/* Copyright (c) 2006 Patrick Fitzgerald (http://www.barelyfitz.com/projects/tabber/)*/

function tabberObj(argsObj)
{
  var arg; /* name of an argument to override */

  /* Element for the main tabber div. If you supply this in argsObj,
     then the init() method will be called.
  */
  this.div = null;

  /* Class of the main tabber div */
  this.classMain = "tabber";

  /* Rename classMain to classMainLive after tabifying
     (so a different style can be applied)
  */
  this.classMainLive = "tabberlive";

  /* Class of each DIV that contains a tab */
  this.classTab = "tab";

  /* Class to indicate which tab should be active on startup */
  this.classTabDefault = "tabdefault";

  /* Class for the navigation UL */
  this.classNav = "tabnav";

  /* When a tab is to be hidden, instead of setting display='none', we
     set the class of the div to classTabHide. In your screen
     stylesheet you should set classTabHide to display:none.  In your
     print stylesheet you should set display:block to ensure that all
     the information is printed.
  */
  this.classTabHide = "tabhide";

  /* Class to set the navigation LI when the tab is active, so you can
     use a different style on the active tab.
  */
  this.classNavActive = "tabactive";

  /* Class to indicate that this tab is inactive */
  this.classTabInactive = "tabinactive";

  /* You can override the defaults listed above by passing in an object:
     var mytab = new tabber({property:value,property:value});
  */
  for (arg in argsObj) { this[arg] = argsObj[arg]; }

  /* Create regular expressions for the class names; Note: if you
     change the class names after a new object is created you must
     also change these regular expressions.
  */
  this.REclassMain = new RegExp('\\b' + this.classMain + '\\b', 'gi');
  this.REclassMainLive = new RegExp('\\b' + this.classMainLive + '\\b', 'gi');
  this.REclassTab = new RegExp('\\b' + this.classTab + '\\b', 'gi');
  this.REclassTabDefault = new RegExp('\\b' + this.classTabDefault + '\\b', 'gi');
  this.REclassTabHide = new RegExp('\\b' + this.classTabHide + '\\b', 'gi');

  /* Array of objects holding info about each tab */
  this.tabs = new Array();

  /* If the main tabber div was specified, call init() now */
  if (this.div) {

    this.init(this.div);

    /* We don't need the main div anymore, and to prevent a memory leak
       in IE, we must remove the circular reference between the div
       and the tabber object. */
    this.div = null;
  }
}


/*--------------------------------------------------
  Methods for tabberObj
  --------------------------------------------------*/


tabberObj.prototype.init = function(e)
{
  /* Set up the tabber interface.

     e = element (the main containing div)

     Example:
     init(document.getElementById('mytabberdiv'))
   */

  var
  childNodes, /* child nodes of the tabber div */
  i, i2, /* loop indices */
  t, /* object to store info about a single tab */
  defaultTab=0, /* which tab to select by default */
  DOM_ul, /* tabbernav list */
  DOM_li, /* tabbernav list item */
  DOM_a, /* tabbernav link */
  aId, /* A unique id for DOM_a */
  headingElement; /* searching for text to use in the tab */

  /* Verify that the browser supports DOM scripting */
  if (!document.getElementsByTagName) { return false; }

  /* If the main DIV has an ID then save it. */
  if (e.id) {
    this.id = e.id;
  }

  /* Clear the tabs array (but it should normally be empty) */
  this.tabs.length = 0;

  /* Loop through an array of all the child nodes within our tabber element. */
  childNodes = e.childNodes;
  for(i=0; i < childNodes.length; i++) {

    /* Find the nodes where class="tab" */
    if(childNodes[i].className &&
       childNodes[i].className.match(this.REclassTab)) {
      
      /* Create a new object to save info about this tab */
      t = new Object();
      
      /* Save a pointer to the div for this tab */
      t.div = childNodes[i];
      
      /* Add the new object to the array of tabs */
      this.tabs[this.tabs.length] = t;

      /* If the class name contains classTabDefault,
	 then select this tab by default.
      */
      if (childNodes[i].className.search(this.REclassTabDefault) != -1) {
	defaultTab = this.tabs.length-1;
      }
    }
  }

  /* Create a new UL list to hold the tab headings */
  DOM_ul = document.createElement("ul");
  DOM_ul.className = this.classNav;
  
  /* Loop through each tab we found */
  for (i=0; i < this.tabs.length; i++) {

    t = this.tabs[i];

    /* Get the label to use for this tab from the title attribute on the DIV */
    t.headingText = t.div.title;

    /* Remove the title attribute to prevent a tooltip from appearing */
    t.div.title = '';

    /* Create a list element for the tab */
    DOM_li = document.createElement("li");

    /* Save a reference to this list item so we can later change it to
       the "active" class */
    t.li = DOM_li;

    /* Create a link to activate the tab */
    DOM_a = document.createElement("a");
    DOM_a.appendChild(document.createTextNode(t.headingText));
    DOM_a.href = "javascript:void(null);";
    DOM_a.title = t.headingText;
    DOM_a.onclick = this.navClick;

    /* Add some properties to the link so we can identify which tab
       was clicked. Later the navClick method will need this.
    */
    DOM_a.tabber = this;
    DOM_a.tabberIndex = i;

    /* Add the link to the list element */
    DOM_li.appendChild(DOM_a);
    
    /* fuege ggf. die inaktiv-Klasse hinzu /HRS */
    if (t.div.className.indexOf(this.classTabInactive) != -1) {
      DOM_a.className = this.classTabInactive;
    }

    /* Add the list element to the list */
    DOM_ul.appendChild(DOM_li);
  }

  /* Add the UL list to the beginning of the tabber div */
  e.insertBefore(DOM_ul, e.firstChild);

  /* Make the tabber div "live" so different CSS can be applied */
  e.className = e.className.replace(this.REclassMain, this.classMainLive);

  /* Activate the default tab, and do not call the onclick handler */
  this.tabShow(defaultTab);

  /* If the user specified an onLoad function, call it now. */
  if (typeof this.onLoad == 'function') {
    this.onLoad({tabber:this});
  }

  return this;
};


tabberObj.prototype.navClick = function(event)
{
  /* This method should only be called by the onClick event of an <A>
     element, in which case we will determine which tab was clicked by
     examining a property that we previously attached to the <A>
     element.

     Since this was triggered from an onClick event, the variable
     "this" refers to the <A> element that triggered the onClick
     event (and not to the tabberObj).

     When tabberObj was initialized, we added some extra properties
     to the <A> element, for the purpose of retrieving them now. Get
     the tabberObj object, plus the tab number that was clicked.
  */

  var
  rVal, /* Return value from the user onclick function */
  a, /* element that triggered the onclick event */
  self, /* the tabber object */
  tabberIndex, /* index of the tab that triggered the event */
  onClickArgs; /* args to send the onclick function */

  a = this;
  if (!a.tabber) { return false; }

  self = a.tabber;
  tabberIndex = a.tabberIndex;

  /* Remove focus from the link because it looks ugly.
     I don't know if this is a good idea...
  */
  a.blur();

  /* If the user specified an onClick function, call it now.
     If the function returns false then do not continue.
  */
  if (typeof self.onClick == 'function') {

    onClickArgs = {'tabber':self, 'index':tabberIndex, 'event':event};

    /* IE uses a different way to access the event object */
    if (!event) { onClickArgs.event = window.event; }

    rVal = self.onClick(onClickArgs);
    if (rVal === false) { return false; }
  }

  self.tabShow(tabberIndex);

  return false;
};


tabberObj.prototype.tabHideAll = function()
{
  var i; /* counter */

  /* Hide all tabs and make all navigation links inactive */
  for (i = 0; i < this.tabs.length; i++) {
    this.tabHide(i);
  }
};


tabberObj.prototype.tabHide = function(tabberIndex)
{
  var div;

  if (!this.tabs[tabberIndex]) { return false; }

  /* Hide a single tab and make its navigation link inactive */
  div = this.tabs[tabberIndex].div;

  /* Hide the tab contents by adding classTabHide to the div */
  if (!div.className.match(this.REclassTabHide)) {
    div.className += ' ' + this.classTabHide;
  }
  this.navClearActive(tabberIndex);

  return this;
};


tabberObj.prototype.tabShow = function(tabberIndex)
{
  /* Show the tabberIndex tab and hide all the other tabs */

  var div;

  if (!this.tabs[tabberIndex]) { return false; }

  /* Hide all the tabs first */
  this.tabHideAll();

  /* Get the div that holds this tab */
  div = this.tabs[tabberIndex].div;

  /* Remove classTabHide from the div */
  div.className = div.className.replace(this.REclassTabHide, '');

  /* Mark this tab navigation link as "active" */
  this.navSetActive(tabberIndex);

  /* If the user specified an onTabDisplay function, call it now. */
  if (typeof this.onTabDisplay == 'function') {
    this.onTabDisplay({'tabber':this, 'index':tabberIndex});
  }

  return this;
};

tabberObj.prototype.navSetActive = function(tabberIndex)
{
  /* Note: this method does *not* enforce the rule
     that only one nav item can be active at a time.
  */

  /* Set classNavActive for the navigation list item */
  this.tabs[tabberIndex].li.className = this.classNavActive;

  return this;
};


tabberObj.prototype.navClearActive = function(tabberIndex)
{
  /* Note: this method does *not* enforce the rule
     that one nav should always be active.
  */

  /* Remove classNavActive from the navigation list item */
  this.tabs[tabberIndex].li.className = '';

  return this;
};