gistfile1.txt

/**
  * Custom events
  *
  * (c) 2010 Jeremy Ashkenas, DocumentCloud Inc.
  * License: MIT License
  *
  * Usage:
  * > bind('widgetClicked', function() {
  *     console.log("Button was clicked");
  *   }
  * > trigger('widgetClicked');
  *
  */

// Bind an event, specified by a string name, `ev`, to a `callback` function.
// Passing `"all"` will bind the callback to all events fired.
window.bind = function(ev, callback) {
  var calls = window._callbacks || (window._callbacks = {});
  var list  = window._callbacks[ev] || (window._callbacks[ev] = []);
  list.push(callback);
  return this;
}

// Remove one or many callbacks. If `callback` is null, removes all
// callbacks for the event. If `ev` is null, removes all bound callbacks
// for all events.
window.unbind = function(ev, callback) {
  var calls;
  if (!ev) {
    window._callbacks = {};
  } else if (calls = window._callbacks) {
    if (!callback) {
      calls[ev] = [];
    } else {
      var list = calls[ev];
      if (!list) return this;
      for (var i = 0, l = list.length; i < l; i++) {
        if (callback === list[i]) {
          list.splice(i, 1);
          break;
        }
      }
    }
  }
  return this;
}


// Trigger an event, firing all bound callbacks. Callbacks are passed the
// same arguments as `trigger` is, apart from the event name.
// Listening for `"all"` passes the true event name as the first argument.
window.trigger = function(ev) {
  var list, calls, i, l;
  if (!(calls = window._callbacks)) return this;
  if (list = calls[ev]) {
    for (i = 0, l = list.length; i < l; i++) {
      list[i].apply(this, Array.prototype.slice.call(arguments, 1));
    }
  }
  if (list = calls['all']) {
    for (i = 0, l = list.length; i < l; i++) {
      list[i].apply(this, arguments);
    }
  }
  return this;
}