/**
* Filename.......: calendar.js
* Project........: Popup Calendar
* Last Modified..: $Date: 2002/07/22 18:17:05 $
* 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 border="0" bgcolor="#eeeeee">';
                html += '<tr><td class="dynCalendar_header">' + prevLinkHTML + '</td><td colspan="5" align="center" class="dynCalendar_header">' + monthCombo + ' ' + yearCombo + '</td><td align="right" 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.jpg" 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);
                }
        }