// ----------------------------------------------
// Allgemeine Funktionen
// ----------------------------------------------

// event handler erweitern
function addEventToObject(obj,evt,func) {
	var oldhandler = obj[evt];
	obj[evt] = (typeof obj[evt] != 'function') ? func : function(){oldhandler();func();};
}



// ----------------------------------------------
// Stylesheet Changer
// ----------------------------------------------

function setActiveStyleSheet(title) {
  var i, a, main;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
      a.disabled = true;
      if(a.getAttribute("title") == title) a.disabled = false;
    }
  }
}

function getActiveStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled) return a.getAttribute("title");
  }
  return null;
}

function getPreferredStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1
       && a.getAttribute("rel").indexOf("alt") == -1
       && a.getAttribute("title")
       ) return a.getAttribute("title");
  }
  return null;
}

function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}

window.onload = function(e) {
  var cookie = readCookie("style");
  var title = cookie ? cookie : getPreferredStyleSheet();
  setActiveStyleSheet(title);
}

window.onunload = function(e) {
  var title = getActiveStyleSheet();
  createCookie("style", title, 365);
}

var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);



// ----------------------------------------------
// Default search box text (thank you, Dunstan)
// ----------------------------------------------

var Searchbox =
{
	init : function()
	{
		var sBox = document.getElementById('headSearchQuery');
		if (sBox)
		{
			addEventToObject(sBox,'onclick',Searchbox.click);
			addEventToObject(sBox,'onblur',Searchbox.blur);
		}	
	},
	click : function()
	{
		var sBox = document.getElementById('headSearchQuery');
		if (sBox.value == 'Webseiten durchsuchen...')
		{
			sBox.value = '';
		}
	},
	blur : function()
	{
		var sBox = document.getElementById('headSearchQuery');
		if (sBox.value == '' || sBox.value == ' ')
		{
		  sBox.value = 'Webseiten durchsuchen...';
		}
	}
};

// add event onload
addEventToObject(window,'onload',Searchbox.init);



// ----------------------------------------------
// Barrierefreier Popup-Loader
// ----------------------------------------------

/**
 * neues fenster mit def. parametern
 * funktioniert mit JS aber auch ohne!
 * beispiel:
 * <a href="http://example.com" target="_blank" onclick="link_popup(this); return false">pop me up</a>
**/
function raw_popup(url, target, features)
{
  var _POPUP_FEATURES = 'location=0, statusbar=0, menubar=0, width=400, height=300';
  if (!features)
    features = _POPUP_FEATURES;
  if (!target)
    target = '_blank';
  var theWindow = window.open(url, target, features);
  theWindow.focus();

  return theWindow;
}

function link_popup(src, features)
{
  return raw_popup(src.getAttribute('href'),
                   src.getAttribute('target') || '_blank',
                   features);
}



// ----------------------------------------------
// Hyperlinks in neuem Fenster
// ----------------------------------------------

/**
 * Oeffnet Hyperlinks, die das Attribut 'rel="openInNewWindow"' 
 * gesetzt haben, in einem neuen Fenster
 */
function substituteTargetBlank()
{
  if (!document.getElementsByTagName)
    return;
  var anchors = document.getElementsByTagName("a");
  for (var i=0; i<anchors.length; i++)
  {
    var anchor = anchors[i];
    if (anchor.getAttribute("href") &&
       anchor.getAttribute("rel") == "openInNewWindow")
      anchor.target = "_blank";
  }
}

// add event onload
addEventToObject(window,'onload',substituteTargetBlank);