use gpui::{    div, prelude::*, px, rgb, size, App, Application, Bounds, Context, SharedString, Timer, Window,    WindowBounds, WindowKind, WindowOptions,}; struct SubWindow {    custom_titlebar: bool,} fn button(text: &str, on_click: impl Fn(&mut Window, &mut App) + 'static) -> impl IntoElement {    div()        .id(SharedString::from(text.to_string()))        .flex_none()        .px_2()        .bg(rgb(0xf7f7f7))        .active(|this| this.opacity(0.85))        .border_1()        .border_color(rgb(0xe0e0e0))        .rounded_md()        .cursor_pointer()        .child(text.to_string())        .on_click(move |_, window, cx| on_click(window, cx))} impl Render for SubWindow {    fn render(&mut self, _window: &mut Window, _: &mut Context<Self>) -> impl IntoElement {        div()            .flex()            .flex_col()            .bg(rgb(0xffffff))            .size_full()            .gap_2()            .when(self.custom_titlebar, |cx| {                cx.child(                    div()                        .flex()                        .h(px(32.))                        .px_4()                        .bg(gpui::blue())                        .text_color(gpui::white())                        .w_full()                        .child(                            div()                                .flex()                                .items_center()                                .justify_center()                                .size_full()                                .child("Custom Titlebar"),                        ),                )            })            .child(                div()                    .p_8()                    .gap_2()                    .child("SubWindow")                    .child(button("Close", |window, _| {                        window.remove_window();                    })),            )    }} struct WindowDemo {} impl Render for WindowDemo {    fn render(&mut self, _window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {        let window_bounds =            WindowBounds::Windowed(Bounds::centered(None, size(px(300.0), px(300.0)), cx));         div()            .p_4()            .flex()            .flex_wrap()            .bg(rgb(0xffffff))            .size_full()            .justify_center()            .items_center()            .gap_2()            .child(button("Normal", move |_, cx| {                cx.open_window(                    WindowOptions {                        window_bounds: Some(window_bounds),                        ..Default::default()                    },                    |_, cx| {                        cx.new(|_| SubWindow {                            custom_titlebar: false,                        })                    },                )                .unwrap();            }))            .child(button("Popup", move |_, cx| {                cx.open_window(                    WindowOptions {                        window_bounds: Some(window_bounds),                        kind: WindowKind::PopUp,                        ..Default::default()                    },                    |_, cx| {                        cx.new(|_| SubWindow {                            custom_titlebar: false,                        })                    },                )                .unwrap();            }))            .child(button("Custom Titlebar", move |_, cx| {                cx.open_window(                    WindowOptions {                        titlebar: None,                        window_bounds: Some(window_bounds),                        ..Default::default()                    },                    |_, cx| {                        cx.new(|_| SubWindow {                            custom_titlebar: true,                        })                    },                )                .unwrap();            }))            .child(button("Invisible", move |_, cx| {                cx.open_window(                    WindowOptions {                        show: false,                        window_bounds: Some(window_bounds),                        ..Default::default()                    },                    |_, cx| {                        cx.new(|_| SubWindow {                            custom_titlebar: false,                        })                    },                )                .unwrap();            }))            .child(button("Unmovable", move |_, cx| {                cx.open_window(                    WindowOptions {                        is_movable: false,                        titlebar: None,                        window_bounds: Some(window_bounds),                        ..Default::default()                    },                    |_, cx| {                        cx.new(|_| SubWindow {                            custom_titlebar: false,                        })                    },                )                .unwrap();            }))            .child(button("Hide Application", |window, cx| {                cx.hide();                 // Restore the application after 3 seconds                window                    .spawn(cx, |mut cx| async move {                        Timer::after(std::time::Duration::from_secs(3)).await;                        cx.update(|_, cx| {                            cx.activate(false);                        })                    })                    .detach();            }))    }} fn main() {    Application::new().run(|cx: &mut App| {        let bounds = Bounds::centered(None, size(px(800.0), px(600.0)), cx);        cx.open_window(            WindowOptions {                window_bounds: Some(WindowBounds::Windowed(bounds)),                ..Default::default()            },            |_, cx| cx.new(|_| WindowDemo {}),        )        .unwrap();    });}