caimei-applets-mcare/components/cm-custom/cm-drag.vue

<template>
	<view>
		<view
			id="_drag_button"
			class="cart-icon"
			:style="'left: ' + left + 'px; top:' + top + 'px;'"
			@touchstart="touchstart"
			@touchmove.stop.prevent="touchmove"
			@touchend="touchend"
			@click.stop.prevent="click"
			:class="{ transition: isDock && !isMove }"
		>
			<text v-if="cartNum > 0" class="uni-badge uni-badge-error uni-small uni-badge--small icon-num">
				{{ cartNum >= 100 ? '99+' : cartNum }}
			</text>
			<image :src="staticUrl + 'icon-cart-active@3x.png'" mode=""></image>
		</view>
	</view>
</template>

<script>
export default {
	name: 'drag-button',
	props: {
		cartNum: {
			type: Number,
			default: 0
		},
		isDock: {
			type: Boolean,
			default: false
		},
		existTabBar: {
			type: Boolean,
			default: false
		}
	},
	data() {
		return {
			staticUrl: this.global.staticUrl,
			top: 300,
			left: 150,
			width: 0,
			height: 0,
			offsetWidth: 0,
			offsetHeight: 0,
			windowWidth: 0,
			windowHeight: 0,
			isMove: true,
			edge: 10
		}
	},
	mounted() {
		const sys = uni.getSystemInfoSync()
		this.windowWidth = sys.windowWidth
		this.windowHeight = sys.windowHeight
		// #ifdef APP-PLUS
		this.existTabBar && (this.windowHeight -= 50)
		// #endif
		if (sys.windowTop) {
			this.windowHeight += sys.windowTop
		}
		// console.log(sys)
		const query = uni.createSelectorQuery().in(this)
		query
			.select('#_drag_button')
			.boundingClientRect(data => {
				this.width = data.width
				this.height = data.height
				this.offsetWidth = data.width / 2
				this.offsetHeight = data.height / 2
				this.left = this.windowWidth - this.width - this.edge - 5
				this.top = this.windowHeight - this.height - this.edge - 150
			})
			.exec()
	},
	methods: {
		click() {
			this.$emit('btnClick')
		},
		touchstart(e) {
			this.$emit('btnTouchstart')
		},
		touchmove(e) {
			// 单指触摸
			if (e.touches.length !== 1) {
				return false
			}
			this.isMove = true
			this.left = e.touches[0].clientX - this.offsetWidth
			let clientY = e.touches[0].clientY - this.offsetHeight
			// #ifdef H5
			clientY += this.height
			// #endif
			let edgeBottom = this.windowHeight - this.height - this.edge
			// 上下触及边界
			if (clientY < this.edge) {
				this.top = this.edge
			} else if (clientY > edgeBottom) {
				this.top = edgeBottom
			} else {
				this.top = clientY
			}
		},
		touchend(e) {
			if (this.isDock) {
				let edgeRigth = this.windowWidth - this.width - this.edge

				if (this.left < this.windowWidth / 2 - this.offsetWidth) {
					this.left = this.edge
				} else {
					this.left = edgeRigth
				}
			}

			this.isMove = false
			this.$emit('btnTouchend')
		}
	}
}
</script>

<style lang="scss">
.cart-icon {
	width: 92rpx;
	height: 92rpx;
	border-radius: 50%;
	background: rgba(0,0,0,0.3);
	position: fixed;
	right: 24rpx;
	bottom: 28%;
	display: flex;
	align-items: center;
	justify-content: center;
	cursor: pointer;
	z-index: 20;
	image {
		width: 58rpx;
		height: 58rpx;
	}
	text {
		font-size: 28rpx;
		position: absolute;
		top: -10rpx;
		right: 0;
	}
	&.transition {
		transition: left 0.3s ease, top 0.3s ease;
	}
}
</style>