<template>
    <view @longtap.stop="longtap">
		<canvas 
			:width="destWidth" 
			:height="destHeight" 
			:canvas-id="item.id" 
			:id="item.id" 
			:style="{width:width,height: height}" 
			v-for="(item,index) in listCode" 
			:key="item.id"
			@error="handleError"></canvas>
	</view>
</template>
<script>
	import {QRCode,GetCodeImg,GetPixelRatio,GetPx}  from '../../js_sdk';
	import { getUUid, deepClone, platform } from '../../common/helper.js'
	export default {
		name: 'WQrcode',
		props:{
			options:{
				type: Object,
				required: true,
				default: () =>{
					return {
						
					}
				}
			}
		},
		data () {
			return {
				destHeight: 0,
				destWidth: 0,
				width: 0,
				height: 0,
				listCode:[],
				id: getUUid(),
			}
		},
		mounted() {
			this.height = this.width = GetPx(this.options.size) + 'px';
			this.destHeight = this.destWidth = GetPx(this.options.size) * GetPixelRatio() + 'px';
			this.SpecialTreatment(this.options)
			this.$nextTick(()=>{
				this.generateCode();
			})
		},
		watch: {
			options:{
				deep: true,
				handler (val) {
					this.height = this.width = GetPx(val.size) + 'px';
					this.destHeight = this.destWidth = GetPx(val.size) * GetPixelRatio() + 'px';
					this.SpecialTreatment(val)
					setTimeout(()=>{// h5平台动态改变canvas大小
						this.generateCode();
					},50)
				}
			}
		},
		methods: {
			longtap (e){
				this.$emit('press',e)
			},
			handleError (e) {//当发生错误时触发 error 事件，字节跳动小程序与飞书小程序不支持
				this.$emit('error',e.detail)
			},
			SpecialTreatment (val) {//微信小程序渲染多个canvas特殊处理
					let obj = deepClone(val);
					obj.id = this.id;
					this.listCode = [obj]
			},
			generateCode () {
				try{
					const parameter = {...this.options,source: platform(),id: this.id,ctx: this};
					QRCode(parameter,(res)=>{
						this.$emit('generate',res)
					})
				}catch(err){}
			},
			async GetCodeImg (){
				try{
					return  await GetCodeImg({id: this.id,width: this.options.size,height: this.options.size,ctx: this});
				}catch(e){}
			}
		}
	}
</script>