[js] 画面全体をオーバーレイする

(function($){//BEGIN $ = jQuery
    
    //$.pageSize使うよ。なきゃここで。
    $.pageSize = $.pageSize || function(){
        var xScroll, yScroll;
        if(window.innerHeight && window.scrollMaxY){
            xScroll = window.innerWidth + window.scrollMaxX;
            yScroll = window.innerHeight + window.scrollMaxY;
        }else if(document.body.scrollHeight > document.body.offsetHeight){
            xScroll = document.body.scrollWidth;
            yScroll = document.body.scrollHeight;
        }else{
            xScroll = document.body.offsetWidth;
            yScroll = document.body.offsetHeight;
        }
        
        var windowWidth, windowHeight;
        if(self.innerHeight) {
            if(document.documentElement.clientWidth){
                windowWidth = document.documentElement.clientWidth;
            } else {
                windowWidth = self.innerWidth;
            }
            windowHeight = self.innerHeight;
        }else if(document.documentElement && document.documentElement.clientHeight){
            windowWidth = document.documentElement.clientWidth;
            windowHeight = document.documentElement.clientHeight;
        }else if(document.body){
            windowWidth = document.body.clientWidth;
            windowHeight = document.body.clientHeight;
        }
        
        var pageWidth = xScroll < windowWidth ? xScroll : windowWidth;
        var pageHeight = yScroll < windowHeight ? windowHeight : yScroll;
        
        return [pageWidth,pageHeight,windowWidth,windowHeight];
    };
    
    //initialize
    $.overlay = function(settings){
        var _this = this;
        settings = $.extend({
              bg_color: "#000000"
            , opacity: 0.5
            , fade_speed: 400
            , overlay_class: "pageOverlay"
            , click_close: true // true|falseか、this.closeへの引数（引数が複数なら配列で）。
        }, settings);
        var click_close = settings.click_close;
        
        var pageSize = $.overlay.pageSize = $.pageSize();
        
        this.fade_speed = settings.fade_speed;
        this.opacity = settings.opacity;
        this.overlay_id = settings.overlay_class + $.overlay.uid++;
        this.click_close = settings.click_close;
        this.$select;
        this.opend = false;
        
        //overlay
        var $overlay = this.$obj = $('<div></div>').attr({
                  'class': settings.overlay_class
                , id: this.overlay_id
            }).css({
                  display:            "none"
                , width: pageSize[2]
                , height: pageSize[1]
                , position:            "absolute"
                , top:                0
                , left:                0
                , backgroundColor:    settings.bg_color
                , opacity:            0
            });
        $overlay.appendTo($('body'));
        $.overlay.$objs = $.overlay.$objs.add($overlay);
        
        //click_close
        if(click_close){
            $overlay.click(function(){
                if(click_close === true){
                    _this.close();
                }else{
                    _this.close.apply(_this, $.makeArray(click_close));
                }
            });
        }
        
        //onresize
        $(window).unbind('resize.overlay_resize').bind('resize.overlay_resize', function(){
            pageSize = $.overlay.pageSize = $.pageSize();
            $.overlay.$objs.css({
                width: pageSize[2],
                height: pageSize[1]
            });
        });
    }
    
    //uid
    $.overlay.uid = 0;
    
    //jQuery objects
    $.overlay.$objs = $([]);
    
    //pageSize
    $.overlay.pageSize = [];
    
    //prototype
    $.overlay.prototype = {
        //open
          open: function(speed, callback){
            var _this = this;
            var $overlay = this.$obj;
            this.$select = $('select:visible').hide();
            if(!callback && $.isFunction(speed)){
                callback = speed;
                speed = null;
            }
            $overlay
                .show()
                .fadeTo(speed || this.fade_speed, this.opacity, function(){
                    _this.opend = true;
                    if(callback && $.isFunction(callback)) callback.apply(this, arguments);
                });
        }
        //close
        , close: function(speed, callback){
            var _this = this;
            if(_this.opend){
                var $overlay = this.$obj;
                var $select = this.$select;
                if(!callback && $.isFunction(speed)){
                    callback = speed;
                    speed = null;
                }
                _this.opend = false;
                $overlay
                    .stop()
                    .fadeTo(speed || this.fade_speed, 0, function(){
                        $overlay.hide();
                        $select.show();
                        if(callback && $.isFunction(callback)) callback.apply(this, arguments);
                    });
            }
        }
    };
    
    
})(jQuery);//END $ = jQuery