long-list: 更新指示器线，使用 transform

pages/template/long-list/long-list.uvue

@@ -4,21 +4,19 @@
       <input placeholder="搜索..." />
     </view>
     <view class="swiper-list">
-      <scroll-view class="swiper-tabs" :scroll-left="tabsScrollLeft" :scroll-x="true" :show-scrollbar="false">
+      <scroll-view ref="tabScroll" class="swiper-tabs" :scroll-x="true" :show-scrollbar="false">
+        <!-- TODO 多一层 view -->
         <view>
           <view class="flex-row">
-            <text class="swiper-tabs-item" :class="swiperIndex==index ? 'swiper-tabs-item-active' : ''"
-              v-for="(item, index) in swiperList" ref="swipertab" :key="index" @click="onTabClick(index)">
+            <text ref="swipertab" class="swiper-tabs-item" :class="swiperIndex==index ? 'swiper-tabs-item-active' : ''"
+              v-for="(item, index) in swiperList" :key="index" @click="onTabClick(index)">
               {{item.name}}
             </text>
           </view>
-          <view class="swiper-tabs-indicator">
-            <view class="swiper-tabs-underline"
-              :style="{left: swiperIndicatorLineLeft + 'px', width: swiperIndicatorLineWidth + 'px'}"></view>
-          </view>
+          <view ref="indicator" class="swiper-tabs-indicator"></view>
         </view>
       </scroll-view>
-      <swiper class="swiper-view" ref="swiper" :current="swiperIndex" @transition="onSwiperTransition"
+      <swiper ref="swiper" class="swiper-view" :current="swiperIndex" @transition="onSwiperTransition"
         @animationfinish="onSwiperAnimationfinish">
         <swiper-item class="swiper-item" v-for="(item, index) in swiperList" :key="index">
           <long-page ref="longPage" :type="item.type" :preload="item.preload"></long-page>
@@ -69,9 +67,8 @@
           } as SwiperViewItem
         ] as SwiperViewItem[],
         swiperIndex: -1,
-        tabsScrollLeft: 0,
-        swiperIndicatorLineLeft: 0,
-        swiperIndicatorLineWidth: 0,
+        $tabScrollView: null as null | INode,
+        $indicatorNode: null as null | INode,
         $headerHeight: 0,
         $animationFinishIndex: 0,
         $swiperWidth: 0,
@@ -79,6 +76,8 @@
       }
     },
     onReady() {
+      this.$tabScrollView = this.$refs.get('tabScroll') as INode
+      this.$indicatorNode = this.$refs.get('indicator') as INode
       this.$headerHeight = (this.$refs["header"] as INode).offsetHeight
       this.$swiperWidth = (this.$refs["swiper"] as INode).getBoundingClientRect().width
       this.queryTabItemsSize()
@@ -88,40 +87,32 @@
       onTabClick(index : number) {
         this.setSwiperIndex(index, false)
       },
-      /// 兼容微信 skyline 和 webview, uni-app-x 和 webview 行为一致
-      /// skyline 每项完成触发 Animationfinish，偏移值重置
-      /// webview 全部完成触发 Animationfinish，偏移值累加
-      /// 在滑动到下一个项的过程中，再次反向滑动，偏移值递减
       onSwiperTransition(e : SwiperTransitionEvent) {
+        // 微信 skyline 每项完成触发 Animationfinish，偏移值重置
+        // 微信 webview 全部完成触发 Animationfinish，偏移值累加
+        // 在滑动到下一个项的过程中，再次反向滑动，偏移值递减
+        // uni-app-x 微信 webview 行为一致
+
         const offset_x = e.detail.dx
 
-        // 重置差异，计算当前实时索引位置
+        // 重置差异，计算当前索引
         const current_offset_x = offset_x % this.$swiperWidth
         const current_offset_i = offset_x / this.$swiperWidth
         const current_index = this.$animationFinishIndex + current_offset_i.toInt()
 
-        // 边界检查
+        // 更新索引及边界检查
         let move_to_index = current_index
-        if (current_offset_x > 0) {
-          if (move_to_index < this.$swiperTabsRect.length - 1) {
+        if (current_offset_x > 0 && move_to_index < this.swiperList.length - 1) {
           move_to_index += 1
-          }
-        } else if (current_offset_x < 0) {
-          if (move_to_index > 0) {
+        } else if (current_offset_x < 0 && move_to_index > 0) {
           move_to_index -= 1
         }
-        }
 
-        // 计算蛇形线位置和大小
+        // 计算偏移百分比
         const percentage = Math.abs(current_offset_x) / this.$swiperWidth
-        const current_size = this.$swiperTabsRect[current_index]
-        const move_to_size = this.$swiperTabsRect[move_to_index]
-        const indicator_line_l = current_size.x + (move_to_size.x - current_size.x) * percentage
-        const indicator_line_w = current_size.w + (move_to_size.w - current_size.w) * percentage
 
-        // 更新蛇形线位置和大小
-        // 这代码写的不对，不能在拖动滚动中使用vue绑定样式，只能用ref+transform
-        // this.updateTabIndicator(indicator_line_l, indicator_line_w)
+        // 通知更新指示线
+        this.updateTabIndicator(current_index, move_to_index, percentage)
 
         // 首次可见时初始化数据
         this.initSwiperItemPage(move_to_index)
@@ -144,18 +135,29 @@
         if (this.swiperIndex === index) {
           return
         }
+
         this.swiperIndex = index
 
         this.initSwiperItemPage(index)
 
         if (updateIndicator) {
-          this.updateTabIndicator(this.$swiperTabsRect[index].x, this.$swiperTabsRect[index].w)
+          this.updateTabIndicator(index, index, 1)
         }
       },
-      updateTabIndicator(left : Number, width : Number) {
-        this.swiperIndicatorLineLeft = left
-        this.swiperIndicatorLineWidth = width
-        this.tabsScrollLeft = left + width / 2 - this.$swiperWidth / 2
+      updateTabIndicator(current_index : number, move_to_index : number, percentage : number) {
+        // 计算指示线
+        const current_size = this.$swiperTabsRect[current_index]
+        const move_to_size = this.$swiperTabsRect[move_to_index]
+        const indicator_line_l = current_size.x + (move_to_size.x - current_size.x) * percentage
+        const indicator_line_w = current_size.w + (move_to_size.w - current_size.w) * percentage
+
+        // 更新指示线
+        const x = indicator_line_l + indicator_line_w / 2
+        this.$indicatorNode?.style?.setProperty('transform', `translateX(${x}px) scaleX(${indicator_line_w})`)
+
+        // 将指示线滚动到水平中心位置
+        const scroll_x = x - this.$swiperWidth / 2
+        this.$tabScrollView?.setAttribute('scrollLeft', scroll_x)
       },
       initSwiperItemPage(index : Number) {
         if (!this.swiperList[index].preload) {
@@ -200,15 +202,8 @@
   }
 
   .swiper-tabs-indicator {
-    position: relative;
+    width: 1px;
     height: 2px;
-  }
-
-  .swiper-tabs-underline {
-    position: absolute;
-    top: 0;
-    bottom: 0;
-    width: 0;
     background-color: #007AFF;
   }
 

pages/template/swiper-list/swiper-list.uvue

 <template>
   <view class="swiper-list">
     <scroll-view ref="tabScroll" class="swiper-tabs" :scroll-x="true" :show-scrollbar="false">
+      <!-- TODO 多一层 view -->
       <view>
         <view class="flex-row">
           <text ref="swipertab" class="swiper-tabs-item" :class="swiperIndex==index ? 'swiper-tabs-item-active' : ''"
@@ -62,10 +63,10 @@
         this.setSwiperIndex(index, false)
       },
       onSwiperTransition(e : SwiperTransitionEvent) {
-        // skyline 每项完成触发 Animationfinish，偏移值重置
-        // webview 全部完成触发 Animationfinish，偏移值累加
+        // 微信 skyline 每项完成触发 Animationfinish，偏移值重置
+        // 微信 webview 全部完成触发 Animationfinish，偏移值累加
         // 在滑动到下一个项的过程中，再次反向滑动，偏移值递减
-        // uni-app-x 和 webview 行为一致
+        // uni-app-x 和 微信 webview 行为一致
 
         const offset_x = e.detail.dx
 
@@ -74,29 +75,21 @@
         const current_offset_i = offset_x / this.$swiperWidth
         const current_index = this.$animationFinishIndex + current_offset_i.toInt()
 
-        // 边界检查
+        // 更新索引及边界检查
         let move_to_index = current_index
-        if (current_offset_x > 0) {
-          if (move_to_index < this.$swiperTabsRect.length - 1) {
+        if (current_offset_x > 0 && move_to_index < this.swiperList.length - 1) {
           move_to_index += 1
-          }
-        } else if (current_offset_x < 0) {
-          if (move_to_index > 0) {
+        } else if (current_offset_x < 0 && move_to_index > 0) {
           move_to_index -= 1
         }
-        }
 
-        // 计算指示线位置和大小
+        // 计算偏移百分比
         const percentage = Math.abs(current_offset_x) / this.$swiperWidth
-        const current_size = this.$swiperTabsRect[current_index]
-        const move_to_size = this.$swiperTabsRect[move_to_index]
-        const indicator_line_l = current_size.x + (move_to_size.x - current_size.x) * percentage
-        const indicator_line_w = current_size.w + (move_to_size.w - current_size.w) * percentage
 
-        // 更新指示线位置和大小
-        this.updateTabIndicator(indicator_line_l, indicator_line_w)
+        // 通知更新指示线
+        this.updateTabIndicator(current_index, move_to_index, percentage)
 
-        // console.log(current_index + "->" + move_to_index + " x=" + offset_x + " p=" + percentage)
+        // console.log(current_index + "->" + move_to_index+ " p=" + percentage + " x=" + offset_x )
       },
       onSwiperAnimationfinish(e : SwiperAnimationFinishEvent) {
         this.setSwiperIndex(e.detail.current, true)
@@ -120,13 +113,19 @@
         this.swiperIndex = index
 
         if (updateIndicator) {
-          this.updateTabIndicator(this.$swiperTabsRect[index].x, this.$swiperTabsRect[index].w)
+          this.updateTabIndicator(index, index, 1)
         }
       },
-      updateTabIndicator(left : number, width : number) {
+      updateTabIndicator(current_index : number, move_to_index : number, percentage : number) {
+        // 计算指示线
+        const current_size = this.$swiperTabsRect[current_index]
+        const move_to_size = this.$swiperTabsRect[move_to_index]
+        const indicator_line_l = current_size.x + (move_to_size.x - current_size.x) * percentage
+        const indicator_line_w = current_size.w + (move_to_size.w - current_size.w) * percentage
+
         // 更新指示线
-        const x = left + width / 2
-        this.$indicatorNode?.style?.setProperty('transform', `translateX(${x}px) scaleX(${width}px)`)
+        const x = indicator_line_l + indicator_line_w / 2
+        this.$indicatorNode?.style?.setProperty('transform', `translateX(${x}px) scaleX(${indicator_line_w})`)
 
         // 将指示线滚动到水平中心位置
         const scroll_x = x - this.$swiperWidth / 2