/**********************************************************************

*          Calendar JavaScript [DOM] v3.09 by Michael Loesler          *

************************************************************************

* Copyright (C) 2005-08 by Michael Loesler, http//derletztekick.com    *

*                                                                      *

*                                                                      *

* This program is free software; you can redistribute it and/or modify *

* it under the terms of the GNU General Public License as published by *

* the Free Software Foundation; either version 3 of the License, or    *

* (at your option) any later version.                                  *

*                                                                      *

* This program is distributed in the hope that it will be useful,      *

* but WITHOUT ANY WARRANTY; without even the implied warranty of       *

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *

* GNU General Public License for more details.                         *

*                                                                      *

* You should have received a copy of the GNU General Public License    *

* along with this program; if not, see <http://www.gnu.org/licenses/>  *

* or write to the                                                      *

* Free Software Foundation, Inc.,                                      *

* 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.            *

*                                                                      *

 **********************************************************************/



	function CalendarJS() {

		this.now = new Date();

		this.dayname = ["Mo","Di","Mi","Do","Fr","Sa","So"];

		this.monthname = ["Januar","Februar","März","April","Mai","Juni","Juli","August","September","Oktober","November","Dezember"];	

		this.tooltip = ["vorheriger Monat","nächster Monat","aktuelles Datum"];

		this.monthCell = document.createElement("th");

		this.tableHead = null;

		this.parEl = null;

		

		this.init = function( id ) {

			this.date = this.now.getDate();

			this.month = this.mm = this.now.getMonth();

			this.year = this.yy = this.now.getFullYear();

			this.monthCell.colSpan = 5;

			this.monthCell.appendChild(document.createTextNode( this.monthname[this.mm]+" "+this.yy ));

			this.tableHead = this.createTableHead();

			this.parEl = document.getElementById( id );

			this.show();

			this.checkDate();

		},

		

		

		this.checkDate = function() {

			var self = this;

			var today = new Date();

			if (this.date != today.getDate()) {

				this.date  = today.getDate();

				if (this.mm == this.month && this.yy == this.year)

					this.switchMonth("current");

				this.month = today.getMonth();

				if (this.mm == this.month && this.yy == this.year)

					this.switchMonth("current");

				this.year  = today.getFullYear();

				if (this.mm == this.month && this.yy == this.year)

					this.switchMonth("current");

 

			}

			window.setTimeout(function() { self.checkDate(); }, Math.abs(new Date(this.year, this.month, this.date, 24, 0, 0)-this.now));

		},

		

		this.removeElements = function( Obj ) {

			for (var i=0; i<Obj.childNodes.length; i++)

				Obj.removeChild(Obj.childNodes[i]);

			return Obj;

		},

			

		this.show = function() {

			this.parEl = this.removeElements( this.parEl );

			this.monthCell.firstChild.replaceData(0, this.monthCell.firstChild.nodeValue.length, this.monthname[this.mm]+" "+this.yy);

			var table = document.createElement("table");

			table.appendChild( this.createTableBody() );

			table.appendChild( this.tableHead );

			this.parEl.appendChild( table );

		},

				

		this.createTableHead = function() {

			var thead = document.createElement("thead");

			var tr = document.createElement("tr");

			var th = this.getCell( "th", "\u00AB", "last_month" )

			th.Instanz = this;

			th.onclick = function() { this.Instanz.switchMonth("prev"); };

			th.title = this.tooltip[0];

			try { th.style.cursor = "pointer"; } catch(e){ th.style.cursor = "hand"; }

			tr.appendChild( th );

			this.monthCell.Instanz = this;

			this.monthCell.onclick = function() { this.Instanz.switchMonth("current"); };

			this.monthCell.title = this.tooltip[2];

			try { this.monthCell.style.cursor = "pointer"; } catch(e){ this.monthCell.style.cursor = "hand"; }

			tr.appendChild( this.monthCell );			

			th = this.getCell( "th", "\u00BB", "next_month" )

			th.Instanz = this;

			th.onclick = function() { this.Instanz.switchMonth("next"); };

			th.title = this.tooltip[1];

			try { th.style.cursor = "pointer"; } catch(e){ th.style.cursor = "hand"; }

			tr.appendChild( th );

			thead.appendChild( tr );

			tr = document.createElement('tr');

			for (var i=0; i<this.dayname.length; i++)

				tr.appendChild( this.getCell("th", this.dayname[i], "weekday" ) );

			thead.appendChild( tr );

			return thead;

		},

		

		this.createTableBody = function() {

			var dayspermonth = [31,28,31,30,31,30,31,31,30,31,30,31];

			var sevendaysaweek = 0;

			var begin = new Date(this.yy, this.mm, 1);

			var firstday = begin.getDay()-1;

			if (firstday < 0)

				firstday = 6;

			if ((this.yy%4==0) && ((this.yy%100!=0) || (this.yy%400==0)))

				dayspermonth[1] = 29;

			var tbody = document.createElement("tbody");

			var tr = document.createElement('tr');

			if (firstday == 0) {

				for (var i=0; i<this.dayname.length; i++) {

					var prevMonth = (this.mm == 0)?11:this.mm-1;

					tr.appendChild( this.getCell( "td", dayspermonth[prevMonth]-6+i, "last_month" ) );

				}

				tbody.appendChild( tr );

				tr = document.createElement('tr');

			}

			

			for (var i=0; i<firstday; i++, sevendaysaweek++) {

				var prevMonth = (this.mm == 0)?11:this.mm-1;

				tr.appendChild( this.getCell( "td", dayspermonth[prevMonth]-firstday+i+1, "last_month" ) );

				

			}



			for (var i=1; i<=dayspermonth[this.mm]; i++, sevendaysaweek++){

				if (this.dayname.length == sevendaysaweek){

					tbody.appendChild( tr );

					tr = document.createElement('tr');

					sevendaysaweek = 0;

				}

				if (i==this.date && this.mm==this.month && this.yy==this.year && (sevendaysaweek == 5 || sevendaysaweek == 6))

					tr.appendChild( this.getCell( "td", i, "today weekend" ) );

				else if (i==this.date && this.mm==this.month && this.yy==this.year)

					tr.appendChild( this.getCell( "td", i, "today" ) );

				else if (sevendaysaweek == 5)

					tr.appendChild( this.getCell( "td", i, "saturday weekend" ) );

				else if (sevendaysaweek == 6)

					tr.appendChild( this.getCell( "td", i, "sunday weekend" ) );

				else

					tr.appendChild( this.getCell( "td", i, null ) );

			}

	

			var daysNextMonth = 1;

			for (var i=sevendaysaweek; i<this.dayname.length; i++) 

				tr.appendChild( this.getCell( "td", daysNextMonth++, "next_month"  ) );

				

			tbody.appendChild( tr );

			

			while (tbody.getElementsByTagName("tr").length<6) {

				tr = document.createElement('tr');

				for (var i=0; i<this.dayname.length; i++) 

					tr.appendChild( this.getCell( "td", daysNextMonth++, "next_month"  ) );

				tbody.appendChild( tr );

			}

		

			

			return tbody;

			

		},

		

		this.getCell = function(tag, str, cssClass) {

			var El = document.createElement( tag );

			El.appendChild(document.createTextNode( str ));

			if (cssClass != null)

				El.className = cssClass;

			return El;

		},

		

		this.switchMonth = function( s ){

			switch (s) {

				case "prev": 

					this.yy = (this.mm == 0)?this.yy-1:this.yy;

					this.mm = (this.mm == 0)?11:this.mm-1;

				break;

				

				case "next":

					this.yy = (this.mm == 11)?this.yy+1:this.yy;

					this.mm = (this.mm == 11)?0:this.mm+1;

				break;

				

				case "current":

					this.yy = this.year;

					this.mm = this.month;

				break;

			}

			this.show();

		}

	}

	

	var DOMContentLoaded = false;

	function addContentLoadListener (func) {

		if (document.addEventListener) {

			var DOMContentLoadFunction = function () {

				window.DOMContentLoaded = true;

				func();

			};

			document.addEventListener("DOMContentLoaded", DOMContentLoadFunction, false);

		}

		var oldfunc = (window.onload || new Function());

		window.onload = function () {

			if (!window.DOMContentLoaded) {

				oldfunc();

				func();

			}

		};

	}

	

	addContentLoadListener( function() { 

			new CalendarJS().init("calendar");

	} );