<template>
  <div class="water-marker" >
      <div v-waterMarker="{text:'卡洛背心 - 版權(quán)所有',textColor:'rgba(180, 180, 180, 0.4)'}">
        <div class="water-marker-item">測(cè)試問(wèn)題啊測(cè)試問(wèn)題啊測(cè)試問(wèn)題啊測(cè)試問(wèn)題啊測(cè)試問(wèn)題啊測(cè)試問(wèn)題啊</div>
      </div>
  </div>
</template>

<script>
import waterMarker from '../../directive/test/waterMarker'
export default {
  directives: {
    waterMarker
  },
  data(){
    return{
    }
  },
  methods:{
  }
}
</script>

<style lang="scss">
.water-marker{
  height: 300px;
  .water-marker-item{
    line-height: 300px;
  }
}
</style>

function addWaterMarker(str, parentNode, font, textColor) {
  // 水印文字，父元素，字體，文字顏色
  var can = document.createElement('canvas')
  parentNode.appendChild(can)
  can.width = 200
  can.height = 150
  can.style.display = 'none'
  var cans = can.getContext('2d')
  cans.rotate((-20 * Math.PI) / 180)
  cans.font = font || '16px Microsoft JhengHei'
  cans.fillStyle = textColor || 'rgba(180, 180, 180, 0.3)'
  cans.textAlign = 'left'
  cans.textBaseline = 'Middle'
  cans.fillText(str, can.width / 10, can.height / 2)
  parentNode.style.backgroundImage = 'url(' + can.toDataURL('image/png') + ')'
}

const waterMarker = {
  bind: function (el, binding) {
    addWaterMarker(binding.value.text, el, binding.value.font, binding.value.textColor)
  },
}

export default waterMarker