v1.9.3 - fix taskbar cal issue

CHANGELOG.md

@@ -5,6 +5,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.9.3] - 2026-03-05
+
+### Added
+- 🎉 新增：GanttChart 新增 enableTaskDrawerAutoClose 属性，设置为 false 时禁用 TaskDrawer 的自动关闭行为
+- 🎉 Added: GanttChart new prop enableTaskDrawerAutoClose — set to false to disable the automatic closing behavior of the TaskDrawer
+
+### Fixed
+- 🔧 修复：周视图下拖拽 TaskBar 左右移动后任务宽度（持续时间）自动缩短的问题
+- 🔧 Fixed: TaskBar width (duration) shrinking after dragging left and right in weekly view
+
 ## [1.9.2] - 2026-02-26
 
 ### Added

README-EN.md

@@ -226,6 +226,7 @@ npm run dev
 | `showTaskbarTab` ![v1.9.0](https://img.shields.io/badge/v1.9.0-409EFF?style=flat-square&labelColor=ECF5FF) | `boolean`                                                                                 | `true` | Whether to display resource tab on TaskBar (shows resource allocation label on TaskBar in resource view) |
 | `enableTaskListCollapsible` ![v1.9.2](https://img.shields.io/badge/v1.9.2-409EFF?style=flat-square&labelColor=ECF5FF) | `boolean`                                                                                 | `true` | Whether to allow collapsing/expanding the TaskList panel. When `false`: forcibly hides TaskList, SplitterBar and collapse button; Timeline takes full width |
 | `taskListVisible` ![v1.9.2](https://img.shields.io/badge/v1.9.2-409EFF?style=flat-square&labelColor=ECF5FF) | `boolean`                                                                                 | `true` | Controls TaskList visibility (reactive). Only effective when `enableTaskListCollapsible=true` |
+| `enableTaskDrawerAutoClose` ![v1.9.3](https://img.shields.io/badge/v1.9.3-409EFF?style=flat-square&labelColor=ECF5FF) | `boolean`                                                                                 | `true` | Whether to allow TaskDrawer to auto-close (closes on outside click or Esc key). Set to `false` to disable auto-close — the drawer can only be closed via its internal close button |
 
 #### TaskListColumn Component Props
 
@@ -3637,7 +3638,13 @@ View the complete [Contributors list](./CONTRIBUTORS.md)。
 
 ---
 
-## 📄 Open Source License
+## � Troubleshooting
+
+For common issues and solutions, please refer to [Troubleshooting-EN.md](./Troubleshooting-EN.md).
+
+---
+
+## �📄 Open Source License
 
 [MIT License](./LICENSE) © 2025 JORDIUM.COM
 

README.md

@@ -224,6 +224,7 @@ npm run dev
 | `showTaskbarTab` ![v1.9.0](https://img.shields.io/badge/v1.9.0-409EFF?style=flat-square&labelColor=ECF5FF) | `boolean`                                                                                 | `true` | 是否显示TaskBar上的资源Tab标签（资源视图下TaskBar的资源分配标签） |
 | `enableTaskListCollapsible` ![v1.9.2](https://img.shields.io/badge/v1.9.2-409EFF?style=flat-square&labelColor=ECF5FF) | `boolean`                                                                                 | `true` | 是否允许折叠/展开 TaskList 面板。`false` 时强制隐藏 TaskList、SplitterBar 及折叠按钮，Timeline 独占全宽 |
 | `taskListVisible` ![v1.9.2](https://img.shields.io/badge/v1.9.2-409EFF?style=flat-square&labelColor=ECF5FF) | `boolean`                                                                                 | `true` | 控制 TaskList 的显隐状态（响应式）。仅在 `enableTaskListCollapsible=true` 时有效 |
+| `enableTaskDrawerAutoClose` ![v1.9.3](https://img.shields.io/badge/v1.9.3-409EFF?style=flat-square&labelColor=ECF5FF) | `boolean`                                                                                 | `true` | 是否允许 TaskDrawer 自动关闭（外总点击或按 Esc 时自动关闭）。设为 `false` 时禁用自动关闭，仅可通过内部按钮手动关闭 |
 
 #### TaskListColumn 属性
 
@@ -3630,7 +3631,13 @@ TaskList 组件经过深度重构，采用模块化设计，提升了代码可
 
 ---
 
-## 📄 开源协议
+## � Troubleshooting
+
+常见问题与解决方案请参阅 [Troubleshooting.md](./Troubleshooting.md)。
+
+---
+
+## �📄 开源协议
 
 [MIT License](./LICENSE) © 2025 JORDIUM.COM
 

Troubleshooting-EN.md

@@ -0,0 +1,69 @@
+# Troubleshooting
+
+Common issues and solutions for `jordium-gantt-vue3`.
+
+---
+
+## Table of Contents
+
+- [High Memory Usage / Browser Freeze with Large Datasets](#issue-13-high-memory-usage--browser-freeze-with-large-datasets)
+
+---
+
+## Issue #13: High Memory Usage / Browser Freeze with Large Datasets
+
+**Labels**: `performance`, `answer`  
+**Status**: ✅ Resolved  
+**Issue**: [#13 Memory leak and high CPU use](https://github.com/nelson820125/jordium-gantt-vue3/issues/13) → converted to Discussion [#16](https://github.com/nelson820125/jordium-gantt-vue3/discussions/16)
+
+### Symptoms
+
+When loading ~80+ tasks, the page becomes severely sluggish, memory grows continuously, and the browser may crash.
+
+### Root Cause
+
+The problem is **not in the component itself**, but in how the caller binds data:
+
+1. **Using `reactive` to deeply wrap the task array** — Vue creates deep watchers for every object in the array. With a large dataset, the number of watchers explodes and memory can exceed 10 GB.
+2. **Incorrect date format** — The API returns ISO datetime strings (e.g. `"2026-03-07T08:34:00.230"`), but the component expects plain date strings (`"2026-03-07"`).
+
+### Solution (credit: [@eldrift](https://github.com/eldrift))
+
+#### 1. Use `shallowRef` instead of `reactive` to store the task list
+
+```ts
+// ❌ Wrong — deep reactivity, performance disaster
+const data = reactive({ tasks: [] as Task[] })
+
+// ✅ Correct — Vue only watches the array reference, not each object deeply
+const tasks = shallowRef<Task[]>([])
+```
+
+#### 2. Truncate ISO datetime strings to plain date format
+
+```ts
+tasks.value = res.data.map((t: Task) => ({
+  ...t,
+  startDate: t.startDate?.substring(0, 10) ?? t.startDate,
+  endDate:   t.endDate?.substring(0, 10)   ?? t.endDate,
+}))
+```
+
+#### 3. Use the correct Task type
+
+Ensure the data passed to the component conforms to the `Task` interface to avoid hidden computation overhead from type mismatches.
+
+### References
+
+- Full discussion & report: [Discussion #16](https://github.com/nelson820125/jordium-gantt-vue3/discussions/16)
+- Original issue: [#13 Memory leak and high CPU use](https://github.com/nelson820125/jordium-gantt-vue3/issues/13)
+
+---
+
+## Feedback
+
+If you encounter an issue not listed here, feel free to submit one:
+
+- [GitHub Issues](https://github.com/nelson820125/jordium-gantt-vue3/issues)
+- [Gitee Issues](https://gitee.com/jordium/jordium-gantt-vue3/issues)
+- 📧 ning.li@jordium.com

Troubleshooting.md

@@ -0,0 +1,69 @@
+# Troubleshooting
+
+常见问题与解决方案 / Common issues and solutions.
+
+---
+
+## 目录 / Table of Contents
+
+- [内存占用过高 / 浏览器卡死（大数据量场景）](#issue-13-内存占用过高--浏览器卡死大数据量场景)
+
+---
+
+## Issue #13: 内存占用过高 / 浏览器卡死（大数据量场景）
+
+**标签 / Labels**: `performance`, `answer`  
+**状态 / Status**: ✅ 已解决 / Resolved  
+**Issue 地址**: [#13 Memory leak and high CPU use](https://github.com/nelson820125/jordium-gantt-vue3/issues/13) → 已转为 Discussion [#16](https://github.com/nelson820125/jordium-gantt-vue3/discussions/16)
+
+### 现象
+
+在加载约 80+ 条任务数据时，页面出现严重卡顿、内存持续增长甚至浏览器崩溃。
+
+### 根本原因
+
+问题**不在组件本身**，而在于调用方的数据绑定方式：
+
+1. **使用 `reactive` 深层包裹任务数组** — Vue 会为数组内每一个对象建立深层侦听器，数据量较大时侦听器数量爆炸，导致内存超过 10 GB。
+2. **日期格式错误** — API 返回 ISO 日期时间字符串（如 `"2026-03-07T08:34:00.230"`），但组件要求纯日期格式（`"2026-03-07"`）。
+
+### 解决方案（来自 [@eldrift](https://github.com/eldrift)）
+
+#### 1. 使用 `shallowRef` 替代 `reactive` 存储任务列表
+
+```ts
+// ❌ 错误 — 深层响应性，性能灾难
+const data = reactive({ tasks: [] as Task[] })
+
+// ✅ 正确 — Vue 只监听数组引用，不深入每个对象
+const tasks = shallowRef<Task[]>([])
+```
+
+#### 2. 截断 ISO 日期时间为纯日期格式
+
+```ts
+tasks.value = res.data.map((t: Task) => ({
+  ...t,
+  startDate: t.startDate?.substring(0, 10) ?? t.startDate,
+  endDate:   t.endDate?.substring(0, 10)   ?? t.endDate,
+}))
+```
+
+#### 3. 使用正确的 Task 类型
+
+确保传入组件的数据符合 `Task` 接口定义，避免类型不匹配导致的隐性计算开销。
+
+### 参考
+
+- 完整讨论与报告：[Discussion #16](https://github.com/nelson820125/jordium-gantt-vue3/discussions/16)
+- 原始 Issue：[#13 Memory leak and high CPU use](https://github.com/nelson820125/jordium-gantt-vue3/issues/13)
+
+---
+
+## 反馈 / Feedback
+
+如果遇到未收录的问题，欢迎提交 Issue：
+
+- [GitHub Issues](https://github.com/nelson820125/jordium-gantt-vue3/issues)
+- [Gitee Issues](https://gitee.com/jordium/jordium-gantt-vue3/issues)
+- 📧 ning.li@jordium.com

demo/App.vue

@@ -2377,6 +2377,7 @@ const handleCustomMenuAction = (action: string, task: Task) => {
         :complete-task-background-color="completeTaskBackgroundColor"
         :ongoing-task-background-color="ongoingTaskBackgroundColor"
         :use-default-drawer="useDefaultDrawer"
+        :enable-task-drawer-auto-close="false"
         @milestone-saved="handleMilestoneSaved"
         @milestone-deleted="handleMilestoneDeleted"
         @milestone-icon-changed="handleMilestoneIconChanged"

demo/version-history.json

@@ -576,5 +576,17 @@
       "🔧 Fixed: GanttToolbar showViewMode:false had no effect due to missing v-if guard",
       "<span style=\"font-weight: bold; color: #f00;\">Special thanks to Andrés Jorge from Berlin, Germany for their use and feedback</span>"
     ]
+  },
+  {
+    "version": "1.9.3",
+    "date": "2026-03-05",
+    "notes": [
+      "🎉 新增：GanttChart 新增 enableTaskDrawerAutoClose 属性，设置为 false 时禁用 TaskDrawer 的自动关闭行为",
+      "🔧 修复：周视图下拖拽 TaskBar 左右移动后任务宽度（持续时间）自动缩短的问题",
+      "<span style=\"font-weight: bold; color: #f00;\">特别感谢来自xuhang513@gitee的使用与反馈</span>",
+      "🎉 Added: GanttChart new prop enableTaskDrawerAutoClose — set to false to disable the automatic closing behavior of the TaskDrawer",
+      "🔧 Fixed: TaskBar width (duration) shrinking after dragging left and right in weekly view",
+      "<span style=\"font-weight: bold; color: #f00;\">Special thanks to xuhang513@gitee for their use and feedback</span>"
+    ]
   }
 ]

package.json

@@ -1,6 +1,6 @@
 {
   "name": "jordium-gantt-vue3",
-  "version": "1.9.2",
+  "version": "1.9.3",
   "type": "module",
   "main": "npm-package/dist/jordium-gantt-vue3.cjs.js",
   "module": "npm-package/dist/jordium-gantt-vue3.es.js",

src/components/GanttChart.vue

@@ -77,6 +77,7 @@ const props = withDefaults(defineProps<Props>(), {
   theme: undefined, // 不设置默认值，允许自动检测系统主题
   enableTaskListCollapsible: true,
   taskListVisible: true,
+  enableTaskDrawerAutoClose: true,
 })
 
 const emit = defineEmits([
@@ -559,6 +560,12 @@ interface Props {
    * 可通过 prop 传入或通过 defineExpose 暴露的方法控制
    */
   taskListVisible?: boolean
+  /**
+   * 是否允许点击遮罩层关闭 TaskDrawer，默认为 true（保持原有行为）
+   * 设置为 false 可防止 TaskDrawer 在失去焦点（点击遮罩区域）时自动关闭
+   * 仅在 useDefaultDrawer=true 时有效
+   */
+  enableTaskDrawerAutoClose?: boolean
 }
 
 // TaskList的固定总长度（所有列的最小宽度之和 + 边框等额外空间）
@@ -1601,31 +1608,30 @@ const tasksForTimeline = computed(() => {
     }
 
     // 递归更新任务树中所有父任务的时间范围（从叶子节点开始向上）
+    // 优化：叶子任务直接返回原引用，避免无效 { ...task } 对象创建
+    // （后续 smartFlattenTasks 会在 spread 时附加 level，不会污染原对象）
     const updateParentDateRanges = (tasks: Task[]): Task[] => {
       return tasks.map(task => {
-        let updatedTask = { ...task }
+        // 叶子任务：无需创建新对象，直接返回原引用
-
+        if (!task.children || task.children.length === 0) {
-        // 先递归更新子任务
+          return task
-        if (task.children && task.children.length > 0) {
-          updatedTask.children = updateParentDateRanges(task.children)
         }
 
-        // 基于任务类型判断是否为父任务
+        // 父任务：先递归处理子任务
-        const isParent =
+        const updatedChildren = updateParentDateRanges(task.children)
-          task.type === 'story' || (updatedTask.children && updatedTask.children.length > 0)
+        const isParent = task.type === 'story' || true
-        updatedTask.isParent = isParent
 
-        // 如果是父任务且有子任务，重新计算时间范围
+        // 重新计算父任务时间范围
-        if (isParent && updatedTask.children && updatedTask.children.length > 0) {
+        const taskWithChildren = { ...task, children: updatedChildren }
-          const { startDate, endDate } = calculateParentDateRange(updatedTask)
+        const { startDate, endDate } = calculateParentDateRange(taskWithChildren)
-          updatedTask = {
+
-            ...updatedTask,
+        return {
-            startDate,
+          ...task,
-            endDate,
+          children: updatedChildren,
-          }
+          isParent,
+          startDate,
+          endDate,
         }
-
-        return updatedTask
       })
     }
 
@@ -3530,6 +3536,7 @@ defineExpose({
       :delay-task-background-color="props.delayTaskBackgroundColor"
       :complete-task-background-color="props.completeTaskBackgroundColor"
       :ongoing-task-background-color="props.ongoingTaskBackgroundColor"
+      :enable-close-on-overlay-click="props.enableTaskDrawerAutoClose"
       @submit="handleTaskDrawerSubmit"
       @close="taskDrawerVisible = false"
       @start-timer="handleStartTimer"

src/components/TaskBar.vue

@@ -1569,8 +1569,14 @@ const handleMouseMove = (e: MouseEvent) => {
       } else {
         // 其他情况：使用原有的简单计算
         const newStartDate = addDaysToLocalDate(props.startDate, newLeft / props.dayWidth)
-        const duration = dragStartWidth.value / props.dayWidth
+
-        const newEndDate = addDaysToLocalDate(newStartDate, duration - 1)
+        // 从原始任务日期计算持续天数，避免从像素宽度反推（dragStartWidth / dayWidth）
+        // 导致的精度损失（WEEK视图 dayWidth=60/7 非整数，parseInt截断后往返计算误差会缩短任务）
+        const originalStartDate = createLocalDate(props.task.startDate) || props.startDate
+        const originalEndDate = createLocalDate(props.task.endDate) || props.startDate
+        const durationMs = originalEndDate.getTime() - originalStartDate.getTime()
+        const duration = Math.round(durationMs / (1000 * 60 * 60 * 24))
+        const newEndDate = addDaysToLocalDate(newStartDate, duration)
 
         // 只更新临时数据，不触发事件
         tempTaskData.value = {

src/components/TaskDrawer.vue

@@ -27,6 +27,8 @@ interface Props {
   delayTaskBackgroundColor?: string
   completeTaskBackgroundColor?: string
   ongoingTaskBackgroundColor?: string
+  /** 是否允许点击遮罩层关闭抽屉，默认为 true（保持原有行为）。设置为 false 可防止失去焦点时自动关闭 */
+  enableCloseOnOverlayClick?: boolean
 }
 
 const props = withDefaults(defineProps<Props>(), {
@@ -45,6 +47,7 @@ const props = withDefaults(defineProps<Props>(), {
   delayTaskBackgroundColor: '#f56c6c',
   completeTaskBackgroundColor: '#67c23a',
   ongoingTaskBackgroundColor: '#409eff',
+  enableCloseOnOverlayClick: true,
 })
 
 const emit = defineEmits<{
@@ -484,7 +487,9 @@ const handleClose = () => {
 
 // 点击遮罩层关闭
 const handleOverlayClick = () => {
-  handleClose()
+  if (props.enableCloseOnOverlayClick) {
+    handleClose()
+  }
 }
 
 // 提交表单

src/components/TaskList/composables/taskList/useTaskListLayout.ts

@@ -65,41 +65,31 @@ export function useTaskListLayout(tasks: Ref<Task[]>) {
   const flattenedTasks = computed(() => getFlattenedVisibleTasks(tasks.value))
 
   /**
-   * v1.9.0 计算每个任务/资源的累计高度位置（支持动态行高）
+   * 资源视图专用：累计高度数组（动态行高，需要数组+二分查找）
+   * 任务视图固定行高，直接用公式计算，不构造此数组，避免 O(n) 分配
    */
   const cumulativeHeights = computed<number[]>(() => {
-    if (viewMode.value === 'resource') {
+    if (viewMode.value !== 'resource') return []
-      // 资源视图：使用每个资源的实际高度
-      const resources = dataSource.value as Resource[]
-      const heights: number[] = [0] // 第一个位置是0
-      let cumulative = 0
 
-      resources.forEach(resource => {
+    const resources = dataSource.value as Resource[]
-        const layout = resourceTaskLayouts.value.get(resource.id)
+    const heights: number[] = [0]
-        const height = layout?.totalHeight || ROW_HEIGHT
+    let cumulative = 0
-        cumulative += height
+    resources.forEach(resource => {
-        heights.push(cumulative)
+      const layout = resourceTaskLayouts.value.get(resource.id)
-      })
+      const height = layout?.totalHeight || ROW_HEIGHT
-
+      cumulative += height
-      return heights
+      heights.push(cumulative)
-    } else {
+    })
-      // 任务视图：使用固定行高
+    return heights
-      const heights: number[] = [0]
-      for (let i = 1; i <= flattenedTasks.value.length; i++) {
-        heights.push(i * ROW_HEIGHT)
-      }
-      return heights
-    }
   })
 
   /**
-   * 根据滚动位置查找对应的任务/资源索引（二分查找）
+   * 资源视图专用：根据滚动位置查找资源索引（二分查找）
    */
   const findIndexByScrollTop = (scrollTop: number): number => {
     const heights = cumulativeHeights.value
     let left = 0
     let right = heights.length - 1
-
     while (left < right) {
       const mid = Math.floor((left + right) / 2)
       if (heights[mid] <= scrollTop) {
@@ -108,38 +98,37 @@ export function useTaskListLayout(tasks: Ref<Task[]>) {
         right = mid
       }
     }
-
     return Math.max(0, left - 1)
   }
 
   /**
-   * 计算可视区域任务范围（支持动态行高）
+   * 计算可视区域任务范围
+   * - 任务视图：固定行高，O(1) 公式直接计算（不依赖 cumulativeHeights）
+   * - 资源视图：动态行高，使用累计高度数组 + 二分查找
    */
   const visibleTaskRange = computed<VisibleTaskRange>(() => {
     const scrollTop = taskListScrollTop.value
     const containerHeight = taskListBodyHeight.value || 600
-    const heights = cumulativeHeights.value
 
-    if (heights.length <= 1) {
+    if (viewMode.value === 'resource') {
-      return { startIndex: 0, endIndex: 0 }
+      const heights = cumulativeHeights.value
-    }
+      if (heights.length <= 1) return { startIndex: 0, endIndex: 0 }
 
-    // 找到起始索引（考虑缓冲区）
+      const total = (dataSource.value as Resource[]).length
-    let startIndex = findIndexByScrollTop(scrollTop)
+      let startIndex = Math.max(0, findIndexByScrollTop(scrollTop) - VERTICAL_BUFFER)
-    startIndex = Math.max(0, startIndex - VERTICAL_BUFFER)
+      const scrollBottom = scrollTop + containerHeight
-
+      let endIndex = Math.min(heights.length - 1, findIndexByScrollTop(scrollBottom) + VERTICAL_BUFFER + 1)
-    // 找到结束索引（考虑缓冲区）
+      return {
-    const scrollBottom = scrollTop + containerHeight
+        startIndex: Math.min(startIndex, total),
-    let endIndex = findIndexByScrollTop(scrollBottom)
+        endIndex: Math.min(endIndex, total),
-    endIndex = Math.min(heights.length - 1, endIndex + VERTICAL_BUFFER + 1)
+      }
-
+    } else {
-    const total = viewMode.value === 'resource'
+      // 任务视图：固定行高 ROW_HEIGHT，O(1) 直接计算，不访问 cumulativeHeights
-      ? (dataSource.value as Resource[]).length
+      const total = flattenedTasks.value.length
-      : flattenedTasks.value.length
+      if (total === 0) return { startIndex: 0, endIndex: 0 }
-
+      const startIndex = Math.max(0, Math.floor(scrollTop / ROW_HEIGHT) - VERTICAL_BUFFER)
-    return {
+      const endIndex = Math.min(total, Math.ceil((scrollTop + containerHeight) / ROW_HEIGHT) + VERTICAL_BUFFER)
-      startIndex: Math.min(startIndex, total),
+      return { startIndex, endIndex }
-      endIndex: Math.min(endIndex, total),
     }
   })
 
@@ -149,7 +138,6 @@ export function useTaskListLayout(tasks: Ref<Task[]>) {
   const visibleTasks = computed<TaskWithLevelAndIndex[]>(() => {
     const { startIndex, endIndex } = visibleTaskRange.value
     const slicedTasks = flattenedTasks.value.slice(startIndex, endIndex)
-    // 添加 rowIndex（基于在扁平化列表中的实际索引）
     return slicedTasks.map((item, index) => ({
       ...item,
       rowIndex: startIndex + index,
@@ -157,22 +145,31 @@ export function useTaskListLayout(tasks: Ref<Task[]>) {
   })
 
   /**
-   * Spacer 高度用于撑起滚动区域（支持动态行高）
+   * Spacer 高度撑起滚动区域
+   * 任务视图：O(1) 乘法；资源视图：从累计高度数组读取
    */
   const totalContentHeight = computed(() => {
-    const heights = cumulativeHeights.value
+    if (viewMode.value === 'resource') {
-    return heights.length > 0 ? heights[heights.length - 1] : 0
+      const heights = cumulativeHeights.value
+      return heights.length > 0 ? heights[heights.length - 1] : 0
+    }
+    return flattenedTasks.value.length * ROW_HEIGHT
   })
 
   const startSpacerHeight = computed(() => {
-    const startIdx = visibleTaskRange.value.startIndex
+    if (viewMode.value === 'resource') {
-    return cumulativeHeights.value[startIdx] || 0
+      return cumulativeHeights.value[visibleTaskRange.value.startIndex] || 0
+    }
+    return visibleTaskRange.value.startIndex * ROW_HEIGHT
   })
 
   const endSpacerHeight = computed(() => {
-    const endIdx = visibleTaskRange.value.endIndex
+    if (viewMode.value === 'resource') {
-    const endHeight = cumulativeHeights.value[endIdx] || 0
+      const endIdx = visibleTaskRange.value.endIndex
-    return Math.max(0, totalContentHeight.value - endHeight)
+      const endHeight = cumulativeHeights.value[endIdx] || 0
+      return Math.max(0, totalContentHeight.value - endHeight)
+    }
+    return Math.max(0, (flattenedTasks.value.length - visibleTaskRange.value.endIndex) * ROW_HEIGHT)
   })
 
   return {