Sticky scroll

Made in answer to http://stackoverflow.com/questions/18614301/keep-overflow-div-scrolled-to-bottom-unless-user-scrolls-up

by dotnetCarpenter

HTML

<div id="out" style="overflow:auto"></div>

CSS

#out {
    height: 100px;
}

JavaScript

var out = document.getElementById("out");
var c = 0;
var add = setInterval(function() {
    // allow 1px inaccuracy by adding 1
    var isScrolledToBottom = out.scrollHeight - out.clientHeight <= out.scrollTop + 1;
    console.log(out.scrollHeight - out.clientHeight,  out.scrollTop + 1);
    var newElement = document.createElement("div");
    newElement.innerHTML = c++;
    out.appendChild(newElement);
    // scroll to bottom if isScrolledToBotto
    if(isScrolledToBottom)
      out.scrollTop = out.scrollHeight - out.clientHeight;
}, 1000);