use crate::prelude::*;use gpui::{AnyElement, FocusHandle, ScrollAnchor, ScrollHandle}; /// An element that can be navigated through via keyboard. Intended for use with scrollable views that want to usepub struct Navigable {    child: AnyElement,    selectable_children: Vec<NavigableEntry>,} /// An entry of [Navigable] that can be navigated to.#[derive(Clone)]pub struct NavigableEntry {    #[allow(missing_docs)]    pub focus_handle: FocusHandle,    #[allow(missing_docs)]    pub scroll_anchor: Option<ScrollAnchor>,} impl NavigableEntry {    /// Creates a new [NavigableEntry] for a given scroll handle.    pub fn new(scroll_handle: &ScrollHandle, cx: &mut App) -> Self {        Self {            focus_handle: cx.focus_handle(),            scroll_anchor: Some(ScrollAnchor::for_handle(scroll_handle.clone())),        }    }    /// Create a new [NavigableEntry] that cannot be scrolled to.    pub fn focusable(cx: &mut App) -> Self {        Self {            focus_handle: cx.focus_handle(),            scroll_anchor: None,        }    }}impl Navigable {    /// Creates new empty [Navigable] wrapper.    pub fn new(child: AnyElement) -> Self {        Self {            child,            selectable_children: vec![],        }    }     /// Add a new entry that can be navigated to via keyboard.    ///    /// The order of calls to [Navigable::entry] determines the order of traversal of    /// elements via successive uses of `menu:::SelectNext/SelectPrev`    pub fn entry(mut self, child: NavigableEntry) -> Self {        self.selectable_children.push(child);        self    }     fn find_focused(        selectable_children: &[NavigableEntry],        window: &mut Window,        cx: &mut App,    ) -> Option<usize> {        selectable_children            .iter()            .position(|entry| entry.focus_handle.contains_focused(window, cx))    }} impl RenderOnce for Navigable {    fn render(self, _window: &mut Window, _: &mut App) -> impl crate::IntoElement {        div()            .on_action({                let children = self.selectable_children.clone();                 move |_: &menu::SelectNext, window, cx| {                    let target = Self::find_focused(&children, window, cx)                        .and_then(|index| {                            index.checked_add(1).filter(|index| *index < children.len())                        })                        .unwrap_or(0);                    if let Some(entry) = children.get(target) {                        entry.focus_handle.focus(window);                        if let Some(anchor) = &entry.scroll_anchor {                            anchor.scroll_to(window, cx);                        }                    }                }            })            .on_action({                let children = self.selectable_children;                move |_: &menu::SelectPrev, window, cx| {                    let target = Self::find_focused(&children, window, cx)                        .and_then(|index| index.checked_sub(1))                        .or(children.len().checked_sub(1));                    if let Some(entry) = target.and_then(|target| children.get(target)) {                        entry.focus_handle.focus(window);                        if let Some(anchor) = &entry.scroll_anchor {                            anchor.scroll_to(window, cx);                        }                    }                }            })            .size_full()            .child(self.child)    }}