Javascript scrollIntoView() middle alignment?

Question

Javascript .scrollIntoView(boolean) provide only two alignment option.

1. top
2. bottom

What if I want to scroll the view such t

Answer 1

Use window.scrollTo() for this. Get the top of the element you want to move to, and subtract one half the window height.

Demo: http://jsfiddle.net/ThinkingStiff/MJ69d/

Element.prototype.documentOffsetTop = function () {
    return this.offsetTop + ( this.offsetParent ? this.offsetParent.documentOffsetTop() : 0 );
};

var top = document.getElementById( 'middle' ).documentOffsetTop() - ( window.innerHeight / 2 );
window.scrollTo( 0, top );