/* this is a bit complex : we use a list to queue the tweets to display, for

     two reasons :

     - first, We want the pane to retract when there's no tweets to see - it's doable

       but it would lead for race conditions - imagine that the user clicks on a tweet

       and wants it displayed, it would display in an empty pane

     - second case, the pane displays a tweet and the user clicks before that the tweet

       has finished displaying - he wants his tweet to be displayed now, not after the

       previous tweet has finished.

     So, we queue every tweet in a message queue, which gets consumed at every call of

     displayTweet.

  */

  this._messageQueue = [];

  /* a variable for an edge case : when the user has clicked on a tweet and clicks on another

     one before that the first has been cleared. In this case, the second one will be displayed

     but cleared before its time.

  */

  this._tweetClearedBeforeEnd = false;

IriSP.TweetsWidget.prototype.displayTweet = function(annotation) {

};

IriSP.TweetsWidget.prototype.pushQueue = function(annotation) {

  this._messageQueue.push(annotation);

  // we're pushing in the queue before another tweet has been

  // displayed

  if (this._messageQueue.length != 0)

    this._tweetClearedBeforeEnd = true;

  var annotation = this._messageQueue[0];

  this.displayTweet(annotation);

  var time = this._Popcorn.currentTime();

  this._Popcorn = this._Popcorn.code({ start : time + 0.1, end: time + 10, 

                                       onEnd: IriSP.wrap(this, this.clearQueue)});

};

/* this does essentially the same job than handleQueue, except that it's only

   called by handleQueue to cleanup after a tweet. */

IriSP.TweetsWidget.prototype.clearQueue = function() {  

  var annotation = this._messageQueue.shift();

  if( this._tweetClearedBeforeEnd === true) {  

    this._tweetClearedBeforeEnd;

    return;

  }

  if (this._messageQueue === []) {

    this.closePanel();

  }

};

IriSP.TweetsWidget.prototype.closePanel = function() {

  if (this._displayingTweet)

    return;

  else {

    this.selector.hide(50);

  }

  this.pushQueue(annotation);