feat: 轮播改造为 只要有一条数据就能轮播

src/pages/Discovery/components/CardSwiper/index.vue

@@ -1,7 +1,7 @@
 <template>
   <view
     class="card-swiper"
-    :class="{ 'is-single': !canLoop }"
+    :class="{ 'is-single': props.list.length <= 1 }"
     @touchstart="handleTouchStart"
     @touchmove.stop.prevent="handleTouchMove"
     @touchend="handleTouchEnd"
@@ -34,7 +34,7 @@
           </view>
 
           <view
-            v-if="canLoop"
+            v-if="canSwipe"
             class="card-mask"
             :style="getMaskStyle(slot.role)"
           />
@@ -71,7 +71,7 @@ const { windowWidth = 375 } = uni.getWindowInfo();
 const sideOffset = Math.max(108, Math.min(windowWidth * 0.26, 148));
 const hiddenOffset = sideOffset + 92;
 
-const activeIndex = ref(0);
+const activeCursor = ref(0);
 const deltaX = ref(0);
 const isDragging = ref(false);
 const isAnimating = ref(false);
@@ -87,9 +87,14 @@ const hasExternalModel = Object.prototype.hasOwnProperty.call(
   "modelValue"
 );
 
-const canLoop = computed(() => props.list.length > 1);
+const actualCount = computed(() => props.list.length);
+const virtualCount = computed(() => {
+  if (actualCount.value === 1) return 3;
+  return actualCount.value;
+});
+const canSwipe = computed(() => virtualCount.value > 1);
 const progress = computed(() => {
-  if (!canLoop.value) return 0;
+  if (!canSwipe.value) return 0;
   return clamp(deltaX.value / sideOffset, -1, 1);
 });
 
@@ -98,8 +103,18 @@ const normalizeIndex = (index, total) => {
   return ((index % total) + total) % total;
 };
 
-const syncActiveIndex = (incomingIndex = 0) => {
-  activeIndex.value = normalizeIndex(incomingIndex, props.list.length);
+const getActualIndex = (virtualIndex) => {
+  if (!actualCount.value) return 0;
+  return normalizeIndex(virtualIndex, actualCount.value);
+};
+
+const getItemByVirtualIndex = (virtualIndex) => {
+  if (!actualCount.value) return null;
+  return props.list[getActualIndex(virtualIndex)] || null;
+};
+
+const syncActiveCursor = (incomingIndex = 0) => {
+  activeCursor.value = normalizeIndex(incomingIndex, virtualCount.value);
 };
 
 function clearSettleTimer() {
@@ -116,10 +131,10 @@ watch(
     deltaX.value = 0;
     isDragging.value = false;
     isAnimating.value = false;
-    const nextIndex = hasExternalModel
+    const nextCursor = hasExternalModel
       ? props.modelValue
-      : activeIndex.value;
-    syncActiveIndex(nextIndex);
+      : activeCursor.value;
+    syncActiveCursor(nextCursor);
   },
   { deep: true, immediate: true }
 );
@@ -129,23 +144,20 @@ watch(
   (value) => {
     if (!hasExternalModel) return;
     if (isAnimating.value || isDragging.value) return;
-    syncActiveIndex(value);
+    syncActiveCursor(value);
   }
 );
 
-const getItemKey = (index, role) => {
-  const item = props.list[index] || {};
+const getItemKey = (virtualIndex, role) => {
+  const item = getItemByVirtualIndex(virtualIndex) || {};
   const baseKey =
     item.id ??
     item.commodityId ??
     item.tabLabel ??
     item.title ??
-    index;
-  const prevIndex = normalizeIndex(activeIndex.value - 1, props.list.length);
-  const nextIndex = normalizeIndex(activeIndex.value + 1, props.list.length);
-  const hasDuplicateSide = prevIndex === nextIndex && role !== "current";
+    virtualIndex;
 
-  return hasDuplicateSide ? `${baseKey}-${role}` : `${baseKey}`;
+  return `${baseKey}-${virtualIndex}-${role}`;
 };
 
 const states = {
@@ -216,7 +228,7 @@ const getCardZIndex = (role) => {
 };
 
 const getSlotState = (role) => {
-  if (!canLoop.value) return states.center;
+  if (!canSwipe.value) return states.center;
 
   const currentProgress = progress.value;
   if (currentProgress < 0) {
@@ -251,7 +263,7 @@ const buildCardStyle = (role) => {
 };
 
 const getMaskOpacity = (role) => {
-  if (!canLoop.value) return 0;
+  if (!canSwipe.value) return 0;
 
   const currentProgress = progress.value;
   const baseOpacity = 0.42;
@@ -279,43 +291,31 @@ const getMaskStyle = (role) => ({
 });
 
 const renderSlots = computed(() => {
-  if (!props.list.length) return [];
+  if (!actualCount.value) return [];
 
-  if (!canLoop.value) {
-    return [
-      {
-        key: getItemKey(activeIndex.value, "current"),
-        role: "current",
-        index: activeIndex.value,
-        item: props.list[activeIndex.value],
-        style: buildCardStyle("current"),
-      },
-    ];
-  }
-
-  const prevIndex = normalizeIndex(activeIndex.value - 1, props.list.length);
-  const nextIndex = normalizeIndex(activeIndex.value + 1, props.list.length);
+  const prevIndex = normalizeIndex(activeCursor.value - 1, virtualCount.value);
+  const nextIndex = normalizeIndex(activeCursor.value + 1, virtualCount.value);
 
   return [
     {
       key: getItemKey(prevIndex, "prev"),
       role: "prev",
-      index: prevIndex,
-      item: props.list[prevIndex],
+      index: getActualIndex(prevIndex),
+      item: getItemByVirtualIndex(prevIndex),
       style: buildCardStyle("prev"),
     },
     {
-      key: getItemKey(activeIndex.value, "current"),
+      key: getItemKey(activeCursor.value, "current"),
       role: "current",
-      index: activeIndex.value,
-      item: props.list[activeIndex.value],
+      index: getActualIndex(activeCursor.value),
+      item: getItemByVirtualIndex(activeCursor.value),
       style: buildCardStyle("current"),
     },
     {
       key: getItemKey(nextIndex, "next"),
       role: "next",
-      index: nextIndex,
-      item: props.list[nextIndex],
+      index: getActualIndex(nextIndex),
+      item: getItemByVirtualIndex(nextIndex),
       style: buildCardStyle("next"),
     },
   ];
@@ -335,16 +335,17 @@ const finishSwipe = (step) => {
   deltaX.value = step > 0 ? -sideOffset : sideOffset;
   clearSettleTimer();
   settleTimer = setTimeout(() => {
-    const nextIndex = normalizeIndex(activeIndex.value + step, props.list.length);
-    activeIndex.value = nextIndex;
-    emit("update:modelValue", nextIndex);
-    emit("change", nextIndex);
+    const nextCursor = normalizeIndex(activeCursor.value + step, virtualCount.value);
+    activeCursor.value = nextCursor;
+    const actualIndex = getActualIndex(nextCursor);
+    emit("update:modelValue", actualIndex);
+    emit("change", actualIndex);
     resetGesture();
   }, DURATION);
 };
 
 const handleTouchStart = (event) => {
-  if (!canLoop.value || isAnimating.value) return;
+  if (!canSwipe.value || isAnimating.value) return;
 
   const touch = event.touches?.[0] || event.changedTouches?.[0];
   if (!touch) return;
@@ -357,7 +358,7 @@ const handleTouchStart = (event) => {
 };
 
 const handleTouchMove = (event) => {
-  if (!canLoop.value || !isDragging.value || isAnimating.value) return;
+  if (!canSwipe.value || !isDragging.value || isAnimating.value) return;
 
   const touch = event.touches?.[0] || event.changedTouches?.[0];
   if (!touch) return;
@@ -378,7 +379,7 @@ const handleTouchMove = (event) => {
 };
 
 const handleTouchEnd = () => {
-  if (!canLoop.value || !isDragging.value) return;
+  if (!canSwipe.value || !isDragging.value) return;
 
   isDragging.value = false;
 
@@ -396,7 +397,7 @@ const handleTouchEnd = () => {
 };
 
 const handleTouchCancel = () => {
-  if (!canLoop.value) return;
+  if (!canSwipe.value) return;
   clearSettleTimer();
   deltaX.value = 0;
   isDragging.value = false;