// ==UserScript==
// @name 平滑的滚动到顶部/底部
// @author burningall
// @description 为网页增加滚到顶部和底部按钮
// @version 2015.3.23-2.0
// @include http://*
// @include https://*
// @include ftp://*
// @supportURL http://www.burningall.com
// @contributionURL [email protected]|alipay.com
// @namespace https://greatest.deepsurf.us/zh-CN/users/3400-axetroy
// ==/UserScript==
//绑定事件函数
//使用方法：addEvent(ovj,'event',function(){})
function addEvent(obj,event,fn){
return obj.addEventListener ? obj.addEventListener(event,fn,false) : obj.attachEventListener('on'+event,fn);
}
(addEvent(window,'load',function(){
//元素ID选择
//使用方法：$('id')
function $(id){
return document.getElementById(id)
}
//获取元素的属性/样式
//使用方法getStyle(对象，"属性")，像素带px
//parseInt(getStyle($("scrollMars"),"width"))获取不带px的数据
function getStyle(obj,attr){
return obj.currentStyle ? obj.currentStyle[attr] :getComputedStyle(obj)[attr];
}
//获取滚动条位置
function getScrollTop(){
return document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop;
}
//获取浏览器可见的窗口高度
function getClientHeight(){
return document.documentElement ? document.documentElement.clientHeight : document.body.clientHeight
}
//获取文档总高度
//scrollTop + clientHeight == scrollHeight
//滚动条高度+浏览器可是区域高度=文档总高度
function getScrollHeight(){
return document.body ? bodyScrollHeight = document.body.scrollHeight : document.documentElement.scrollHeight;
}
//创建元素
//使用方法 createElement("div","demo","width:500px;height:500px",document.documentElement)
function createElement(tagName,idName,styleList,appendPosition){
var newElement = document.createElement(tagName);//创建元素的标签命
newElement.id=idName;//设置元素的属性
newElement.style.cssText=styleList;//设置元素样式
appendPosition.appendChild(newElement);//插入元素
}
//元素的属性变化/移动
//使用方法doMove(obj,"left",20,800),对象，属性，速度，目标点
function doMove(obj,attr,dir,target,endFn){
dir=parseInt(getStyle(obj,attr))<target ? dir : -dir; //对于方向矫正
clearInterval(obj.timer)
obj.timer=setInterval(function(){
var speed=parseInt(getStyle(obj,attr))+dir //步长
if(speed>target&&dir>0 || speed<target&&dir<0){ //判断往前或往后
speed=target
}
obj.style[attr]=speed+"px" //赋值
if(speed==target){
clearInterval(obj.timer)
endFn &&endFn() //回掉函数
}
},30)
}
//创建滚动按钮
createElement("div", "scrollMars", "width:100px;height:120px;position:fixed;right:20px;top:200px", document.documentElement);
scrollMars.innerHTML = "<div id='goTop' class='Top-and-Btn'></div>" + "<div id='goBtn' class='Top-and-Btn'></div>";
var scrollStyle = "width:40px;height:40px;text-align:center;padding:5px;margin:5px auto;background:#303030;color:#fff;display:block;opacity:0.8;fitter:alpha(opacity:80);cursor:pointer;border-radius:50%;box-shadow:2px 2px 40px 2px #303030;";
$('goTop').style.cssText = scrollStyle;
$('goBtn').style.cssText = scrollStyle;
$('goTop').innerHTML = "顶" + "<br/>" + "部";
$('goBtn').innerHTML = "底" + "<br/>" + "部";
//向上滚动
addEvent($("goTop"), 'click',
function() {
clearInterval($("goTop").timer);
$("goTop").timer = setInterval(function() {
var speed = (getScrollTop() / 5) + 10;
position = getScrollTop() - speed;
if (position <= 0) {
document.body.scrollTop = document.documentElement.scrollTop = 0;
clearInterval($("goTop").timer);
$("goTop").timer=null;
}
document.body.scrollTop = document.documentElement.scrollTop = position;
},
30)
})
//向下滚动
addEvent($("goBtn"), 'click',
function() {
clearInterval($("goTop").timer);
$("goTop").timer = setInterval(function() {
var speed = (getScrollTop() / 5) + 10;
position = getScrollTop() + speed;
if (position + getClientHeight() >= getScrollHeight()) {
document.body.scrollTop = document.documentElement.scrollTop = getScrollHeight();
clearInterval($("goTop").timer);
$("goTop").timer=null;
}
document.body.scrollTop = document.documentElement.scrollTop = position;
},
30)
})
//鼠标移入与移出
addEvent($("scrollMars"), 'mouseover',
function() { //鼠标移入
doMove($("scrollMars"), 'right', 10, 20,
function() {
doMove($("scrollMars"), 'width', 20, 100)
})
});
addEvent($("scrollMars"), 'mouseout',
function() { //鼠标移出
doMove($("scrollMars"), 'right', 10, -80,
function() {
doMove($("scrollMars"), 'width', 20, 160)
})
})
addEvent($("goTop"), 'mouseover',function(){$("goTop").style.background = "#FF0004";})
addEvent($("goTop"), 'mouseout',function(){$("goTop").style.background = "#303030";})
addEvent($("goBtn"), 'mouseover',function(){$("goBtn").style.background = "#FF0004";})
addEvent($("goBtn"), 'mouseout',function(){$("goBtn").style.background = "#303030";})
}))
