[get text long in pxs] Uses canvas.measureText to compute and return the width of the given text of given font in pixels #Canvas

getTextWidth.js

    /**
     * Uses canvas.measureText to compute and return the width of the given text of given font in pixels.
     *
     * @param {String} text The text to be rendered.
     * @param {String} font The css font descriptor that text is to be rendered with (e.g. "bold 14px verdana").
     *
     * @see http://stackoverflow.com/questions/118241/calculate-text-width-with-javascript/21015393#21015393
     */
    function getTextWidth(text, font) {
        // if given, use cached canvas for better performance
        // else, create new canvas
        var canvas = document.createElement("canvas");
        var context = canvas.getContext("2d");
        context.font = font;
        var metrics = context.measureText(text);
        return metrics.width;
    }