// Copyright (c) 2009 notions (http://www.notions.de)
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.


var NewsSwitcher = Class.create();
NewsSwitcher.prototype = {
	currentItem: null,
	interval: 6,
	effectDuration: 0.5,
	
	initialize: function() {
    this.currentItem = $('news-1');
    new PeriodicalExecuter(function(executer) {
      this.selectNextItem();
    }.bind(this), this.interval);
	},
	
	selectItem: function(item) {
    if ( this.currentItem == item ) {
      return;
    }
	
    if ( this.currentItem ) {
      new Effect.Fade(this.currentItem, { duration: this.effectDuration });
    }

    this.currentItem = $(item);

    if ( this.currentItem ) {
      new Effect.Appear(this.currentItem, { duration: this.effectDuration });
    }
  },

	selectNextItem: function() {
    var nextItemId = parseInt($(this.currentItem).id.substr(5))+1;
    if ( $('news-'+nextItemId) ) {
      this.selectItem('news-'+nextItemId);
    }
    else {
      this.selectItem('news-1');
    }
	}
};

document.observe("dom:loaded", function() {
  new NewsSwitcher();
});