/**
* Filename.......: calendar.js
* Project........: Popup Calendar
* Last Modified..: $Date: 2010/04/22 09:10:11 $
* CVS Revision...: $Revision: 1.2 $
* Copyright......: 2001, 2002 Richard Heyes
*/

/**
* Global variables
*/
dynCalendar_layers          = new Array();
dynCalendar_mouseoverStatus = false;
dynCalendar_mouseX          = 0;
dynCalendar_mouseY          = 0;

/**
* The calendar constructor
*
* @access public
* @param string objName      Name of the object that you create
* @param string callbackFunc Name of the callback function
* @param string OPTIONAL     Optional layer name
* @param string OPTIONAL     Optional images path
*/
function dynCalendar(objName, callbackFunc)	{
    /**
    * Properties
    */
	// Todays date
	this.today          = new Date();
	this.date           = this.today.getDate();
	this.month          = this.today.getMonth();
	this.year           = this.today.getFullYear();

	this.objName        = objName;
	this.callbackFunc   = callbackFunc;
	this.imagesPath     = arguments[2] ? arguments[2] : 'images/';
	this.layerID        = arguments[3] ? arguments[3] : 'dynCalendar_layer_' + dynCalendar_layers.length;

	this.offsetX        = 5;
	this.offsetY        = 5;

	this.useMonthCombo  = true;
	this.useYearCombo   = true;
	this.yearComboRange = 5;

	this.currentMonth   = this.month;
	this.currentYear    = this.year;

	/**
    * Public Methods
    */
	this.show              = dynCalendar_show;
	this.writeHTML         = dynCalendar_writeHTML;

	// Accessor methods
	this.setOffset         = dynCalendar_setOffset;
	this.setOffsetX        = dynCalendar_setOffsetX;
	this.setOffsetY        = dynCalendar_setOffsetY;
	this.setImagesPath     = dynCalendar_setImagesPath;
	this.setMonthCombo     = dynCalendar_setMonthCombo;
	this.setYearCombo      = dynCalendar_setYearCombo;
	this.setCurrentMonth   = dynCalendar_setCurrentMonth;
	this.setCurrentYear    = dynCalendar_setCurrentYear;
	this.setYearComboRange = dynCalendar_setYearComboRange;

	/**
    * Private methods
    */
	// Layer manipulation
	this._getLayer         = dynCalendar_getLayer;
	this._hideLayer        = dynCalendar_hideLayer;
	this._showLayer        = dynCalendar_showLayer;
	this._setLayerPosition = dynCalendar_setLayerPosition;
	this._setHTML          = dynCalendar_setHTML;

	// Miscellaneous
	this._getDaysInMonth   = dynCalendar_getDaysInMonth;
	this._mouseover        = dynCalendar_mouseover;

	/**
    * Constructor type code
    */
	dynCalendar_layers[dynCalendar_layers.length] = this;
	this.writeHTML();
}

/**
* Shows the calendar, or updates the layer if
* already visible.
*
* @access public
* @param integer month Optional month number (0-11)
* @param integer year  Optional year (YYYY format)
*/
function dynCalendar_show()	{
    // Variable declarations to prevent globalisation
	var month, year, monthnames, numdays, thisMonth, firstOfMonth;
	var ret, row, i, cssClass, linkHTML, previousMonth, previousYear;
	var nextMonth, nextYear, prevImgHTML, prevLinkHTML, nextImgHTML, nextLinkHTML;
	var monthComboOptions, monthCombo, yearComboOptions, yearCombo, html;
		
	this.currentMonth = month = arguments[0] != null ? arguments[0] : this.currentMonth;
	this.currentYear  = year  = arguments[1] != null ? arguments[1] : this.currentYear;

	monthnames = new Array('January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December');
	numdays    = this._getDaysInMonth(month, year);

	thisMonth    = new Date(year, month, 1);
	firstOfMonth = thisMonth.getDay();

	// First few blanks up to first day
	ret = new Array(new Array());
	for(i=0; i<firstOfMonth; i++) {
	    ret[0][ret[0].length] = '<td>&nbsp;</td>';
	}

	// Main body of calendar
	row = 0;
	i   = 1;
	while(i <= numdays) {
	    if(ret[row].length == 7) {
		    ret[++row] = new Array();
		}

		/**
        * Generate this cells' HTML
        */
		cssClass = (i == this.date && month == this.month && year == this.year) ? 'dynCalendar_today' : 'dynCalendar_day';
		linkHTML = '<a href="javascript: ' + this.callbackFunc + '(' + i + ', ' + (Number(month) + 1) + ', ' + year + '); ' + this.objName + '._hideLayer()">' + (i++) + '</a>';
		ret[row][ret[row].length] = '<td align="center" class="' + cssClass + '">' + linkHTML + '</td>';
	}

	// Format the HTML
	for(i=0; i<ret.length; i++) {
	    ret[i] = ret[i].join('\n') + '\n';
	}

	previousYear  = thisMonth.getFullYear();
	previousMonth = thisMonth.getMonth() - 1;
	if(previousMonth < 0) {
	    previousMonth = 11;
		previousYear--;
	}
		
	nextYear  = thisMonth.getFullYear();
	nextMonth = thisMonth.getMonth() + 1;
	if(nextMonth > 11) {
	    nextMonth = 0;
		nextYear++;
	}

	prevImgHTML  = '<img src="' + this.imagesPath + '/prev.gif" alt="<<" border="0" />';
	prevLinkHTML = '<a href="javascript: ' + this.objName + '.show(' + previousMonth + ', ' + previousYear + ')">' + prevImgHTML + '</a>';
	nextImgHTML  = '<img src="' + this.imagesPath + '/next.gif" alt="<<" border="0" />';
	nextLinkHTML = '<a href="javascript: ' + this.objName + '.show(' + nextMonth + ', ' + nextYear + ')">' + nextImgHTML + '</a>';

	/**
    * Build month combo
    */
	if (this.useMonthCombo) {
	    monthComboOptions = '';
		for (i=0; i<12; i++) {
		    selected = (i == thisMonth.getMonth() ? 'selected="selected"' : '');
			monthComboOptions += '<option value="' + i + '" ' + selected + '>' + monthnames[i] + '</option>';
		}
		monthCombo = '<select name="months" onchange="' + this.objName + '.show(this.options[this.selectedIndex].value, ' + this.objName + '.currentYear)">' + monthComboOptions + '</select>';
	} else {
	    monthCombo = monthnames[thisMonth.getMonth()];
	}
		
	/**
    * Build year combo
    */
	if (this.useYearCombo) {
	    yearComboOptions = '';
		for (i = thisMonth.getFullYear() - this.yearComboRange; i <= (thisMonth.getFullYear() + this.yearComboRange); i++) {
		    selected = (i == thisMonth.getFullYear() ? 'selected="selected"' : '');
			yearComboOptions += '<option value="' + i + '" ' + selected + '>' + i + '</option>';
		}
		yearCombo = '<select style="border: 1px groove" name="years" onchange="' + this.objName + '.show(' + this.objName + '.currentMonth, this.options[this.selectedIndex].value)">' + yearComboOptions + '</select>';
	} else {
	    yearCombo = thisMonth.getFullYear();
	}

	html = '<table cellpadding="0" cellspacing="0">';
	html += '<tr><td class="dynCalendar_header">' + prevLinkHTML + '</td><td colspan="5" align="center" class="dynCalendar_header">' + monthCombo + ' ' + yearCombo + '</td><td class="dynCalendar_header">' + nextLinkHTML + '</td></tr>';
	html += '<tr>';
	html += '<td class="dynCalendar_dayname">Sun</td>';
	html += '<td class="dynCalendar_dayname">Mon</td>';
	html += '<td class="dynCalendar_dayname">Tue</td>';
	html += '<td class="dynCalendar_dayname">Wed</td>';
	html += '<td class="dynCalendar_dayname">Thu</td>';
	html += '<td class="dynCalendar_dayname">Fri</td>';
	html += '<td class="dynCalendar_dayname">Sat</td></tr>';
	html += '<tr>' + ret.join('</tr>\n<tr>') + '</tr>';
	html += '</table>';

	this._setHTML(html);
	if (!arguments[0] && !arguments[1]) {
	    this._showLayer();
		this._setLayerPosition();
	}
}

/**
* Writes HTML to document for layer
*
* @access public
*/
function dynCalendar_writeHTML() {
    if (is_ie5up || is_nav6up || is_gecko) {
	    document.write('<a href="javascript: ' + this.objName + '.show()"><img src="' + this.imagesPath + 'dynCalendar.gif" border="0" width="16" height="16" /></a>');
		document.write('<div class="dynCalendar" id="' + this.layerID + '" onmouseover="' + this.objName + '._mouseover(true)" onmouseout="' + this.objName + '._mouseover(false)"></div>');
	}
}

/**
* Sets the offset to the mouse position
* that the calendar appears at.
*
* @access public
* @param integer Xoffset Number of pixels for vertical
*                        offset from mouse position
* @param integer Yoffset Number of pixels for horizontal
*                        offset from mouse position
*/
function dynCalendar_setOffset(Xoffset, Yoffset) {
    this.setOffsetX(Xoffset);
	this.setOffsetY(Yoffset);
}

/**
* Sets the X offset to the mouse position
* that the calendar appears at.
*
* @access public
* @param integer Xoffset Number of pixels for horizontal
*                        offset from mouse position
*/
function dynCalendar_setOffsetX(Xoffset) {
    this.offsetX = Xoffset;
}

/**
* Sets the Y offset to the mouse position
* that the calendar appears at.
*
* @access public
* @param integer Yoffset Number of pixels for vertical
*                        offset from mouse position
*/
function dynCalendar_setOffsetY(Yoffset) {
    this.offsetY = Yoffset;
}
	
/**
* Sets the images path
*
* @access public
* @param string path Path to use for images
*/
function dynCalendar_setImagesPath(path) {
    this.imagesPath = path;
}

/**
* Turns on/off the month dropdown
*
* @access public
* @param boolean useMonthCombo Whether to use month dropdown or not
*/
function dynCalendar_setMonthCombo(useMonthCombo) {
    this.useMonthCombo = useMonthCombo;
}

/**
* Turns on/off the year dropdown
*
* @access public
* @param boolean useYearCombo Whether to use year dropdown or not
*/
function dynCalendar_setYearCombo(useYearCombo) {
    this.useYearCombo = useYearCombo;
}

/**
* Sets the current month being displayed
*
* @access public
* @param boolean month The month to set the current month to
*/
function dynCalendar_setCurrentMonth(month)	{
    this.currentMonth = month;
}

/**
* Sets the current month being displayed
*
* @access public
* @param boolean year The year to set the current year to
*/
function dynCalendar_setCurrentYear(year) {
    this.currentYear = year;
}

/**
* Sets the range of the year combo. Displays this number of
* years either side of the year being displayed.
*
* @access public
* @param integer range The range to set
*/
function dynCalendar_setYearComboRange(range) {
    this.yearComboRange = range;
}

/**
* Returns the layer object
*
* @access private
*/
function dynCalendar_getLayer()	{
    var layerID = this.layerID;

	if (document.getElementById(layerID)) {
	    return document.getElementById(layerID);
	} else if (document.all(layerID)) {
	    return document.all(layerID);
	}
}

/**
* Hides the calendar layer
*
* @access private
*/
function dynCalendar_hideLayer() {
    this._getLayer().style.visibility = 'hidden';
}

/**
* Shows the calendar layer
*
* @access private
*/
function dynCalendar_showLayer() {
    this._getLayer().style.visibility = 'visible';
}

/**
* Sets the layers position
*
* @access private
*/
function dynCalendar_setLayerPosition() {
    this._getLayer().style.top  = (dynCalendar_mouseY + this.offsetY) + 'px';
	this._getLayer().style.left = (dynCalendar_mouseX + this.offsetX) + 'px';
}

/**
* Sets the innerHTML attribute of the layer
*
* @access private
*/
function dynCalendar_setHTML(html) {
    this._getLayer().innerHTML = html;
}

/**
* Returns number of days in the supplied month
*
* @access private
* @param integer month The month to get number of days in
* @param integer year  The year of the month in question
*/
function dynCalendar_getDaysInMonth(month, year) {
    monthdays = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
	if (month != 1) {
	    return monthdays[month];
	} else {
	    return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0 ? 29 : 28);
	}
}

/**
* onMouse(Over|Out) event handler
*
* @access private
* @param boolean status Whether the mouse is over the
*                       calendar or not
*/
function dynCalendar_mouseover(status) {
    dynCalendar_mouseoverStatus = status;
	return true;
}

/**
* onMouseMove event handler
*/
dynCalendar_oldOnmousemove = document.onmousemove ? document.onmousemove : new Function;

document.onmousemove = function () {
    if (is_ie5up || is_nav6up || is_gecko) {
	    if (arguments[0]) {
		    dynCalendar_mouseX = arguments[0].pageX;
			dynCalendar_mouseY = arguments[0].pageY;
		} else {
		    dynCalendar_mouseX = event.clientX + document.body.scrollLeft;
			dynCalendar_mouseY = event.clientY + document.body.scrollTop;
			arguments[0] = null;
		}

		dynCalendar_oldOnmousemove();
	}
}

/**
* Callbacks for document.onclick
*/
dynCalendar_oldOnclick = document.onclick ? document.onclick : new Function;

document.onclick = function () {
    if (is_ie5up || is_nav6up || is_gecko) {
	    if(!dynCalendar_mouseoverStatus) {
		    for(i=0; i<dynCalendar_layers.length; ++i) {
			    dynCalendar_layers[i]._hideLayer();
			}
		}	
	    dynCalendar_oldOnclick(arguments[0] ? arguments[0] : null);
	}
}