correct approach is to use element.getBoundingClientRect():
var rect = element.getBoundingClientRect();
console.log(rect.top, rect.right, rect.bottom, rect.left);
Internet Explorer has supported this since as long as you are likely to care about and it was finally standardized in CSSOM Views. All other browsers adopted it a long time ago.
Some browsers also return height and width properties, though this is non-standard. If you're worried about older browser compatibility, check this answer's revisions for an optimised degrading implementation.
The values returned by element.getBoundingClientRect() are relative to the viewport. If you need it relative to another element, simply subtract one rectangle from the other:
var bodyRect = document.body.getBoundingClientRect(),
elemRect = element.getBoundingClientRect(),
offset = elemRect.top - bodyRect.top;
alert('Element is ' + offset + ' vertical pixels from <body>');

This function returns an element's position relative to the whole document (page):
function getOffset(el) {
const rect = el.getBoundingClientRect();
return {
left: rect.left + window.scrollX,
top: rect.top + window.scrollY
};
}
Using this we can get the X position:
getOffset(element).left
... or the Y position:
getOffset(element).top

The libraries go to some lengths to get accurate offsets for an element.
here's a simple function that does the job in every circumstances that I've tried.
function getOffset( el ) {
var _x = 0;
var _y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
_x += el.offsetLeft - el.scrollLeft;
_y += el.offsetTop - el.scrollTop;
el = el.offsetParent;
}
return { top: _y, left: _x };
}
var x = getOffset( document.getElementById('yourElId') ).left;

If you want it done only in javascript, here are some one liners using getBoundingClientRect()
window.scrollY + document.querySelector('#elementId').getBoundingClientRect().top // Y
window.scrollX + document.querySelector('#elementId').getBoundingClientRect().left // X
The first line will return offsetTop say Y relative to document.
The second line will return offsetLeft say X relative to document.
getBoundingClientRect() is a javascript function that returns the position of the element relative to viewport of window.

HTML elements on most browsers will have:-
offsetLeft
offsetTop
These specifiy the position of the element relative its nearest parent that has layout. This parent can often be accessed bif the offsetParent property.
IE and FF3 have
clientLeft
clientTop
These properties are less common, they specify an elements position with its parents client area (padded area is part of the client area but border and margin is not).

If page includes - at least- any "DIV", the function given by meouw throws the "Y" value beyond current page limits. In order to find the exact position, you need to handle both offsetParent's and parentNode's.
Try the code given below (it is checked for FF2):
var getAbsPosition = function(el){
var el2 = el;
var curtop = 0;
var curleft = 0;
if (document.getElementById || document.all) {
do {
curleft += el.offsetLeft-el.scrollLeft;
curtop += el.offsetTop-el.scrollTop;
el = el.offsetParent;
el2 = el2.parentNode;
while (el2 != el) {
curleft -= el2.scrollLeft;
curtop -= el2.scrollTop;
el2 = el2.parentNode;
}
} while (el.offsetParent);
} else if (document.layers) {
curtop += el.y;
curleft += el.x;
}
return [curtop, curleft];
};

You can add two properties to Element.prototype to get the top/left of any element.
Object.defineProperty( Element.prototype, 'documentOffsetTop', {
get: function () {
return this.offsetTop + ( this.offsetParent ? this.offsetParent.documentOffsetTop : 0 );
}
} );
Object.defineProperty( Element.prototype, 'documentOffsetLeft', {
get: function () {
return this.offsetLeft + ( this.offsetParent ? this.offsetParent.documentOffsetLeft : 0 );
}
} );
This is called like this:
var x = document.getElementById( 'myDiv' ).documentOffsetLeft;
Here's a demo comparing the results to jQuery's offset().top and .left: http://jsfiddle.net/ThinkingStiff/3G7EZ/

To retrieve the position relative to the page efficiently, and without using a recursive function: (includes IE also)
var element = document.getElementById('elementId'); //replace elementId with your element's Id.
var rect = element.getBoundingClientRect();
var elementLeft,elementTop; //x and y
var scrollTop = document.documentElement.scrollTop?
document.documentElement.scrollTop:document.body.scrollTop;
var scrollLeft = document.documentElement.scrollLeft?
document.documentElement.scrollLeft:document.body.scrollLeft;
elementTop = rect.top+scrollTop;
elementLeft = rect.left+scrollLeft;

How about something like this, by passing ID of the element and it will return the left or top, we can also combine them:
1) find left
function findLeft(element) {
var rec = document.getElementById(element).getBoundingClientRect();
return rec.left + window.scrollX;
} //call it like findLeft('#header');
2) find top
function findTop(element) {
var rec = document.getElementById(element).getBoundingClientRect();
return rec.top + window.scrollY;
} //call it like findTop('#header');
or 3) find left and top together
function findTopLeft(element) {
var rec = document.getElementById(element).getBoundingClientRect();
return {top: rec.top + window.scrollY, left: rec.left + window.scrollX};
} //call it like findTopLeft('#header');

Here's a modern 1-liner using vanilla JS to recursively iterate over element.offsetTop and element.offsetParent:
Function:
getTop = el => el.offsetTop + (el.offsetParent && getTop(el.offsetParent))
Usage:
const el = document.querySelector('#div_id');
const elTop = getTop(el)
Advantage:
Always returns the absolute vertical offset, regardless of the current scroll position.
Traditional syntax:
function getTop(el) {
return el.offsetTop + (el.offsetParent && getTop(el.offsetParent));
}

jQuery .offset() will get the current coordinates of the first element, or set the coordinates of every element, in the set of matched elements, relative to the document.

Update:
The recursion approach (in my old answer) creates many call stacks. We can use a while loop to avoid recursion in this case:
/**
*
* #param {HTMLElement} el
* #return {{top: number, left: number}}
*/
function getDocumentOffsetPosition(el) {
let top = 0, left = 0;
while (el !== null) {
top += el.offsetTop;
left += el.offsetLeft;
el = el.offsetParent;
}
return {top, left};
}
Old answer:
/**
*
* #param {HTMLElement} el
* #return {{top: number, left: number}}
*/
function getDocumentOffsetPosition(el) {
var position = {
top: el.offsetTop,
left: el.offsetLeft
};
if (el.offsetParent) {
var parentPosition = getDocumentOffsetPosition(el.offsetParent);
position.top += parentPosition.top;
position.left += parentPosition.left;
}
return position;
}
Thank ThinkingStiff for the answer, this is only another version.

You might be better served by using a JavaScript framework, that has functions to return such information (and so much more!) in a browser-independant fashion. Here are a few:
Prototype
jQuery
MooTools
YUI (yahoo)
With these frameworks, you could do something like:
$('id-of-img').top
to get the y-pixel coordinate of the image.

I've taken #meouw's answer, added in the clientLeft that allows for the border, and then created three versions:
getAbsoluteOffsetFromBody - similar to #meouw's, this gets the absolute position relative to the body or html element of the document (depending on quirks mode)
getAbsoluteOffsetFromGivenElement - returns the absolute position relative to the given element (relativeEl). Note that the given element must contain the element el, or this will behave the same as getAbsoluteOffsetFromBody. This is useful if you have two elements contained within another (known) element (optionally several nodes up the node tree) and want to make them the same position.
getAbsoluteOffsetFromRelative - returns the absolute position relative to the first parent element with position: relative. This is similar to getAbsoluteOffsetFromGivenElement, for the same reason but will only go as far as the first matching element.
getAbsoluteOffsetFromBody = function( el )
{ // finds the offset of el from the body or html element
var _x = 0;
var _y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) )
{
_x += el.offsetLeft - el.scrollLeft + el.clientLeft;
_y += el.offsetTop - el.scrollTop + el.clientTop;
el = el.offsetParent;
}
return { top: _y, left: _x };
}
getAbsoluteOffsetFromGivenElement = function( el, relativeEl )
{ // finds the offset of el from relativeEl
var _x = 0;
var _y = 0;
while( el && el != relativeEl && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) )
{
_x += el.offsetLeft - el.scrollLeft + el.clientLeft;
_y += el.offsetTop - el.scrollTop + el.clientTop;
el = el.offsetParent;
}
return { top: _y, left: _x };
}
getAbsoluteOffsetFromRelative = function( el )
{ // finds the offset of el from the first parent with position: relative
var _x = 0;
var _y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) )
{
_x += el.offsetLeft - el.scrollLeft + el.clientLeft;
_y += el.offsetTop - el.scrollTop + el.clientTop;
el = el.offsetParent;
if (el != null)
{
if (getComputedStyle !== 'undefined')
valString = getComputedStyle(el, null).getPropertyValue('position');
else
valString = el.currentStyle['position'];
if (valString === "relative")
el = null;
}
}
return { top: _y, left: _x };
}
If you are still having problems, particularly relating to scrolling, you could try looking at http://www.greywyvern.com/?post=331 - I noticed at least one piece of questionable code in getStyle which should be fine assuming browsers behave, but haven't tested the rest at all.

Difference between small and little
function getPosition( el ) {
var x = 0;
var y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
x += el.offsetLeft - el.scrollLeft;
y += el.offsetTop - el.scrollTop;
el = el.offsetParent;
}
return { top: y, left: x };
}
Look a example coordinates:
http://javascript.info/tutorial/coordinates

If you are using jQuery, this could be a simple solution:
<script>
var el = $("#element");
var position = el.position();
console.log( "left: " + position.left + ", top: " + position.top );
</script>

if using jQuery, the dimensions plugin is excellent and allows you specify exactly what you want.
e.g.
Relative position, absolute position, absolute position without padding, with padding...
It goes on, let's just say there is a lot you can do with it.
Plus the bonus of using jQuery is it's lightweight file size and easy use, you won't go back to JavaScript without it afterwards.

The cleanest approach I have found is a simplified version of the technique used by jQuery's offset. Similar to some of the other answers it starts with getBoundingClientRect; it then uses the window and the documentElement to adjust for scroll position as well as things like the margin on the body (often the default).
var rect = el.getBoundingClientRect();
var docEl = document.documentElement;
var rectTop = rect.top + window.pageYOffset - docEl.clientTop;
var rectLeft = rect.left + window.pageXOffset - docEl.clientLeft;
var els = document.getElementsByTagName("div");
var docEl = document.documentElement;
for (var i = 0; i < els.length; i++) {
var rect = els[i].getBoundingClientRect();
var rectTop = rect.top + window.pageYOffset - docEl.clientTop;
var rectLeft = rect.left + window.pageXOffset - docEl.clientLeft;
els[i].innerHTML = "<b>" + rectLeft + ", " + rectTop + "</b>";
}
div {
width: 100px;
height: 100px;
background-color: red;
border: 1px solid black;
}
#rel {
position: relative;
left: 10px;
top: 10px;
}
#abs {
position: absolute;
top: 250px;
left: 250px;
}
<div id="rel"></div>
<div id="abs"></div>
<div></div>

To get the total offset of an element, you could recursively sum up all parent offsets:
function getParentOffset(el): number {
if (el.offsetParent) {
return el.offsetParent.offsetTop + getParentOffset(el.offsetParent);
} else {
return 0;
}
}
with this utility function the total top offset of a dom element is:
el.offsetTop + getParentOffset(el);

This is the best code I've managed to create (works in iframes as well, unlike jQuery's offset()). Seems webkit has a bit of a different behavior.
Based on meouw's comment:
function getOffset( el ) {
var _x = 0;
var _y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
_x += el.offsetLeft - el.scrollLeft;
_y += el.offsetTop - el.scrollTop;
// chrome/safari
if ($.browser.webkit) {
el = el.parentNode;
} else {
// firefox/IE
el = el.offsetParent;
}
}
return { top: _y, left: _x };
}

While this is very likely to be lost at the bottom of so many answers, the top solutions here were not working for me.
As far as I could tell neither would any of the other answers have helped.
Situation:
In an HTML5 page I had a menu that was a nav element inside a header (not THE header but a header in another element).
I wanted the navigation to stick to the top once a user scrolled to it, but previous to this the header was absolute positioned (so I could have it overlay something else slightly).
The solutions above never triggered a change because .offsetTop was not going to change as this was an absolute positioned element. Additionally the .scrollTop property was simply the top of the top most element... that is to say 0 and always would be 0.
Any tests I performed utilizing these two (and same with getBoundingClientRect results) would not tell me if the top of the navigation bar ever scrolled to the top of the viewable page (again, as reported in console, they simply stayed the same numbers while scrolling occurred).
Solution
The solution for me was utilizing
window.visualViewport.pageTop
The value of the pageTop property reflects the viewable section of the screen, therefore allowing me to track where an element is in reference to the boundaries of the viewable area.
Probably unnecessary to say, anytime I am dealing with scrolling I expect to use this solution to programatically respond to movement of elements being scrolled.
Hope it helps someone else.
IMPORTANT NOTE: This appears to work in Chrome and Opera currently & definitely not in Firefox (6-2018)... until Firefox supports visualViewport I recommend NOT using this method, (and I hope they do soon... it makes a lot more sense than the rest).
UPDATE:
Just a note regarding this solution. While I still find what I discovered to be very valuable for situations in which "...programmatically respond to movement of elements being scrolled." is applicable. The better solution for the problem that I had was to use CSS to set position: sticky on the element. Using sticky you can have an element stay at the top without using javascript (NOTE: there are times this will not work as effectively as changing the element to fixed but for most uses the sticky approach will likely be superior)
UPDATE01:
So I realized that for a different page I had a requirement where I needed to detect the position of an element in a mildly complex scrolling setup (parallax plus elements that scroll past as part of a message).
I realized in that scenario that the following provided the value I utilized to determine when to do something:
let bodyElement = document.getElementsByTagName('body')[0];
let elementToTrack = bodyElement.querySelector('.trackme');
trackedObjPos = elementToTrack.getBoundingClientRect().top;
if(trackedObjPos > 264)
{
bodyElement.style.cssText = '';
}
Hope this answer is more widely useful now.

I did it like this so it was cross-compatible with old browsers.
// For really old browser's or incompatible ones
function getOffsetSum(elem) {
var top = 0,
left = 0,
bottom = 0,
right = 0
var width = elem.offsetWidth;
var height = elem.offsetHeight;
while (elem) {
top += elem.offsetTop;
left += elem.offsetLeft;
elem = elem.offsetParent;
}
right = left + width;
bottom = top + height;
return {
top: top,
left: left,
bottom: bottom,
right: right,
}
}
function getOffsetRect(elem) {
var box = elem.getBoundingClientRect();
var body = document.body;
var docElem = document.documentElement;
var scrollTop = window.pageYOffset || docElem.scrollTop || body.scrollTop;
var scrollLeft = window.pageXOffset || docElem.scrollLeft || body.scrollLeft;
var clientTop = docElem.clientTop;
var clientLeft = docElem.clientLeft;
var top = box.top + scrollTop - clientTop;
var left = box.left + scrollLeft - clientLeft;
var bottom = top + (box.bottom - box.top);
var right = left + (box.right - box.left);
return {
top: Math.round(top),
left: Math.round(left),
bottom: Math.round(bottom),
right: Math.round(right),
}
}
function getOffset(elem) {
if (elem) {
if (elem.getBoundingClientRect) {
return getOffsetRect(elem);
} else { // old browser
return getOffsetSum(elem);
}
} else
return null;
}
More about coordinates in JavaScript here: http://javascript.info/tutorial/coordinates

HTML program to show (x, y) of an
element by dragging mouse over it you just copied it and use it on your own
<!DOCTYPE html>
<html>
<head>
<title>
position of an element
</title>
<!-- scropt to get position -->
<script type = "text/javascript">
function getPositionXY(element) {
var rect = element.getBoundingClientRect();
document.getElementById('text').innerHTML
= 'X: ' + rect.x + '<br>' + 'Y: ' + rect.y;
}
</script>
</head>
<body>
<p>Move the mouse over the text</p>
<div onmouseover = "getPositionXY(this)">
Position:
<p id = 'text'></p>
</div>
</body>
</html>

i could just like element.offsetLeft or element.offsetTop. Example :
document.getElementById('profileImg').offsetLeft

I successfully used Andy E's solution to position a bootstrap 2 modal depending on what link in a table row a user clicks on. The page is a Tapestry 5 page and javascript below is imported in the java page class.
javascript:
function setLinkPosition(clientId){
var bodyRect = document.body.getBoundingClientRect(),
elemRect = clientId.getBoundingClientRect(),
offset = elemRect.top - bodyRect.top;
offset = offset + 20;
$('#serviceLineModal').css("top", offset);
}
My modal code:
<div id="serviceLineModal" class="modal hide fade add-absolute-position" data-backdrop="static"
tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true" style="top:50%;">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-hidden="true">x</button>
<h3 id="myModalLabel">Modal header</h3>
</div>
<div class="modal-body">
<t:zone t:id="modalZone" id="modalZone">
<p>You selected service line number: ${serviceLineNumberSelected}</p>
</t:zone>
</div>
<div class="modal-footer">
<button class="btn" data-dismiss="modal" aria-hidden="true">Close</button>
<!-- <button class="btn btn-primary">Save changes</button> -->
</div>
The link in the loop:
<t:loop source="servicesToDisplay" value="service" encoder="encoder">
<tr style="border-right: 1px solid black;">
<td style="white-space:nowrap;" class="add-padding-left-and-right no-border">
<a t:type="eventLink" t:event="serviceLineNumberSelected" t:context="service.serviceLineNumber"
t:zone="pageZone" t:clientId="modalLink${service.serviceLineNumber}"
onmouseover="setLinkPosition(this);">
<i class="icon-chevron-down"></i> <!-- ${service.serviceLineNumber} -->
</a>
</td>
And the java code in the page class:
void onServiceLineNumberSelected(String number){
checkForNullSession();
serviceLineNumberSelected = number;
addOpenServiceLineDialogCommand();
ajaxResponseRenderer.addRender(modalZone);
}
protected void addOpenServiceLineDialogCommand() {
ajaxResponseRenderer.addCallback(new JavaScriptCallback() {
#Override
public void run(JavaScriptSupport javascriptSupport) {
javascriptSupport.addScript("$('#serviceLineModal').modal('show');");
}
});
}
Hope this helps someone, this post helped out.

After much research and testing this seems to work
function getPosition(e) {
var isNotFirefox = (navigator.userAgent.toLowerCase().indexOf('firefox') == -1);
var x = 0, y = 0;
while (e) {
x += e.offsetLeft - e.scrollLeft + (isNotFirefox ? e.clientLeft : 0);
y += e.offsetTop - e.scrollTop + (isNotFirefox ? e.clientTop : 0);
e = e.offsetParent;
}
return { x: x + window.scrollX, y: y + window.scrollY };
}
see http://jsbin.com/xuvovalifo/edit?html,js,output

Just thought I'd throw this out there as well.
I haven't been able to test it in older browsers, but it works in the latest of the top 3. :)
Element.prototype.getOffsetTop = function() {
return ( this.parentElement )? this.offsetTop + this.parentElement.getOffsetTop(): this.offsetTop;
};
Element.prototype.getOffsetLeft = function() {
return ( this.parentElement )? this.offsetLeft + this.parentElement.getOffsetLeft(): this.offsetLeft;
};
Element.prototype.getOffset = function() {
return {'left':this.getOffsetLeft(),'top':this.getOffsetTop()};
};

This is easy as two lines in JS :
var elem = document.getElementById("id");
alert(elem.getBoundingClientRect());

Since different browsers are rendering border, padding, margin and etc in different way. I wrote a little function to retrieve top and left positions of specific element in every root element that you want in precise dimension:
function getTop(root, offset) {
var rootRect = root.getBoundingClientRect();
var offsetRect = offset.getBoundingClientRect();
return offsetRect.top - rootRect.top;
}
For retrieve left position you must return:
return offsetRect.left - rootRect.left;

Get position of div in respect to left and Top
var elm = $('#div_id'); //get the div
var posY_top = elm.offset().top; //get the position from top
var posX_left = elm.offset().left; //get the position from left

Related

How to get location of the element after it was clicked? [duplicate]

I want to know how to get the X and Y position of HTML elements such as img and div in JavaScript.

The correct approach is to use element.getBoundingClientRect():
var rect = element.getBoundingClientRect();
console.log(rect.top, rect.right, rect.bottom, rect.left);
Internet Explorer has supported this since as long as you are likely to care about and it was finally standardized in CSSOM Views. All other browsers adopted it a long time ago.
Some browsers also return height and width properties, though this is non-standard. If you're worried about older browser compatibility, check this answer's revisions for an optimised degrading implementation.
The values returned by element.getBoundingClientRect() are relative to the viewport. If you need it relative to another element, simply subtract one rectangle from the other:
var bodyRect = document.body.getBoundingClientRect(),
elemRect = element.getBoundingClientRect(),
offset = elemRect.top - bodyRect.top;
alert('Element is ' + offset + ' vertical pixels from <body>');

This function returns an element's position relative to the whole document (page):
function getOffset(el) {
const rect = el.getBoundingClientRect();
return {
left: rect.left + window.scrollX,
top: rect.top + window.scrollY
};
}
Using this we can get the X position:
getOffset(element).left
... or the Y position:
getOffset(element).top

The libraries go to some lengths to get accurate offsets for an element.
here's a simple function that does the job in every circumstances that I've tried.
function getOffset( el ) {
var _x = 0;
var _y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
_x += el.offsetLeft - el.scrollLeft;
_y += el.offsetTop - el.scrollTop;
el = el.offsetParent;
}
return { top: _y, left: _x };
}
var x = getOffset( document.getElementById('yourElId') ).left;

If you want it done only in javascript, here are some one liners using getBoundingClientRect()
window.scrollY + document.querySelector('#elementId').getBoundingClientRect().top // Y
window.scrollX + document.querySelector('#elementId').getBoundingClientRect().left // X
The first line will return offsetTop say Y relative to document.
The second line will return offsetLeft say X relative to document.
getBoundingClientRect() is a javascript function that returns the position of the element relative to viewport of window.

HTML elements on most browsers will have:-
offsetLeft
offsetTop
These specifiy the position of the element relative its nearest parent that has layout. This parent can often be accessed bif the offsetParent property.
IE and FF3 have
clientLeft
clientTop
These properties are less common, they specify an elements position with its parents client area (padded area is part of the client area but border and margin is not).

If page includes - at least- any "DIV", the function given by meouw throws the "Y" value beyond current page limits. In order to find the exact position, you need to handle both offsetParent's and parentNode's.
Try the code given below (it is checked for FF2):
var getAbsPosition = function(el){
var el2 = el;
var curtop = 0;
var curleft = 0;
if (document.getElementById || document.all) {
do {
curleft += el.offsetLeft-el.scrollLeft;
curtop += el.offsetTop-el.scrollTop;
el = el.offsetParent;
el2 = el2.parentNode;
while (el2 != el) {
curleft -= el2.scrollLeft;
curtop -= el2.scrollTop;
el2 = el2.parentNode;
}
} while (el.offsetParent);
} else if (document.layers) {
curtop += el.y;
curleft += el.x;
}
return [curtop, curleft];
};

You can add two properties to Element.prototype to get the top/left of any element.
Object.defineProperty( Element.prototype, 'documentOffsetTop', {
get: function () {
return this.offsetTop + ( this.offsetParent ? this.offsetParent.documentOffsetTop : 0 );
}
} );
Object.defineProperty( Element.prototype, 'documentOffsetLeft', {
get: function () {
return this.offsetLeft + ( this.offsetParent ? this.offsetParent.documentOffsetLeft : 0 );
}
} );
This is called like this:
var x = document.getElementById( 'myDiv' ).documentOffsetLeft;
Here's a demo comparing the results to jQuery's offset().top and .left: http://jsfiddle.net/ThinkingStiff/3G7EZ/

To retrieve the position relative to the page efficiently, and without using a recursive function: (includes IE also)
var element = document.getElementById('elementId'); //replace elementId with your element's Id.
var rect = element.getBoundingClientRect();
var elementLeft,elementTop; //x and y
var scrollTop = document.documentElement.scrollTop?
document.documentElement.scrollTop:document.body.scrollTop;
var scrollLeft = document.documentElement.scrollLeft?
document.documentElement.scrollLeft:document.body.scrollLeft;
elementTop = rect.top+scrollTop;
elementLeft = rect.left+scrollLeft;

How about something like this, by passing ID of the element and it will return the left or top, we can also combine them:
1) find left
function findLeft(element) {
var rec = document.getElementById(element).getBoundingClientRect();
return rec.left + window.scrollX;
} //call it like findLeft('#header');
2) find top
function findTop(element) {
var rec = document.getElementById(element).getBoundingClientRect();
return rec.top + window.scrollY;
} //call it like findTop('#header');
or 3) find left and top together
function findTopLeft(element) {
var rec = document.getElementById(element).getBoundingClientRect();
return {top: rec.top + window.scrollY, left: rec.left + window.scrollX};
} //call it like findTopLeft('#header');

Here's a modern 1-liner using vanilla JS to recursively iterate over element.offsetTop and element.offsetParent:
Function:
getTop = el => el.offsetTop + (el.offsetParent && getTop(el.offsetParent))
Usage:
const el = document.querySelector('#div_id');
const elTop = getTop(el)
Advantage:
Always returns the absolute vertical offset, regardless of the current scroll position.
Traditional syntax:
function getTop(el) {
return el.offsetTop + (el.offsetParent && getTop(el.offsetParent));
}

jQuery .offset() will get the current coordinates of the first element, or set the coordinates of every element, in the set of matched elements, relative to the document.

Update:
The recursion approach (in my old answer) creates many call stacks. We can use a while loop to avoid recursion in this case:
/**
*
* #param {HTMLElement} el
* #return {{top: number, left: number}}
*/
function getDocumentOffsetPosition(el) {
let top = 0, left = 0;
while (el !== null) {
top += el.offsetTop;
left += el.offsetLeft;
el = el.offsetParent;
}
return {top, left};
}
Old answer:
/**
*
* #param {HTMLElement} el
* #return {{top: number, left: number}}
*/
function getDocumentOffsetPosition(el) {
var position = {
top: el.offsetTop,
left: el.offsetLeft
};
if (el.offsetParent) {
var parentPosition = getDocumentOffsetPosition(el.offsetParent);
position.top += parentPosition.top;
position.left += parentPosition.left;
}
return position;
}
Thank ThinkingStiff for the answer, this is only another version.

You might be better served by using a JavaScript framework, that has functions to return such information (and so much more!) in a browser-independant fashion. Here are a few:
Prototype
jQuery
MooTools
YUI (yahoo)
With these frameworks, you could do something like:
$('id-of-img').top
to get the y-pixel coordinate of the image.

I've taken #meouw's answer, added in the clientLeft that allows for the border, and then created three versions:
getAbsoluteOffsetFromBody - similar to #meouw's, this gets the absolute position relative to the body or html element of the document (depending on quirks mode)
getAbsoluteOffsetFromGivenElement - returns the absolute position relative to the given element (relativeEl). Note that the given element must contain the element el, or this will behave the same as getAbsoluteOffsetFromBody. This is useful if you have two elements contained within another (known) element (optionally several nodes up the node tree) and want to make them the same position.
getAbsoluteOffsetFromRelative - returns the absolute position relative to the first parent element with position: relative. This is similar to getAbsoluteOffsetFromGivenElement, for the same reason but will only go as far as the first matching element.
getAbsoluteOffsetFromBody = function( el )
{ // finds the offset of el from the body or html element
var _x = 0;
var _y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) )
{
_x += el.offsetLeft - el.scrollLeft + el.clientLeft;
_y += el.offsetTop - el.scrollTop + el.clientTop;
el = el.offsetParent;
}
return { top: _y, left: _x };
}
getAbsoluteOffsetFromGivenElement = function( el, relativeEl )
{ // finds the offset of el from relativeEl
var _x = 0;
var _y = 0;
while( el && el != relativeEl && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) )
{
_x += el.offsetLeft - el.scrollLeft + el.clientLeft;
_y += el.offsetTop - el.scrollTop + el.clientTop;
el = el.offsetParent;
}
return { top: _y, left: _x };
}
getAbsoluteOffsetFromRelative = function( el )
{ // finds the offset of el from the first parent with position: relative
var _x = 0;
var _y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) )
{
_x += el.offsetLeft - el.scrollLeft + el.clientLeft;
_y += el.offsetTop - el.scrollTop + el.clientTop;
el = el.offsetParent;
if (el != null)
{
if (getComputedStyle !== 'undefined')
valString = getComputedStyle(el, null).getPropertyValue('position');
else
valString = el.currentStyle['position'];
if (valString === "relative")
el = null;
}
}
return { top: _y, left: _x };
}
If you are still having problems, particularly relating to scrolling, you could try looking at http://www.greywyvern.com/?post=331 - I noticed at least one piece of questionable code in getStyle which should be fine assuming browsers behave, but haven't tested the rest at all.

Difference between small and little
function getPosition( el ) {
var x = 0;
var y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
x += el.offsetLeft - el.scrollLeft;
y += el.offsetTop - el.scrollTop;
el = el.offsetParent;
}
return { top: y, left: x };
}
Look a example coordinates:
http://javascript.info/tutorial/coordinates

If you are using jQuery, this could be a simple solution:
<script>
var el = $("#element");
var position = el.position();
console.log( "left: " + position.left + ", top: " + position.top );
</script>

if using jQuery, the dimensions plugin is excellent and allows you specify exactly what you want.
e.g.
Relative position, absolute position, absolute position without padding, with padding...
It goes on, let's just say there is a lot you can do with it.
Plus the bonus of using jQuery is it's lightweight file size and easy use, you won't go back to JavaScript without it afterwards.

The cleanest approach I have found is a simplified version of the technique used by jQuery's offset. Similar to some of the other answers it starts with getBoundingClientRect; it then uses the window and the documentElement to adjust for scroll position as well as things like the margin on the body (often the default).
var rect = el.getBoundingClientRect();
var docEl = document.documentElement;
var rectTop = rect.top + window.pageYOffset - docEl.clientTop;
var rectLeft = rect.left + window.pageXOffset - docEl.clientLeft;
var els = document.getElementsByTagName("div");
var docEl = document.documentElement;
for (var i = 0; i < els.length; i++) {
var rect = els[i].getBoundingClientRect();
var rectTop = rect.top + window.pageYOffset - docEl.clientTop;
var rectLeft = rect.left + window.pageXOffset - docEl.clientLeft;
els[i].innerHTML = "<b>" + rectLeft + ", " + rectTop + "</b>";
}
div {
width: 100px;
height: 100px;
background-color: red;
border: 1px solid black;
}
#rel {
position: relative;
left: 10px;
top: 10px;
}
#abs {
position: absolute;
top: 250px;
left: 250px;
}
<div id="rel"></div>
<div id="abs"></div>
<div></div>

To get the total offset of an element, you could recursively sum up all parent offsets:
function getParentOffset(el): number {
if (el.offsetParent) {
return el.offsetParent.offsetTop + getParentOffset(el.offsetParent);
} else {
return 0;
}
}
with this utility function the total top offset of a dom element is:
el.offsetTop + getParentOffset(el);

This is the best code I've managed to create (works in iframes as well, unlike jQuery's offset()). Seems webkit has a bit of a different behavior.
Based on meouw's comment:
function getOffset( el ) {
var _x = 0;
var _y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
_x += el.offsetLeft - el.scrollLeft;
_y += el.offsetTop - el.scrollTop;
// chrome/safari
if ($.browser.webkit) {
el = el.parentNode;
} else {
// firefox/IE
el = el.offsetParent;
}
}
return { top: _y, left: _x };
}

I did it like this so it was cross-compatible with old browsers.
// For really old browser's or incompatible ones
function getOffsetSum(elem) {
var top = 0,
left = 0,
bottom = 0,
right = 0
var width = elem.offsetWidth;
var height = elem.offsetHeight;
while (elem) {
top += elem.offsetTop;
left += elem.offsetLeft;
elem = elem.offsetParent;
}
right = left + width;
bottom = top + height;
return {
top: top,
left: left,
bottom: bottom,
right: right,
}
}
function getOffsetRect(elem) {
var box = elem.getBoundingClientRect();
var body = document.body;
var docElem = document.documentElement;
var scrollTop = window.pageYOffset || docElem.scrollTop || body.scrollTop;
var scrollLeft = window.pageXOffset || docElem.scrollLeft || body.scrollLeft;
var clientTop = docElem.clientTop;
var clientLeft = docElem.clientLeft;
var top = box.top + scrollTop - clientTop;
var left = box.left + scrollLeft - clientLeft;
var bottom = top + (box.bottom - box.top);
var right = left + (box.right - box.left);
return {
top: Math.round(top),
left: Math.round(left),
bottom: Math.round(bottom),
right: Math.round(right),
}
}
function getOffset(elem) {
if (elem) {
if (elem.getBoundingClientRect) {
return getOffsetRect(elem);
} else { // old browser
return getOffsetSum(elem);
}
} else
return null;
}
More about coordinates in JavaScript here: http://javascript.info/tutorial/coordinates

HTML program to show (x, y) of an
element by dragging mouse over it you just copied it and use it on your own
<!DOCTYPE html>
<html>
<head>
<title>
position of an element
</title>
<!-- scropt to get position -->
<script type = "text/javascript">
function getPositionXY(element) {
var rect = element.getBoundingClientRect();
document.getElementById('text').innerHTML
= 'X: ' + rect.x + '<br>' + 'Y: ' + rect.y;
}
</script>
</head>
<body>
<p>Move the mouse over the text</p>
<div onmouseover = "getPositionXY(this)">
Position:
<p id = 'text'></p>
</div>
</body>
</html>

i could just like element.offsetLeft or element.offsetTop. Example :
document.getElementById('profileImg').offsetLeft

I successfully used Andy E's solution to position a bootstrap 2 modal depending on what link in a table row a user clicks on. The page is a Tapestry 5 page and javascript below is imported in the java page class.
javascript:
function setLinkPosition(clientId){
var bodyRect = document.body.getBoundingClientRect(),
elemRect = clientId.getBoundingClientRect(),
offset = elemRect.top - bodyRect.top;
offset = offset + 20;
$('#serviceLineModal').css("top", offset);
}
My modal code:
<div id="serviceLineModal" class="modal hide fade add-absolute-position" data-backdrop="static"
tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true" style="top:50%;">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-hidden="true">x</button>
<h3 id="myModalLabel">Modal header</h3>
</div>
<div class="modal-body">
<t:zone t:id="modalZone" id="modalZone">
<p>You selected service line number: ${serviceLineNumberSelected}</p>
</t:zone>
</div>
<div class="modal-footer">
<button class="btn" data-dismiss="modal" aria-hidden="true">Close</button>
<!-- <button class="btn btn-primary">Save changes</button> -->
</div>
The link in the loop:
<t:loop source="servicesToDisplay" value="service" encoder="encoder">
<tr style="border-right: 1px solid black;">
<td style="white-space:nowrap;" class="add-padding-left-and-right no-border">
<a t:type="eventLink" t:event="serviceLineNumberSelected" t:context="service.serviceLineNumber"
t:zone="pageZone" t:clientId="modalLink${service.serviceLineNumber}"
onmouseover="setLinkPosition(this);">
<i class="icon-chevron-down"></i> <!-- ${service.serviceLineNumber} -->
</a>
</td>
And the java code in the page class:
void onServiceLineNumberSelected(String number){
checkForNullSession();
serviceLineNumberSelected = number;
addOpenServiceLineDialogCommand();
ajaxResponseRenderer.addRender(modalZone);
}
protected void addOpenServiceLineDialogCommand() {
ajaxResponseRenderer.addCallback(new JavaScriptCallback() {
#Override
public void run(JavaScriptSupport javascriptSupport) {
javascriptSupport.addScript("$('#serviceLineModal').modal('show');");
}
});
}
Hope this helps someone, this post helped out.

After much research and testing this seems to work
function getPosition(e) {
var isNotFirefox = (navigator.userAgent.toLowerCase().indexOf('firefox') == -1);
var x = 0, y = 0;
while (e) {
x += e.offsetLeft - e.scrollLeft + (isNotFirefox ? e.clientLeft : 0);
y += e.offsetTop - e.scrollTop + (isNotFirefox ? e.clientTop : 0);
e = e.offsetParent;
}
return { x: x + window.scrollX, y: y + window.scrollY };
}
see http://jsbin.com/xuvovalifo/edit?html,js,output

Just thought I'd throw this out there as well.
I haven't been able to test it in older browsers, but it works in the latest of the top 3. :)
Element.prototype.getOffsetTop = function() {
return ( this.parentElement )? this.offsetTop + this.parentElement.getOffsetTop(): this.offsetTop;
};
Element.prototype.getOffsetLeft = function() {
return ( this.parentElement )? this.offsetLeft + this.parentElement.getOffsetLeft(): this.offsetLeft;
};
Element.prototype.getOffset = function() {
return {'left':this.getOffsetLeft(),'top':this.getOffsetTop()};
};

This is easy as two lines in JS :
var elem = document.getElementById("id");
alert(elem.getBoundingClientRect());

Since different browsers are rendering border, padding, margin and etc in different way. I wrote a little function to retrieve top and left positions of specific element in every root element that you want in precise dimension:
function getTop(root, offset) {
var rootRect = root.getBoundingClientRect();
var offsetRect = offset.getBoundingClientRect();
return offsetRect.top - rootRect.top;
}
For retrieve left position you must return:
return offsetRect.left - rootRect.left;

Get position of div in respect to left and Top
var elm = $('#div_id'); //get the div
var posY_top = elm.offset().top; //get the position from top
var posX_left = elm.offset().left; //get the position from left

Determinating location of span element for absolute positioning of floating div

I need to create a "popup" div over a span element.
I try to determinate its position and size to give correct boundary to place floating div.
<html>
<body>
<p>text a</p>
<div style="padding-left:200px;padding-top:500px">
<table class="message">
<tr><td>test <span id="test">hello</span> world</td></tr>
</table>
</div>
</body>
</html>
I try to get this information for an element id=test
I tried two methods:
First I get span
var span = document.getElementById('test');
Than I calculate either using approach proposed at Retrieve the position (X,Y) of an HTML element
var x0 = 0;
var y0 = 0;
var el = span;
while(el && !isNaN(el.offsetLeft) && !isNaN(el.offsetTop)) {
x0 += el.offsetLeft - el.scrollLeft;
y0 += el.offsetTop - el.scrollTop;
el = el.offsetParent;
}
var x1 = x0 + span.offsetWidth;
var y1 = y0 + span.offsetHeight;
And I also try it by using:
var rect = span.getBoundingClientRect();
x0 = rect.left;
x1 = rect.right;
y0 = rect.top;
y1 = rect.bottom;
Than I log:
console.log(JSON.stringify([x0,x1,y0,y1]));
In both cases I get:
[236,264,381,401]
Which can't be correct as the margin above the table of 500 pixels.
How can I solve this problem correctly?
i.e. how can I put a div with position:ablosute over this element at
correct location?
Note: I can't use JQuery or other fat toolkits, I rather need a portable solution in plane JavaScript.
Edit: I noted that it does not work if the page requires scolling, i.e. the head part of page is hidden, how can it be compensated?

Your code looks fine — PPK has published an article on a slightly neater way of doing it, but as far as I can work out it's functionally identical. If his solution doesn't work, maybe you can try replicating your issue on jsFiddle?

Even if you can't use the jQuery offset method or other toolkits have a look at it. This is the way jQuery calculates the position (I just modified the win variable and removed the test if the element is existing):
function getPos(elem) {
var docElem, win,
box = { top: 0, left: 0 },
doc = elem && elem.ownerDocument;
if ( !doc ) { return; }
docElem = doc.documentElement;
if ( typeof elem.getBoundingClientRect !== typeof undefined ) {
box = elem.getBoundingClientRect();
}
win = self;
return {
top: box.top + ( win.pageYOffset || docElem.scrollTop ) - ( docElem.clientTop || 0 ),
left: box.left + ( win.pageXOffset || docElem.scrollLeft ) - ( docElem.clientLeft || 0 )
};
}
Here is a fiddle, to test (click on the span with the ID#test)

Get div position (top) in javascript?

One div i set the height in css using top:-26px;. I have other divs other places where i'd like to align with that div. I notice in jquery writing .css('top') gets me my css and not the y coord of the div. How do i get the absolute x,y position using javascript?

I will give you the vanilla solution.. don't complain.. add a [0] to your element and it's fixed! :P hope this helps.
function getOffset( el ) {
var _x = 0;
var _y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
_x += el.offsetLeft - el.scrollLeft;
_y += el.offsetTop - el.scrollTop;
el = el.offsetParent;
}
return { top: _y, left: _x };
}
var x = getOffset( document.getElementById('yourElId') ).left;

You can use jQuery(element).offset().top
Hope it helps.

Try this code:
function getElementPosition(id) {
var offsetTrail = document.getElementById(id);
var offsetLeft = 0;
var offsetTop = 0;
while (offsetTrail) {
offsetLeft += offsetTrail.offsetLeft;
offsetTop += offsetTrail.offsetTop;
offsetTrail = offsetTrail.offsetParent;
}
return {
left: offsetLeft,
top: offsetTop
};
}
It will return an object with left and top variables.
If you use JQuery try offset() method:
var pos = $("#element").offset();
console.log(pos.left)
console.log(pos.top)

Cross browser safe down to IE 8, possibly even 7 or 6:
function offset(el) {
var rect = el.getBoundingClientRect(),
scrollLeft = window.pageXOffset || document.documentElement.scrollLeft,
scrollTop = window.pageYOffset || document.documentElement.scrollTop;
return { top: rect.top + scrollTop, left: rect.left + scrollLeft }
}
var offsetEl = offset(document.getElementById('some_id'));
console.log(offsetEl.left, offsetEl.top);
Short and fast and no jQuery needed.

With standard JavaScript:
var elem=document.getElementById("elemID");
var top=elem.offsetTop;
var left=elem.offsetLeft;
With jQuery:
var top=$("#elemID").offset().top;
var left=$("#elemID").offset().left;

Use jQuery(element).offset()
Hope it helps.
For example
var elementPosition = jQuery(element).offset();
var elementTopPositon = elementPosition.top;

var MyElement = document.getElementById("...Your_DIV_Control...");
var top = MyElement.getBoundingClientRect().top;

javascript - position functions returns 0

Icefaces has a method for positioning a popup WHERE you click the mouse. I disabled the portion of the code where the coordinates of the mouse click are taken because I want to put this menuPopup at the position where my targComp (which is actually a div) is located (so fixed location iso mouse location).
The javascript method called is:
function contextMenuPopup(event, popupMenu, targComp) {
var dynamic = $(popupMenu + "_dynamic");
if (!event) {
event = window.event;
}
if (event) {
event.returnValue = false;
event.cancelBubble = true;
if (event.stopPropagation) {
event.stopPropagation();
}
var posx = 0; // Mouse position relative to
var posy = 0; // the document
/*
* if (event.pageX || event.pageY) { posx = event.pageX; posy =
* event.pageY; } else if (event.clientX || event.clientY) { posx =
* event.clientX + document.body.scrollLeft +
* document.documentElement.scrollLeft; posy = event.clientY +
* document.body.scrollTop + document.documentElement.scrollTop; }
*/
alert(Left(targComp));
Ice.Menu.showIt(posX, posY, popupMenu, targComp);
}
}
You see that I only commented old code and add an alert to find out if my methods which return the position of the targComp are correctly calculating the value.
function Left( el ) {
var _x = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
_x += el.offsetLeft - el.scrollLeft;
el = el.parentNode;
}
return _x;
}
function Top( el ) {
var _y = 0;
while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
_y += el.offsetTop - el.scrollTop;
el = el.parentNode;
}
return _y;
}
I do not understand why my alert return 0 when I surely know that my targComp div is not at that left coordinate...
Do you see any problem? (yeah, I know I have to replace the posX and posY at the showIt method, but I'll do that after I am sure that Left and Top are correct (which by the way are copied from here so already confirmed that these methods are working fine...)
Then where it's the problem?
Html code:
<div class="icePnlGrp graMainMenuTabDefault" id="frmMainMenu:divMenuPopupAP" onmouseover="contextMenuPopup(event, 'frmMainMenu:menuPopupAP_sub', 'frmMainMenu:divMenuPopupAPSmall');return false;">
<label class="iceOutLbl graMainMenuTabText" id="frmMainMenu:j_id54">Application Portfolio</label>
<div class="icePnlGrp" id="frmMainMenu:divMenuPopupAPSmall" style="border-style:solid; border-width:1px;">
</div>
</div>
Update (after solving the above problem): I attach a screenshot wondering why the mouse position is calculated correctly when I press click inside that targetComp div but the position of the div is wrong...?
Update solved: seems that I do need targCompObject.offsetLeft, targCompObject.offsetTop,
instead of calliny those Top and Left functions.
where
targCompObject = document.getElementById(targComp);
So the final call is:
Ice.Menu.showIt(targCompObject.offsetLeft, targCompObject.offsetTop,
popupMenu, targComp);

You're passing in the id of the target element, not the element itself.
Somewhere in the popup handler you need
targComp = document.getElementById(targComp);
You could make it check first to see whether it's a string, so that you could optionally call it with a DOM element reference too.

Check if element is visible on screen [duplicate]

This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
jQuery - Check if element is visible after scroling
I'm trying to determine if an element is visible on screen. In order to to this, I'm trying to find the element's vertical position using offsetTop, but the value returned is not correct. In this case, the element is not visible unless you scroll down. But despite of this, offsetTop returns a value of 618 when my screen height is 703, so according to offsetTop the element should be visible.
The code I'm using looks like this:
function posY(obj)
{
var curtop = 0;
if( obj.offsetParent )
{
while(1)
{
curtop += obj.offsetTop;
if( !obj.offsetParent )
{
break;
}
obj = obj.offsetParent;
}
} else if( obj.y )
{
curtop += obj.y;
}
return curtop;
}
Thank you in advance!

--- Shameless plug ---
I have added this function to a library I created
vanillajs-browser-helpers: https://github.com/Tokimon/vanillajs-browser-helpers/blob/master/inView.js
-------------------------------
Intersection Observer
In modern browsers you can use the IntersectionObserver which detects where an element is on the screen or compared to a parent.
The Intersection Observer API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport.
Today I would probably lean toward this API if I need to detect and react to when an element has entered or exited the screen.
But for a quick test/lookup when you just want to verify if an emelemt is currently on screen I would go with the version just below using the getBoundingClientRect.
Using getBoundingClientRect
Short version
This is a lot shorter and should do it as well:
function checkVisible(elm) {
var rect = elm.getBoundingClientRect();
var viewHeight = Math.max(document.documentElement.clientHeight, window.innerHeight);
return !(rect.bottom < 0 || rect.top - viewHeight >= 0);
}
with a fiddle to prove it: http://jsfiddle.net/t2L274ty/1/
Longer version
And a version with threshold and mode included:
function checkVisible(elm, threshold, mode) {
threshold = threshold || 0;
mode = mode || 'visible';
var rect = elm.getBoundingClientRect();
var viewHeight = Math.max(document.documentElement.clientHeight, window.innerHeight);
var above = rect.bottom - threshold < 0;
var below = rect.top - viewHeight + threshold >= 0;
return mode === 'above' ? above : (mode === 'below' ? below : !above && !below);
}
and with a fiddle to prove it: http://jsfiddle.net/t2L274ty/2/
A more traditional way to do it
As BenM stated, you need to detect the height of the viewport + the scroll position to match up with your top position. The function you are using is ok and does the job, though its a bit more complex than it needs to be.
If you don't use jQuery then the script would be something like this:
function posY(elm) {
var test = elm, top = 0;
while(!!test && test.tagName.toLowerCase() !== "body") {
top += test.offsetTop;
test = test.offsetParent;
}
return top;
}
function viewPortHeight() {
var de = document.documentElement;
if(!!window.innerWidth)
{ return window.innerHeight; }
else if( de && !isNaN(de.clientHeight) )
{ return de.clientHeight; }
return 0;
}
function scrollY() {
if( window.pageYOffset ) { return window.pageYOffset; }
return Math.max(document.documentElement.scrollTop, document.body.scrollTop);
}
function checkvisible( elm ) {
var vpH = viewPortHeight(), // Viewport Height
st = scrollY(), // Scroll Top
y = posY(elm);
return (y > (vpH + st));
}
Using jQuery is a lot easier:
function checkVisible( elm, evalType ) {
evalType = evalType || "visible";
var vpH = $(window).height(), // Viewport Height
st = $(window).scrollTop(), // Scroll Top
y = $(elm).offset().top,
elementHeight = $(elm).height();
if (evalType === "visible") return ((y < (vpH + st)) && (y > (st - elementHeight)));
if (evalType === "above") return ((y < (vpH + st)));
}
This even offers a second parameter. With "visible" (or no second parameter) it strictly checks whether an element is on screen. If it is set to "above" it will return true when the element in question is on or above the screen.
See in action: http://jsfiddle.net/RJX5N/2/
I hope this answers your question.

Could you use jQuery, since it's cross-browser compatible?
function isOnScreen(element)
{
var curPos = element.offset();
var curTop = curPos.top;
var screenHeight = $(window).height();
return (curTop > screenHeight) ? false : true;
}
And then call the function using something like:
if(isOnScreen($('#myDivId'))) { /* Code here... */ };

We Keep Coding

JavaScript is the programming language of the Web.