lib-nested/nested/src/index/map_key.rs

pub use {
    crate::{
        core::{
            InnerViewPort, Observer, ObserverBroadcast, ObserverExt, OuterViewPort, View, ViewPort,
        },
        grid::GridView,
        index::{IndexArea, IndexView},
    },
    std::sync::RwLock,
    std::{boxed::Box, sync::Arc},
};

impl<SrcKey, Item> OuterViewPort<dyn IndexView<SrcKey, Item = Item>>
where
    SrcKey: Clone + Send + Sync + 'static,
    Item: 'static,
{
    pub fn map_key<
        DstKey: Clone + Send + Sync + 'static,
        F1: Fn(&SrcKey) -> DstKey + Send + Sync + 'static,
        F2: Fn(&DstKey) -> Option<SrcKey> + Send + Sync + 'static,
    >(
        &self,
        f1: F1,
        f2: F2,
    ) -> OuterViewPort<dyn IndexView<DstKey, Item = Item>> {
        let port = ViewPort::new();
        port.add_update_hook(Arc::new(self.0.clone()));

        let map = MapIndexKey::new(port.inner(), f1, f2);
        self.add_observer(map.clone());
        port.into_outer()
    }
}

impl<Item> OuterViewPort<dyn IndexView<usize, Item = Item>>
where
    Item: 'static,
{
    pub fn to_grid_horizontal(&self) -> OuterViewPort<dyn GridView<Item = Item>> {
        self.map_key(
            |idx| cgmath::Point2::new(*idx as i16, 0),
            |pt| if pt.y == 0 { Some(pt.x as usize) } else { None },
        )
    }

    pub fn to_grid_vertical(&self) -> OuterViewPort<dyn GridView<Item = Item>> {
        self.map_key(
            |idx| cgmath::Point2::new(0, *idx as i16),
            |pt| if pt.x == 0 { Some(pt.y as usize) } else { None },
        )
    }
}

pub struct MapIndexKey<DstKey, SrcKey, SrcView, F1, F2>
where
    DstKey: Clone + Send + Sync,
    SrcKey: Clone + Send + Sync,
    SrcView: IndexView<SrcKey> + ?Sized,
    F1: Fn(&SrcKey) -> DstKey + Send + Sync,
    F2: Fn(&DstKey) -> Option<SrcKey> + Send + Sync,
{
    src_view: Option<Arc<SrcView>>,
    f1: F1,
    f2: F2,
    cast: Arc<RwLock<ObserverBroadcast<dyn IndexView<DstKey, Item = SrcView::Item>>>>,
}

impl<DstKey, SrcKey, SrcView, F1, F2> MapIndexKey<DstKey, SrcKey, SrcView, F1, F2>
where
    DstKey: Clone + Send + Sync + 'static,
    SrcKey: Clone + Send + Sync + 'static,
    SrcView: IndexView<SrcKey> + ?Sized + 'static,
    SrcView::Item: 'static,
    F1: Fn(&SrcKey) -> DstKey + Send + Sync + 'static,
    F2: Fn(&DstKey) -> Option<SrcKey> + Send + Sync + 'static,
{
    fn new(
        port: InnerViewPort<dyn IndexView<DstKey, Item = SrcView::Item>>,
        f1: F1,
        f2: F2,
    ) -> Arc<RwLock<Self>> {
        let map = Arc::new(RwLock::new(MapIndexKey {
            src_view: None,
            f1,
            f2,
            cast: port.get_broadcast(),
        }));

        port.set_view(Some(map.clone()));
        map
    }
}

impl<DstKey, SrcKey, SrcView, F1, F2> View for MapIndexKey<DstKey, SrcKey, SrcView, F1, F2>
where
    DstKey: Clone + Send + Sync,
    SrcKey: Clone + Send + Sync,
    SrcView: IndexView<SrcKey> + ?Sized,
    F1: Fn(&SrcKey) -> DstKey + Send + Sync,
    F2: Fn(&DstKey) -> Option<SrcKey> + Send + Sync,
{
    type Msg = IndexArea<DstKey>;
}

impl<DstKey, SrcKey, SrcView, F1, F2> IndexView<DstKey>
    for MapIndexKey<DstKey, SrcKey, SrcView, F1, F2>
where
    DstKey: Clone + Send + Sync,
    SrcKey: Clone + Send + Sync,
    SrcView: IndexView<SrcKey> + ?Sized,
    F1: Fn(&SrcKey) -> DstKey + Send + Sync,
    F2: Fn(&DstKey) -> Option<SrcKey> + Send + Sync,
{
    type Item = SrcView::Item;

    fn get(&self, key: &DstKey) -> Option<Self::Item> {
        self.src_view.get(&(self.f2)(key)?)
    }

    fn area(&self) -> IndexArea<DstKey> {
        self.src_view.area().map(&self.f1)
    }
}

impl<DstKey, SrcKey, SrcView, F1, F2> Observer<SrcView>
    for MapIndexKey<DstKey, SrcKey, SrcView, F1, F2>
where
    DstKey: Clone + Send + Sync,
    SrcKey: Clone + Send + Sync,
    SrcView: IndexView<SrcKey> + ?Sized,
    F1: Fn(&SrcKey) -> DstKey + Send + Sync,
    F2: Fn(&DstKey) -> Option<SrcKey> + Send + Sync,
{
    fn reset(&mut self, view: Option<Arc<SrcView>>) {
        let old_area = self.area();
        self.src_view = view;
        self.cast.notify(&old_area);
        self.cast.notify(&self.area());
    }

    fn notify(&mut self, msg: &IndexArea<SrcKey>) {
        self.cast.notify(&msg.map(&self.f1));
    }
}