feat(component): add affix component

docs/.vitepress/config.ts

@@ -83,6 +83,10 @@ const components = [
     text: 'Navigation',
     collapsed: false,
     items: [
+      {
+        text: 'Affix',
+        link: '/components/affix',
+      },
       {
         text: 'Backtop',
         link: '/components/backtop',

docs/components/affix.md

@@ -0,0 +1,59 @@
+---
+title: Affix
+lang: en-US
+---
+
+# Affix <new-badge/>
+
+Fix the element to a specific visible area.
+
+## Basic usage
+
+Affix is fixed at the top of the page by default.
+
+You can set `offset` attribute to change the offset top，the default value is 0.
+
+<demo src="../example/affix/basic.vue"></demo>
+
+## Target Container
+
+You can set `target` attribute to keep the affix in the container at all times. It will be hidden if out of range.
+
+Please notice that the container avoid having scrollbar.
+
+<demo src="../example/affix/target.vue"></demo>
+
+## Fixed Position
+
+The affix component provides two fixed positions: `top` and `bottom`.
+
+You can set `position` attribute to change the fixed position, the default value is `top`.
+
+<demo src="../example/affix/fixed.vue"></demo>
+
+## Affix Props
+| Name | Type | Default | Description |
+| --- | --- | --- | --- |
+| offset | `number` | `0` | Offset distance.
+| position | `'top' \| 'bottom'` | `'top'` | Position of affix.
+| target | `string` | `''` |  Target container. (CSS selector)  |
+| z-index | `number` | `100` | `z-index` of affix |
+
+
+## Affix Methods
+| Name | Parameters | Description | 
+| --- | --- | --- |
+| change | `(fixed: boolean) => void` | Triggers when fixed state changed. |
+| scroll | `(value: { scrollTop: number, fixed: boolean }) => void` | Triggers when scrolling. |
+
+
+## Affix Slots
+| Name | Parameters | Description | 
+| --- | --- | --- |
+| default | `()` | Customize default content. |
+
+## Affix Exposes
+| Name | Parameters | Description | 
+| --- | --- | --- |
+| update | `() => void` | Update affix state manually. |
+| updateRoot | `() => void` | Update rootRect info. |

docs/example/affix/basic.vue

@@ -0,0 +1,14 @@
+<template>
+  <div fscw gap-2>
+    <o-affix>
+      <o-button shadow dashed type="primary">
+        Offset top 0px
+      </o-button>
+    </o-affix>
+    <o-affix :offset="120">
+      <o-button shadow dashed type="secondary">
+        Offset top 120px
+      </o-button>
+    </o-affix>
+  </div>
+</template>

docs/example/affix/fixed.vue

@@ -0,0 +1,9 @@
+<template>
+  <div fscw gap-2>
+    <o-affix position="bottom" :offset="20">
+      <o-button shadow dashed type="success">
+        Offset bottom 20px
+      </o-button>
+    </o-affix>
+  </div>
+</template>

docs/example/affix/target.vue

@@ -0,0 +1,9 @@
+<template>
+  <div class="affix-container text-center w-full h-400px rounded-4px bg-blue-300">
+    <o-affix target=".affix-container" :offset="80">
+      <o-button shadow dashed type="primary">
+        Target container
+      </o-button>
+    </o-affix>
+  </div>
+</template>

example/src/components/TheAffix.vue

@@ -0,0 +1,38 @@
+<script setup lang='ts'>
+
+</script>
+
+<template>
+  <OCard title="Affix">
+    <div space-y-2>
+      <div fsc gap-2>
+        <o-affix>
+          <o-button shadow dashed type="primary">
+            Offset top 0px
+          </o-button>
+        </o-affix>
+        <o-affix :offset="40">
+          <o-button shadow dashed type="secondary">
+            Offset top 40px
+          </o-button>
+        </o-affix>
+      </div>
+      <div fsc gap-2>
+        <div class="affix-container text-center w-full h-400px rounded-4px bg-blue-300">
+          <o-affix target=".affix-container" :offset="80">
+            <o-button shadow dashed type="primary">
+              Target container
+            </o-button>
+          </o-affix>
+        </div>
+      </div>
+      <div fsc gap-2>
+        <o-affix position="bottom" :offset="20">
+          <o-button shadow dashed type="success">
+            Offset bottom 20px
+          </o-button>
+        </o-affix>
+      </div>
+    </div>
+  </OCard>
+</template>

example/src/pages/index.vue

@@ -10,6 +10,7 @@
     <TheBadge />
     <TheTag /> -->
     <TheMessage />
+    <TheAffix />
     <TheEmpty />
     <TheLink />
     <TheRadio />

packages/components/affix/index.ts

@@ -0,0 +1,7 @@
+import { withInstall } from '@onu-ui/utils'
+import Affix from './src/affix.vue'
+
+export const OAffix = withInstall(Affix)
+export default OAffix
+
+export * from './src/affix'

packages/components/affix/src/affix.ts

@@ -0,0 +1,30 @@
+import type { ExtractPropTypes } from 'vue'
+import { isBoolean, isNumber } from './../../../utils/shared/is'
+
+export const affixProps = {
+  zIndex: {
+    type: Number,
+    default: 100,
+  },
+  target: {
+    type: String,
+    default: '',
+  },
+  offset: {
+    type: Number,
+    default: 0,
+  },
+  position: {
+    type: String,
+    values: ['top', 'bottom'],
+    default: 'top',
+  },
+} as const
+
+export type OAffixProps = ExtractPropTypes<typeof affixProps>
+
+export const affixEmits = {
+  scroll: ({ scrollTop, fixed }: { scrollTop: number; fixed: boolean }) => isNumber(scrollTop) && isBoolean(fixed),
+  change: (fixed: boolean) => isBoolean(fixed),
+}
+export type OAffixEmits = typeof affixEmits

packages/components/affix/src/affix.vue

@@ -0,0 +1,118 @@
+<script setup lang="ts" name="OAffix">
+import { getScrollContainer } from '@onu-ui/utils'
+import type { CSSProperties } from 'vue'
+import { affixEmits, affixProps } from './affix'
+
+const props = defineProps(affixProps)
+const emit = defineEmits(affixEmits)
+
+const target = shallowRef<HTMLElement>()
+const root = shallowRef<HTMLDivElement>()
+const scrollContainer = shallowRef<HTMLElement | Window>()
+const { height: windowHeight } = useWindowSize()
+const {
+  height: rootHeight,
+  width: rootWidth,
+  top: rootTop,
+  bottom: rootBottom,
+  update: updateRoot,
+} = useElementBounding(root, { windowScroll: false })
+const targetRect = useElementBounding(target)
+
+const fixed = ref(false)
+const scrollTop = ref(0)
+const transform = ref(0)
+
+const rootStyle = computed<CSSProperties>(() => {
+  return {
+    height: fixed.value ? `${rootHeight.value}px` : '',
+    width: fixed.value ? `${rootWidth.value}px` : '',
+  }
+})
+
+const affixStyle = computed<CSSProperties>(() => {
+  if (!fixed.value)
+    return {}
+
+  const offset = props.offset ? `${props.offset}px` : 0
+  return {
+    height: `${rootHeight.value}px`,
+    width: `${rootWidth.value}px`,
+    top: props.position === 'top' ? offset : '',
+    bottom: props.position === 'bottom' ? offset : '',
+    transform: transform.value ? `translateY(${transform.value}px)` : '',
+    zIndex: props.zIndex,
+  }
+})
+
+const update = () => {
+  if (!scrollContainer.value)
+    return
+
+  const isTop = props.position === 'top'
+  const isTarget = props.target
+  const isFixed
+          = (isTop && isTarget)
+            ? (props.offset > rootTop.value && targetRect.bottom.value > 0)
+            : isTop
+              ? props.offset > rootTop.value
+              : isTarget
+                ? (windowHeight.value - props.offset < rootBottom.value && windowHeight.value > targetRect.top.value)
+                : windowHeight.value - props.offset < rootBottom.value
+  const difference
+          = (isTop && isTarget)
+            ? targetRect.bottom.value - props.offset - rootHeight.value
+            : (!isTop && isTarget)
+                ? windowHeight.value - targetRect.top.value - props.offset - rootHeight.value
+                : 0
+  scrollTop.value = scrollContainer.value instanceof Window ? document.documentElement.scrollTop : (scrollContainer.value.scrollTop || 0)
+  transform.value = difference < 0 ? (isTop ? difference : -difference) : 0
+  fixed.value = isFixed
+}
+
+const handleScroll = () => {
+  updateRoot()
+  emit('scroll', {
+    scrollTop: scrollTop.value,
+    fixed: fixed.value,
+  })
+}
+
+useEventListener(scrollContainer, 'scroll', handleScroll)
+watchEffect(update)
+
+watch(fixed, val => emit('change', val))
+
+onMounted(() => {
+  const targetElement = props.target
+    ? document.querySelector<HTMLElement>(props.target)
+    : document.documentElement
+  if (!targetElement)
+    throw new Error(`[OAffix] target is not existed: ${props.target}`)
+  target.value = targetElement
+  scrollContainer.value = getScrollContainer(root.value!, true)
+  updateRoot()
+})
+
+defineExpose({
+  /** @description update affix status */
+  update,
+  /** @description update rootRect info */
+  updateRoot,
+})
+</script>
+
+<template>
+  <div
+    ref="root" :style="rootStyle"
+  >
+    <div
+      :class="[
+        fixed && `fixed`,
+      ]"
+      :style="affixStyle"
+    >
+      <slot />
+    </div>
+  </div>
+</template>

packages/components/index.ts

@@ -20,3 +20,4 @@ export * from './backtop'
 export * from './link'
 export * from './radio'
 export * from './radio-group'
+export * from './affix'

packages/onu-ui/src/components.ts

@@ -1,4 +1,5 @@
 import {
+  OAffix,
   OAlert,
   OAvatar,
   OAvatarGroup,
@@ -48,4 +49,5 @@ export default [
   OLink,
   ORadio,
   ORadioGroup,
+  OAffix,
 ] as Plugin[]

packages/utils/shared/index.ts

@@ -2,3 +2,5 @@ export * from './common'
 export * from './is'
 export * from './vue-helper'
 export * from './dom'
+export * from './scroll'
+export * from './style'

packages/utils/shared/scroll.ts

@@ -0,0 +1,38 @@
+import { isClient } from '@vueuse/core'
+import { getStyle } from './style'
+
+export const isScroll = (el: HTMLElement, isVertical?: boolean): boolean => {
+  if (!isClient)
+    return false
+
+  const key = (
+    {
+      undefined: 'overflow',
+      true: 'overflow-y',
+      false: 'overflow-x',
+    } as const
+  )[String(isVertical)]!
+  const overflow = getStyle(el, key)
+  return ['scroll', 'auto', 'overlay'].some(s => overflow.includes(s))
+}
+
+export const getScrollContainer = (
+  el: HTMLElement,
+  isVertical?: boolean,
+): Window | HTMLElement | undefined => {
+  if (!isClient)
+    return
+
+  let parent: HTMLElement = el
+  while (parent) {
+    if ([window, document, document.documentElement].includes(parent))
+      return window
+
+    if (isScroll(parent, isVertical))
+      return parent
+
+    parent = parent.parentNode as HTMLElement
+  }
+
+  return parent
+}

packages/utils/shared/style.ts

@@ -0,0 +1,25 @@
+import { isClient } from '@vueuse/core'
+import type { CSSProperties } from 'vue'
+import { camelize } from 'vue'
+
+export const getStyle = (
+  element: HTMLElement,
+  styleName: keyof CSSProperties,
+): string => {
+  if (!isClient || !element || !styleName)
+    return ''
+
+  let key = camelize(styleName)
+  if (key === 'float')
+    key = 'cssFloat'
+  try {
+    const style = (element.style as any)[key]
+    if (style)
+      return style
+    const computed: any = document.defaultView?.getComputedStyle(element, '')
+    return computed ? computed[key] : ''
+  }
+  catch {
+    return (element.style as any)[key]
+  }
+}