//! # Component Preview//!//! A view for exploring Zed components. use component::{components, ComponentMetadata};use gpui::{list, prelude::*, uniform_list, App, EventEmitter, FocusHandle, Focusable, Window};use gpui::{ListState, ScrollHandle, UniformListScrollHandle};use ui::{prelude::*, ListItem}; use workspace::{item::ItemEvent, Item, Workspace, WorkspaceId}; pub fn init(cx: &mut App) {    cx.observe_new(|workspace: &mut Workspace, _, _cx| {        workspace.register_action(            |workspace, _: &workspace::OpenComponentPreview, window, cx| {                let component_preview = cx.new(|cx| ComponentPreview::new(window, cx));                workspace.add_item_to_active_pane(                    Box::new(component_preview),                    None,                    true,                    window,                    cx,                )            },        );    })    .detach();} struct ComponentPreview {    focus_handle: FocusHandle,    _view_scroll_handle: ScrollHandle,    nav_scroll_handle: UniformListScrollHandle,    components: Vec<ComponentMetadata>,    component_list: ListState,    selected_index: usize,} impl ComponentPreview {    pub fn new(_window: &mut Window, cx: &mut Context<Self>) -> Self {        let components = components().all_sorted();        let initial_length = components.len();         let component_list = ListState::new(initial_length, gpui::ListAlignment::Top, px(500.0), {            let this = cx.entity().downgrade();            move |ix, window: &mut Window, cx: &mut App| {                this.update(cx, |this, cx| {                    this.render_preview(ix, window, cx).into_any_element()                })                .unwrap()            }        });         Self {            focus_handle: cx.focus_handle(),            _view_scroll_handle: ScrollHandle::new(),            nav_scroll_handle: UniformListScrollHandle::new(),            components,            component_list,            selected_index: 0,        }    }     fn scroll_to_preview(&mut self, ix: usize, cx: &mut Context<Self>) {        self.component_list.scroll_to_reveal_item(ix);        self.selected_index = ix;        cx.notify();    }     fn get_component(&self, ix: usize) -> ComponentMetadata {        self.components[ix].clone()    }     fn render_sidebar_entry(        &self,        ix: usize,        selected: bool,        cx: &Context<Self>,    ) -> impl IntoElement {        let component = self.get_component(ix);         ListItem::new(ix)            .child(Label::new(component.name().clone()).color(Color::Default))            .selectable(true)            .toggle_state(selected)            .inset(true)            .on_click(cx.listener(move |this, _, _, cx| {                this.scroll_to_preview(ix, cx);            }))    }     fn render_preview(        &self,        ix: usize,        window: &mut Window,        cx: &Context<Self>,    ) -> impl IntoElement {        let component = self.get_component(ix);         let name = component.name();        let scope = component.scope();         let description = component.description();         v_flex()            .py_2()            .child(                v_flex()                    .border_1()                    .border_color(cx.theme().colors().border)                    .rounded_md()                    .w_full()                    .gap_4()                    .py_4()                    .px_6()                    .flex_none()                    .child(                        v_flex()                            .gap_1()                            .child(                                h_flex()                                    .gap_1()                                    .text_xl()                                    .child(div().child(name))                                    .when_some(scope, |this, scope| {                                        this.child(div().opacity(0.5).child(format!("({})", scope)))                                    }),                            )                            .when_some(description, |this, description| {                                this.child(                                    div()                                        .text_ui_sm(cx)                                        .text_color(cx.theme().colors().text_muted)                                        .max_w(px(600.0))                                        .child(description),                                )                            }),                    )                    .when_some(component.preview(), |this, preview| {                        this.child(preview(window, cx))                    }),            )            .into_any_element()    }} impl Render for ComponentPreview {    fn render(&mut self, _window: &mut Window, cx: &mut Context<'_, Self>) -> impl IntoElement {        h_flex()            .id("component-preview")            .key_context("ComponentPreview")            .items_start()            .overflow_hidden()            .size_full()            .track_focus(&self.focus_handle)            .px_2()            .bg(cx.theme().colors().editor_background)            .child(                uniform_list(                    cx.entity().clone(),                    "component-nav",                    self.components.len(),                    move |this, range, _window, cx| {                        range                            .map(|ix| this.render_sidebar_entry(ix, ix == this.selected_index, cx))                            .collect()                    },                )                .track_scroll(self.nav_scroll_handle.clone())                .pt_4()                .w(px(240.))                .h_full()                .flex_grow(),            )            .child(                v_flex()                    .id("component-list")                    .px_8()                    .pt_4()                    .size_full()                    .child(                        list(self.component_list.clone())                            .flex_grow()                            .with_sizing_behavior(gpui::ListSizingBehavior::Auto),                    ),            )    }} impl EventEmitter<ItemEvent> for ComponentPreview {} impl Focusable for ComponentPreview {    fn focus_handle(&self, _: &App) -> gpui::FocusHandle {        self.focus_handle.clone()    }} impl Item for ComponentPreview {    type Event = ItemEvent;     fn tab_content_text(&self, _window: &Window, _cx: &App) -> Option<SharedString> {        Some("Component Preview".into())    }     fn telemetry_event_text(&self) -> Option<&'static str> {        None    }     fn show_toolbar(&self) -> bool {        false    }     fn clone_on_split(        &self,        _workspace_id: Option<WorkspaceId>,        window: &mut Window,        cx: &mut Context<Self>,    ) -> Option<gpui::Entity<Self>>    where        Self: Sized,    {        Some(cx.new(|cx| Self::new(window, cx)))    }     fn to_item_events(event: &Self::Event, mut f: impl FnMut(workspace::item::ItemEvent)) {        f(*event)    }}