年份选择器

<template>
  <div class="yearPicker" ref="yearPicker" :style="{ width: width + 'px' }">
    <div class="_inner labelText" :style="{ width: labelWidth + 'px' }">{{ labelText }}</div>
    <input
      class="_inner"
      ref="inputLeft"
      v-model="startShowYear"
      @focus="onFocus"
      type="text"
      @click="clickInput"
      name="yearInput"
      @input="checkStartInput($event)"
      placeholder="选择年份"
    />
    <span>{{ sp }}</span>
    <input
      class="_inner"
      ref="inputRight"
      v-model="endShowYear"
      @focus="onFocus"
      type="text"
      @click="clickInput"
      name="yearInput"
      @input="checkEndInput($event)"
      placeholder="选择年份"
    />
    <div class="_inner floatPanel" v-if="showPanel">
      <div class="_inner leftPanel">
        <div class="_inner panelHead">
          <i class="_inner el-icon-d-arrow-left" @click="onClickLeft"></i>
          {{ leftYearList[0] + '-' + leftYearList[9] }}
        </div>
        <div class="_inner panelContent">
          <div
            v-for="item in leftYearList"
            :class="{
              disabled: checkValidYear(item) != 0,
              oneSelected: item === startYear && oneSelected,
              startSelected: item === startYear,
              endSelected: item === endYear,
              _inner: true,
              betweenSelected: item > startYear && item < endYear
            }"
            :key="item"
          >
            <a
              :class="{
                cell: true,
                _inner: true,
                selected: item === startYear || item === endYear
              }"
              @click="onClickItem(item)"
              @mouseover="onHoverItem(item)"
            >
              {{ item }}
            </a>
          </div>
        </div>
      </div>
      <div class="_inner rightPanel">
        <div class="_inner panelHead">
          <i class="_inner el-icon-d-arrow-right" @click="onClickRight"></i>
          {{ rightYearList[0] + '-' + rightYearList[9] }}
        </div>
        <div class="_inner panelContent">
          <div
            :class="{
              disabled: checkValidYear(item) != 0,
              startSelected: item === startYear,
              endSelected: item === endYear,
              betweenSelected: item > startYear && item < endYear
            }"
            v-for="item in rightYearList"
            :key="item"
          >
            <a
              :class="{
                cell: true,
                _inner: true,
                selected: item === endYear || item === startYear
              }"
              @click="onClickItem(item)"
              @mouseover="onHoverItem(item)"
            >
              {{ item }}
            </a>
          </div>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
const SELECT_STATE = {
  unselect: 0,
  selecting: 1,
  selected: 2
};
export default {
  name: 'YearPicker',
  computed: {
    oneSelected() {
      return this.curState === SELECT_STATE.selecting && (this.startYear === this.endYear || this.endYear == null);
    },
    startDate() {
      return this.startYear;
    },
    leftYearList() {
      return this.yearList.slice(0, 10);
    },
    rightYearList() {
      return this.yearList.slice(10, 20);
    }
  },
  props: {
    width: {
      default: 200
    },
    labelWidth: {
      default: 80
    },
    labelText: {
      default: ''
    },
    sp: {
      default: '至'
    },
    initYear: {
      default: null
    },
    value: {
      default: () => []
    }
  },
  data() {
    return {
      itemBg: {},
      startShowYear: null,
      endShowYear: null,
      yearList: [],
      showPanel: false,
      startYear: null,
      endYear: null,
      curYear: 0,
      curSelectedYear: 0,
      curState: SELECT_STATE.unselect
    };
  },
  methods: {
    checkValidYear(iYear) {
      if (this.initYear) {
        if (iYear > this.initYear.endYear) {
          return 1;
        } else if (iYear < this.initYear.startYear) {
          return -1;
        }
      }
      return 0;
    },
    checkStartInput(event) {
      if (isNaN(this.startShowYear)) {
        this.startShowYear = this.startYear;
      } else {
        this.startYear = this.startShowYear * 1;
      }
    },

    checkEndInput() {
      if (isNaN(this.endShowYear)) {
        this.endShowYear = this.endYear;
      } else {
        this.endYear = this.endShowYear * 1;
      }
    },
    changeYear() {
      if (this.startYear > this.endYear) {
        let tmp = this.endYear;
        this.endYear = this.startYear;
        this.startYear = tmp;
      }
      if (this.initYear) {
        this.startYear = Math.max(this.startYear, this.initYear.startYear);
        this.endYear = Math.min(this.endYear, this.initYear.endYear);
      }
      this.startShowYear = this.startYear;
      this.endShowYear = this.endYear;

      if (this.startYear && this.endYear) {
        this.$emit('input', [this.startYear, this.endYear + '']);
        this.$emit('change', [this.startYear, this.endYear + '']);
      } else {
        console.warn('WARN:年份不合法', this.startYear, this.endYear);
      }
    },
    onHoverItem(iYear) {
      if (this.checkValidYear(iYear) != 0) {
        return;
      }
      if (this.curState === SELECT_STATE.selecting) {
        let tmpStart = this.curSelectedYear;
        this.endYear = Math.max(tmpStart, iYear);
        this.startYear = Math.min(tmpStart, iYear);
      }
    },
    onClickItem(iYear) {
      if (this.checkValidYear(iYear) != 0) {
        return;
      }

      if (this.curState === SELECT_STATE.unselect || this.curState === SELECT_STATE.selected) {
        this.startYear = iYear;
        this.curSelectedYear = iYear;
        this.endYear = null;
        this.curState = SELECT_STATE.selecting;
      } else if (this.curState === SELECT_STATE.selecting) {
        this.endShowYear = this.endYear;
        this.startShowYear = this.startYear;
        this.curState = SELECT_STATE.selected;
        setTimeout(() => {
          //为动画留的时间，可优化
          this.showPanel = false;
        }, 300);
      }
    },
    onFocus() {
      this.$nextTick(() => {
        this.showPanel = true;
      });
    },
    clickInput(e) {
      e.stopPropagation();
      return false;
    },

    updateYearList() {
      let iStart = Math.floor(this.curYear / 10) * 10 - 10;
      iStart = iStart < 0 ? 0 : iStart;
      this.yearList = [];
      for (let index = 0; index < 20; index++) {
        this.yearList.push(iStart + index);
      }
    },

    checkValidYear(iYear) {
      if (this.initYear) {
        if (iYear > this.initYear.endYear) {
          return 1;
        } else if (iYear < this.initYear.startYear) {
          return -1;
        }
      }
      return 0;
    },
    closePanel(e) {
      if (!this.showPanel) {
        return;
      }
      if (typeof e.target.className !== 'string' || e.target.className === '') {
        this.$nextTick(() => {
          this.changeYear();
          this.showPanel = false;
        });
        return;
      }
      if (
        e.target.className.indexOf('_inner') === -1 ||
        (e.target.name === 'yearInput' && e.target !== this.$refs.inputLeft && e.target !== this.$refs.inputRight)
      ) {
        this.$nextTick(() => {
          this.changeYear();
          this.showPanel = false;
        });
      }

      e.stopPropagation();
      return false;
    },
    onClickLeft() {
      this.curYear = this.curYear * 1 - 10;
      this.updateYearList();
    },
    onClickRight() {
      this.curYear = this.curYear * 1 + 10;
      this.updateYearList();
    }
  },

  created() {
    this.curYear = new Date().getFullYear();
    this.updateYearList();
  },
  watch: {
    value(n) {
      const [startYear, endYear] = n;
      this.startYear = startYear;
      this.endYear = endYear;
    }
  },
  beforeUnmount() {
    document.removeEventListener('click', this.closePanel.bind(this));
  },

  mounted() {
    document.addEventListener('click', this.closePanel.bind(this));
  }
};
</script>
<style lang="scss" scoped>
.yearPicker {
  font-size: 14px;
  display: flex;
  position: relative;
  transition: all 0.3s;
  input {
    text-align: center;
  }

  input:first-child {
    text-align: right;
  }

  background-color: #fff;

  .labelText {
    text-align: center;
  }

  span {
    padding: 0 8px;
    height: 32px;
    line-height: 32px;
  }

  border: 1px solid #eff1f3;
  height: 34px;
  line-height: 34px;
  border-radius: 4px;
  padding: 0 28px 0 8px;
  box-sizing: border-box;

  .floatPanel {
    > div {
      width: 50%;
    }

    padding: 0 16px;
    position: absolute;
    display: flex;
    background-color: #fff;
    z-index: 2000;
    border-radius: 4px;
    width: 650px;
    height: 250px;
    top: 40px;
    left: -10px;
    box-shadow: 0 2px 12px 0 rgba(0, 0, 0, 0.1);

    .panelContent {
      display: flex;
      flex-wrap: wrap;
      width: 100%;
      height: calc(100% - 70px);

      .disabled {
        color: #ccc;
      }

      .oneSelected {
        border-top-right-radius: 24px;
        border-bottom-right-radius: 24px;
      }

      .startSelected {
        background-color: #f6f6f7;
        border-top-left-radius: 24px;
        border-bottom-left-radius: 24px;
      }

      .endSelected {
        background-color: #f6f6f7;
        border-top-right-radius: 24px;
        border-bottom-right-radius: 24px;
      }

      .betweenSelected {
        background-color: #f6f6f7;
      }

      > div {
        width: 75px;
        height: 48px;
        line-height: 48px;
        margin: 3px 0;
        // border-radius: 24px;
        text-align: center;

        a {
          display: inline-block;
          width: 60px;
          height: 36px;
          cursor: pointer;
          line-height: 36px;
          border-radius: 18px;
        }

        .selected {
          background-color: #3e77fc;
          color: #fff;
        }
      }
    }

    .panelHead {
      position: relative;
      height: 46px;
      line-height: 46px;
      text-align: center;

      i {
        position: absolute;
        cursor: pointer;

        &:hover {
          color: #3e77fc;
        }
      }
    }

    .rightPanel {
      padding-left: 8px;
    }

    .leftPanel .panelHead i {
      left: 20px;
      top: 15px;
    }

    .rightPanel .panelHead i {
      right: 20px;
      top: 15px;
    }
  }

  .floatPanel::before {
    content: '';
    height: 100%;
    position: absolute;
    left: 50%;
    width: 1px;
    border-left: 1px solid #e4e4e4;
  }
}

input {
  width: 60px;
  border: none;
  height: 32px;
  line-height: 32px;
  box-sizing: border-box;
  background-color: transparent;
}

input:focus {
  outline: none;
  background-color: transparent;
}

.yearPicker:hover {
  border-color: #3e77fc;
}

.dateIcon {
  position: absolute;
  right: 16px;
  top: 9px;
  color: #adb2bc;
}
</style>