vue指令实现布局拉伸需求

游客2024-09-07 07:53:02

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实现一个简单的右拉伸

1.首先我们创建两个相邻 div
2.实现 resize 触发时机
3.实现右拉伸功能

方案一：限制最小宽度
方案二：鼠标弹起后释放对应拉伸事件

开始进阶

实现左右拉伸功能

实现 v-resize.left.right

在实际项目开发中，经常会有布局拉伸的需求，接下来让我们一步步用 vue 指令 实现这个需求。本文为转载文章，来源于稀土掘金技术社区，作者是前端手术刀。

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实现一个简单的右拉伸

下面让我们来实现一个简单的右拉伸功能，既然用指令，肯定是越简单越好。

笔者决定用 vue 提供的修饰符， v-resize.right

1.首先我们创建两个相邻 div

<template>
  <div >
    <div
      v-resize.right
      
    />
    <div  />
  </div>
</template>
<style lang="scss" scoped>
.container {
  width: 400px;
  height: 100px;
  > div {
    float: left;
    height: 100%;
    width: 50%;
  }
  .left {
    background-color: lightcoral;
  }
  .right {
    background-color: lightblue;
  }
}
</style>

效果如下：

vue指令实现布局拉伸需求 1

非常丝滑, 当然我们还需要考虑传递最小宽度最大宽度过渡区等多种业务属性，但是这对于各位彦祖来说都是鸡毛蒜皮的小事，自行改造就行了。

完整代码

Js 版本：

const elEventsWeakMap = new WeakMap()
const MIN_WIDTH = 50
const MIN_HEIGHT = 50
const TRIGGER_SIZE = 8
const TOP = 'top'
const BOTTOM = 'bottom'
const LEFT = 'left'
const RIGHT = 'right'
const COL_RESIZE = 'col-resize'
const ROW_RESIZE = 'row-resize'

function getElStyleAttr(element, attr) {
  const styles = window.getComputedStyle(element)
  return styles[attr]
}

function getSiblingByPosition(el, position) {
  const siblingMap = {
    left: el.previousElementSibling,
    right: el.nextElementSibling,
    bottom: el.nextElementSibling,
    top: el.previousElementSibling
  }
  return siblingMap[position]
}

function getSiblingsSize(el, attr) {
  const siblings = el.parentNode.childNodes
  return [...siblings].reduce((prev, next) => (next.getBoundingClientRect()[attr] + prev), 0)
}

function updateSize({
  el,
  sibling,
  formatter = 'px',
  elSize,
  siblingSize,
  attr = 'width'
}) {
  let totalSize = elSize + siblingSize
  if (formatter === 'px') {
    el.style[attr] = elSize + formatter
    sibling.style[attr] = siblingSize + formatter
  } else if (formatter === 'flex') {
    totalSize = getSiblingsSize(el, attr)
    el.style.flex = elSize / totalSize * 10 // 修复 flex-grow <1 sibling.style.flex = siblingSize / totalSize * 10 } } const initResize = ({ el, positions, minWidth = MIN_WIDTH, minHeight = MIN_HEIGHT, triggerSize = TRIGGER_SIZE, formatter = 'px' }) => {
  if (!el) return
  const resizeState = {}
  const defaultCursor = getElStyleAttr(el, 'cursor')
  const elStyle = el.style

  const canLeftResize = positions.includes(LEFT)
  const canRightResize = positions.includes(RIGHT)
  const canTopResize = positions.includes(TOP)
  const canBottomResize = positions.includes(BOTTOM)

  if (!canLeftResize && !canRightResize && !canTopResize && !canBottomResize) { return } // 未指定方向

  const pointermove = (e) => {
    if (resizeState.resizing) return
    e.preventDefault()
    const { left, right, top, bottom } = el.getBoundingClientRect()
    const { clientX, clientY } = e
    // 左右拉伸
    if (canLeftResize || canRightResize) {
      if (clientX - left < triggerSize) resizeState.position = LEFT
      else if (right - clientX < triggerSize) resizeState.position = RIGHT
      else resizeState.position = ''

      if (resizeState.position === '') {
        elStyle.cursor = defaultCursor
      } else {
        if (getSiblingByPosition(el, resizeState.position)) { elStyle.cursor = COL_RESIZE }
        e.stopPropagation()
      }
    } else if (canTopResize || canBottomResize) {
      // 上下拉伸
      if (clientY - top < triggerSize) resizeState.position = TOP
      else if (bottom - clientY < triggerSize) resizeState.position = BOTTOM else resizeState.position = '' if (resizeState.position === '') { elStyle.cursor = defaultCursor } else { if (getSiblingByPosition(el, resizeState.position)) { elStyle.cursor = ROW_RESIZE } e.stopPropagation() } } } const pointerleave = (e) => {
    e.stopPropagation()
    resizeState.position = ''
    elStyle.cursor = defaultCursor
    el.releasePointerCapture(e.pointerId)
  }
  const pointerdown = (e) => {
    const { resizing, position } = resizeState
    if (resizing || !position) return

    if (position) e.stopPropagation() // 如果当前节点存在拉伸方向 需要阻止冒泡(用于嵌套拉伸)
    el.setPointerCapture(e.pointerId)

    const isFlex = getElStyleAttr(el.parentNode, 'display') === 'flex'
    if (isFlex) formatter = 'flex'

    resizeState.resizing = true
    resizeState.startPointerX = e.clientX
    resizeState.startPointerY = e.clientY

    const { width, height } = el.getBoundingClientRect()

    const sibling = getSiblingByPosition(el, position)
    if (!sibling) {
      console.error('未找到兄弟节点', position)
      return
    }

    const rectSibling = sibling.getBoundingClientRect()

    const { startPointerX, startPointerY } = resizeState
    const onDocumentMouseMove = (e) => {
      if (!resizeState.resizing) return
      elStyle.cursor =
        canLeftResize || canRightResize ? COL_RESIZE : ROW_RESIZE
      const { clientX, clientY } = e

      if (position === LEFT || position === RIGHT) {
        const offsetX = clientX - startPointerX
        const elSize = position === RIGHT ? width + offsetX : width - offsetX

        const siblingSize =
          position === RIGHT
            ? rectSibling.width - offsetX
            : rectSibling.width + offsetX
        if (elSize <= minWidth || siblingSize <= minWidth) return

        updateSize({ el, sibling, elSize, siblingSize, formatter })
      } else if (position === TOP || position === BOTTOM) {
        const offsetY = clientY - startPointerY
        const elSize =
          position === BOTTOM ? height + offsetY : height - offsetY

        const siblingSize =
          position === BOTTOM
            ? rectSibling.height - offsetY
            : rectSibling.height + offsetY
        if (elSize <= minHeight || siblingSize <= minHeight) return updateSize({ el, sibling, elSize, siblingSize, formatter }) } } const onDocumentMouseUp = (e) => {
      document.removeEventListener('mousemove', onDocumentMouseMove)
      document.removeEventListener('mouseup', onDocumentMouseUp)
      resizeState.resizing = false
      elStyle.cursor = defaultCursor
    }

    document.addEventListener('mousemove', onDocumentMouseMove)
    document.addEventListener('mouseup', onDocumentMouseUp)
  }

  const bindElEvents = () => {
    el.addEventListener('pointermove', pointermove)
    el.addEventListener('pointerleave', pointerleave)
    el.addEventListener('pointerup', pointerleave)
    el.addEventListener('pointerdown', pointerdown)
  }

  const unBindElEvents = () => {
    el.removeEventListener('pointermove', pointermove)
    el.removeEventListener('pointerleave', pointerleave)
    el.removeEventListener('pointerup', pointerleave)
    el.removeEventListener('pointerdown', pointerdown)
  }

  bindElEvents()

  // 设置解绑事件
  elEventsWeakMap.set(el, unBindElEvents)
}
export const resize = {
  inserted: function(el, binding) {
    const { modifiers, value } = binding
    const positions = Object.keys(modifiers)
    initResize({ el, positions, ...value })
  },
  unbind: function(el) {
    const unBindElEvents = elEventsWeakMap.get(el)
    unBindElEvents()
  }
}

Ts 版本：

import type { DirectiveBinding } from 'vue'

const elEventsWeakMap = new WeakMap()
const MIN_WIDTH = 50
const MIN_HEIGHT = 50
const TRIGGER_SIZE = 8

enum RESIZE_CURSOR {
  COL_RESIZE = 'col-resize',
  ROW_RESIZE = 'row-resize',
}

enum POSITION {
  TOP = 'top',
  BOTTOM = 'bottom',
  LEFT = 'left',
  RIGHT = 'right',
}

type Positions = [POSITION.TOP, POSITION.BOTTOM, POSITION.LEFT, POSITION.RIGHT]

interface ResizeState {
  resizing: boolean
  position?: POSITION
  startPointerX?: number
  startPointerY?: number
}
type WidthHeight = 'width' | 'height'

type ElAttr = WidthHeight | 'cursor' | 'display' // 后面补充

type ResizeFormatter = 'px' | 'flex'

interface ResizeInfo {
  el: HTMLElement
  positions: Positions
  minWidth: number
  minHeight: number
  triggerSize: number
  formatter: ResizeFormatter
}

function getElStyleAttr(element: HTMLElement, attr: ElAttr) {
  const styles = window.getComputedStyle(element)
  return styles[attr]
}

function getSiblingByPosition(el: HTMLElement, position: POSITION) {
  const siblingMap = {
    left: el.previousElementSibling,
    right: el.nextElementSibling,
    bottom: el.nextElementSibling,
    top: el.previousElementSibling,
  }
  return siblingMap[position]
}

function getSiblingsSize(el: HTMLElement, attr: WidthHeight) {
  const siblings = (el.parentNode && el.parentNode.children) || []
  return [...siblings].reduce(
    (prev, next) => next.getBoundingClientRect()[attr] + prev,
    0,
  )
}

function updateSize({
  el,
  sibling,
  formatter = 'px',
  elSize,
  siblingSize,
  attr = 'width',
}: {
  el: HTMLElement
  sibling: HTMLElement
  formatter: ResizeFormatter
  elSize: number
  siblingSize: number
  attr?: WidthHeight
}) {
  let totalSize = elSize + siblingSize
  if (formatter === 'px') {
    el.style[attr] = elSize + formatter
    sibling.style[attr] = siblingSize + formatter
  } else if (formatter === 'flex') {
    totalSize = getSiblingsSize(el as HTMLElement, attr)
    el.style.flex = `${(elSize / totalSize) * 10}` // 修复 flex-grow <1 sibling.style.flex = `${(siblingSize / totalSize) * 10}` } } const initResize = ({ el, positions, minWidth = MIN_WIDTH, minHeight = MIN_HEIGHT, triggerSize = TRIGGER_SIZE, formatter = 'px', }: ResizeInfo) => {
  if (!el || !(el instanceof HTMLElement)) return
  const resizeState: ResizeState = {
    resizing: false,
  }
  const defaultCursor = getElStyleAttr(el, 'cursor')
  const elStyle = el.style

  const canLeftResize = positions.includes(POSITION.LEFT)
  const canRightResize = positions.includes(POSITION.RIGHT)
  const canTopResize = positions.includes(POSITION.TOP)
  const canBottomResize = positions.includes(POSITION.BOTTOM)

  if (!canLeftResize && !canRightResize && !canTopResize && !canBottomResize) {
    return
  } // 未指定方向

  const pointermove = (e: PointerEvent) => {
    if (resizeState.resizing) return
    e.preventDefault()
    const { left, right, top, bottom } = el.getBoundingClientRect()
    const { clientX, clientY } = e
    // 左右拉伸
    if (canLeftResize || canRightResize) {
      if (clientX - left < triggerSize) resizeState.position = POSITION.LEFT
      else if (right - clientX < triggerSize)
        resizeState.position = POSITION.RIGHT
      else resizeState.position = undefined

      if (resizeState.position === undefined) {
        elStyle.cursor = defaultCursor
      } else {
        if (getSiblingByPosition(el, resizeState.position)) {
          elStyle.cursor = RESIZE_CURSOR.COL_RESIZE
        }
        e.stopPropagation()
      }
    } else if (canTopResize || canBottomResize) {
      // 上下拉伸
      if (clientY - top < triggerSize) resizeState.position = POSITION.TOP
      else if (bottom - clientY < triggerSize) resizeState.position = POSITION.BOTTOM else resizeState.position = undefined if (resizeState.position === undefined) { elStyle.cursor = defaultCursor } else { if (getSiblingByPosition(el, resizeState.position)) { elStyle.cursor = RESIZE_CURSOR.ROW_RESIZE } e.stopPropagation() } } } const pointerleave = (e: PointerEvent) => {
    e.stopPropagation()
    resizeState.position = undefined
    elStyle.cursor = defaultCursor
    el.releasePointerCapture(e.pointerId)
  }
  const pointerdown = (e: PointerEvent) => {
    const { resizing, position } = resizeState
    if (resizing || !position) return

    if (position) e.stopPropagation() // 如果当前节点存在拉伸方向 需要阻止冒泡(用于嵌套拉伸)
    el.setPointerCapture(e.pointerId)

    if (el.parentElement) {
      const isFlex = getElStyleAttr(el.parentElement, 'display') === 'flex'
      if (isFlex) formatter = 'flex'
    }

    resizeState.resizing = true
    resizeState.startPointerX = e.clientX
    resizeState.startPointerY = e.clientY

    const { width, height } = el.getBoundingClientRect()

    const sibling: HTMLElement = getSiblingByPosition(
      el,
      position,
    ) as HTMLElement
    if (!sibling || !(sibling instanceof HTMLElement)) {
      console.error('未找到兄弟节点', position)
      return
    }

    const rectSibling = sibling.getBoundingClientRect()

    const { startPointerX, startPointerY } = resizeState
    const onDocumentMouseMove = (e: MouseEvent) => {
      if (!resizeState.resizing) return
      elStyle.cursor =
        canLeftResize || canRightResize
          ? RESIZE_CURSOR.COL_RESIZE
          : RESIZE_CURSOR.ROW_RESIZE
      const { clientX, clientY } = e

      if (position === POSITION.LEFT || position === POSITION.RIGHT) {
        const offsetX = clientX - startPointerX
        const elSize =
          position === POSITION.RIGHT ? width + offsetX : width - offsetX

        const siblingSize =
          position === POSITION.RIGHT
            ? rectSibling.width - offsetX
            : rectSibling.width + offsetX
        if (elSize <= minWidth || siblingSize <= minWidth) return

        updateSize({ el, sibling, elSize, siblingSize, formatter })
      } else if (position === POSITION.TOP || position === POSITION.BOTTOM) {
        const offsetY = clientY - startPointerY
        const elSize =
          position === POSITION.BOTTOM ? height + offsetY : height - offsetY

        const siblingSize =
          position === POSITION.BOTTOM
            ? rectSibling.height - offsetY
            : rectSibling.height + offsetY
        if (elSize <= minHeight || siblingSize <= minHeight) return updateSize({ el, sibling, elSize, siblingSize, formatter, attr: 'height', }) } } const onDocumentMouseUp = () => {
      document.removeEventListener('mousemove', onDocumentMouseMove)
      document.removeEventListener('mouseup', onDocumentMouseUp)
      resizeState.resizing = false
      elStyle.cursor = defaultCursor
    }

    document.addEventListener('mousemove', onDocumentMouseMove)
    document.addEventListener('mouseup', onDocumentMouseUp)
  }

  const bindElEvents = () => {
    el.addEventListener('pointermove', pointermove)
    el.addEventListener('pointerleave', pointerleave)
    el.addEventListener('pointerup', pointerleave)
    el.addEventListener('pointerdown', pointerdown)
  }

  const unBindElEvents = () => {
    el.removeEventListener('pointermove', pointermove)
    el.removeEventListener('pointerleave', pointerleave)
    el.removeEventListener('pointerup', pointerleave)
    el.removeEventListener('pointerdown', pointerdown)
  }

  bindElEvents()

  // 设置解绑事件
  elEventsWeakMap.set(el, unBindElEvents)
}
export const resize = {
  mounted: function (el: HTMLElement, binding: DirectiveBinding) {
    const { modifiers, value } = binding
    const positions = Object.keys(modifiers)
    initResize({ el, positions, ...value })
  },
  beforeUnmount: function (el: HTMLElement) {
    const unBindElEvents = elEventsWeakMap.get(el)
    unBindElEvents()
  },
}

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vue指令实现布局拉伸需求

实现一个简单的右拉伸

1.首先我们创建两个相邻 div

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