jQuery Plugin for responsively scaling text to fill it's parent width.

jquery.scale-text.js

/*!
 *  jQuery Plugin for responsively scaling text to fill it's parent width.
 *
 * Copyright 2016 James Buncle
 * 
 * Released under the MIT license.
 * http://jquery.org/license
 *
 */
(function ($) {

    $.fn.scaleText = function (options) {
        var defaults = {
            increment: 5,
            maxwidth: 'auto',
            minwidth: 0
        };
        var settings = $.extend(defaults, options);

        return this.each(function () {
            var $this = $(this);
            $(window).resize(function () {
                scaleText($this, settings);
            });
            scaleText($this, settings);
        });
    };

    function scaleText($obj, settings) {
        var targetWidth = $obj.parent().width();
        if (settings.maxwidth !== 'auto') {
            if (targetWidth > settings.maxwidth) {
                targetWidth = settings.maxwidth;
            }
        }
        if (targetWidth < settings.minwidth) {
            targetWidth = settings.minwidth;
        }
        targetWidth = parseFloat(targetWidth);
        var initialFontSize = parseFloat(2.5);

        //Calculate scale factor
        $obj.css({
            'font-size': initialFontSize + 'px',
            'width': 'auto',
            'display': 'inline',
            'position': 'relative'
        });
        var currentWidth = parseFloat($obj.width());
        var scale = targetWidth / currentWidth;
        var newFontSize = Math.floor((initialFontSize) * scale);
        $obj.css({
            'font-size': newFontSize,
            'display': '',
            'position': ''
        });
    }
})(jQuery);