How do I get the background-position-y in firefox using jQuery?

Question

$(elem).css('backgroundPositionY')

does it on chrome, ie, and safari, but not Firefox (nor Opera I believe). You'd think jQuery would have a polyfill but it doesn't, as of 1.5. How can I easily get the background Y position for e.g. background animations (for e.g. parallax)?

EDIT: Tell Mozilla you want background-position-[x,y] support. (use the "vote" feature, not comment, unless you have something prescient to add). Bug has been open since 2010 tho (3 years now) so don't hold your breath for a fix. :)

Answer 1

var backgroundPos = $(elem).css('backgroundPosition').split(" ");
//now contains an array like ["0%", "50px"]

var xPos = backgroundPos[0],
    yPos = backgroundPos[1];