paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

devinrhode2

/**
 * Like, basically PERFECT scrollbars
 */

/* 
   It's pure CSS. 
   Since a quick google search will confirm people going crazy about Mac OS Lion scrollbars...
   this has no fade-out effect.
  
   In Mac OS Lion, the lowest common denominator is always showing scrollbars by a setting.