(function ($) {
  AblePlayer.prototype.initSignLanguage = function() {
    // Sign language is only currently supported in HTML5 player, not fallback or YouTube
    if (this.player === 'html5') {
      // check to see if there's a sign language video accompanying this video
      // check only the first source
      // If sign language is provided, it must be provided for all sources
      this.signFile = this.$sources.first().attr('data-sign-src');
      if (this.signFile) {
        if (this.debug) {
          console.log('This video has an accompanying sign language video: ' + this.signFile);
        }
        this.hasSignLanguage = true;
        this.injectSignPlayerCode();
      }
      else {
        this.hasSignLanguage = false;
      }
    }
  };

  AblePlayer.prototype.injectSignPlayerCode = function() {

    // create and inject surrounding HTML structure
    // If IOS:
    //  If video:
    //   IOS does not support any of the player's functionality
    //   - everything plays in its own player
    //   Therefore, AblePlayer is not loaded & all functionality is disabled
    //   (this all determined. If this is IOS && video, this function is never called)
    //  If audio:
    //   HTML cannot be injected as a *parent* of the <audio> element
    //   It is therefore injected *after* the <audio> element
    //   This is only a problem in IOS 6 and earlier,
    //   & is a known bug, fixed in IOS 7

    var thisObj, signVideoId, signVideoWidth, i, signSrc, srcType, $signSource;

    thisObj = this;

    signVideoWidth = this.getDefaultWidth('sign');

    signVideoId = this.mediaId + '-sign';
    this.$signVideo = $('<video>',{
      'id' : signVideoId,
      'tabindex' : '-1'
    });
    this.signVideo = this.$signVideo[0];
    // for each original <source>, add a <source> to the sign <video>
    for (i=0; i < this.$sources.length; i++) {
      signSrc = this.$sources[i].getAttribute('data-sign-src');
      srcType = this.$sources[i].getAttribute('type');
      if (signSrc) {
        $signSource = $('<source>',{
          'src' : signSrc,
          'type' : srcType
        });
        this.$signVideo.append($signSource);
      }
      else {
        // source is missing a sign language version
        // can't include sign language
        this.hasSignLanguage = false;
        break;
      }
    }

    this.$signWindow = $('<div>',{
      'class' : 'able-sign-window',
      'tabindex': '-1'
    });
    this.$signToolbar = $('<div>',{
      'class': 'able-window-toolbar able-' + this.toolbarIconColor + '-controls'
    });

    this.$signWindow.append(this.$signToolbar, this.$signVideo);

    this.$ableWrapper.append(this.$signWindow);

    // make it draggable
    this.initDragDrop('sign');

    if (this.prefSign === 1) {
      // sign window is on. Go ahead and position it and show it
      this.positionDraggableWindow('sign',this.getDefaultWidth('sign'));
    }
    else {
      this.$signWindow.hide();
    }
  };

})(jQuery);