<template>
  <!-- Vue 2 要求模板恰好一个根元素：mask 与 sheet 同为 position:fixed，
       包一层普通 div 不影响两者的视口定位（fixed 不受静态父级影响）。 -->
  <div class="kole-sheet-root">
    <div class="kole-sheet-mask" :class="{ 'is-open': visible }" @click="$emit('close')"></div>
    <div class="kole-sheet" :class="{ 'is-open': visible }"
         @pointerdown="onDown" @pointerup="onUp">
      <div class="kole-sheet-handle"></div>
      <div class="kole-sheet-header" v-if="title">{{ title }}</div>
      <div class="kole-sheet-body"><slot>默认内容</slot></div>
      <div class="kole-sheet-footer" v-if="$slots.footer"><slot name="footer"></slot></div>
    </div>
  </div>
</template>

<script>
export default {
  name: 'KoleBottomSheet',
  props: { visible: { type: Boolean, default: false }, title: { type: String, default: '' } },
  data: function () { return { startY: 0 }; },
  methods: {
    onDown: function (e) { this.startY = e.clientY; },
    onUp: function (e) { if (this.startY - e.clientY < -80) this.$emit('close'); }
  }
};
</script>

<style src="./BottomSheet.css"></style>
