/*
 * jQuery columnHover plugin
 * Version: 0.1.1
 *
 * Copyright (c) 2007 Roman Weich
 * http://p.sohei.org
 *
 * Dual licensed under the MIT and GPL licenses 
 * (This means that you can choose the license that best suits your project, and use it accordingly):
 *   http://www.opensource.org/licenses/mit-license.php
 *   http://www.gnu.org/licenses/gpl.html
 *
 * Changelog: 
 * v 0.1.1 - 2007-08-05
 *	-change: included new option "ignoreCols", through which columns can be excluded from the highlighting process
 * v 0.1.0 - 2007-05-25
 */
(function ($) {
    /**
     * Calculates the actual cellIndex value of all cells in the table and stores it in the realCell property of each cell.
     * Thats done because the cellIndex value isn't correct when colspans or rowspans are used.
     * Originally created by Matt Kruse for his table library - Big Thanks! (see http://www.javascripttoolbox.com/)
     * @param {element} table	The table element.
     */
    var fixCellIndexes = function (table) {
            var rows = table.rows;
            var len = rows.length;
            var matrix = [];
            for (var i = 0; i < len; i++) {
                var cells = rows[i].cells;
                var clen = cells.length;
                for (var j = 0; j < clen; j++) {
                    var c = cells[j];
                    var rowSpan = c.rowSpan || 1;
                    var colSpan = c.colSpan || 1;
                    var firstAvailCol = -1;
                    if (!matrix[i]) {
                        matrix[i] = [];
                    }
                    var m = matrix[i];
                    // Find first available column in the first row
                    while (m[++firstAvailCol]) {}
                    c.realIndex = firstAvailCol;
                    for (var k = i; k < i + rowSpan; k++) {
                        if (!matrix[k]) {
                            matrix[k] = [];
                        }
                        var matrixrow = matrix[k];
                        for (var l = firstAvailCol; l < firstAvailCol + colSpan; l++) {
                            matrixrow[l] = 1;
                        }
                    }
                }
            }
        };

    /**
     * Highlight whole table columns when hovering over a table.
     * Works on tables with rowspans and colspans.
     *
     * @param {map} options			An object for optional settings (options described below).
     *
     * @option {string} hoverClass		A CSS class that is set on the cells in the column with the mouse over.
     *							Default value: 'hover'
     * @option {boolean} eachCell		Allows highlighting the column while hovering over the table body or table footer. When disabled, highlighting is allowed only through the table header.
     *							Default value: false
     * @option {boolean} includeSpans		Includes columns with the colspan attribute set in the hover and highlight process.
     *							Default value: true
     * @option {array} ignoreCols		An array of numbers. Each column with the matching column index won't be included in the highlighting process.
     *							Index starting at 1!
     *							Default value: [] (empty array)
     *
     * @example $('#table').columnHover();
     * @desc Allow column hovering/highlighting for the table using the default settings.
     *
     * @example $('#table').columnHover({eachCell:true, hoverClass:'someclass'});
     * @desc Allow column hovering/highlighting for the whole table (including the body and footer). Set the class "someclass" to the cells in the column with the mouse over.
     *
     * @type jQuery
     *
     * @name columnHover
     * @cat Plugins/columnHover
     * @author Roman Weich (http://p.sohei.org)
     */
    $.fn.columnHover = function (options) {
        var settings = $.extend({
            hoverClass: 'hover',
            eachCell: false,
            includeSpans: true,
            ignoreCols: []
        }, options);

        /**
         * Adds or removes the hover style on the column.
         * @param {element} cell	The cell with the mouseover/mouseout event.
         * @param {array} colIndex	The index with the stored columns.
         * @param {boolean} on		Defines whether the style will be set or removed.
         */
        var hover = function (cell, colIndex, on) {
                var a = colIndex[cell.realIndex];
                var i = 0;
                if ($(settings.ignoreCols).index(cell.realIndex + 1) != -1) {
                    return; //dont highlight the columns in the ignoreCols array
                }
                while (++i < cell.colSpan) {
                    a = a.concat(colIndex[cell.realIndex + i]);
                }
                if (on) {
                    $(a).addClass(settings.hoverClass);
                } else {
                    $(a).removeClass(settings.hoverClass);
                }
            };

        /**
         * Adds the hover events to the cell.
         * @param {jQuery result array} $s	The elements to add the events to.
         * @param {array} colIndex	The index with the stored columns.
         */
        var addHover = function ($s, colIndex) {
                $s.bind('mouseover', function () {
                    hover(this, colIndex, true);
                }).bind('mouseout', function () {
                    hover(this, colIndex, false);
                });
            };

        return this.each(function () {
            var colIndex = [];
            var tbl = this;
            var body, row, c, tboI, rowI, cI, rI, s;

            if (!tbl.tBodies || !tbl.tBodies.length || !tbl.tHead || !settings.hoverClass.length) {
                return;
            }
            fixCellIndexes(tbl);
            //create index - loop through the bodies
            for (tboI = 0; tboI < tbl.tBodies.length; tboI++) {
                body = tbl.tBodies[tboI];
                //loop through the rows
                for (rowI = 0; rowI < body.rows.length; rowI++) {
                    row = body.rows[rowI];
                    //each cell
                    for (cI = 0; cI < row.cells.length; cI++) {
                        c = row.cells[cI];
                        //ignore cells with colspan?
                        if (!settings.includeSpans && c.colSpan > 1) {
                            continue;
                        }
                        s = (settings.includeSpans) ? c.colSpan : 1;
                        while (--s >= 0) {
                            rI = c.realIndex + s;
                            if (!colIndex[rI]) {
                                colIndex[rI] = [];
                            }
                            colIndex[rI].push(c);
                        }
                        //add hover event?
                        if (settings.eachCell) {
                            addHover($(c), colIndex);
                        }
                    }
                }
            }
            //events
            addHover($('td, th', tbl.tHead), colIndex);
            //add hover event to footer?
            if (settings.eachCell && tbl.tFoot) {
                addHover($('td, th', tbl.tFoot), colIndex);
            }
        });
    };
})(jQuery);