«
返回顶部小助手

时间:2022-3   



; (function(global) {
    "use strict";
    //构造函数
    function HeiGoBackTop(mode, el, speed, distance) {
        this.mode = mode === undefined ? 0 : mode;
        this.el = el === undefined ? '#__go-back-top': el;
        this.speed = speed === undefined ? 5000 : speed;
        this.distance = distance === undefined ? 100 : distance;
        this.show_height = 400;
        this.flag = false;
        this.show_flag = false;
        this.width = '150px';
        this.height = '40px';
        this.top = '90%';
        this.right = '5%';
        this.text = '~';
        this.text_color = '#fff';
        this.radius = '40px';
        this.themes = 0;
        this.color = 'linear-gradient(to right,#6966ff,#37e2d3,#63e8dd,#ccff66)';
        this.shadow = '0 4px 15px 0 rgba(41, 163, 163,0.75)';
        this.version = 'V1.0.1';
        this.home = 'https://github.com/hei-jack/HeiGoBackTop/';
        //页面加载结束才进行初始化 没有必要执行实时载入
        this.onLoad(this);
    };

    //拓展方法
    HeiGoBackTop.prototype = {
        constructor: HeiGoBackTop,
        //钩子回调
        hook: function(func) {
            return func === undefined ? false: this.callBack(func.bind(this));
        },
        //beforeCreate 初始化之前执行
        onBeforeCreate: function(func) {
            this.beforeCreate = func;
        },
        //初始化结束事件
        onAfterCreate: function(func) {
            this.afterCreate = func;
        },
        onShow: function(func) {
            this.show = func;
        },
        onHide: function(func) {
            this.hide = func;
        },
        onClick: function(func) {
            this.click = func;
        },
        //回调
        callBack: function(func) {
            return func();
        },
        //初始化方法
        init: function() {
            this.showVersion();
            this.hook(this.beforeCreate);
            this.unset('onBeforeCreate', null);
            this.unset('beforeCreate');
            //检查参数合法性
            if (!this.checkArgs()) throw (new Error('arguments is error!'));
            this.unset('checkNum', null);
            this.unset('checkEl', null);
            this.unset('checkArgs', null);
            //初始化按钮
            this.createBtn();
            this.unset('createBtn', null);
            this.unset('unsetUseless', null);
            //绑定自定义鼠标滑动事件到全局滑动事件
            this.bindOn(window, 'scroll', this.checkBtn);
            this.bindOn(window, 'scroll', this.scroll);
            this.controller();
            this.unset('controller', null);
            this.hook(this.afterCreate);
            this.unset('onAfterCreate', null);
            this.unset('afterCreate');
            this.unset('bindOn', null);
            this.unset('addEventListener', null);
            this.unset('isBrowser', null);
            this.unset('onLoad', null)
        },
        //检查参数
        checkArgs: function() {
            if (this.checkNum(this.mode)) return false;
            if (this.mode > 3 || this.mode < 0) return false;
            if (this.checkNum(this.speed) || this.speed <= 0) return false;
            if (this.checkNum(this.distance) || this.distance <= 0) return false;
            if (this.checkEl(this.el)) return false;
            return true
        },
        //检查参数类型是否为数字
        checkNum: function(arg) {
            return typeof(arg) !== 'number';
        },
        //检查参数类型是否为不为0 且包含#号的字符串
        checkEl: function(arg) {
            return typeof(arg) !== 'string' || arg.length === 0 || arg.indexOf('#') === -1;
        },
        //创建按钮
        createBtn: function() {
            //如果不是初始元素id 说明用户自定义挂载元素
            if (this.el !== '#__go-back-top') {
                this.el = this.el.replace('#', '');
                if (document.getElementById(this.el)) {
                    this.btn = document.getElementById(this.el);
                    this.unsetUseless();
                    return false
                }
                //挂载元素id没有发现 直接抛出错误
                throw (new Error('element is error!'));
            }
            var style_text = '#__go-back-top{display:none;position:fixed;width:' + this.width + ';height:' + this.height + ';top:' + this.top + ';right:' + this.right + ';z-index:9999;}.__go-back-btn{width:' + this.width + ';height:' + this.height + ';background:' + this.color + ';background-size: 300% 100%;cursor: pointer;border:none;border-radius:' + this.radius + ';box-shadow:' + this.shadow + ';color:' + this.text_color + ';outline:none;letter-spacing:2px;font-weight:600;font-family: "YouYuan","Microsoft YaHei","SimHei","SimSun","Arial",sans-serif;transition: all .4s ease-in-out;moz-transition: all .4s ease-in-out;-o-transition: all .4s ease-in-out;-webkit-transition: all .4s ease-in-out;}.__go-back-btn:hover{background-position: 100% 0%;moz-transition: all .4s ease-in-out;-o-transition: all .4s ease-in-out;-webkit-transition: all .4s ease-in-out;transition: all .4s ease-in-out;}.__go-back-btn:focus{border:none;outline:none;}.go-back-top-themes1{background-image:linear-gradient(to right,#25aae1,#40e495,#30dd8a,#2bb673);box-shadow:0 4px 15px 0 rgba(49,196,190,0.75);}.go-back-top-themes2{background-image:linear-gradient(to right,#f5ce62,#e43603,#fa7199,#e85a19);box-shadow:0 4px 15px 0 rgba(229,66,10,0.75);}.go-back-top-themes3{background-image:linear-gradient(to right,#667eea,#764ba2,#6B8DD6,#8E37D7);box-shadow:0 4px 15px 0 rgba(116,79,168,0.75);}.go-back-top-themes4{background-image:linear-gradient(to right,#fc6076,#ff9a44,#ef9d43,#e75516);box-shadow:0 4px 15px 0 rgba(252,104,110,0.75);}.go-back-top-themes5{background-image:linear-gradient(to right,#0ba360,#3cba92,#30dd8a,#2bb673);box-shadow:0 4px 15px 0 rgba(23,168,108,0.75);}.go-back-top-themes6{background-image:linear-gradient(to right,#009245,#FCEE21,#00A8C5,#D9E021);box-shadow:0 4px 15px 0 rgba(83,176,57,0.75);}.go-back-top-themes7{background-image:linear-gradient(to right,#6253e1,#852D91,#A3A1FF,#F24645);box-shadow:0 4px 15px 0 rgba(126,52,161,0.75);}.go-back-top-themes8{background-image:linear-gradient(to right,#29323c,#485563,#2b5876,#4e4376);box-shadow:0 4px 15px 0 rgba(45,54,65,0.75);}.go-back-top-themes9{background-image:linear-gradient(to right,#25aae1,#4481eb,#04befe,#3f86ed);box-shadow:0 4px 15px 0 rgba(65,132,234,0.75);}.go-back-top-themes10{background-image:linear-gradient(to right,#ed6ea0,#ec8c69,#f7186a,#FBB03B);box-shadow:0 4px 15px 0 rgba(236,116,149,0.75);}.go-back-top-themes11{background-image:linear-gradient(to right,#eb3941,#f15e64,#e14e53,#e2373f);box-shadow:0 5px 15px rgba(242,97,103,.4);}';
            var style_el = document.createElement('style');
            var style_node = document.createTextNode(style_text);
            style_el.appendChild(style_node);
            document.body.appendChild(style_el);
            var div = document.createElement('div');
            div.setAttribute('id', this.el.replace('#', ''));
            var btn = document.createElement('button');
            //设置主题  为0是默认主题 只有默认主题允许更改样式
            this.themes === 0 ? btn.setAttribute('class', this.el.replace('#', '').replace('top', 'btn')) : btn.setAttribute('class', this.el.replace('#', '').replace('top', 'btn') + ' go-back-top-themes' + this.themes);
            var btn_name = document.createTextNode(this.text);
            btn.appendChild(btn_name);
            div.appendChild(btn);
            document.body.appendChild(div);
            this.btn = div;
            //创建结束 销毁已经没用的属性
            this.unsetUseless();
        },
        showBtn: function() {
            if (!this.show_flag) {
                this.btn.style.cssText = 'display:block';
                this.hook(this.show);
                this.show_flag = true;
            }
        },
        hideBtn: function() {
            if (this.show_flag) {
                this.btn.style.cssText = 'display:none';
                this.hook(this.hide);
                this.show_flag = false;
            }
        },
        //载入方法 在页面加载结束后开始执行初始化工作
        onLoad: function(self) {
            if (!this.isBrowser()) throw (new Error('The current environment is not the browser!'));
            if (this.isIE() && this.getIEVersion() < 9) throw (new Error('HeiGoBackTop does not support ie 9 the following browsers!'));
            this.bindOn(window, 'load', self.init);
        },
        //当滑动事件发生时
        onScroll: function(func) {
            this.scroll = func;
        },
        //绑定元素事件
        bindOn: function(el, event, func) {
            if (func === undefined) return false;
            this.addEventListener(el, event, func.bind(this))
        },
        //获取页面滚动的距离
        getScrollTop: function() {
            return document.documentElement.scrollTop || document.body.scrollTop;
        },
        //检查按钮何时显示和隐藏
        checkBtn: function() {
            this.getScrollTop() > this.show_height ? this.showBtn() : this.hideBtn();
        },
        //绑定元素事件兼容处理函数
        addEventListener: function(el, type, fn) {
            if (el.addEventListener) {
                el.addEventListener(type, fn, false);
            } else if (el.attachEvent) {
                el.attachEvent('on' + type, fn);
            } else {
                return false;
            }
        },
        //展示版本信息
        showVersion: function() {
            this.isIE() ? console.log("HeiGoBackTop " + this.version + ' ' + this.home) : console.log("\n\n %c HeiGoBackTop " + this.version + " %c " + this.home + " \n\n", "color: #fff; background: linear-gradient(90deg, #8080ff, #ff99ff); padding:5px 1px;", "background: linear-gradient(90deg,#ffccff,#80ffd4); padding:5px 0px;")
        },
        //模式分发控制器
        controller: function() {
            switch (this.mode) {
            case 0:
                this.bindOn(this.btn, 'click', this.goBackTop);
                break;
            case 1:
                this.bindOn(this.btn, 'click', this.goDown);
                break;
            case 2:
                this.bindOn(this.btn, 'click', this.goBackTopSlow);
                break;
            case 3:
                this.bindOn(this.btn, 'click', this.goDownSlow)
            }
        },
        //返回顶部
        goBackTop: function() {
            this.setScrollTop(0);
            //滑动结束钩子
            this.hook(this.scrollOver);
        },
        //慢滑到顶部
        goBackTopSlow: function() {
            this.scrollSpeed(this.getScrollTop(), 0);
        },
        //跳转底部
        goDown: function() {
            this.setScrollTop(this.getScrollHeight());
            this.hook(this.scrollOver)
        },
        //慢滑到底部
        goDownSlow: function() {
            this.scrollSpeed(this.getScrollTop(), this.getScrollHeight());
        },
        /*
         * 滑动方法
         * @param number start 开始滑动位置
         * @param number end 结束滑动位置
         * 
         */
        scrollSpeed: function(start, end) {
            //防止重复点击导致定时器多次调用
            if (this.flag) return false;
            this.flag = true;
            var timer = null;
            if (end === 0) {
                //如果是滑动到顶部
                timer = setInterval(function() {
                    var scroll_top = this.getScrollTop();
                    if (scroll_top >= this.distance) {
                        start -= this.distance;
                        this.setScrollTop(start);
                    } else {
                        if (scroll_top === 0) {
                            this.flag = false;
                            clearInterval(timer);
                            this.hook(this.scrollOver);
                        } else {
                            this.setScrollTop(0);
                        }
                    }
                }.bind(this), this.speed);
            } else {
                //如果是滑动到底部
                timer = setInterval(function() {
                    //getLast方法获取滚动条距离底部还剩多少距离 如果大于0 说明未到达底部 只管继续滑动即可
                    if (this.getLast() > 0) {
                        start += this.distance;
                        this.setScrollTop(start);
                    } else {
                        this.flag = false;
                        this.setScrollTop(end);
                        clearInterval(timer);
                        this.hook(this.scrollOver);
                    }
                }.bind(this), this.speed);
            }
        },
        //设置当前滚动所在高度
        setScrollTop: function(height) {
            //处理兼容性问题
            document.documentElement.scrollTop ? document.documentElement.scrollTop = height : document.body.scrollTop = height;
        },
        //获取滚动条高度 即可滚动的高度
        getScrollHeight: function() {
            //兼容标准模式 strict mode 和 混杂模式 quirks mode
            return document.compatMode === 'CSS1Compat' ? document.documentElement.scrollHeight : document.body.scrollHeight;
        },
        /*
         * 销毁属性和方法
         * @param string key 属性或方法名称
         * @param set 可选参数 传入除undefined任意值则说明是方法 不传表示属性
         */
        unset: function(key, set) {
            if (set === undefined) {
                delete this[key];
            } else {
                //ie不支持delete方法
                this.isIE() && this.getIEVersion() <= 10 ? this[key] = undefined : this.__proto__[key] = undefined;
            }
        },
        unsetUseless: function() {
            this.unset('el');
            this.unset('width');
            this.unset('height');
            this.unset('top');
            this.unset('right');
            this.unset('text');
            this.unset('text_color');
            this.unset('radius');
            this.unset('themes');
            this.unset('color');
            this.unset('shadow')
        },
        //获取当前滚动条所在位置到页面底部还剩多少距离
        getLast: function() {
            var margin_bot = 0;
            if (document.compatMode === "CSS1Compat") {
                margin_bot = document.documentElement.scrollHeight - (document.documentElement.scrollTop + document.body.scrollTop) - document.documentElement.clientHeight;
            } else {
                margin_bot = document.body.scrollHeight - document.body.scrollTop - document.body.clientHeight;
            }
            return margin_bot;
        },
        //滑动结束执行事件
        onScrollOver: function(func) {
            this.scrollOver = func;
        },
        //获取当前浏览器是否为ie
        isIE:function(){
            if (!!window.ActiveXObject || "ActiveXObject" in window) return true;
            return false;
        },
        //获取当前ie版本号
        getIEVersion: function() {
            var ua = navigator.userAgent;
            //如果不是ie浏览器 设置初始值0
      var ver = 0;
      if(ua){
        if(ua.match(/MSIE\s+([\d]+)\./i)){
                    //其他ie版本
          ver = RegExp.$1;
        }else if(ua.match(/Trident.*rv\s*:\s*([\d]+)\./i)){
                    //ie11
          ver = RegExp.$1;
        }
      }
      return parseInt(ver);
        },
        //获取当前运行环境是否为浏览器
        isBrowser: function() {
            return typeof(window) === "undefined" ? false : true;
        }
    };
    if (typeof module !== 'undefined' && module.exports) {
        module.exports = HeiGoBackTop;
    } else if (typeof define === 'function') {
        define(function() {
            return HeiGoBackTop;
        })
    } else {
        global.HeiGoBackTop = HeiGoBackTop;
    }
})(this);