https://llewellyn.com/js/jquery-backToTop/jquery-backToTop.min.js

1(function(a){if(typeof define==="function"&&define.amd){define(["jquery"],a)}else{a(jQuery)}}(function(a){let _BackToTop=function(c){this._version="0.2.5";this._body=a("body");let _defaults={_positionX:"",_positionY:"",backgroundColor:"#5D5D5D",color:"#FFFFFF",container:this._body,effect:"spin",enabled:true,height:70,icon:"fas fa-chevron-up",marginX:20,marginY:20,position:"bottom right",pxToTrigger:600,scrollAnimation:0,theme:"default",width:70,zIndex:999};this._options=a.extend(_defaults,c);this._obj=null;this._opened=false;this._actualTheme="";this._actualEffect={off:"",on:""};this._fixed=false;this._isWindowContainer=false;const self=this;this._randomID=function(){return"xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(/[xy]/g,function(d){let r=Math.random()*16|0,v=d==="x"?r:(r&3|8);return v.toString(16)})};this._parseNumber=function(d){return parseFloat(d.toString())};this._warn=function(d){console.warn("jquery-backToTop v"+this._version+": "+d.toString())};this._applyTheme=function(d){if(this._obj===null){return}if(this._actualTheme!==""){this._obj.removeClass(this._actualTheme)}this._actualTheme="jquery-back-to-top-theme-"+d;this._obj.addClass(this._actualTheme);this._obj.css({"background-color":this._options.backgroundColor,color:this._options.color,"float":this._options._positionX,width:this._options.width+"px","z-index":this._options.zIndex});this.resize(this._options.width,this._options.height);if(this._options._positionX==="right"){this._obj.css("right",this._options.marginX+"px")}else{this._obj.css("left",this._options.marginX+"px")}if(this._options._positionY==="bottom"){this._obj.css("bottom",this._options.marginY+"px")}else{this._obj.css("top",this._options.marginY+"px")}if(!this._fixed){this._obj.css("position","sticky")}else{this._obj.css("position","fixed")}};this.resize=function(d,e){this._obj.css({height:this._parseNumber(e)+"px","line-height":this._parseNumber(e)+"px",width:this._parseNumber(d)+"px"})};this.changeTheme=function(d){this._options.theme=d;this._applyTheme(d);if(this._opened){this.show(true)}};this._applyEffect=function(d){if(this._obj===null){return}if(this._actualEffect.on!==""){this._obj.removeClass(this._actualEffect.on)}if(this._actualEffect.off!==""){this._obj.removeClass(this._actualEffect.off)}this._actualEffect.on="jquery-back-to-top-status-on jquery-back-to-top-effect-"+d+"-on";this._actualEffect.off="jquery-back-to-top-status-off jquery-back-to-top-effect-"+d+"-off"};this.changeEffect=function(d){this._options.effect=d;this._applyEffect(d);if(this._opened){this.show(true)}};this.show=function(d){if(self._options.container.scrollTop()>self._options.pxToTrigger){this._obj.removeClass(this._actualEffect.off);if(d){this._obj.addClass("jquery-back-to-top-status-on")}else{this._obj.addClass(this._actualEffect.on)}self._opened=true}};this.hide=function(d){this._obj.removeClass(this._actualEffect.on);if(d){this._obj.addClass("jquery-back-to-top-status-off")}else{this._obj.addClass(this._actualEffect.off)}self._opened=false};this.toggle=function(d){if(self._opened){this.hide(d)}else{this.show(d)}};this.enable=function(d,e){this._options.enabled=d;if(!this._options.enabled&&this._opened){this.hide(e)}if(this._options.enabled&&!this._options){this.show(e)}};this._checkScroll=function(){if(!self._options.enabled){return}if(self._options.container.scrollTop()>self._options.pxToTrigger){if(self._opened){return}self.show()}else{if(!self._opened){return}self.hide()}};this._initEvent=function(){let $id=this._randomID();self._options.container.on("scroll."+$id,function(){self._checkScroll()});this._obj.off("click.backToTop");this._obj.on("click.backToTop",function(d){d.preventDefault();if(self._options.scrollAnimation===0){self._options.container.scrollTop(0)}else{if(self._isWindowContainer){a("html,body").stop().animate({scrollTop:0},self._options.scrollAnimation)}else{self._options.container.animate({scrollTop:0},self._options.scrollAnimation)}}})};if(a(this._options.container).find(".back-to-top-container").length===0){try{this._options.marginX=this._parseNumber(this._options.marginX)}catch(b){this._warn("marginX parameter not valid")}try{this._options.marginY=this._parseNumber(this._options.marginY)}catch(b){this._warn("marginY parameter not valid")}try{this._options.pxToTrigger=Math.max(0,this._parseNumber(this._options.pxToTrigger))}catch(b){this._warn("pxToTrigger parameter not valid")}try{this._options.scrollAnimation=Math.max(0,this._parseNumber(this._options.scrollAnimation))}catch(b){this._warn("scrollAnimation parameter not valid")}try{this._options.zIndex=this._parseNumber(this._options.zIndex)}catch(b){this._warn("zIndex parameter not valid")}if(!(this._options.container instanceof jQuery)||this._options.container.length===0){this._warn("Container is not jQuery instance or it's empty, using container=body and enabled=false");this._options.container=this._body;this._options.enabled=false}let $pos=this._options.position.toLowerCase().split(" ");

1if($pos.length!==2){this._warn("Position is not valid");$pos=["bottom","right"]}if($pos[0]==="left"||$pos[0]==="right"){self._options._positionX=$pos[0];self._options._positionY=$pos[1]}else{self._options._positionX=$pos[1];self._options._positionY=$pos[0]}if(!(self._options._positionX==="left"||self._options._positionX==="right")){this._warn("Position in X is not correct (left/right)");self._options._positionX="right"}if(!(self._options._positionY==="bottom"||self._options._positionY==="top")){this._warn("Position in Y is not correct (bottom/top)");self._options._positionY="bottom"}let $id=this._randomID();a(this._options.container).append('<div id="'+$id+'" class="jquery-back-to-top"><i class="'+this._options.icon+'"></i></div>');self._obj=a("#"+$id);if(this._options.container.get(0)===this._body.get(0)){self._isWindowContainer=true;self._options.container=a(window);self._fixed=true}else{if(self._options._positionY==="top"){this._warn("Position top inside div is actually not allowed");self._options._positionY="bottom"}}this._applyTheme(this._options.theme);this._applyEffect(this._options.effect);this._initEvent()}};a.backToTop=function(b){return new _BackToTop(b)}}));