static/ext/src/dom/Element_style.js
function() {
        var me = this,
            w = Math.max(me.dom.offsetWidth, me.dom.clientWidth);

        if (!w) {
            w = parseFloat(me.getStyle(WIDTH)) || 0;
            if (!me.isBorderBox()) {
                w += me.getFrameWidth('lr');
            }
        }
        return w;
    }
function() {
        var me = this,
            w = Math.max(me.dom.offsetWidth, me.dom.clientWidth);

        if (!w) {
            w = parseFloat(me.getStyle(WIDTH)) || 0;
            if (!me.isBorderBox()) {
                w += me.getFrameWidth('lr');
            }
        }
        return w;
    }
Returns either the offsetWidth or the width of this element based on CSS width adjusted by padding or borders
when needed to simulate offsetWidth when offsets aren't available. This may not work on display:none elements
if a width has not been set using CSS.
@return {Number}