element/packages/date-picker/src/panel/time-select.vue

<template>
  <transition name="md-fade-bottom" @after-leave="$emit('dodestroy')">
    <div
      v-show="visible"
      :style="{ width: width + 'px' }"
      class="el-picker-panel time-select">
      <div class="el-picker-panel__content">
        <div class="time-select-item"
          v-for="item in items"
          :class="{ selected: value === item.value, disabled: item.disabled }"
          :disabled="item.disabled"
          @click="handleClick(item)">{{ item.value }}</div>
      </div>
    </div>
  </transition>
</template>

<script type="text/babel">
  const parseTime = function(time) {
    const values = ('' || time).split(':');
    if (values.length >= 2) {
      const hours = parseInt(values[0], 10);
      const minutes = parseInt(values[1], 10);

      return {
        hours,
        minutes
      };
    }
    return null;
  };

  const compareTime = function(time1, time2) {
    const value1 = parseTime(time1);
    const value2 = parseTime(time2);

    const minutes1 = value1.minutes + value1.hours * 60;
    const minutes2 = value2.minutes + value2.hours * 60;

    if (minutes1 === minutes2) {
      return 0;
    }

    return minutes1 > minutes2 ? 1 : -1;
  };

  const formatTime = function(time) {
    return (time.hours < 10 ? '0' + time.hours : time.hours) + ':' + (time.minutes < 10 ? '0' + time.minutes : time.minutes);
  };

  const nextTime = function(time, step) {
    const timeValue = parseTime(time);
    const stepValue = parseTime(step);

    const next = {
      hours: timeValue.hours,
      minutes: timeValue.minutes
    };

    next.minutes += stepValue.minutes;
    next.hours += stepValue.hours;

    next.hours += Math.floor(next.minutes / 60);
    next.minutes = next.minutes % 60;

    return formatTime(next);
  };

  export default {
    watch: {
      minTime(val) {
        if (this.value && val && compareTime(this.value, val) === -1) {
          this.$emit('pick');
        }
      },

      value(val, old) {
        if (val && this.items.some(i => i.value === val && !i.disabled)) {
          this.$emit('pick', val, true);
        } else {
          this.$emit('pick', old, true);
        }
      }
    },

    methods: {
      handleClick(item) {
        if (!item.disabled) {
          this.$emit('pick', item.value);
        }
      }
    },

    data() {
      return {
        start: '09:00',
        end: '18:00',
        step: '00:30',
        value: '',
        visible: false,
        minTime: '',
        width: 0
      };
    },

    computed: {
      items() {
        const start = this.start;
        const end = this.end;
        const step = this.step;

        const result = [];

        if (start && end && step) {
          let current = start;
          while (compareTime(current, end) <= 0) {
            result.push({
              value: current,
              disabled: compareTime(current, this.minTime || '00:00') <= 0
            });
            current = nextTime(current, step);
          }
        }

        return result;
      }
    }
  };
</script>