lib-nested/nested/src/sequence/seq2idx.rs

81 lines
2.2 KiB
Rust

use {
std::{
sync::Arc
},
std::sync::RwLock,
crate::{
core::{
View, Observer, ObserverExt, ObserverBroadcast,
ViewPort, InnerViewPort, OuterViewPort
},
sequence::SequenceView,
index::IndexView
}
};
/// Transforms a SequenceView into IndexView<usize>
pub struct Sequence2Index<SrcView>
where SrcView: SequenceView + ?Sized + 'static {
src_view: Option<Arc<SrcView>>,
cast: Arc<RwLock<ObserverBroadcast<dyn IndexView<usize, Item = SrcView::Item>>>>
}
impl<SrcView> Sequence2Index<SrcView>
where SrcView: SequenceView + ?Sized + 'static {
pub fn new(
port: InnerViewPort<dyn IndexView<usize, Item = SrcView::Item>>
) -> Arc<RwLock<Self>> {
let s2i = Arc::new(RwLock::new(
Sequence2Index {
src_view: None,
cast: port.get_broadcast()
}
));
port.set_view(Some(s2i.clone()));
s2i
}
}
impl<Item: 'static> OuterViewPort<dyn SequenceView<Item = Item>> {
pub fn to_index(&self) -> OuterViewPort<dyn IndexView<usize, Item = Item>> {
let port = ViewPort::new();
port.add_update_hook(Arc::new(self.0.clone()));
self.add_observer(Sequence2Index::new(port.inner()));
port.into_outer()
}
}
impl<SrcView> View for Sequence2Index<SrcView>
where SrcView: SequenceView + ?Sized + 'static {
type Msg = usize;
}
impl<SrcView> IndexView<usize> for Sequence2Index<SrcView>
where SrcView: SequenceView + ?Sized + 'static {
type Item = SrcView::Item;
fn get(&self, key: &usize) -> Option<Self::Item> {
self.src_view.get(key)
}
fn area(&self) -> Option<Vec<usize>> {
Some((0 .. self.src_view.len()?).collect())
}
}
impl<SrcView> Observer<SrcView> for Sequence2Index<SrcView>
where SrcView: SequenceView + ?Sized + 'static {
fn reset(&mut self, view: Option<Arc<SrcView>>) {
let old_area = self.area();
self.src_view = view;
let new_area = self.area();
if let Some(area) = old_area { self.cast.notify_each(area); }
if let Some(area) = new_area { self.cast.notify_each(area); }
}
fn notify(&mut self, msg: &usize) {
self.cast.notify(msg);
}
}