measureString = function(str, $parent) {
		if (!str) {
			return 0;
		}
	
		var $test = $('<test>').css({
			position: 'absolute',
			top: -99999,
			left: -99999,
			width: 'auto',
			padding: 0,
			whiteSpace: 'pre'
		}).text(str).appendTo('body');
	
		transferStyles($parent, $test, [
			'letterSpacing',
			'fontSize',
			'fontFamily',
			'fontWeight',
			'textTransform'
		]);
	
		var width = $test.width();
		$test.remove();
	
		return width;
	}
Measures the width of a string within a
parent element (in pixels).

@param {string} str
@param {object} $parent
@returns {int}