HTML 적응형 글꼴 크기

***.directive("doCalculateFontsize",['$timeout',function ($timeout) {
    /*
    *   通用的字体大小自适应，通过在改变字体大小的同时计算dom元素的宽高是否超界实现
    * */
    return function(scope, element, attr) {
        attr.$observe("doCalculateFontsize",function (interpolatedValue) {
            if(interpolatedValue!=undefined&&interpolatedValue!="") {
                var maxwidth = parseInt(attr.domMaxWidth);
                var maxheight = parseInt(attr.domMaxHeight);
                var th = parseInt(attr.domTotalHeight);
                var text = attr.doCalculateFontsize;
                var nowsize = 12;
                var maxsize = 200;
                angular.element(element).css("visibility", "hidden").html(text).css("font-size", nowsize + "px");

                for (; nowsize < maxsize; nowsize++) {
                    var nowwidth = angular.element(element)[0].offsetWidth;
                    var nowheight = angular.element(element)[0].offsetHeight;

                    if (nowwidth >= maxwidth || nowheight >= maxheight) {
                        break;
                    }
                    else {
                        angular.element(element).css("font-size", nowsize + "px").css("marginTop", (th - 0.5 * nowheight) + "px").css("visibility", "visible");
                    }
                }
            }
            else{
                angular.element(element).css("visibility", "visible").html("").css("font-size", "12px");
            }
        })
    };
}])