Method write

canvas/src/canvas.rs:32–67

Writes to the canvas core

(&mut self, actions: Vec<Draw>)

    /// Writes to the canvas core
    ///
    pub fn write(&mut self, actions: Vec<Draw>) -> Vec<Waker> {
        // Write to the main core
        self.main_core.write(actions.iter().cloned());

        // Write to each of the streams
        let mut remove_idx  = vec![];
        let mut wakers      = vec![];

        for (idx, stream) in self.streams.iter().enumerate() {
            if let Some(stream) = stream.upgrade() {
                wakers.push(stream.sync(|stream| {
                    stream.write(iter::once(Draw::StartFrame));
                    stream.write(actions.iter().cloned());
                    stream.write(iter::once(Draw::ShowFrame));
                    stream.take_waker()
                }));
            } else {
                remove_idx.push(idx);
            }
        }

        // Tidy any streams that are no longer listening
        if remove_idx.len() > 0 {
            let remove_idx  = remove_idx.into_iter().collect::<HashSet<_>>();
            let old_streams = mem::take(&mut self.streams);

            self.streams    = old_streams.into_iter()
                .enumerate()
                .filter(|(idx, _item)| !remove_idx.contains(idx))
                .map(|(_idx, item)| item)
                .collect();
        }

        // Return the wakers
        wakers.into_iter().flatten().collect()
    }
}

///