tehran_taj/apps/user-app/src/components/home/ShowcaseSlider.vue

<!--
  Editorial hero for the home screen. Self-contained, dependency-free slider:
  no swiper CSS to fight, no autoplay jitter, and it keeps working when a
  slide has no artwork.

  Swipe support: the app sets `direction: rtl !important` on #app (see
  src/App.vue), so — same fix as GallerySlider.vue — the track is an isolated
  `direction: ltr` subtree (.showcase__track). Inside it, index 0 is first and
  a positive translateX moves right, plain LTR arithmetic, regardless of the
  page's own direction. The drag gesture itself is still read in screen space
  (dragging left = next slide) so it feels natural to an RTL user; only the
  track's internal layout/maths is pinned to LTR.
-->
<template>
  <section class="showcase" v-if="slides.length">
    <div
      ref="root"
      class="showcase__frame"
      :class="{ 'is-dragging': dragging }"
      @pointerdown="onPointerDown"
      @pointermove="onPointerMove"
      @pointerup="onPointerUp"
      @pointercancel="onPointerCancel"
    >
      <div class="showcase__track" :style="trackStyle">
        <article
          v-for="(slide, i) in slides"
          :key="slide.key"
          class="showcase__slide"
          :class="{ 'is-active': i === index }"
          @click="onSlideClick(slide)"
        >
          <img v-if="slide.image" :src="slide.image" alt="" class="showcase__art" draggable="false" />
        </article>
      </div>
    </div>

    <div class="showcase__dots" v-if="slides.length > 1">
      <button
        v-for="(slide, i) in slides"
        :key="slide.key"
        type="button"
        class="showcase__dot"
        :class="{ 'is-active': i === index }"
        :aria-label="slide.title"
        @click="go(i)"
      />
    </div>
  </section>
</template>

<script setup lang="ts">
import { computed, onBeforeUnmount, onMounted, ref } from 'vue'
import { useAppearanceStore } from '../../stores/appearanceStore'

export interface ShowcaseSlide {
  key: string
  eyebrow: string
  title: string
  subtitle: string
  cta: string
  image?: string
  categoryId?: string
  /** Admin-uploaded slide's own destination (manage/Const.vue), when it has
   *  one. Takes priority over `categoryId` in the click handler. */
  link?: string
}

const props = defineProps<{ slides: ShowcaseSlide[] }>()
const emit = defineEmits<{ (e: 'select', slide: ShowcaseSlide): void }>()

const index = ref(0)
let timer: ReturnType<typeof setInterval> | undefined
const appearance = useAppearanceStore()

function go(i: number) {
  index.value = i
  restart()
}
function restart() {
  if (timer) clearInterval(timer)
  // No autoplay in reduced-motion mode: a slide changing on its own every
  // six seconds is exactly the background motion that mode turns off.
  if (props.slides.length > 1 && !appearance.isReducedMotion) {
    timer = setInterval(() => {
      index.value = (index.value + 1) % props.slides.length
    }, 6000)
  }
}

onMounted(restart)
onBeforeUnmount(() => {
  if (timer) clearInterval(timer)
})

// ── Drag / swipe ─────────────────────────────────────────────
const root = ref<HTMLElement | null>(null)
const dragging = ref(false)
const dragX = ref(0)
let pointerId: number | null = null
let startX = 0
let startY = 0
let trackWidth = 0
let isSwipe = false

const DRAG_COMMIT_RATIO = 0.18
const TAP_MAX_PX = 6

function onPointerDown(e: PointerEvent) {
  if (props.slides.length < 2 || pointerId !== null) return
  const el = root.value
  if (!el) return
  pointerId = e.pointerId
  startX = e.clientX
  startY = e.clientY
  trackWidth = el.getBoundingClientRect().width || 1
  dragX.value = 0
  dragging.value = true
  isSwipe = false
  el.setPointerCapture?.(e.pointerId)
}

function onPointerMove(e: PointerEvent) {
  if (!dragging.value || e.pointerId !== pointerId) return
  const dx = e.clientX - startX
  const dy = e.clientY - startY
  if (!isSwipe && Math.abs(dx) > Math.abs(dy) && Math.abs(dx) > TAP_MAX_PX) isSwipe = true
  if (isSwipe) dragX.value = dx
}

function endDrag() {
  if (!dragging.value) return
  const dx = dragX.value
  const ratio = dx / trackWidth

  dragging.value = false
  pointerId = null
  dragX.value = 0

  // Screen-space drag direction: dragging left (negative dx) is "next slide",
  // matching what the gesture means to the person doing it.
  if (ratio <= -DRAG_COMMIT_RATIO && index.value < props.slides.length - 1) index.value++
  else if (ratio >= DRAG_COMMIT_RATIO && index.value > 0) index.value--

  if (isSwipe) restart()
  isSwipe = false
}

function onPointerUp(e: PointerEvent) {
  if (e.pointerId !== pointerId) return
  endDrag()
}

function onPointerCancel(e: PointerEvent) {
  if (e.pointerId !== pointerId) return
  dragging.value = false
  pointerId = null
  dragX.value = 0
  isSwipe = false
}

function onSlideClick(slide: ShowcaseSlide) {
  // A drag also fires a trailing click on release; only treat it as a tap
  // (i.e. open the slide) when the gesture never turned into a swipe.
  if (isSwipe) return
  emit('select', slide)
}

const trackStyle = computed(() => {
  const base = -index.value * 100
  const dragPercent = trackWidth ? (dragX.value / trackWidth) * 100 : 0
  return {
    transform: `translate3d(${base + dragPercent}%, 0, 0)`,
    transition: dragging.value ? 'none' : undefined,
  }
})

onBeforeUnmount(() => {
  if (pointerId !== null && root.value) {
    try {
      root.value.releasePointerCapture(pointerId)
    } catch {
      /* element may already be detached */
    }
  }
})
</script>

<style scoped lang="less">
.showcase__frame {
  position: relative;
  border-radius: 22px;
  overflow: hidden;
  // Neutral rather than @ink: this only shows before artwork loads, and a
  // dark fill read as an unwanted border wherever it was visible at all.
  background: @hairlineSoft;
  box-shadow: 0 26px 50px -34px rgba(20, 22, 26, 0.85);
  aspect-ratio: 320 / 208;
  touch-action: pan-y;
  user-select: none;
  -webkit-user-select: none;
  // Forces its own compositing layer so `overflow: hidden` actually clips the
  // translated track on Safari/iOS — without this, a sliver of the next
  // slide peeks past the rounded edge because the browser composites the
  // transformed child (.showcase__track) on a layer that ignores the
  // parent's clip until it's promoted the same way.
  transform: translateZ(0);
  -webkit-transform: translateZ(0);
}

// Isolated from the page's `direction: rtl` — see the file header. Everything
// under this node uses plain LTR layout and LTR-signed transforms.
.showcase__track {
  direction: ltr;
  display: flex;
  height: 100%;
  width: 100%;
  // A gentle, slightly-overshooting ease — softer settle than a linear/
  // ease-out curve, which is what makes the swipe feel "alive" rather than
  // mechanical. Slowed down a touch from the old 0.42s so the motion reads
  // as a deliberate glide instead of a snap.
  transition: transform 0.56s cubic-bezier(0.16, 0.86, 0.3, 1);
  will-change: transform;
}

.showcase__frame.is-dragging .showcase__track {
  transition: none;
}

.showcase__slide {
  position: relative;
  flex: 0 0 100%;
  width: 100%;
  height: 100%;
  cursor: pointer;
  // Clips its own image's scale-in (.showcase__art below) to this slide's own
  // box, so the 1.06x zoom never bleeds into the neighbouring slide.
  overflow: hidden;
}

.showcase__art {
  // A plain block filling the slide, NOT an absolutely-positioned box.
  // `position: absolute` + `inset` made the image's own box a second,
  // independently-rounded measurement of the same area the frame already
  // sizes via `aspect-ratio`; on real devices the two disagreed by a
  // fraction of a pixel and the frame's dark background showed through as a
  // hairline border around the artwork. Sizing it as ordinary in-flow
  // content removes that second measurement entirely.
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  -webkit-user-drag: none;
  user-select: none;
  // Never settles below 1x: the "breathe in" flourish now runs from a larger
  // scale down to exactly 1, so the image is always at least as big as the
  // slide and can never reveal what sits behind it.
  transform: scale(1.06);
  transition: transform 0.56s cubic-bezier(0.16, 0.86, 0.3, 1);
}

.showcase__slide.is-active .showcase__art {
  transform: scale(1);
}

.showcase__frame.is-dragging .showcase__art {
  transition: none;
}

.showcase__dots {
  display: flex;
  justify-content: center;
  gap: 6px;
  padding-top: 12px;
}

.showcase__dot {
  width: 6px;
  height: 6px;
  padding: 0;
  border: 0;
  cursor: pointer;
  border-radius: 999px;
  background: @hairline;
  transition: width 0.42s cubic-bezier(0.16, 0.86, 0.3, 1), background 0.3s ease;
}
.showcase__dot.is-active {
  width: 20px;
  background: @wine;
}
</style>