flutter pub add visibility_detector根據套件公開資料產生的選型評估，僅供參考。
visibility_detector 套件提供了一個監視其子組件是否在螢幕上可見的元件。當子組件進入或離開畫面範圍時，會觸發回呼，以實現高效渲染與效能最佳化。非常適合用於懶加載內容、動畫，或追蹤使用者對特定 UI 元素的參與度。此套件支援所有主要平台，包括 Android、iOS、Web、macOS、Windows 與 Linux，讓跨平台應用具有高度的彈性。
以下為關聯原始碼儲存庫的 README 原文快照，最新內容請造訪原始碼儲存庫。
This repository contains the source code for various Flutter widgets that are developed by Google but not by the core Flutter team.
The product and source code here are neither endorsed by Google nor the Flutter team. They are mainly made available as a reference. Support is best-effort.
| Package | Description | Version |
|---|---|---|
| flutter_simple_treeview | A widget, that visualises a tree structure, where a node can be any widget. |  |
| linked_scroll_controller | A scroll controller that allows two or more scroll views to be in sync. |  |
| scrollable_positioned_list | A list with helper methods to programmatically scroll to an item. |  |
| self_storing_input | A set of input widgets that automatically save and load the entered value to a data store. |  |
| visibility_detector | A widget that detects the visibility of its child and notifies a callback. |  |
Please file any issues, bugs, or feature requests in the this repo.
If you wish to contribute a change to any of the existing widgets in this repo, please review our contribution guide, and send a pull request.