Feat/dropdown (#199)

package.json

@@ -3,7 +3,7 @@
   "private": true,
   "version": "0.0.0",
   "scripts": {
-    "cz": "git add -A && npx git-cz",
+    "cz": "npx git-cz",
     "test": "jest",
     "gen": "bash ./scripts/gc.sh",
     "storybook": "start-storybook",

packages/checkbox/doc/basic.vue

@@ -5,7 +5,8 @@
     <el-checkbox v-model="checked2" disabled>{{ checked2 }}</el-checkbox>
     <el-checkbox v-model="checked1" label="A" border />
     <el-checkbox v-model="checked2" border />
-
+    <el-checkbox v-model="checked4" true-label="a" :false-label="3" />
+    {{ checked4 }}
     <el-checkbox-group v-model="checkList">
       <el-checkbox label="A" />
       <el-checkbox label="B" />
@@ -25,6 +26,7 @@ export default defineComponent({
       checked1: false,
       checked2: true,
       checkList: ['Ha','A'],
+      checked4: 3,
     }
   },
   methods: {

packages/checkbox/src/checkbox-button.vue

@@ -52,7 +52,7 @@ import {
   defineComponent,
   ref,
   computed,
-  // nextTick,
+  PropType,
   watch,
 } from 'vue'
 import { useCheckbox } from './useCheckbox'
@@ -61,12 +61,11 @@ export default defineComponent({
   name: 'ElCheckboxButton',
   props: {
     modelValue: {
-      type: [Object, Boolean],
+      type: [Object, Boolean, String, Number] as PropType<Record<string, unknown> | boolean | number>,
       default: () => undefined,
     },
     label: {
-      type: [Object, Boolean, String],
-      default: () => ({}),
+      type: [Object, Boolean, String] as PropType<Record<string, unknown> | boolean | string>,
     },
     indeterminate: Boolean,
     disabled: Boolean,

packages/checkbox/src/checkbox.vue

@@ -64,7 +64,7 @@ import {
   getCurrentInstance,
   watch,
   onMounted,
-  // nextTick,
+  PropType,
 } from 'vue'
 import { useCheckbox } from './useCheckbox'
 
@@ -72,12 +72,11 @@ export default defineComponent({
   name: 'ElCheckbox',
   props: {
     modelValue: {
-      type: [Object, Boolean],
+      type: [Object, Boolean, String, Number] as PropType<Record<string, unknown> | boolean | number>,
       default: () => undefined,
     },
     label: {
-      type: [Object, Boolean, String],
-      default: '  ',
+      type: [Object, Boolean, String] as PropType<Record<string, unknown> | boolean | string>,
     },
     indeterminate: Boolean,
     disabled: Boolean,

packages/checkbox/src/useCheckbox.ts

@@ -9,7 +9,6 @@ export const useCheckbox = () => {
   const focus = ref(false)
   const isGroup = computed(() => _checkboxGroup && _checkboxGroup.name === 'ElCheckboxGroup')
   const _elFormItemSize = computed(() => {
-
     return (elFormItem || {} as any).elFormItemSize
   })
   return {

packages/dropdown/__tests__/dropdown.spec.ts

@@ -0,0 +1,273 @@
+import { mount } from '@vue/test-utils'
+import { eventKeys } from '@element-plus/utils/aria'
+import Dropdown from '../src/dropdown.vue'
+import DropdownItem from '../src/dropdown-item.vue'
+import DropdownMenu from '../src/dropdown-menu.vue'
+
+const MOUSE_ENTER_EVENT = 'mouseenter'
+const MOUSE_LEAVE_EVENT = 'mouseleave'
+const CLICK = 'click'
+
+const _mount = (template: string, data, otherObj?) => mount({
+  components: {
+    [Dropdown.name]: Dropdown,
+    [DropdownItem.name]: DropdownItem,
+    [DropdownMenu.name]: DropdownMenu,
+  },
+  template,
+  data,
+  ...otherObj,
+})
+const sleep = (time = 250) => new Promise(resolve => setTimeout(resolve, time))
+export const timeout = async (fn, time = 250) => {
+  await sleep(time)
+  fn()
+}
+
+describe('Dropdown', () => {
+  test('create', async () => {
+    const wrapper = _mount(
+      `
+      <el-dropdown ref="b" placement="right">
+        <span class="el-dropdown-link" ref="a">
+          dropdown<i class="el-icon-arrow-down el-icon--right"></i>
+        </span>
+        <template #dropdown>
+          <el-dropdown-menu>
+            <el-dropdown-item>Apple</el-dropdown-item>
+            <el-dropdown-item>Orange</el-dropdown-item>
+            <el-dropdown-item>Cherry</el-dropdown-item>
+            <el-dropdown-item disabled>Peach</el-dropdown-item>
+            <el-dropdown-item divided>Pear</el-dropdown-item>
+          </el-dropdown-menu>
+        </template>
+      </el-dropdown>
+      `,
+      () => ({}),
+    )
+    const content = wrapper.findComponent({ ref: 'b' }).vm.$refs.popper as any
+    const triggerElm = wrapper.find('.el-dropdown-link')
+    expect(content.value).toBe(false)
+    await triggerElm.trigger(MOUSE_ENTER_EVENT)
+    await sleep()
+    expect(content.value).toBe(true)
+    await triggerElm.trigger(MOUSE_LEAVE_EVENT)
+    await sleep()
+    expect(content.value).toBe(false)
+  })
+
+  test('menu click', async () => {
+    const wrapper = _mount(
+      `
+      <el-dropdown ref="b" @command="commandHandler" placement="right">
+        <span class="el-dropdown-link" ref="a">
+          dropdown<i class="el-icon-arrow-down el-icon--right"></i>
+        </span>
+        <template #dropdown>
+          <el-dropdown-menu>
+            <el-dropdown-item command="a">Apple</el-dropdown-item>
+            <el-dropdown-item command="b">Orange</el-dropdown-item>
+            <el-dropdown-item ref="c" :command="myCommandObject">Cherry</el-dropdown-item>
+            <el-dropdown-item command="d">Peach</el-dropdown-item>
+            <el-dropdown-item command="e">Pear</el-dropdown-item>
+          </el-dropdown-menu>
+        </template>
+      </el-dropdown>
+      `,
+      () => ({
+        myCommandObject: { name: 'CommandC' },
+        name: '',
+      }),
+      {
+        methods: {
+          commandHandler(command) {
+            this.name = command.name
+          },
+        },
+      },
+    )
+    // const content = wrapper.findComponent({ ref: 'b' }).vm.$refs.popper as any
+    const triggerElm = wrapper.find('.el-dropdown-link')
+    await triggerElm.trigger(MOUSE_ENTER_EVENT)
+    await sleep()
+    await wrapper.findComponent({ ref: 'c' }).trigger('click')
+    await sleep()
+    expect((wrapper.vm as any).name).toBe('CommandC')
+  })
+
+  test('trigger', async () => {
+    const wrapper = _mount(
+      `
+      <el-dropdown trigger="click" ref="b" placement="right">
+        <span class="el-dropdown-link" ref="a">
+          dropdown<i class="el-icon-arrow-down el-icon--right"></i>
+        </span>
+        <template #dropdown>
+          <el-dropdown-menu>
+            <el-dropdown-item command="a">Apple</el-dropdown-item>
+            <el-dropdown-item command="b">Orange</el-dropdown-item>
+            <el-dropdown-item ref="c" :command="myCommandObject">Cherry</el-dropdown-item>
+            <el-dropdown-item command="d">Peach</el-dropdown-item>
+            <el-dropdown-item command="e">Pear</el-dropdown-item>
+          </el-dropdown-menu>
+        </template>
+      </el-dropdown>
+      `,
+      () => ({
+        myCommandObject: { name: 'CommandC' },
+        name: '',
+      }),
+    )
+    const content = wrapper.findComponent({ ref: 'b' }).vm.$refs.popper as any
+    const triggerElm = wrapper.find('.el-dropdown-link')
+    expect(content.value).toBe(false)
+    await triggerElm.trigger(MOUSE_ENTER_EVENT)
+    await sleep()
+    expect(content.value).toBe(false)
+    await triggerElm.trigger(CLICK)
+    await sleep()
+    expect(content.value).toBe(true)
+  })
+
+  test('split button', async () => {
+    const wrapper = _mount(
+      `
+      <el-dropdown  @click="handleClick" split-button type="primary" ref="b" placement="right">
+        dropdown
+        <template #dropdown>
+          <el-dropdown-menu>
+            <el-dropdown-item command="a">Apple</el-dropdown-item>
+            <el-dropdown-item command="b">Orange</el-dropdown-item>
+            <el-dropdown-item ref="c" :command="myCommandObject">Cherry</el-dropdown-item>
+            <el-dropdown-item command="d">Peach</el-dropdown-item>
+            <el-dropdown-item command="e">Pear</el-dropdown-item>
+          </el-dropdown-menu>
+        </template>
+      </el-dropdown>
+      `,
+      () => ({
+        myCommandObject: { name: 'CommandC' },
+        name: '',
+      }),
+      {
+        methods: {
+          handleClick() {
+            this.name = 'click'
+          },
+        },
+      },
+    )
+    const content = wrapper.findComponent({ ref: 'b' }).vm.$refs.popper as any
+    const triggerElm = wrapper.find('.el-dropdown__caret-button')
+    const button = wrapper.find('.el-button')
+    expect(content.value).toBe(false)
+    await button.trigger('click')
+    expect((wrapper.vm as any).name).toBe('click')
+    await triggerElm.trigger(MOUSE_ENTER_EVENT)
+    await sleep()
+    expect(content.value).toBe(true)
+  })
+
+  test('hide on click', async () => {
+    const wrapper = _mount(
+      `
+      <el-dropdown ref="b" placement="right" :hide-on-click="false">
+        <span class="el-dropdown-link" ref="a">
+          dropdown<i class="el-icon-arrow-down el-icon--right"></i>
+        </span>
+        <template #dropdown>
+          <el-dropdown-menu>
+            <el-dropdown-item>Apple</el-dropdown-item>
+            <el-dropdown-item>Orange</el-dropdown-item>
+            <el-dropdown-item ref="c">Cherry</el-dropdown-item>
+            <el-dropdown-item disabled>Peach</el-dropdown-item>
+            <el-dropdown-item divided>Pear</el-dropdown-item>
+          </el-dropdown-menu>
+        </template>
+      </el-dropdown>
+      `,
+      () => ({}),
+    )
+
+    const content = wrapper.findComponent({ ref: 'b' }).vm.$refs.popper as any
+    const triggerElm = wrapper.find('.el-dropdown-link')
+    await triggerElm.trigger(MOUSE_ENTER_EVENT)
+    await sleep()
+    await wrapper.findComponent({ ref: 'c' }).trigger('click')
+    await sleep()
+    expect(content.value).toBe(true)
+  })
+
+  test('triggerElm keydown', async () => {
+    const wrapper = _mount(
+      `
+      <el-dropdown ref="b" placement="right" :hide-on-click="false">
+        <span class="el-dropdown-link" ref="a">
+          dropdown<i class="el-icon-arrow-down el-icon--right"></i>
+        </span>
+        <template #dropdown>
+          <el-dropdown-menu>
+            <el-dropdown-item>Apple</el-dropdown-item>
+            <el-dropdown-item>Orange</el-dropdown-item>
+            <el-dropdown-item ref="c">Cherry</el-dropdown-item>
+            <el-dropdown-item disabled>Peach</el-dropdown-item>
+            <el-dropdown-item divided>Pear</el-dropdown-item>
+          </el-dropdown-menu>
+        </template>
+      </el-dropdown>
+      `,
+      () => ({}),
+    )
+
+    const content = wrapper.findComponent({ ref: 'b' }).vm.$refs.popper as any
+    const triggerElm = wrapper.find('.el-dropdown-link')
+    await triggerElm.trigger(MOUSE_ENTER_EVENT)
+    await sleep()
+    await triggerElm.trigger('keydown', {
+      keyCode: eventKeys.enter,
+    })
+    await sleep()
+    expect(content.value).toBe(false)
+
+    await triggerElm.trigger(MOUSE_ENTER_EVENT)
+    await sleep()
+    await triggerElm.trigger('keydown', {
+      keyCode: eventKeys.tab,
+    })
+    await sleep()
+    expect(content.value).toBe(false)
+  })
+
+  test('dropdown menu keydown', async () => {
+    const wrapper = _mount(
+      `
+      <el-dropdown ref="b" placement="right" :hide-on-click="false">
+        <span class="el-dropdown-link" ref="a">
+          dropdown<i class="el-icon-arrow-down el-icon--right"></i>
+        </span>
+        <template #dropdown>
+          <el-dropdown-menu ref="a">
+            <el-dropdown-item ref="d">Apple</el-dropdown-item>
+            <el-dropdown-item>Orange</el-dropdown-item>
+            <el-dropdown-item ref="c">Cherry</el-dropdown-item>
+            <el-dropdown-item disabled>Peach</el-dropdown-item>
+            <el-dropdown-item divided>Pear</el-dropdown-item>
+          </el-dropdown-menu>
+        </template>
+      </el-dropdown>
+      `,
+      () => ({}),
+    )
+
+    const content = wrapper.findComponent({ ref: 'a' })
+    const triggerElm = wrapper.find('.el-dropdown-link')
+    await triggerElm.trigger(MOUSE_ENTER_EVENT)
+    await sleep()
+    await content.trigger('keydown', {
+      keyCode: eventKeys.down,
+    })
+    await sleep()
+    expect(wrapper.findComponent({ ref: 'd' }).attributes('tabindex')).toBe('0')
+
+  })
+})

packages/dropdown/doc/basic.vue

@@ -0,0 +1,164 @@
+<template>
+  <div class="block">
+    <el-dropdown ref="c" placement="right" :hide-on-click="false">
+      <span ref="a" class="el-dropdown-link">
+        dropdown<i class="el-icon-arrow-down el-icon--right"></i>
+      </span>
+      <template #dropdown>
+        <el-dropdown-menu ref="b">
+          <el-dropdown-item>Apple</el-dropdown-item>
+          <el-dropdown-item>Orange</el-dropdown-item>
+          <el-dropdown-item>Cherry</el-dropdown-item>
+          <el-dropdown-item disabled>Peach</el-dropdown-item>
+          <el-dropdown-item divided>Pear</el-dropdown-item>
+        </el-dropdown-menu>
+      </template>
+    </el-dropdown>
+    <br>
+    <br>
+    <el-dropdown trigger="click" :hide-on-click="false">
+      <span class="el-dropdown-link">
+        dropdown<i class="el-icon-arrow-down el-icon--right"></i>
+      </span>
+      <template #dropdown>
+        <el-dropdown-menu>
+          <el-dropdown-item>Apple</el-dropdown-item>
+          <el-dropdown-item>Orange</el-dropdown-item>
+          <el-dropdown-item>Cherry</el-dropdown-item>
+          <el-dropdown-item disabled>Peach</el-dropdown-item>
+          <el-dropdown-item divided>Pear</el-dropdown-item>
+        </el-dropdown-menu>
+      </template>
+    </el-dropdown>
+    <br>
+    <br>
+    <el-dropdown>
+      <el-button type="primary">
+        dropdown<i class="el-icon-arrow-down el-icon--right"></i>
+      </el-button>
+      <template #dropdown>
+        <el-dropdown-menu>
+          <el-dropdown-item>Apple</el-dropdown-item>
+          <el-dropdown-item>Orange</el-dropdown-item>
+          <el-dropdown-item>Cherry</el-dropdown-item>
+          <el-dropdown-item disabled>Peach</el-dropdown-item>
+          <el-dropdown-item divided>Pear</el-dropdown-item>
+        </el-dropdown-menu>
+      </template>
+    </el-dropdown>
+    <br>
+    <br>
+    <el-dropdown @command="handleCommand">
+      <el-button type="primary">
+        dropdown<i class="el-icon-arrow-down el-icon--right"></i>
+      </el-button>
+      <template #dropdown>
+        <el-dropdown-menu>
+          <el-dropdown-item command="a">Apple</el-dropdown-item>
+          <el-dropdown-item command="b">Orange</el-dropdown-item>
+          <el-dropdown-item command="c">Cherry</el-dropdown-item>
+          <el-dropdown-item command="d" disabled>Peach</el-dropdown-item>
+          <el-dropdown-item command="e" divided>Pear</el-dropdown-item>
+        </el-dropdown-menu>
+      </template>
+    </el-dropdown>
+    <br>
+    <br>
+    <el-dropdown split-button type="primary" @click="handleClick">
+      dropdown
+      <template #dropdown>
+        <el-dropdown-menu>
+          <el-dropdown-item>Apple</el-dropdown-item>
+          <el-dropdown-item>Orange</el-dropdown-item>
+          <el-dropdown-item>Cherry</el-dropdown-item>
+          <el-dropdown-item disabled>Peach</el-dropdown-item>
+          <el-dropdown-item divided>Pear</el-dropdown-item>
+        </el-dropdown-menu>
+      </template>
+    </el-dropdown>
+    <br>
+    <br>
+    <el-dropdown
+      split-button
+      size="medium"
+      type="primary"
+      @click="handleClick"
+    >
+      dropdown
+      <template #dropdown>
+        <el-dropdown-menu>
+          <el-dropdown-item>Apple</el-dropdown-item>
+          <el-dropdown-item>Orange</el-dropdown-item>
+          <el-dropdown-item>Cherry</el-dropdown-item>
+          <el-dropdown-item disabled>Peach</el-dropdown-item>
+          <el-dropdown-item divided>Pear</el-dropdown-item>
+        </el-dropdown-menu>
+      </template>
+    </el-dropdown>
+    <br>
+    <br>
+    <el-dropdown
+      split-button
+      size="small"
+      type="primary"
+      @click="handleClick"
+    >
+      dropdown
+      <template #dropdown>
+        <el-dropdown-menu>
+          <el-dropdown-item>Apple</el-dropdown-item>
+          <el-dropdown-item>Orange</el-dropdown-item>
+          <el-dropdown-item>Cherry</el-dropdown-item>
+          <el-dropdown-item disabled>Peach</el-dropdown-item>
+          <el-dropdown-item divided>Pear</el-dropdown-item>
+        </el-dropdown-menu>
+      </template>
+    </el-dropdown>
+    <br>
+    <br>
+    <el-dropdown
+      split-button
+      size="mini"
+      type="primary"
+      @click="handleClick"
+    >
+      dropdown
+      <template #dropdown>
+        <el-dropdown-menu>
+          <el-dropdown-item>Apple</el-dropdown-item>
+          <el-dropdown-item>Orange</el-dropdown-item>
+          <el-dropdown-item>Cherry</el-dropdown-item>
+          <el-dropdown-item disabled>Peach</el-dropdown-item>
+          <el-dropdown-item divided>Pear</el-dropdown-item>
+        </el-dropdown-menu>
+      </template>
+    </el-dropdown>
+  </div>
+</template>
+
+<script lang="tsx">
+import { defineComponent } from 'vue'
+export default defineComponent({
+  methods: {
+    handleClick() {
+      alert('button click')
+    },
+    handleCommand(command) {
+      alert('click on item ' + command)
+    },
+  },
+})
+</script>
+
+<style>
+.el-dropdown-link {
+  cursor: pointer;
+  color: #409EFF;
+}
+.el-icon-arrow-down {
+  font-size: 12px;
+}
+.el-dropdown-menu__item {
+  word-break: keep-all;
+}
+</style>

packages/dropdown/doc/index.stories.ts

@@ -0,0 +1,6 @@
+export { default as BasicUsage } from './basic.vue'
+
+export default {
+  title: 'Dropdown',
+}
+

packages/dropdown/index.ts

@@ -0,0 +1,10 @@
+import { App } from 'vue'
+import Dropdown from './src/dropdown.vue'
+import DropdownItem from './src/dropdown-item.vue'
+import DropdownMenu from './src/dropdown-menu.vue'
+
+export default (app: App): void => {
+  app.component(Dropdown.name, Dropdown)
+  app.component(DropdownItem.name, DropdownItem)
+  app.component(DropdownMenu.name, DropdownMenu)
+}

packages/dropdown/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "@element-plus/dropdown",
+  "version": "0.0.0",
+  "main": "dist/index.js",
+  "license": "MIT",
+  "peerDependencies": {
+    "vue": "^3.0.0-rc.1"
+  },
+  "devDependencies": {
+    "@vue/test-utils": "^2.0.0-beta.0"
+  }
+}

packages/dropdown/src/dropdown-item.vue

@@ -0,0 +1,49 @@
+<template>
+  <li
+    class="el-dropdown-menu__item"
+    :class="{
+      'is-disabled': disabled,
+      'el-dropdown-menu__item--divided': divided
+    }"
+    :aria-disabled="disabled"
+    :tabindex="disabled ? null : -1"
+    @click="handleClick"
+  >
+    <i v-if="icon" :class="icon"></i>
+    <slot></slot>
+  </li>
+</template>
+<script lang='ts'>
+import { defineComponent, getCurrentInstance } from 'vue'
+import { useDropdown } from './useDropdown'
+
+export default defineComponent({
+  name: 'ElDropdownItem',
+  props: {
+    command: {
+      type: [Object, String, Number],
+      defautl: () => ({}),
+    },
+    disabled: Boolean,
+    divided: Boolean,
+    icon: String,
+  },
+  setup(props) {
+    const { elDropdown } = useDropdown()
+    const _instance = getCurrentInstance()
+
+    function handleClick(e: UIEvent) {
+      if (elDropdown.hideOnClick.value) {
+        elDropdown.handleClick?.()
+      }
+      elDropdown.commandHandler?.(props.command, _instance, e)
+    }
+
+    return {
+      handleClick,
+    }
+  },
+})
+</script>
+<style scoped>
+</style>

packages/dropdown/src/dropdown-menu.vue

@@ -0,0 +1,59 @@
+<template>
+  <ul
+    v-clickOutside:[_trigger]="_hide"
+    :class="[size && `el-dropdown-menu--${size}`]"
+    class="el-dropdown-menu"
+    @mouseenter.stop="show"
+    @mouseleave.stop="hide"
+  >
+    <slot></slot>
+  </ul>
+</template>
+<script lang='ts'>
+import { defineComponent, getCurrentInstance, onMounted, ref } from 'vue'
+import ClickOutside from '@element-plus/directives/click-outside'
+import { useDropdown, initDropdownDomEvent } from './useDropdown'
+
+export default defineComponent({
+  name: 'ElDropdownMenu',
+  directives: {
+    ClickOutside,
+  },
+  setup() {
+    const { _elDropdownSize, elDropdown } = useDropdown()
+    const size = _elDropdownSize.value
+    const _trigger = ref(null)
+    function show() {
+      elDropdown.show?.()
+    }
+    function hide() {
+      if (elDropdown.trigger.value === 'click') return
+      _hide()
+    }
+    function _hide() {
+      elDropdown.hide?.()
+    }
+
+    onMounted(() => {
+      const dropdownMenu = getCurrentInstance()
+      _trigger.value = elDropdown.triggerElm.value
+      initDropdownDomEvent(dropdownMenu, _trigger.value, elDropdown.instance)
+    })
+
+    return {
+      size,
+      show,
+      hide,
+      _trigger,
+      _hide,
+    }
+  },
+})
+</script>
+<style>
+.el-dropdown-menu {
+  position: relative;
+  margin: 0;
+  box-shadow: none;
+}
+</style>

packages/dropdown/src/dropdown.d.ts

@@ -0,0 +1,18 @@
+import {
+  ComponentInternalInstance,
+  ComputedRef,
+  Ref,
+} from 'vue'
+
+export interface IElDropdownInstance {
+  instance?: ComponentInternalInstance
+  dropdownSize?: ComputedRef<string>
+  visible?: Ref<boolean>
+  handleClick?: () => void
+  commandHandler?: (...arg) => void
+  show?: () => void
+  hide?:  () => void
+  trigger?: ComputedRef<string>
+  hideOnClick?: ComputedRef<boolean>
+  triggerElm?: ComputedRef<Nullable<HTMLButtonElement>>
+}

packages/dropdown/src/dropdown.vue

@@ -0,0 +1,261 @@
+<script lang='ts'>
+import {
+  defineComponent,
+  h,
+  provide,
+  getCurrentInstance,
+  ref,
+  computed,
+  watch,
+  onMounted,
+  VNode,
+} from 'vue'
+import { on, addClass, removeClass } from '@element-plus/utils/dom'
+import ClickOutside from '@element-plus/directives/click-outside'
+import ElButton from '@element-plus/button/src/button.vue'
+import ElButtonGroup from '@element-plus/button/src/button-group.vue'
+import ELPopper from '@element-plus/popper/src/index.vue'
+import { useDropdown } from './useDropdown'
+
+export default defineComponent({
+  name: 'ElDropdown',
+  directives: {
+    ClickOutside,
+  },
+  components: {
+    ElButton,
+    ElButtonGroup,
+    ELPopper,
+  },
+  props: {
+    trigger: {
+      type: String,
+      default: 'hover',
+    },
+    type: String,
+    size: {
+      type: String,
+      default: '',
+    },
+    splitButton: Boolean,
+    hideOnClick: {
+      type: Boolean,
+      default: true,
+    },
+    placement: {
+      type: String,
+      default: 'bottom',
+    },
+    showTimeout: {
+      type: Number,
+      default: 250,
+    },
+    hideTimeout: {
+      type: Number,
+      default: 150,
+    },
+    tabindex: {
+      type: Number,
+      default: 0,
+    },
+    effect: {
+      type: String,
+      default: 'light',
+    },
+  },
+  emits: ['visible-change', 'click', 'command'],
+  setup(props, { emit, slots }) {
+    const _instance = getCurrentInstance()
+    const { ELEMENT } = useDropdown()
+
+    const timeout = ref<Nullable<number>>(null)
+
+    const visible = ref(false)
+    watch(
+      () => visible.value,
+      val => {
+        if(val) triggerElmFocus()
+        if(!val) triggerElmBlur()
+        emit('visible-change', val)
+      },
+    )
+
+    const focusing = ref(false)
+    watch(
+      () => focusing.value,
+      val => {
+        const selfDefine = triggerElm.value
+        if (selfDefine) {
+          if (val) {
+            addClass(selfDefine, 'focusing')
+          } else {
+            removeClass(selfDefine, 'focusing')
+          }
+        }
+      },
+    )
+
+    const triggerVnode = ref<Nullable<VNode>>(null)
+    const triggerElm = computed<Nullable<HTMLButtonElement>>(() =>
+      !props.splitButton
+        ? triggerVnode.value?.el
+        : triggerVnode.value?.el.querySelector('.el-dropdown__caret-button'),
+    )
+
+    function handleClick() {
+      if (triggerElm.value?.disabled) return
+      if (visible.value) {
+        hide()
+      } else {
+        show()
+      }
+    }
+
+    function show() {
+      if (triggerElm.value?.disabled) return
+      timeout.value && clearTimeout(timeout.value)
+      timeout.value = window.setTimeout(() => {
+        visible.value = true
+      }, props.trigger === 'click' ? 0 : props.showTimeout)
+    }
+
+    function hide() {
+      if (triggerElm.value?.disabled) return
+      removeTabindex()
+      if (props.tabindex >=0) {
+        resetTabindex(triggerElm.value)
+      }
+      clearTimeout(timeout.value)
+      timeout.value = window.setTimeout(() => {
+        visible.value = false
+      }, props.trigger === 'click' ? 0 : props.hideTimeout)
+    }
+
+    function removeTabindex() {
+      triggerElm.value?.setAttribute('tabindex', '-1')
+    }
+
+    function resetTabindex(ele) {
+      removeTabindex()
+      ele?.setAttribute('tabindex', '0')
+    }
+
+    function triggerElmFocus() {
+      triggerElm.value?.focus?.()
+    }
+    function triggerElmBlur() {
+      triggerElm.value?.blur?.()
+    }
+
+    // for dom
+    Object.assign(_instance, {
+      handleClick,
+      hide,
+      resetTabindex,
+    })
+
+    const dropdownSize = computed(() => props.size || (ELEMENT || {}).size)
+    function commandHandler (...args) {
+      emit('command', ...args)
+    }
+
+    provide('elDropdown', {
+      instance: _instance,
+      dropdownSize,
+      visible,
+      handleClick,
+      commandHandler,
+      show,
+      hide,
+      trigger: computed(() => props.trigger),
+      hideOnClick: computed(() => props.hideOnClick),
+      triggerElm,
+    })
+
+    onMounted(() => {
+      if (!props.splitButton) {
+        on(triggerElm.value, 'focus', () => {
+          focusing.value = true
+        })
+        on(triggerElm.value, 'blur', () => {
+          focusing.value = false
+        })
+        on(triggerElm.value, 'click', () => {
+          focusing.value = false
+        })
+      }
+      if (props.trigger === 'hover') {
+        on(triggerElm.value, 'mouseenter', show)
+        on(triggerElm.value, 'mouseleave', hide)
+      } else if (props.trigger === 'click') {
+        on(triggerElm.value, 'click', handleClick)
+      }
+    })
+
+    const handlerMainButtonClick = event => {
+      emit('click', event)
+      hide()
+    }
+
+    triggerVnode.value = !props.splitButton
+      ? slots.default?.()[0] // trigger must be a single root element
+      : h(ElButtonGroup, {}, {
+        default: () => (
+          [
+            h(ElButton, {
+              type: props.type,
+              size: dropdownSize.value,
+              onClick: handlerMainButtonClick,
+            }, {
+              default: () => slots.default?.()[0],
+            }),
+            h(ElButton, {
+              type: props.type,
+              size: dropdownSize.value,
+              class: 'el-dropdown__caret-button',
+            }, {
+              default: () => h('i', { class: 'el-dropdown__icon el-icon-arrow-down' }),
+            }),
+          ]
+        ),
+      })
+    slots.default?.().length > 1 && console.warn('trigger must be a single root element')
+
+    const dropdownVnode = h('div', {
+      class: 'el-dropdown',
+    }, [triggerVnode.value])
+
+    return () => h(ELPopper, {
+      ref: 'popper',
+      placement: props.placement,
+      effect: props.effect,
+      value: visible.value,
+      manualMode: true,
+      popperClass: 'el-dropdown-popper',
+      trigger: props.trigger,
+    }, {
+      default: () => slots.dropdown?.(),
+      trigger: () => dropdownVnode,
+    })
+  },
+})
+</script>
+<style>
+.el-dropdown-popper {
+  padding: 0px;
+  box-shadow: 0 2px 12px 0 rgba(0,0,0,.1);
+}
+.el-dropdown-popper.is-light {
+  border: 1px solid #EBEEF5;
+}
+.el-dropdown-popper.is-light .el-popper__arrow::before {
+  border: 1px solid #EBEEF5;
+  background: #FFF;
+}
+.el-dropdown-popper .el-dropdown-menu {
+  border: none;
+}
+.el-dropdown-selfdefine {
+  outline: none;
+}
+</style>

packages/dropdown/src/useDropdown.ts

@@ -0,0 +1,115 @@
+import { inject, computed, ref } from 'vue'
+import { generateId } from '@element-plus/utils/util'
+import { eventKeys } from '@element-plus/utils/aria'
+import { on, addClass } from '@element-plus/utils/dom'
+import { IElDropdownInstance } from './dropdown'
+
+export const useDropdown = () => {
+  const ELEMENT = null
+  const elDropdown = inject<IElDropdownInstance>('elDropdown', {})
+  const _elDropdownSize = computed(() => elDropdown?.dropdownSize)
+
+  return {
+    ELEMENT,
+    elDropdown,
+    _elDropdownSize,
+  }
+}
+
+export const initDropdownDomEvent = (dropdownChildren, triggerElm, _instance) => {
+  const menuItems = ref<Nullable<HTMLButtonElement[]>>(null)
+  const menuItemsArray = ref<Nullable<HTMLElement[]>>(null)
+  const dropdownElm = ref<Nullable<HTMLElement>>(null)
+  const listId = ref(`dropdown-menu-${generateId()}`)
+  dropdownElm.value = dropdownChildren?.subTree.el
+
+  function removeTabindex() {
+    triggerElm.setAttribute('tabindex', '-1')
+    menuItemsArray.value?.forEach(item => {
+      item.setAttribute('tabindex', '-1')
+    })
+  }
+
+  function resetTabindex(ele) {
+    removeTabindex()
+    ele?.setAttribute('tabindex', '0')
+  }
+
+  function handleTriggerKeyDown(ev: KeyboardEvent) {
+    /**
+     * https://developer.mozilla.org/zh-CN/docs/Web/API/KeyboardEvent/keyCode
+     * keyCode is deprecated, we should replace the api with event.key
+     * */
+    const keyCode = ev.keyCode
+    if ([eventKeys.up, eventKeys.down].includes(keyCode)) {
+      removeTabindex()
+      resetTabindex(menuItems.value[0])
+      menuItems.value[0].focus()
+      ev.preventDefault()
+      ev.stopPropagation()
+    } else if (keyCode === eventKeys.enter) {
+      _instance.handleClick()
+    } else if ([eventKeys.tab, eventKeys.esc].includes(keyCode)) {
+      _instance.hide()
+    }
+  }
+
+  function handleItemKeyDown(ev) {
+    const keyCode = ev.keyCode
+    const target = ev.target
+    const currentIndex = menuItemsArray.value.indexOf(target)
+    const max = menuItemsArray.value.length - 1
+    let nextIndex
+    if ([eventKeys.up, eventKeys.down].includes(keyCode)) {
+      if (keyCode === eventKeys.up) {
+        nextIndex = currentIndex !== 0 ? currentIndex - 1 : 0
+      } else {
+        nextIndex = currentIndex < max ? currentIndex + 1 : max
+      }
+      removeTabindex()
+      resetTabindex(menuItems.value[nextIndex])
+      menuItems.value[nextIndex].focus()
+      ev.preventDefault()
+      ev.stopPropagation()
+    } else if (keyCode === eventKeys.enter) {
+      triggerElmFocus()
+      target.click()
+      if (_instance.props.hideOnClick) {
+        _instance.hide()
+      }
+    } else if ([eventKeys.tab, eventKeys.esc].includes(keyCode)) {
+      _instance.hide()
+      triggerElmFocus()
+    }
+  }
+
+  function initAria() {
+    dropdownElm.value.setAttribute('id', listId.value)
+    triggerElm.setAttribute('aria-haspopup', 'list')
+    triggerElm.setAttribute('aria-controls', listId.value)
+    if (!_instance.props.splitButton) {
+      triggerElm.setAttribute('role', 'button')
+      triggerElm.setAttribute('tabindex', _instance.tabindex)
+      addClass(triggerElm, 'el-dropdown-selfdefine')
+    }
+  }
+
+  function initEvent() {
+    on(triggerElm, 'keydown', handleTriggerKeyDown)
+    on(dropdownElm.value, 'keydown', handleItemKeyDown, true)
+  }
+
+  function initDomOperation() {
+    menuItems.value = dropdownElm.value.querySelectorAll("[tabindex='-1']") as unknown as HTMLButtonElement[]
+    menuItemsArray.value = [].slice.call(menuItems.value)
+
+    initEvent()
+    initAria()
+  }
+
+  function triggerElmFocus() {
+    triggerElm?.focus?.()
+  }
+
+  initDomOperation()
+}

packages/element-plus/index.ts

@@ -6,6 +6,7 @@ import ElButton from '@element-plus/button'
 import ElBadge from '@element-plus/badge'
 import ElCard from '@element-plus/card'
 import ElCheckbox from '@element-plus/checkbox'
+import ElDropdown from '@element-plus/dropdown'
 import ElTag from '@element-plus/tag'
 import ElLayout from '@element-plus/layout'
 import ElDivider from '@element-plus/divider'
@@ -38,6 +39,7 @@ export {
   ElCard,
   ElCheckbox,
   ElDivider,
+  ElDropdown,
   ElTag,
   ElTimeline,
   ElProgress,
@@ -66,6 +68,7 @@ export default function install(app: App): void {
   ElBadge(app)
   ElCard(app)
   ElCheckbox(app)
+  ElDropdown(app)
   ElTag(app)
   ElLayout(app)
   ElDivider(app)

packages/utils/dom.ts

@@ -11,9 +11,10 @@ export const on = function(
   element: HTMLElement | Document | Window,
   event: string,
   handler: EventListenerOrEventListenerObject,
+  useCapture = false,
 ): void {
   if (element && event && handler) {
-    element.addEventListener(event, handler, false)
+    element.addEventListener(event, handler, useCapture)
   }
 }
 

packages/utils/menu/menu-item.ts

@@ -43,7 +43,7 @@ class MenuItem {
         case keys.space: {
           prevDef = true
 
-          (event.currentTarget as HTMLElement).click()
+          ;(event.currentTarget as HTMLElement).click()
           break
         }
       }