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