lazy-load-custom-fonts.html

<script>
  // Preload font files and finally patch CSS with custom fonts.
  // We do this to avoid displaying unreadable text while waiting for data.
  function finalizer() {
    var n = document.createElement('link');
    n.href = '/res/custom-fonts.css';
    n.media = 'screen, projection';
    n.rel = 'stylesheet';
    n.type = 'text/css';
    document.getElementsByTagName('head').item(0).appendChild(n);
  }
  var countdown = 1;
  function fetch(url) {
    try {
      var req = new XMLHttpRequest();
      req.open('GET', url, true);
      req.onreadystatechange = function () { if (req.readyState == 4) {
        if (--countdown === 0)
          finalizer()
      }};
      req.send();
    } catch (e) {}
  }
  fetch('http://hunch.se/style/fonts/mplus-1m-light.ttf');
  fetch('http://hunch.se/style/fonts/DroidSerif-Regular.woff');
  fetch('http://hunch.se/style/fonts/DroidSerif-Italic.woff');
  fetch('http://hunch.se/style/fonts/DroidSerif-Bold.woff');
  if (--countdown === 0) finalizer();
</script>