/**
 * JQuery shiftcheckbox plugin
 *
 * shiftcheckbox provides a simpler and faster way to select multiple checkboxes within a given range with just two clicks
 *
 * Just call $.shiftcheckbox.init(<class-name>) in $(document).ready
 *
 * @name shiftcheckbox
 * @type jquery
 * @cat Plugin/Form
 * @return JQuery
 * @author Aditya Mooley <adityamooley@sanisoft.com>
 */

jQuery.shiftcheckbox =  {
    prevChecked: null,
    eleName: '',
    
    init: function(en) {
        jQuery.shiftcheckbox.eleName = en;
         
        jQuery("input[@type=checkbox][@class*="+jQuery.shiftcheckbox.eleName+"]").each(function(i) {
            jQuery(this).bind("click", jQuery.shiftcheckbox.handleClick);
        });
    },

    handleClick: function (event)
    {
        var val = this.value;
        var checkStatus = this.checked;
        //get the checkbox number which the user has checked
        
        //check whether user has pressed shift
        if (event.shiftKey && checkStatus) {
            if (jQuery.shiftcheckbox.prevChecked != 'null') {
                //get the current checkbox number
                var ind = 0, found = 0, currentChecked;
                currentChecked = jQuery.shiftcheckbox.getSelected(val);
    
                //Uncheck all the checkboxes first
                jQuery.shiftcheckbox.uncheckAll();
                
                ind = 0;
                if (currentChecked < jQuery.shiftcheckbox.prevChecked) {
                    jQuery("input[@type=checkbox][@class*="+jQuery.shiftcheckbox.eleName+"]").each(function(i) {
                        if (ind >= currentChecked && ind <= jQuery.shiftcheckbox.prevChecked) {
                            this.checked = true;
                        }
                        ind++;
                    });
                } else {
                    jQuery("input[@type=checkbox][@class*="+jQuery.shiftcheckbox.eleName+"]").each(function(i) {
                        if (ind >= jQuery.shiftcheckbox.prevChecked && ind <= currentChecked) {
                            this.checked = true;
                        }
                        ind++;
                    });
                }
            }
        } else {
            if (checkStatus) {
                jQuery.shiftcheckbox.prevChecked = jQuery.shiftcheckbox.getSelected(val);
            }
        }
    },
    
    getSelected: function (val)
    {
        var ind = 0, found = 0, checkedIndex;

        jQuery("input[@type=checkbox][@class*="+jQuery.shiftcheckbox.eleName+"]").each(function(i) {
            if (val == this.value && found != 1) {
                checkedIndex = ind;
                found = 1;
            }
            ind++;
        });

        return checkedIndex;
    },
    
    uncheckAll: function()
    {
        jQuery("input[@type=checkbox][@name*="+jQuery.shiftcheckbox.eleName+"]").each(function(i) {this.checked = false;});
    }
};