时间线组件优化

- 时间线缩放滑块的数值提示限定小数点后两位
- 时间线缩放时，如果播放头在时间线范围内，以播放头为中心缩放，如果看不到播放头，则以时间线组件中心缩放
- 时间线在加载时自适应最小缩放值

src/components/hazard_inspect/timeline/timeline.ts

@@ -39,8 +39,8 @@ export function useTimeline(
 ) {
   const FPS = 30
   const pxPerFrame = ref(2)
-  const minPxPerFrame = 0.5
-  const maxPxPerFrame = 3
+  const minPxPerFrame = ref(0.5)
+  const maxPxPerFrame = ref(3)
   const timelineContainer: Ref<HTMLElement | null> = ref(null)
   const isDragging = ref(false)
   const isPlayheadDragging = ref(false)
@@ -58,15 +58,54 @@ export function useTimeline(
   })
 
   function updatePxPerFrame(): void {
-    if (!timelineContainer.value)
+    if (!timelineContainer.value || props.totalFrames === 0)
       return
     const containerWidth = timelineContainer.value.clientWidth - 20
     const calculatedPxPerFrame = containerWidth / props.totalFrames
-    pxPerFrame.value = Math.max(minPxPerFrame, Math.min(calculatedPxPerFrame, maxPxPerFrame))
+    // 计算最小缩放倍数，确保能看到视频全长
+    const newMinPxPerFrame = Math.max(0.1, containerWidth / props.totalFrames)
+    // 只在必要时更新，避免无限循环
+    if (Math.abs(newMinPxPerFrame - minPxPerFrame.value) > 0.01) {
+      minPxPerFrame.value = newMinPxPerFrame
+    }
+    // 最大值固定为3，不修改
+    pxPerFrame.value = Math.max(minPxPerFrame.value, Math.min(calculatedPxPerFrame, maxPxPerFrame.value))
   }
 
   function setZoom(value: number): void {
-    pxPerFrame.value = Math.max(minPxPerFrame, Math.min(value, maxPxPerFrame))
+    const oldPxPerFrame = pxPerFrame.value
+    const newPxPerFrame = Math.max(minPxPerFrame.value, Math.min(value, maxPxPerFrame.value))
+
+    if (oldPxPerFrame === newPxPerFrame || !timelineContainer.value)
+      return
+
+    const container = timelineContainer.value
+    const containerWidth = container.clientWidth
+    const containerScrollLeft = container.scrollLeft
+    const playheadPosition = props.currentFrame * oldPxPerFrame
+
+    // 检查播放头是否在可见范围内
+    const playheadVisible = playheadPosition >= containerScrollLeft
+      && playheadPosition <= containerScrollLeft + containerWidth
+
+    // 计算缩放前后的位置偏移
+    if (playheadVisible) {
+      // 以播放头为中心缩放
+      const playheadX = playheadPosition - containerScrollLeft
+      const newPlayheadPosition = props.currentFrame * newPxPerFrame
+      const newScrollLeft = newPlayheadPosition - playheadX
+      container.scrollLeft = newScrollLeft
+    }
+    else {
+      // 以容器中心为中心缩放
+      const centerX = containerWidth / 2
+      const centerPosition = containerScrollLeft + centerX
+      const newCenterPosition = centerPosition * (newPxPerFrame / oldPxPerFrame)
+      container.scrollLeft = newCenterPosition - centerX
+    }
+
+    // 最后更新缩放值
+    pxPerFrame.value = newPxPerFrame
   }
 
   const timeTicks: ComputedRef<TimeTick[]> = computed(() => {
@@ -105,10 +144,9 @@ export function useTimeline(
   }
 
   const playheadPos: ComputedRef<number> = computed(() => {
-    if (isPlayheadDragging.value) {
-      return localCurrentFrame.value * pxPerFrame.value
-    }
-    return props.currentFrame * pxPerFrame.value
+    const frame = isPlayheadDragging.value ? localCurrentFrame.value : props.currentFrame
+    const clampedFrame = Math.max(0, Math.min(frame, props.totalFrames - 1))
+    return clampedFrame * pxPerFrame.value
   })
 
   const trackRows: ComputedRef<HazardRow[][]> = computed(() => {
@@ -281,7 +319,10 @@ export function useTimeline(
     if (!progressContainer)
       return
 
+    // 使用 nextTick 确保容器已渲染
+    nextTick(() => {
       updatePxPerFrame()
+    })
 
     progressContainer.addEventListener('wheel', handleWheel, { passive: false })
     progressContainer.addEventListener('mousedown', handleMouseDown)
@@ -291,10 +332,31 @@ export function useTimeline(
   }
 
   watch(() => props.totalFrames, () => {
-    nextTick(() => {
+    // 使用 setTimeout 避免频繁更新
+    setTimeout(() => {
       updatePxPerFrame()
+    }, 100)
   })
-  })
+
+  // 移除 resize 监听，避免无限循环
+  // 监听容器宽度变化
+  // let resizeObserver: ResizeObserver | null = null
+
+  // function handleResize(): void {
+  //   updatePxPerFrame()
+  // }
+
+  // watch(() => timelineContainer.value, (newVal, oldVal) => {
+  //   if (newVal && !oldVal) {
+  //     // 使用 ResizeObserver 代替 window resize 监听
+  //     resizeObserver = new ResizeObserver(handleResize)
+  //     resizeObserver.observe(newVal)
+  //   }
+  //   else if (!newVal && oldVal && resizeObserver) {
+  //     resizeObserver.disconnect()
+  //     resizeObserver = null
+  //   }
+  // })
 
   function initUnmounted(): void {
     window.removeEventListener('mousemove', handleMouseMove)

src/components/hazard_inspect/timeline/timeline.vue

@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import type { Arrayable } from '@vueuse/core'
 import type { TimelineEmits, TimelineProps } from './timeline'
 import { ElScrollbar, ElSlider } from 'element-plus'
 import { computed, onMounted, onUnmounted } from 'vue'
@@ -55,9 +56,9 @@ onUnmounted(() => {
           :max="maxPxPerFrame"
           :step="0.5"
           :show-tooltip="true"
-          :format-tooltip="(val: number) => `缩放: ${val}`"
+          :format-tooltip="(val: number) => `缩放: ${val.toFixed(2)}`"
           class="zoom-slider"
-          @change="(val: number | number[]) => setZoom(Array.isArray(val) ? val[0] : val)"
+          @update:model-value="(val: Arrayable<number>) => setZoom(Array.isArray(val) ? val[0] : val)"
         />
       </div>
     </div>