<template>
<!-- TODO swipe -->
<div id="hy-swiper">
<div class="swiper" @touchstart="touchStart" @touchmove="touchMove" @touchend="touchEnd">
<slot></slot>
</div>
<slot name="indicator">
</slot>
<div class="indicator">
<slot name="indicator" v-if="showIndicator && slideCount>1">
<div v-for="(item, index) in slideCount" class="indi-item" :class="{active: index === currentIndex-1}" :key="index"></div>
</slot>
</div>
</div>
</template>
<script>
export default {
name: "Swiper",
props: {
interval: {
type: Number,
default: 3000
},
animDuration: {
type: Number,
default: 300
},
moveRatio: {
type: Number,
default: 0.25
},
showIndicator: {
type: Boolean,
default: true
}
},
data () {
return {
slideCount: 0, // 元素个数
totalWidth: 0, // swiper的宽度
swiperStyle: {}, // swiper样式
currentIndex: 1, // 当前的index
scrolling: false, // 是否正在滚动
}
},
mounted () {
// 1.操作DOM, 在前后添加Slide
setTimeout(() => {
this.handleDom();
// 2.开启定时器
this.startTimer();
}, 100)
},
methods: {
/**
* 定时器操作
*/
startTimer () {
this.playTimer = window.setInterval(() => {
this.currentIndex++;
this.scrollContent(-this.currentIndex * this.totalWidth);
}, this.interval)
},
stopTimer () {
window.clearInterval(this.playTimer);
},
/**
* 滚动到正确的位置
*/
scrollContent (currentPosition) {
// 0.设置正在滚动
this.scrolling = true;
// 1.开始滚动动画
this.swiperStyle.transition ='transform '+ this.animDuration + 'ms';
this.setTransform(currentPosition);
// 2.判断滚动到的位置
this.checkPosition();
// 4.滚动完成
this.scrolling = false
},
/**
* 校验正确的位置
*/
checkPosition () {
window.setTimeout(() => {
// 1.校验正确的位置
this.swiperStyle.transition = '0ms';
if (this.currentIndex >= this.slideCount + 1) {
this.currentIndex = 1;
this.setTransform(-this.currentIndex * this.totalWidth);
} else if (this.currentIndex <= 0) {
this.currentIndex = this.slideCount;
this.setTransform(-this.currentIndex * this.totalWidth);
}
// 2.结束移动后的回调
this.$emit('transitionEnd', this.currentIndex-1);
}, this.animDuration)
},
/**
* 设置滚动的位置
*/
setTransform (position) {
this.swiperStyle.transform = `translate3d(${position}px, 0, 0)`;
this.swiperStyle['-webkit-transform'] = `translate3d(${position}px), 0, 0`;
this.swiperStyle['-ms-transform'] = `translate3d(${position}px), 0, 0`;
},
/**
* 操作DOM, 在DOM前后添加Slide
*/
handleDom () {
// 1.获取要操作的元素
let swiperEl = document.querySelector('.swiper');
let slidesEls = swiperEl.getElementsByClassName('slide');
// 2.保存个数
this.slideCount = slidesEls.length;
// 3.如果大于1个, 那么在前后分别添加一个slide
if (this.slideCount > 1) {
let cloneFirst = slidesEls[0].cloneNode(true);
let cloneLast = slidesEls[this.slideCount - 1].cloneNode(true);
swiperEl.insertBefore(cloneLast, slidesEls[0]);
swiperEl.appendChild(cloneFirst);
this.totalWidth = swiperEl.offsetWidth;
this.swiperStyle = swiperEl.style;
}
// 4.让swiper元素, 显示第一个(目前是显示前面添加的最后一个元素)
this.setTransform(-this.totalWidth);
},
/**
* 拖动事件的处理
*/
touchStart (e) {
// 1.如果正在滚动, 不可以拖动
if (this.scrolling) return;
// 2.停止定时器
this.stopTimer();
// 3.保存开始滚动的位置
this.startX = e.touches[0].pageX;
},
touchMove (e) {
// 1.计算出用户拖动的距离
this.currentX = e.touches[0].pageX;
this.distance = this.currentX - this.startX;
let currentPosition = -this.currentIndex * this.totalWidth;
let moveDistance = this.distance + currentPosition;
// 2.设置当前的位置
this.setTransform(moveDistance);
},
touchEnd (e) {
// 1.获取移动的距离
let currentMove = Math.abs(this.distance);
// 2.判断最终的距离
if (this.distance === 0) {
return
} else if (this.distance > 0 && currentMove > this.totalWidth * this.moveRatio) { // 右边移动超过0.5
this.currentIndex--
} else if (this.distance < 0 && currentMove > this.totalWidth * this.moveRatio) { // 向左移动超过0.5
this.currentIndex++
}
// 3.移动到正确的位置
this.scrollContent(-this.currentIndex * this.totalWidth);
// 4.移动完成后重新开启定时器
this.startTimer();
},
/**
* 控制上一个, 下一个
*/
previous () {
this.changeItem(-1);
},
next () {
this.changeItem(1);
},
changeItem (num) {
// 1.移除定时器
this.stopTimer();
// 2.修改index和位置
this.currentIndex += num;
this.scrollContent(-this.currentIndex * this.totalWidth);
// 3.添加定时器
this.startTimer();
}
}
}
</script>
<style scoped>
#hy-swiper {
overflow: hidden;
position: relative;
}
.swiper {
display: flex;
}
.indicator {
display: flex;
justify-content: center;
position: absolute;
100%;
bottom: 8px;
}
.indi-item {
box-sizing: border-box;
8px;
height: 8px;
border-radius: 4px;
background-color: #fff;
line-height: 8px;
text-align: center;
font-size: 12px;
margin: 0 5px;
}
.indi-item.active {
background-color: rgba(212,62,46,1.0);
}
</style>