/*
* 添加到购物车动画 脚本
* */
/***
* 动画轨迹控制
* @param addBtnDom 增加按钮的dom元素或者选择器
* @param shopCarDom 购物车的dom元素或选择器
*/
function controllPath(addBtn, shopCar) {
var addBtnDom = null,
shopCarDom = null;
if(typeof addBtn === "string"){
addBtnDom = document.querySelector(addBtn);
} else if(addBtn instanceof HTMLElement){
addBtnDom = addBtn
} else {
alert("传入的参数错误： 第一个参数应为增加按钮的dom元素或该元素的选择器。");
return;
}
if(typeof shopCar === "string"){
shopCarDom = document.querySelector(shopCar);
} else if(shopCar instanceof HTMLElement){
shopCarDom = shopCar;
}else {
alert("传入的参数错误： 第二个参数应为购物车的dom元素或该元素的选择器。");
return;
}
// 获取两个dom的位置
var addBtnposition = addBtnDom.getBoundingClientRect();
var shopCarPosition = shopCarDom.getBoundingClientRect();
var addBtnCenterX = (addBtnposition.left + addBtnposition.right) / 2;
var addBtnCenterY = (addBtnposition.top + addBtnposition.bottom) / 2;
var shopCarCenterX = (shopCarPosition.left + shopCarPosition.right) / 2;
var shopCarCenterY = (shopCarPosition.top + shopCarPosition.bottom) / 2;
//计算增加按钮 是在 相对于购物车的 左边还是右边（用于控制后面的移动方向）
var relativePosition = addBtnCenterX > shopCarCenterX ? -1 : 1;
// 获取连个dom之间的距离
var xDistance = Math.abs(addBtnCenterX - shopCarCenterX);
var yDistance = Math.abs(addBtnCenterY - shopCarCenterY);
// 绘制小球并设置其位置
var ballDom = drawBall();
ballDom.style.top = addBtnCenterY + "px";
ballDom.style.left = addBtnCenterX + "px";
document.body.appendChild(ballDom);
/*
* 根据一元二次方程的轨迹求出对象的系数 y = ax^2 + bx + c
* var coefficientC = 0;
* var coefficientB = 0;
* var coefficientA = yDistance / Math.pow(xDistance, 2);
*/
//小球的横竖坐标
var xAbscissa = 0, yAbscissa = 0;
//设置移动路径
var ballTimer = setInterval(function () {
//每次重新坐标
xAbscissa += 5 * relativePosition;
yAbscissa = (yDistance / Math.pow(xDistance, 2)) * Math.pow(xAbscissa, 2);
ballDom.style.top = addBtnCenterY + yAbscissa + "px";
ballDom.style.left = addBtnCenterX + xAbscissa + "px";
//检查是否到达终点
var surplusDistance = parseInt(ballDom.style.left) - shopCarCenterX;
if (Math.abs(surplusDistance) <= 10) {
clearInterval(ballTimer);
}
}, 25);
}
/*
* 绘制小球
* */
function drawBall() {
var ballDom = document.createElement("div");
ballDom.style.width = "20px";
ballDom.style.height = "20px";
ballDom.style.border = "1px solid #ccc";
ballDom.style.background = "#73dd51";
ballDom.style.borderRadius = "50%";
ballDom.style.position = "absolute";
return ballDom;
}
使用说明
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no"/>
<title>添加到购物车</title>
<style>
html, body {
margin: 0;
padding: 0;
height: 100%;
}
.box {
position: relative;
width: 100%;
height: 100%;
border: 2px solid #cc726f;
box-sizing: border-box;
}
.add-btn {
width: 40px;
height: 40px;
border: 2px solid orange;
border-radius: 50%;
position: absolute;
top: 10px;
left: 10px;
background: antiquewhite;
box-sizing: border-box;
}
.add-btn:before, .add-btn:after {
content: "";
position: absolute;
top: 50%;
left: 10%;
margin-top: -2px;
width: 80%;
height: 4px;
background: white;
}
.add-btn:after {
transform: rotate(90deg);
}
.shop-car {
width: 100px;
height: 40px;
border: 1px solid #ff574d;
position: absolute;
top: 300px;
left: 100px;
text-align: center;
line-height: 40px;
}
</style>
</head>
<body>
<div class="box">
<div class="add-btn"></div>
<div class="shop-car">购物车</div>
</div>
<script src="./addToCar.js"></script>
<script>
var addBtnDom = document.querySelector(".add-btn");
var shopCarDom = document.querySelector(".shop-car");
addBtnDom.addEventListener("click",function () {
//第一种方式
controllPath(addBtnDom, shopCarDom);
//第二种方式
//controllPath(".add-btn", ".shop-car");
})
</script>
</body>
</html>
原文：https://www.cnblogs.com/chenzxl/p/10998198.html