How does MaterialUI do this?

Question

If you look at their autocomplete component: https://mui.com/material-ui/react-autocomplete/

The input box retains focus after clicking on a suggestion in the dropdown...how do they do that? In every variant in my own vue app (not using material UI) I can't get the click event to prevent the input from losing focus.

I've been trying to google this problem for a long time but haven't seen a clear solution. For example, people suggested mousedown/touchstart, but this breaks scrolling (by dragging the dropdown). MaterialUI apparently doesn't have this problem and doesn't seem to use mousedown.

I tried analyzing the event using Chrome Dev Tools, but I can only see a single click event, but with the stripped down code it's hard to tell what's going on.

Vuetify does this too: https://github.com/vuetifyjs/vuetify/blob/master/packages/vuetify/src/components/VAutocomplete/VAutocomplete.ts

If anyone has this problem, I also found this helpful https://codepen.io/Pineapple/pen/MWBVqGW

EditThis is what I'm doing:

 <app-input-autocomplete
    @autocomplete-select="onSelect"
    @autocomplete-close="onClose"
    :open="open">
    <template #default="{ result }">
      <div class="input-autocomplete-address">
        {{ result.address }}
      </div>
    </template>
  </app-input-autocomplete>

Then in app-input-autocomplete:

<template>
  <app-input
    @focus="onFocus"
    @blur="onBlur"
    v-bind="$attrs">
    <template #underInput>
      <div ref="dropdown" v-show="open" class="input-autocomplete-dropdown">
        <div class="input-autocomplete-results">
          <div v-for="result in results" :key="result.id" @click="onClick(result)" class="input-autocomplete-result">
            <slot :result="result" />
          </div>
        </div>
      </div>
    </template>
  </app-input>
</template>

<script>
import { ref, toRef } from 'vue';
import AppInput from '@/components/AppInput.vue';
import { onClickOutside } from '@vueuse/core';

export default {
  components: {
    AppInput,
  },
  inheritAttrs: false,
  props: {
    open: {
      type: Boolean,
      default: false,
    },
    results: {
      type: Array,
      default: () => ([]),
    },
  },
  emits: ['autocomplete-close', 'autocomplete-select'],
  setup(props, { emit }) {
    const dropdown = ref(null);

    const open = toRef(props, 'open');

    const focused = ref(false);

    onClickOutside(dropdown, () => {
      if (!focused.value && open.value) {
        emit('autocomplete-close');
      }
    });

    return {
      dropdown,
      focused,
    };
  },
  methods: {
    onFocus() {
      this.focused = true;
    },
    onBlur() {
      this.focused = false;
    },
    onClick(result) {
      this.$emit('autocomplete-select', result);
    },
  },
};
</script>

Answer 1

I solved this problem by doing the following, thanks to @Claies for the idea and this link:

https://codepen.io/Pineapple/pen/MWBVqGW

1. event.preventDefault on mousedown
2. @click results behave as normal (input closed)
3. @click/@focus input setopen = true
4. @blur set open = false