mirui 0.41.0

A lightweight, no_std ECS-driven UI framework for embedded, desktop, and WebAssembly
Documentation 
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#[cfg(feature = "std")]
use crate::app::plugins::StdInstantClockPlugin;
use crate::prelude::*;
use crate::ui::IdMap;
use crate::ui::dirty::Dirty;
use crate::ui::widgets::{TabBar, Text};
use alloc::format;

#[derive(Clone, Copy, Default)]
pub struct SelectionStats {
    pub last_new: u8,
    pub last_old: u8,
    pub changes: u32,
}

/// 3-tab TabBar with `on SelectionChanged` callback.
///
/// # Required plugins
/// - [`StdInstantClockPlugin`] — gesture timing
///
/// # Resources auto-inserted
/// - [`IdMap`] (if absent) — `find_by_id("selection_label")`
/// - [`SelectionStats`] (if absent) — populated by the handler
#[compose]
pub fn build_widgets() {
    if cx.world_mut().resource::<IdMap>().is_none() {
        cx.world_mut().insert_resource(IdMap::new());
    }
    if cx.world_mut().resource::<SelectionStats>().is_none() {
        cx.world_mut().insert_resource(SelectionStats::default());
    }

    //~focus-start
    ui! {
        Column (grow: 1.0, padding: Padding::all(20)) {
            Text (
                "selected: 0 (was 0, 0 changes)",
                id: "selection_label",
                height: 30
            )
            TabBar (width: 440, height: 44) on SelectionChanged {
                if let Some(s) = ctx.world.resource_mut::<SelectionStats>() {
                    s.last_new = *new;
                    s.last_old = *old;
                    s.changes += 1;
                }
                refresh_label(ctx.world);
            }
        }
    };
    //~focus-end

    let bars = cx.world_mut().query::<TabBar>().collect();
    if let Some(&bar) = bars.first()
        && let Some(tb) = cx.world_mut().get_mut::<TabBar>(bar)
    {
        tb.count = 3;
    }
}

#[cfg(feature = "std")]
pub fn setup_app<B, F>(app: &mut App<B, F>, parent: Entity)
where
    B: Surface,
    F: RendererFactory<B>,
{
    app.add_plugin(StdInstantClockPlugin);
    app.compose(parent, build_widgets);
}

fn refresh_label(world: &mut World) {
    let stats = world
        .resource::<SelectionStats>()
        .copied()
        .unwrap_or_default();
    let text = format!(
        "selected: {} (was {}, {} changes)",
        stats.last_new, stats.last_old, stats.changes,
    );
    let label = match world.find_by_id("selection_label") {
        Some(e) => e,
        None => return,
    };
    if let Some(t) = world.get_mut::<Text>(label) {
        *t = Text::from(text);
    }
    world.insert(label, Dirty);
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::ui::Children;
    use crate::ui::UiScope;

    #[test]
    fn build_widgets_smoke() {
        let mut world = World::new();
        let parent = WidgetBuilder::new(&mut world).id();
        let mut cx = UiScope::new(&mut world, parent);
        build_widgets(&mut cx);
        drop(cx);
        assert!(
            world
                .get::<Children>(parent)
                .is_some_and(|c| !c.0.is_empty())
        );
        assert!(world.resource::<SelectionStats>().is_some());
    }
}