MoonZoon error box

moonzoon_error_box__main.rs

use std::any::Any;
use zoon::{once_cell::sync::Lazy, *, named_color::*};

fn main() {
    start_app("app", root);
}

#[derive(Clone, Copy)]
struct DecreaseButtonPressed;
#[derive(Clone, Copy)]
struct IncreaseButtonPressed;
#[derive(Clone, Copy)]
struct CloseButtonPressed;

static COUNTER: Lazy<Mutable<i32>> = Lazy::new(|| {
    on(|DecreaseButtonPressed| *COUNTER.lock_mut() -= 1);
    on(|IncreaseButtonPressed| *COUNTER.lock_mut() += 1);
    Mutable::new(0)
});

static ERROR_BOX_VISIBLE: Lazy<Mutable<bool>> = Lazy::new(|| {
    on(|CloseButtonPressed| ERROR_BOX_VISIBLE.set(false));
    Mutable::new(true)
});

fn root() -> impl Element {
    Stack::new()
        .s(Height::screen())
        .layer(counter())
        .layer_signal(ERROR_BOX_VISIBLE.signal().map_true(error_box))
}

fn error_box() -> impl Element {
    Row::new()
        .s(Align::center())
        .s(Borders::all(Border::new()))
        .s(Gap::new().x(20))
        .s(Background::new().color(named_color::RED_3))
        .s(Padding::new().x(20).y(10))
        .s(RoundedCorners::all(5))
        .item("Error!")
        .item({
            let (hovered, hovered_signal) = Mutable::new_and_signal(false);
            Button::new()
                .s(Borders::all(Border::new()))
                .s(RoundedCorners::all_max())
                .s(Padding::all(10))
                .s(Background::new().color_signal(hovered_signal.map_bool(|| GRAY_3, || GRAY_4)))
                .label("X")
                .on_hovered_change(move |is_hovered| hovered.set(is_hovered))
                .on_press(|| emit(CloseButtonPressed))
        })
}

fn counter() -> impl Element {
    Row::new()
        .s(Align::center())
        .s(Gap::new().x(15))
        .item(counter_button("-", DecreaseButtonPressed))
        .item_signal(COUNTER.signal())
        .item(counter_button("+", IncreaseButtonPressed))
}

fn counter_button(label: &str, app_event: impl Any + Copy) -> impl Element {
    let (hovered, hovered_signal) = Mutable::new_and_signal(false);
    Button::new()
        .s(Width::exact(45))
        .s(RoundedCorners::all_max())
        .s(Background::new()
            .color_signal(hovered_signal.map_bool(|| hsluv!(300, 75, 85), || hsluv!(300, 75, 75))))
        .on_hovered_change(move |is_hovered| hovered.set(is_hovered))
        .label(label)
        .on_press(move || emit(app_event))
}