feat(miaoPDF): 重构PDF查看器并添加拖拽和缩放功能

- 将margin缩放方案改为更精确的scale缩放方案
- 添加拖拽功能，支持长按后拖动PDF内容
- 重新设计顶部工具栏样式和布局
- 添加缩放比例显示和操作提示

src/plugins/miaoPDF/miaoPDF.vue

@@ -2,48 +2,30 @@
    <miao-message-provider ref="miaoMessageRef">
       <div class="miao-container">
          <div class="miao-container-topBar">
-            <div
-               class="miao-container-topBar-btn"
-               @click="() => handleZoom(10)"
-               title="快速缩小">
-               --
-            </div>
-            <div
-               class="miao-container-topBar-btn"
-               @click="() => handleZoom()"
-               title="缩小">
-               -
-            </div>
-            <div
-               class="miao-container-topBar-btn"
-               @click="() => handleResetMargin()"
-               title="还原">
-               还原缩放
-            </div>
-            <div
-               class="miao-container-topBar-btn"
-               @click="() => handleShrink()"
-               title="放大">
-               +
-            </div>
-            <div
-               class="miao-container-topBar-btn"
-               @click="() => handleShrink(10)"
-               title="快速放大">
-               ++
+            <div class="topBar-main">
+               <div class="top-btn" @click="() => handleZoom(10)" title="快速缩小">--</div>
+               <div class="top-btn" @click="() => handleZoom()" title="缩小">-</div>
+               <div class="top-btn" @click="() => handleResetMargin()" title="重置">重置</div>
+               <div class="top-btn" @click="() => handleShrink()" title="放大">+</div>
+               <div class="top-btn" @click="() => handleShrink(10)" title="快速放大">++</div>
+               <div class="scale-indicator">{{ Math.round(scale * 100) }}%</div>
             </div>
          </div>
-         <NScrollbar>
+         <NScrollbar ref="scrollRef">
             <div
                class="miao-container-pdf"
-               :style="{
-                  alignItems: pdfMargin < 0 ? 'baseline' : 'center'
-               }">
+               @pointerdown="onPointerDown"
+               @pointermove="onPointerMove"
+               @pointerup="onPointerUp"
+               @pointercancel="onPointerCancel"
+               :class="{ 'is-dragging': isDragging}"
+               :style="{'align-items': scale > 1 ? 'unset' : 'center' }">
+
                <div
                   ref="pdfEl"
                   class="miao-container-pdf-content"
                   :style="{
-                     width: `calc( 100% - ${pdfMargin}px)`
+                     width: `${(scale * 100).toFixed(2)}%`,
                   }"></div>
             </div>
          </NScrollbar>
@@ -53,7 +35,7 @@
 
 <script setup lang="ts">
 import miaoMessageProvider from '@/components/miaoAlertTipProvider.vue'
-import { onMounted, ref, shallowReactive } from 'vue'
+import { onMounted, ref, shallowReactive, computed, onBeforeUnmount } from 'vue'
 import PdfjsWorker from 'pdfjs-dist/build/pdf.worker.mjs?worker'
 import { VirtualFile } from '@/class/VirtualDirectory'
 import { NScrollbar } from 'naive-ui'
@@ -64,31 +46,148 @@ const currentFiles = defineModel<VirtualFile[]>('currentFiles', {
 
 const pdfEl = ref<HTMLDivElement>()
 const miaoMessageRef = ref<InstanceType<typeof miaoMessageProvider>>()
-// 通过margin来实现缩小功能
-const pdfMargin = ref<number>(0)
+// 新缩放方案：使用等比scale
+const scale = ref<number>(1)
+const minScale = 0.5
+const maxScale = 4
 
-const pdfPageCount = ref<number>(-1)
+const scrollRef = ref<InstanceType<typeof NScrollbar> | null>(null)
+const isDragging = ref(false)
+let pressTimeoutId: number | null = null
+let dragging = false
+let startX = 0
+let startY = 0
+let startLeft = 0
+let startTop = 0
+const longPressDelay = 100
 
-const canvasList = shallowReactive<HTMLCanvasElement[]>([])
+// 更稳健的滚动容器解析逻辑，避免依赖 $el.querySelector
+const scrollContainer = ref<HTMLElement | null>(null)
+const findScrollableParent = (el: HTMLElement | null): HTMLElement | null => {
+   let cur: HTMLElement | null = el?.parentElement ?? null
+   while (cur) {
+      const style = window.getComputedStyle(cur)
+      const overflowY = style.overflowY
+      const overflowX = style.overflowX
+      const canScroll =
+         (overflowY === 'auto' || overflowY === 'scroll' || overflowX === 'auto' || overflowX === 'scroll') &&
+         (cur.scrollHeight > cur.clientHeight || cur.scrollWidth > cur.clientWidth)
+      if (canScroll) return cur
+      cur = cur.parentElement
+   }
+   return null
+}
+const resolveScrollContainer = () => {
+   const fromScrollbar = pdfEl.value?.closest('.n-scrollbar')?.querySelector('.n-scrollbar-container') as HTMLElement | null
+   scrollContainer.value = fromScrollbar ?? findScrollableParent(pdfEl.value ?? null)
+}
+const getScrollEl = (): HTMLElement | null => {
+   if (!scrollContainer.value) resolveScrollContainer()
+   return scrollContainer.value
+}
+
+const onPointerDown = (e: PointerEvent) => {
+   resolveScrollContainer()
+   const el = getScrollEl()
+   if (!el) return
+   startX = e.clientX
+   startY = e.clientY
+   startLeft = el.scrollLeft
+   startTop = el.scrollTop
+   dragging = false
+   ;(e.currentTarget as HTMLElement).setPointerCapture?.(e.pointerId)
+   if (pressTimeoutId) window.clearTimeout(pressTimeoutId)
+   pressTimeoutId = window.setTimeout(() => {
+      dragging = true
+      isDragging.value = true
+      document.body.style.cursor = 'grabbing'
+   }, longPressDelay)
+}
+
+const onPointerMove = (e: PointerEvent) => {
+   const el = getScrollEl()
+   if (!el || !dragging) return
+   const dx = e.clientX - startX
+   const dy = e.clientY - startY
+   let newLeft = startLeft - dx
+   let newTop = startTop - dy
+   const maxLeft = Math.max(0, el.scrollWidth - el.clientWidth)
+   const maxTop = Math.max(0, el.scrollHeight - el.clientHeight)
+   newLeft = Math.max(0, Math.min(maxLeft, newLeft))
+   newTop = Math.max(0, Math.min(maxTop, newTop))
+   el.scrollLeft = newLeft
+   el.scrollTop = newTop
+   e.preventDefault()
+}
+
+const endDrag = (e: PointerEvent) => {
+   if (pressTimeoutId) {
+      window.clearTimeout(pressTimeoutId)
+      pressTimeoutId = null
+   }
+   if (dragging) {
+      isDragging.value = false
+      document.body.style.cursor = ''
+   }
+   dragging = false
+   try {
+      (e.currentTarget as HTMLElement).releasePointerCapture?.(e.pointerId)
+   } catch {}
+}
+const onPointerUp = endDrag
+const onPointerCancel = endDrag
+
+onBeforeUnmount(() => {
+   if (pressTimeoutId) window.clearTimeout(pressTimeoutId)
+})
+
+// 等比缩放并保持视窗中心不抖动
+const applyZoom = (multiplier: number) => {
+   // const el = getScrollEl()
+   const oldScale = scale.value
+   let newScale = oldScale * multiplier
+   newScale = Math.max(minScale, Math.min(maxScale, newScale))
+   // const ratio = newScale / oldScale
+   // if (el) {
+   //    const cx = el.clientWidth / 2
+   //    const cy = el.clientHeight / 2
+   //    // const targetLeft = (el.scrollLeft + cx) * ratio - cx
+   //    // const targetTop = (el.scrollTop + cy) * ratio - cy
+   //    scale.value = +newScale.toFixed(4)
+   //    // requestAnimationFrame(() => {
+   //    //    const maxLeft = Math.max(0, el.scrollWidth - el.clientWidth)
+   //    //    const maxTop = Math.max(0, el.scrollHeight - el.clientHeight)
+   //    //    el.scrollLeft = Math.max(0, Math.min(maxLeft, targetLeft))
+   //    //    el.scrollTop = Math.max(0, Math.min(maxTop, targetTop))
+   //    // })
+   //    return
+   // }
+   scale.value = +newScale.toFixed(4)
+}
 
 const handleZoom = (index?: number) => {
    const _index = index ?? 1
-   pdfMargin.value += 10 * _index
+   const factor = 1 + 0.1 * _index
+   applyZoom(1 / factor)
 }
 
 const handleShrink = (index?: number) => {
    const _index = index ?? 1
-   // if (pdfMargin.value - 10 * _index <= 0) {
-   //     return pdfMargin.value = 0
-   // }
-   pdfMargin.value -= 10 * _index
+   const factor = 1 + 0.1 * _index
+   applyZoom(factor)
 }
 
 const handleResetMargin = () => {
-   pdfMargin.value = 0
+   const el = getScrollEl()
+   scale.value = 1
 }
 
+const pdfPageCount = ref<number>(-1)
+const canvasList = shallowReactive<HTMLCanvasElement[]>([])
+
 onMounted(async () => {
+   // 初始解析一次滚动容器（等待一帧确保DOM就绪）
+   requestAnimationFrame(() => resolveScrollContainer())
    const setLoadingMessage = miaoMessageRef.value?.alertTip('加载PDF插件中', {
       type: 'info',
       timeout: -1
@@ -134,6 +233,15 @@ onMounted(async () => {
 
 <style scoped lang="scss">
 .miao-container {
+   --bar-height: 44px;
+   --bar-bg: linear-gradient(90deg, #eef1f5 0%, #e3e7ec 100%);
+   --btn-bg: #ffffff;
+   --btn-hover: #f2f4f7;
+   --btn-active: #e6e9ef;
+   --btn-border: #d7dbe2;
+   --text: #1f2328;
+   --subtext: #6b7280;
+
    width: 100%;
    height: 100%;
    background-color: rgb(201, 201, 201);
@@ -144,31 +252,57 @@ onMounted(async () => {
 
    .miao-container-topBar {
       box-sizing: border-box;
-      padding: 0 30px;
-      height: 30px;
+      padding: 0 12px;
+      height: var(--bar-height);
       width: 100%;
-      background-color: rgb(170, 176, 182);
+      background: var(--bar-bg);
       display: flex;
-      justify-content: space-around;
+      justify-content: center;
       align-items: center;
+      border-bottom: 1px solid rgba(0, 0, 0, 0.06);
+      backdrop-filter: saturate(180%) blur(8px);
 
-      &-btn {
-         cursor: pointer;
-         user-select: none;
-         height: 80%;
-         padding: 0 5px;
+      .topBar-main {
          display: flex;
          align-items: center;
-         justify-content: center;
-         font-size: larger;
-         letter-spacing: 1px;
-         color: black;
-         border-radius: 5px;
-
-         &:hover {
-            background-color: #eaeaea42;
-         }
+         gap: 8px;
+         position: relative;
+         user-select: none;
       }
+
+      .top-btn {
+         cursor: pointer;
+         user-select: none;
+         height: 30px;
+         min-width: 34px;
+         padding: 0 10px;
+         display: inline-flex;
+         align-items: center;
+         justify-content: center;
+         font-size: 14px;
+         letter-spacing: 0.5px;
+         color: var(--text);
+         background-color: var(--btn-bg);
+         border: 1px solid var(--btn-border);
+         border-radius: 8px;
+         box-shadow: 0 1px 0 rgba(0,0,0,0.02);
+         transition: background-color .15s ease, transform .08s ease, box-shadow .15s ease;
+
+         &:hover { background-color: var(--btn-hover); }
+         &:active { background-color: var(--btn-active); transform: scale(0.98); }
+      }
+
+      .scale-indicator {
+         position: absolute;
+         right: -60px;
+         min-width: 54px;
+         text-align: center;
+         font-size: 13px;
+         color: var(--subtext);
+         padding: 0 8px;
+      }
+
+      .hint { color: var(--subtext); font-size: 12px; }
    }
 
    .miao-container-pdf {
@@ -176,9 +310,26 @@ onMounted(async () => {
       width: 100%;
       display: flex;
       flex-direction: column;
+      align-items: center; // 居中以便缩小时居中显示
+      touch-action: none; // 以便自定义拖动
+      &.is-dragging { cursor: grabbing; }
+
       .miao-container-pdf-content {
          display: flex;
          flex-direction: column;
+         transition: width .12s ease, padding-top .12s ease;
+         will-change: width, padding-top;
+
+         // 让Canvas随容器宽度等比缩放，保证显示完整
+         canvas {
+            width: 100%;
+            height: auto;
+            display: block;
+            margin: 0 auto 12px auto;
+            background: #fff;
+            border-radius: 6px;
+            box-shadow: 0 1px 3px rgba(0,0,0,0.06);
+         }
       }
    }