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// array holding fired events that are pending to be executed
// useful for avoiding accidental double firing of events
// events in queue are unique per eventType&eventTarget
GvaScript.eventsQueue = Class.create();
Object.extend(GvaScript.eventsQueue, {
    _queue: $A([]),
    hasEvent: function(target, name) {
        return (typeof this._queue.find(function(e) {
            return (e.target == target && e.name == name);
        }) == 'object');
    },
    pushEvent: function(target, name) {
        this._queue.push({target: target, name: name});
    },
    popEvent: function(target, name) {
        this._queue = this._queue.reject(function(e) {
            return (e.target == target && e.name == name);
        });
    }
});

// fireEvent : should be COPIED into controller objects, so that
// 'this' is properly bound to the controller

GvaScript.fireEvent = function(/* type, elem1, elem2, ... */) {

  var event;

  switch (typeof arguments[0]) {
  case "string" :
    event = {type: arguments[0]};
    break;
  case "object" :
    event = arguments[0];
    break;
  default:
    throw new Error("invalid first argument to fireEvent()");
  }

  var propName = "on" + event.type;
  var handler;
  var target   = arguments[1]; // first element where the event is triggered
  var currentTarget;           // where the handler is found

  // event already fired and executing
  if(GvaScript.eventsQueue.hasEvent(target, event.type)) return;

  // try to find the handler, first in the HTML elements, then in "this"
  for (var i = 1, len = arguments.length; i < len; i++) {
    var elem = arguments[i];
    if (handler = elem.getAttribute(propName)) {
      currentTarget = elem;
      break;
    }
  }
  if (currentTarget === undefined)
    if (handler = this[propName])
      currentTarget = this;

  if (handler) {
    // build context and copy into event structure
    var controller = this;