How can I tell if a DOM object is out of the window using JavaScript? [duplicate]

Question

I'm looking for a method to know if a object (as a Div, a img, etc.) is displayed and visible by the user at the window in JavaScript / jQuery.

When I say "is displayed and visible", that's when the user don't scroll the page enough to let's the object visible (If you know what I mean). But if the user scroll the page and the div is no longer visible (is out the window) the function what I'm looking for should know that.

Answer 1

You should use Viewport selectors for jQuery to check if the element is currently visible in the actual viewport.

Here's a demo to show you what I mean.