use std::{cell::RefCell, rc::Rc}; use gpui::{    anchored, deferred, div, px, AnyElement, App, Bounds, Corner, DismissEvent, DispatchPhase,    Element, ElementId, Entity, Focusable as _, GlobalElementId, Hitbox, InteractiveElement,    IntoElement, LayoutId, ManagedView, MouseButton, MouseDownEvent, ParentElement, Pixels, Point,    Window,}; pub struct RightClickMenu<M: ManagedView> {    id: ElementId,    child_builder: Option<Box<dyn FnOnce(bool) -> AnyElement + 'static>>,    menu_builder: Option<Rc<dyn Fn(&mut Window, &mut App) -> Entity<M> + 'static>>,    anchor: Option<Corner>,    attach: Option<Corner>,} impl<M: ManagedView> RightClickMenu<M> {    pub fn menu(mut self, f: impl Fn(&mut Window, &mut App) -> Entity<M> + 'static) -> Self {        self.menu_builder = Some(Rc::new(f));        self    }     pub fn trigger<E: IntoElement + 'static>(mut self, e: E) -> Self {        self.child_builder = Some(Box::new(move |_| e.into_any_element()));        self    }     /// anchor defines which corner of the menu to anchor to the attachment point    /// (by default the cursor position, but see attach)    pub fn anchor(mut self, anchor: Corner) -> Self {        self.anchor = Some(anchor);        self    }     /// attach defines which corner of the handle to attach the menu's anchor to    pub fn attach(mut self, attach: Corner) -> Self {        self.attach = Some(attach);        self    }     fn with_element_state<R>(        &mut self,        global_id: &GlobalElementId,        window: &mut Window,        cx: &mut App,        f: impl FnOnce(&mut Self, &mut MenuHandleElementState<M>, &mut Window, &mut App) -> R,    ) -> R {        window.with_optional_element_state::<MenuHandleElementState<M>, _>(            Some(global_id),            |element_state, window| {                let mut element_state = element_state.unwrap().unwrap_or_default();                let result = f(self, &mut element_state, window, cx);                (result, Some(element_state))            },        )    }} /// Creates a [`RightClickMenu`]pub fn right_click_menu<M: ManagedView>(id: impl Into<ElementId>) -> RightClickMenu<M> {    RightClickMenu {        id: id.into(),        child_builder: None,        menu_builder: None,        anchor: None,        attach: None,    }} pub struct MenuHandleElementState<M> {    menu: Rc<RefCell<Option<Entity<M>>>>,    position: Rc<RefCell<Point<Pixels>>>,} impl<M> Clone for MenuHandleElementState<M> {    fn clone(&self) -> Self {        Self {            menu: Rc::clone(&self.menu),            position: Rc::clone(&self.position),        }    }} impl<M> Default for MenuHandleElementState<M> {    fn default() -> Self {        Self {            menu: Rc::default(),            position: Rc::default(),        }    }} pub struct RequestLayoutState {    child_layout_id: Option<LayoutId>,    child_element: Option<AnyElement>,    menu_element: Option<AnyElement>,} pub struct PrepaintState {    hitbox: Hitbox,    child_bounds: Option<Bounds<Pixels>>,} impl<M: ManagedView> Element for RightClickMenu<M> {    type RequestLayoutState = RequestLayoutState;    type PrepaintState = PrepaintState;     fn id(&self) -> Option<ElementId> {        Some(self.id.clone())    }     fn request_layout(        &mut self,        id: Option<&GlobalElementId>,        window: &mut Window,        cx: &mut App,    ) -> (gpui::LayoutId, Self::RequestLayoutState) {        self.with_element_state(            id.unwrap(),            window,            cx,            |this, element_state, window, cx| {                let mut menu_layout_id = None;                 let menu_element = element_state.menu.borrow_mut().as_mut().map(|menu| {                    let mut anchored = anchored().snap_to_window_with_margin(px(8.));                    if let Some(anchor) = this.anchor {                        anchored = anchored.anchor(anchor);                    }                    anchored = anchored.position(*element_state.position.borrow());                     let mut element = deferred(anchored.child(div().occlude().child(menu.clone())))                        .with_priority(1)                        .into_any();                     menu_layout_id = Some(element.request_layout(window, cx));                    element                });                 let mut child_element = this                    .child_builder                    .take()                    .map(|child_builder| (child_builder)(element_state.menu.borrow().is_some()));                 let child_layout_id = child_element                    .as_mut()                    .map(|child_element| child_element.request_layout(window, cx));                 let layout_id = window.request_layout(                    gpui::Style::default(),                    menu_layout_id.into_iter().chain(child_layout_id),                    cx,                );                 (                    layout_id,                    RequestLayoutState {                        child_element,                        child_layout_id,                        menu_element,                    },                )            },        )    }     fn prepaint(        &mut self,        _id: Option<&GlobalElementId>,        bounds: Bounds<Pixels>,        request_layout: &mut Self::RequestLayoutState,        window: &mut Window,        cx: &mut App,    ) -> PrepaintState {        let hitbox = window.insert_hitbox(bounds, false);         if let Some(child) = request_layout.child_element.as_mut() {            child.prepaint(window, cx);        }         if let Some(menu) = request_layout.menu_element.as_mut() {            menu.prepaint(window, cx);        }         PrepaintState {            hitbox,            child_bounds: request_layout                .child_layout_id                .map(|layout_id| window.layout_bounds(layout_id)),        }    }     fn paint(        &mut self,        id: Option<&GlobalElementId>,        _bounds: Bounds<gpui::Pixels>,        request_layout: &mut Self::RequestLayoutState,        prepaint_state: &mut Self::PrepaintState,        window: &mut Window,        cx: &mut App,    ) {        self.with_element_state(            id.unwrap(),            window,            cx,            |this, element_state, window, cx| {                if let Some(mut child) = request_layout.child_element.take() {                    child.paint(window, cx);                }                 if let Some(mut menu) = request_layout.menu_element.take() {                    menu.paint(window, cx);                    return;                }                 let Some(builder) = this.menu_builder.take() else {                    return;                };                 let attach = this.attach;                let menu = element_state.menu.clone();                let position = element_state.position.clone();                let child_bounds = prepaint_state.child_bounds;                 let hitbox_id = prepaint_state.hitbox.id;                window.on_mouse_event(move |event: &MouseDownEvent, phase, window, cx| {                    if phase == DispatchPhase::Bubble                        && event.button == MouseButton::Right                        && hitbox_id.is_hovered(window)                    {                        cx.stop_propagation();                        window.prevent_default();                         let new_menu = (builder)(window, cx);                        let menu2 = menu.clone();                        let previous_focus_handle = window.focused(cx);                         window                            .subscribe(&new_menu, cx, move |modal, _: &DismissEvent, window, cx| {                                if modal.focus_handle(cx).contains_focused(window, cx) {                                    if let Some(previous_focus_handle) =                                        previous_focus_handle.as_ref()                                    {                                        window.focus(previous_focus_handle);                                    }                                }                                *menu2.borrow_mut() = None;                                window.refresh();                            })                            .detach();                        window.focus(&new_menu.focus_handle(cx));                        *menu.borrow_mut() = Some(new_menu);                        *position.borrow_mut() = if let Some(child_bounds) = child_bounds {                            if let Some(attach) = attach {                                child_bounds.corner(attach)                            } else {                                window.mouse_position()                            }                        } else {                            window.mouse_position()                        };                        window.refresh();                    }                });            },        )    }} impl<M: ManagedView> IntoElement for RightClickMenu<M> {    type Element = Self;     fn into_element(self) -> Self::Element {        self    }}