ScrollArea

<script setup lang="ts">
import { computed } from 'vue'

defineProps<{
  orientation?: 'vertical' | 'horizontal'
}>()

const items = computed(() => Array.from({ length: 1000 }, (_, i) => ({
  id: i + 1,
  title: `Item ${i + 1}`,
  description: `Description for item ${i + 1}`
})))
</script>

<template>
  <UScrollArea
    v-slot="{ item, index }"
    :items="items"
    :orientation="orientation"
    virtualize
    class="w-full data-[orientation=vertical]:h-96 data-[orientation=horizontal]:h-24.5"
  >
    <UPageCard
      v-bind="item"
      :variant="index % 2 === 0 ? 'soft' : 'outline'"
      class="rounded-none"
    />
  </UScrollArea>
</template>

<script setup lang="ts">
import { computed, useTemplateRef } from 'vue'
import { useElementSize } from '@vueuse/core'

const items = Array.from({ length: 1000 }).map((_, index) => ({
  id: index,
  title: `Item ${index + 1}`,
  src: `https://picsum.photos/640/480?v=${index}`,
  width: 640,
  height: 480
}))

const gap = 16
const scrollArea = useTemplateRef('scrollArea')
const { width } = useElementSize(() => scrollArea.value?.$el)

const lanes = computed(() => Math.max(1, Math.min(4, Math.floor(width.value / 200))))
const laneWidth = computed(() => (width.value - (lanes.value - 1) * gap) / lanes.value)
const estimateSize = computed(() => laneWidth.value * (480 / 640))
</script>

<template>
  <UScrollArea
    ref="scrollArea"
    v-slot="{ item }"
    :items="items"
    :virtualize="{
      gap,
      lanes,
      estimateSize,
      skipMeasurement: true
    }"
    class="w-full h-96 p-4"
  >
    <img
      :src="item.src"
      :alt="item.title"
      :width="item.width"
      :height="item.height"
      loading="lazy"
      class="rounded-md size-full object-cover"
    >
  </UScrollArea>
</template>

<script setup lang="ts">
import { ref, computed, watch, useTemplateRef } from 'vue'
import { useElementSize } from '@vueuse/core'

const props = withDefaults(
  defineProps<{
    orientation?: 'vertical' | 'horizontal'
  }>(),
  {
    orientation: 'vertical'
  }
)

type User = {
  id: number
  firstName: string
  lastName: string
  email: string
  image: string
}

const { data: users } = useLazyFetch(
  'https://dummyjson.com/users?limit=100&select=firstName,lastName,email,image',
  {
    key: 'scroll-area-external-scroll-users',
    transform: (data?: { users: User[] }) => data?.users ?? [],
    default: () => [] as User[],
    server: false
  }
)

const isHorizontal = computed(() => props.orientation === 'horizontal')

// The container owns the scroll; the list virtualizes against it so the header and cards share one scrollbar.
const container = useTemplateRef('container')
const title = useTemplateRef('title')
const toolbar = useTemplateRef('toolbar')
const scrollArea = useTemplateRef('scrollArea')

// Item size along the scroll axis: card width when horizontal, row height when vertical.
const itemSize = computed(() => (isHorizontal.value ? 256 : 88))
const getScrollElement = () => container.value

// `scrollMargin` is the title's offset along the scroll axis: its width when it sits left of the cards, its height when it sits above them.
const { width: titleWidth, height: titleHeight } = useElementSize(title, undefined, {
  box: 'border-box'
})
const { height: toolbarHeight } = useElementSize(toolbar, undefined, { box: 'border-box' })
const scrollMargin = computed(() =>
  isHorizontal.value ? titleWidth.value : toolbarHeight.value + titleHeight.value
)

// Find: jump through the items whose name matches the query (like a find toolbar).
const query = ref('')
const matches = computed(() => {
  const q = query.value.trim().toLowerCase()
  if (!q) return []
  return users.value.reduce<number[]>((acc, user, index) => {
    if (`${user.firstName} ${user.lastName}`.toLowerCase().includes(q)) acc.push(index)
    return acc
  }, [])
})
const cursor = ref(0)
const currentMatch = computed(() => matches.value[cursor.value] ?? -1)

function scrollToMatch() {
  if (currentMatch.value < 0) return
  scrollArea.value?.virtualizer?.scrollToIndex(currentMatch.value, {
    align: 'center',
    behavior: 'smooth'
  })
}

function step(delta: number) {
  if (!matches.value.length) return
  cursor.value = (cursor.value + delta + matches.value.length) % matches.value.length
  scrollToMatch()
}

function scrollToStart() {
  container.value?.scrollTo(
    isHorizontal.value ? { left: 0, behavior: 'smooth' } : { top: 0, behavior: 'smooth' }
  )
}

// Re-runs on a new query and when `users` resolves, so the first match centers as soon as results arrive.
watch(matches, () => {
  cursor.value = 0
  scrollToMatch()
})
</script>

<template>
  <div
    ref="container"
    :class="isHorizontal ? 'w-full overflow-x-auto' : 'w-full h-128 overflow-y-auto'"
  >
    <!-- Vertical: the header sits above the toolbar and scrolls away as you scroll down. -->
    <div
      v-if="!isHorizontal"
      ref="title"
      class="flex items-end justify-between gap-4 p-6 bg-elevated/50"
    >
      <div>
        <h2 class="text-2xl font-bold text-highlighted">Members</h2>
        <p class="text-muted">This header scrolls away with the cards, sharing one scrollbar.</p>
      </div>
      <UBadge color="neutral" variant="subtle" :label="`${users.length} members`" />
    </div>

    <div
      ref="toolbar"
      class="z-10 flex items-center px-6 py-3 border-y border-default bg-elevated/50 backdrop-blur"
      :class="isHorizontal ? 'sticky left-0' : 'sticky top-0'"
    >
      <UFieldGroup>
        <UInput
          v-model="query"
          placeholder="Find a member..."
          icon="i-lucide-search"
          aria-describedby="scroll-area-find-count"
          class="w-64"
          :ui="{ trailing: 'pointer-events-none' }"
        >
          <template #trailing>
            <span
              id="scroll-area-find-count"
              class="text-xs text-muted tabular-nums"
              aria-live="polite"
              role="status"
            >
              {{ matches.length ? cursor + 1 : 0 }}/{{ matches.length }}
            </span>
          </template>
        </UInput>
        <UButton
          :icon="isHorizontal ? 'i-lucide-chevron-left' : 'i-lucide-chevron-up'"
          color="neutral"
          variant="outline"
          aria-label="Previous match"
          :disabled="!matches.length"
          @click="step(-1)"
        />
        <UButton
          :icon="isHorizontal ? 'i-lucide-chevron-right' : 'i-lucide-chevron-down'"
          color="neutral"
          variant="outline"
          aria-label="Next match"
          :disabled="!matches.length"
          @click="step(1)"
        />
      </UFieldGroup>

      <UButton
        :icon="isHorizontal ? 'i-lucide-arrow-left-to-line' : 'i-lucide-arrow-up-to-line'"
        color="neutral"
        variant="outline"
        class="ms-auto"
        :label="isHorizontal ? 'Start' : 'Top'"
        @click="scrollToStart"
      />
    </div>

    <!-- Horizontal: the header sits left of the cards (in the row) so it scrolls away with them. -->
    <div :class="isHorizontal && 'flex'">
      <div
        v-if="isHorizontal"
        ref="title"
        class="w-72 shrink-0 flex flex-col justify-center gap-4 p-6 bg-elevated/50 border-r border-default"
      >
        <div>
          <h2 class="text-2xl font-bold text-highlighted">Members</h2>
          <p class="text-muted">This header scrolls away with the cards, sharing one scrollbar.</p>
        </div>
        <UBadge
          color="neutral"
          variant="subtle"
          class="self-start"
          :label="`${users.length} members`"
        />
      </div>

      <UScrollArea
        ref="scrollArea"
        v-slot="{ item, index }"
        :orientation="orientation"
        :items="users"
        :class="isHorizontal && 'h-48 shrink-0'"
        :virtualize="{
          scrollMargin,
          getScrollElement,
          estimateSize: itemSize,
          skipMeasurement: isHorizontal
        }"
      >
        <UPageCard
          class="rounded-none h-full"
          :class="[isHorizontal && 'w-64', index === currentMatch && 'bg-primary/10']"
        >
          <div
            class="flex gap-3 h-full min-w-0"
            :class="
              isHorizontal ? 'flex-col items-center justify-center text-center' : 'items-center'
            "
          >
            <UAvatar
              :src="item.image"
              :alt="item.firstName"
              :size="isHorizontal ? '2xl' : 'lg'"
              loading="lazy"
            />
            <div class="min-w-0">
              <p class="font-medium text-highlighted truncate">
                {{ item.firstName }} {{ item.lastName }}
              </p>
              <p class="text-sm text-muted truncate">
                {{ item.email }}
              </p>
            </div>
          </div>
        </UPageCard>
      </UScrollArea>
    </div>
  </div>
</template>

<script setup lang="ts">
import { ref, computed, useTemplateRef } from 'vue'

const items = computed(() => Array.from({ length: 1000 }, (_, i) => ({
  id: i + 1,
  title: `Item ${i + 1}`
})))

const scrollArea = useTemplateRef('scrollArea')

const targetIndex = ref(500)

function scrollToTop() {
  scrollArea.value?.virtualizer?.scrollToIndex(0, { align: 'start', behavior: 'smooth' })
}

function scrollToBottom() {
  scrollArea.value?.virtualizer?.scrollToIndex(items.value.length - 1, { align: 'end', behavior: 'smooth' })
}

function scrollToItem(index: number) {
  scrollArea.value?.virtualizer?.scrollToIndex(index - 1, { align: 'center', behavior: 'smooth' })
}
</script>

<template>
  <div class="w-full">
    <UScrollArea
      v-slot="{ item, index }"
      ref="scrollArea"
      :items="items"
      :virtualize="{
        estimateSize: 72,
        skipMeasurement: true
      }"
      class="h-96 w-full"
    >
      <UPageCard
        v-bind="item"
        :variant="index % 2 === 0 ? 'soft' : 'outline'"
        class="rounded-none isolate"
        :class="[index === (targetIndex - 1) && 'bg-primary']"
      />
    </UScrollArea>

    <UFieldGroup size="sm" class="px-4 py-3 border-t border-muted w-full">
      <UButton icon="i-lucide-arrow-up-to-line" color="neutral" variant="outline" @click="scrollToTop">
        Top
      </UButton>
      <UButton icon="i-lucide-arrow-down-to-line" color="neutral" variant="outline" @click="scrollToBottom">
        Bottom
      </UButton>
      <UButton icon="i-lucide-navigation" color="neutral" variant="outline" @click="scrollToItem(targetIndex || 500)">
        Go to {{ targetIndex || 500 }}
      </UButton>
    </UFieldGroup>
  </div>
</template>

<script setup lang="ts">
import { ref, watch, onMounted, useTemplateRef } from 'vue'
import { useInfiniteScroll } from '@vueuse/core'

type User = {
  id: number
  firstName: string
  lastName: string
  username: string
  email: string
  image: string
}

type UserResponse = {
  users: User[]
  total: number
  skip: number
  limit: number
}

const skip = ref(0)

const { data, status } = useLazyFetch(
  'https://dummyjson.com/users?limit=10&select=firstName,lastName,username,email,image',
  {
    key: 'scroll-area-users-infinite-scroll',
    params: { skip },
    transform: (data?: UserResponse) => {
      return data?.users
    },
    server: false
  }
)

const users = ref<User[]>([])

watch(data, () => {
  users.value = [...users.value, ...(data.value || [])]
})

const scrollArea = useTemplateRef('scrollArea')

onMounted(() => {
  useInfiniteScroll(
    scrollArea.value?.$el,
    () => {
      skip.value += 10
    },
    {
      distance: 200,
      canLoadMore: () => {
        return status.value !== 'pending'
      }
    }
  )
})
</script>

<template>
  <UScrollArea
    ref="scrollArea"
    v-slot="{ item }"
    :items="users"
    :virtualize="{
      estimateSize: 88,
      skipMeasurement: true
    }"
    class="h-96 w-full"
  >
    <UPageCard orientation="horizontal" class="rounded-none">
      <UUser
        :name="`${item.firstName} ${item.lastName}`"
        :description="item.email"
        :avatar="{ src: item.image, alt: item.firstName, loading: 'lazy' as const }"
        size="lg"
      />
    </UPageCard>
  </UScrollArea>

  <UProgress
    v-if="status === 'pending' || status === 'idle'"
    indeterminate
    size="xs"
    class="absolute top-0 inset-x-0 z-1"
    :ui="{ base: 'bg-default' }"
  />
</template>