jQuery Zoom-Trigger

jQuery.zoom.js

(function($, w, d) {
  function scroll(e) {
    if (!e.ctrlKey) return;
    var oe = e.originalEvent,
        t = oe.wheelDelta > 0 || oe.detail < 0 ? "In" : "Out";
    if (t) trigger(t, e);
  }

  function keyDown(e) {
    if (!e.ctrlKey) return;
    var w = e.which,
        t =
      [189, 109].indexOf(w) >= 0 ? "In" : [187, 107].indexOf(w) >= 0 ? "Out" : [48, 96].indexOf(w) >= 0 ? "Reset" : false;
    if (t) trigger(t, e);
  }

  function trigger(t, e) {
    $(w).trigger('zoom'+t,[e])
    .trigger('zoom',[e]);
  }

  $(w).on("mousewheel DOMMouseScroll", scroll);
  $(d).on("keydown", keyDown);
})(jQuery, window, document);