//Loads fx (animation) package
dojo.require("dojo.fx");
//Loads the behavoir package
dojo.require("dojo.behavior");

//Object to hold all description toggler
var descriptionTogglerList = new Object();

function registerDescriptionToggle(headlineNode) {
    //calculate an id for the headline
    var headlineID = "head" + headlineNode.parentNode.id ;
    //and assign it to the element
    headlineNode.id = headlineID;
   
    //add style to title for pointer
    dojo.style(headlineID, "cursor", "pointer");
   
    //retrieve the description id from the parent node
    var descriptionID = "desc" + headlineNode.parentNode.id ;        
   
    //create a new toggler
    var toggler = new dojo.fx.Toggler({
        node: descriptionID,
        showFunc: dojo.fx.wipeIn,
        hideFunc: dojo.fx.wipeOut
    });
    //hide the description
    toggler.hide();
       
    //store the toggler in the list
    descriptionTogglerListheadlineID = toggler;
}

//shows a description
function showDescription(headlineID){
        descriptionTogglerListheadlineID.show();
}

//hide a description
function hideDescription(headlineID){
        descriptionTogglerListheadlineID.hide();
}


dojo.addOnLoad(function(){        
  // search for all headlines and register a toggler  
  dojo.query("div.session h1").forEach(registerDescriptionToggle);

  // add the behavior to the sessions headlines to open the description on click
  dojo.behavior.add({
      "div.session h1": {
        onclick: function(evt){
          var headlineID = evt.target.id;
          showDescription(headlineID);
      }
    }
  });

  // add the behavior to the description to close on click
  dojo.behavior.add({
      "div.session div.sessionDescription": {
        onclick: function(evt){
          var descriptionID = evt.target.id;
          var headlineID = descriptionID.replace(/^desc/g, "head");
          hideDescription(headlineID);
      }
    }
  });

  dojo.behavior.apply();    
});

//create new object with the toggler and store it in the list
descriptionTogglerListheadlineID = {
    toggler: toggler,
    isVisible: false
};

//shows a description
function showDescription(headlineID){
        descriptionTogglerListheadlineID.toggler.show();
        descriptionTogglerListheadlineID.isVisible = true;
}
//hide a description
function hideDescription(headlineID){
        descriptionTogglerListheadlineID.toggler.hide();
        descriptionTogglerListheadlineID.isVisible = false;
}
//toggle a description
function toggleDescription(headlineID){
        if (descriptionTogglerListheadlineID.isVisible){
                hideDescription(headlineID);                
        } else {
                showDescription(headlineID);
        }        
}