/**
 * Atlas Responsive jquery.apper.js
 * Copyright 2016-2017
 */
 
(function($) {
    $.fn.appear = function(fn, options) {

        var settings = $.extend({


            data: undefined,


            one: true,


            accX: 0,
            accY: 0

        }, options);

        return this.each(function() {

            var t = $(this);


            t.appeared = false;

            if (!fn) {


                t.trigger('appear', settings.data);
                return;
            }

            var w = $(window);


            var check = function() {


                if (!t.is(':visible')) {


                    t.appeared = false;
                    return;
                }


                var a = w.scrollLeft();
                var b = w.scrollTop();
                var o = t.offset();
                var x = o.left;
                var y = o.top;

                var ax = settings.accX;
                var ay = settings.accY;
                var th = t.height();
                var wh = w.height();
                var tw = t.width();
                var ww = w.width();

                if (y + th + ay >= b &&
                    y <= b + wh + ay &&
                    x + tw + ax >= a &&
                    x <= a + ww + ax) {


                    if (!t.appeared) t.trigger('appear', settings.data);

                } else {


                    t.appeared = false;
                }
            };


            var modifiedFn = function() {


                t.appeared = true;


                if (settings.one) {


                    w.unbind('scroll', check);
                    var i = $.inArray(check, $.fn.appear.checks);
                    if (i >= 0) $.fn.appear.checks.splice(i, 1);
                }


                fn.apply(this, arguments);
            };


            if (settings.one) t.one('appear', settings.data, modifiedFn);
            else t.bind('appear', settings.data, modifiedFn);


            w.scroll(check);


            $.fn.appear.checks.push(check);


            (check)();
        });
    };


    $.extend($.fn.appear, {

        checks: [],
        timeout: null,


        checkAll: function() {
            var length = $.fn.appear.checks.length;
            if (length > 0) while (length--) ($.fn.appear.checks[length])();
        },


        run: function() {
            if ($.fn.appear.timeout) clearTimeout($.fn.appear.timeout);
            $.fn.appear.timeout = setTimeout($.fn.appear.checkAll, 20);
        }
    });


    $.each(['append', 'prepend', 'after', 'before', 'attr',
        'removeAttr', 'addClass', 'removeClass', 'toggleClass',
        'remove', 'css', 'show', 'hide'], function(i, n) {
        var old = $.fn[n];
        if (old) {
            $.fn[n] = function() {
                var r = old.apply(this, arguments);
                $.fn.appear.run();
                return r;
            }
        }
    });

})(jQuery);