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This PR improves the performance of the `Listbox` component. Before this PR, the `Listbox` component is built in a way where all the state lives in the `Listbox` itself. If state changes, everything re-renders and re-computes the necessary derived state. However, if you have a 1000 options, then every time the active option changes, all 1000 options have to re-render. To solve this, we can move the state outside of the `Listbox` component, and "subscribe" to state changes using the `useSlice` hook introduced in https://github.com/tailwindlabs/headlessui/pull/3684. This will allow us to subscribe to a slice of the state, and only re-render if the computed slice actually changes. If the active option changes, only 3 things will happen: 1. The `ListboxOptions` will re-render and have an updated `aria-activedescendant` 2. The `ListboxOption` that _was_ active, will re-render and the `data-focus` attribute wil be removed. 3. The `ListboxOption` that is now active, will re-render and the `data-focus` attribute wil be added. Another improvement is that in order to make sure that your arrow keys go to the correct option, we need to sort the DOM nodes and make sure that we go to the correct option when using arrow up and down. This sorting was happening every time a new `ListboxOption` was registered. Luckily, once an array is sorted, you don't have to do a lot, but you still have to loop over `n` options which is not ideal. This PR will now delay the sorting until all `ListboxOption`s are registered. On that note, we also batch the `RegisterOption` so we can perform a single update instead of `n` updates. We use a microTask for the batching (so if you only are registering a single option, you don't have to wait compared to a `setTimeout` or a `requestAnimationFrame`). ## Test plan 1. All tests still pass 2. Tested this in the browser with a 2000 options. In the videos below the only thing I'm doing is holding down the `ArrowDown` key. Before: https://github.com/user-attachments/assets/a2850c84-57f6-428a-aa51-e6f83d2aee97 After: https://github.com/user-attachments/assets/157c6e99-5da8-4d72-87c6-a5e34f122531
@headlessui/react
A set of completely unstyled, fully accessible UI components for React, designed to integrate beautifully with Tailwind CSS.
Installation
npm install @headlessui/react
Documentation
For full documentation, visit headlessui.dev.
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