sui-5.js

// Fuentes instaladas
fp_sources.fonts = {};
var fonts2Check = ['Arial', 'Arial Black', 'Arial Rounded MT Bold', 'Book Antiqua', 'Bookman Old Style', 'Calibri'];
var defaultFont = 'Comic Sans MS, Comic Sans, cursive';
var defaultText = 'mmmmmmmmmmambo';
var defaultWidth = 611;
for (var i=0; i<fonts2Check.length; i++) {
  var fontName = fonts2Check[i];
  var el = document.createElement('div');
  el.style.cssText = 'position:absolute;' +
    'left:0; top:0; z-index:-99999;' +
    'opacity:0; font-size:60px;' +
    'font-family:' + fontName + ', ' +
    defaultFont;
  el.innerHTML = defaultText;
  document.body.appendChild(el);
  var actualWidth = el.offsetWidth;
  var installed = (actualWidth != defaultWidth);
  fp_sources.fonts[fontName] = installed;
}