gdk/assets/js/Posfixed.js

/*!
 * jQuery plugin gapples v1.0
 * posfixed
 * http://gapples.sinaapp.com/
 *
 * Copyright 2013 gapples.sinaapp.com
 * Released under the GPLv2 license
 * http://gapples.sinaapp.com/license
 * 
 * Written by Boyn Xiong
 * Date: 2013-1-3
 */

(function ($) {
    $.extend($.fn, {
        posfixed: function (configSettings) {
            var settings = {
                direction: "top",
                type: "while",
                hide: false,
                distance: 0
            };
            $.extend(settings, configSettings);

            var obj = this;
            var initPos = $(obj).offset().top;
            var anchoredPos = settings.distance;

            if (settings.type == "while") {
                $(window).scroll(function (event) {
                    if (settings.direction == "top") {
                        var objTop = $(obj).offset().top - $(window).scrollTop();
                        if (objTop <= anchoredPos) {
                            $(obj).css("position", "fixed");
                            $(obj).css(settings.direction, anchoredPos + "px");
                        }
                        if ($(obj).offset().top <= initPos) {
                            $(obj).css("position", "static");
                        }
                    } else {
                        var objBottom = $(window).height() - $(obj).offset().top + $(window).scrollTop() - $(obj).outerHeight();
                        if (objBottom <= anchoredPos) {
                            $(obj).css("position", "fixed");
                            $(obj).css(settings.direction, anchoredPos + "px");
                        }
                        if ($(obj).offset().top >= initPos) {
                            $(obj).css("position", "static");
                        }
                    }
                });
            }
            if (settings.type == "always") {
                if (settings.hide) {
                    $(obj).hide();
                }
                $(window).scroll(function (event) {
                    if ($(window).scrollTop() > 300) {
                        $(obj).fadeIn(200);
                    } else {
                        $(obj).fadeOut(200);
                    }
                });
                $(obj).css("position", "fixed");
                $(obj).css(settings.direction, anchoredPos + "px");
                if (settings.tag != null) {
                    if (settings.tag.obj != null) {
                        if (settings.tag.direction == "right") {
                            $(obj).css("left", (settings.tag.obj.offset().left + settings.tag.obj.width() + settings.tag.distance) + "px");
                            $(window).resize(function () {
                                $(obj).css("left", (settings.obj.tag.offset().left + settings.tag.obj.width() + settings.tag.distance) + "px");
                            });
                        } else {
                            console.log(settings.tag.obj.offset().left - settings.tag.obj.width() - settings.tag.distance);
                            $(obj).css("left", (settings.tag.obj.offset().left - $(obj).outerWidth() - settings.tag.distance) + "px");
                            $(window).resize(function () {
                                $(obj).css("left", (settings.tag.obj.offset().left - $(obj).outerWidth() - settings.tag.distance) + "px");
                            });
                        }
                    } else {
                        $(obj).css(settings.tag.direction, settings.tag.distance + "px");
                    }
                }
            }
        }
    });
})(jQuery);