lib-nested/nested/src/terminal/compositor.rs

use {
    std::{
        sync::{Arc}
    },
    std::sync::RwLock,
    cgmath::Point2,
    crate::{
        core::{InnerViewPort, OuterViewPort, View, Observer, ObserverBroadcast},
        index::{IndexArea, IndexView},
        terminal::{TerminalAtom, TerminalView},
        projection::ProjectionHelper
    }
};

//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>

pub struct TerminalCompositor {
    layers: Vec<Arc<dyn TerminalView>>,
    cast: Arc<RwLock<ObserverBroadcast<dyn TerminalView>>>,
    proj_helper: ProjectionHelper<usize, Self>
}

//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>

impl TerminalCompositor {
    pub fn new(
        port: InnerViewPort<dyn TerminalView>
    ) -> Arc<RwLock<Self>> {
        let comp = Arc::new(RwLock::new(
            TerminalCompositor {
                layers: Vec::new(),
                cast: port.get_broadcast(),
                proj_helper: ProjectionHelper::new(port.0.update_hooks.clone())
            }
        ));

        comp.write().unwrap().proj_helper.set_proj(&comp);
        port.set_view(Some(comp.clone()));

        comp
    }

    pub fn push(&mut self, v: OuterViewPort<dyn TerminalView>) {
        let idx = self.layers.len();
        self.layers.push(
            self.proj_helper.new_index_arg(
                idx,
                v,
                |s: &mut Self, area| {
                    s.cast.notify(area);
                }
            )
        );
    }
}

//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>

impl View for TerminalCompositor {
    type Msg = IndexArea<Point2<i16>>;
}

impl IndexView<Point2<i16>> for TerminalCompositor {
    type Item = TerminalAtom;

    fn get(&self, pos: &Point2<i16>) -> Option<TerminalAtom> {
        let mut atom = None;

        for layer in self.layers.iter() {
            match (atom, layer.get(pos)) {
                (None, next) => atom = next,
                (Some(last), Some(next)) => atom = Some(next.add_style_back(last.style)),
                _ => {}
            }
        }

        atom
    }

    fn area(&self) -> IndexArea<Point2<i16>> {
        let mut area = IndexArea::Empty;

        for layer in self.layers.iter() {
            area = area.union(layer.area());
        }

        area
    }
}