feat!(terminal): inline viewport

Cargo.toml

@@ -21,6 +21,7 @@ default = ["termion"]
 curses = ["easycurses", "pancurses"]
 
 [dependencies]
+tracing = "0.1"
 bitflags = "1.3"
 cassowary = "0.3"
 unicode-segmentation = "1.2"
@@ -33,6 +34,7 @@ pancurses = { version = "0.16.1", optional = true, features = ["win32a"] }
 serde = { version = "1", "optional" = true, features = ["derive"]}
 
 [dev-dependencies]
+tracing-subscriber = "0.2"
 rand = "0.8"
 argh = "0.1"
 
@@ -125,3 +127,8 @@ required-features = ["crossterm"]
 name = "curses_demo"
 path = "examples/curses_demo.rs"
 required-features = ["curses"]
+
+[[example]]
+name = "inline"
+path = "examples/inline.rs"
+required-features = ["crossterm"]

examples/inline.rs

@@ -0,0 +1,303 @@
+use rand::distributions::{Distribution, Uniform};
+use std::{
+    collections::{BTreeMap, VecDeque},
+    error::Error,
+    io,
+    sync::mpsc,
+    thread,
+    time::{Duration, Instant},
+};
+use tracing::{event, span, Level};
+use tui::{
+    backend::CrosstermBackend,
+    layout::{Alignment, Constraint, Direction, Layout, Rect},
+    style::{Color, Modifier, Style},
+    symbols,
+    text::{Span, Spans},
+    widgets::{Block, Gauge, LineGauge, List, ListItem, Paragraph, Widget},
+    Terminal, TerminalOptions, ViewportVariant,
+};
+
+const NUM_DOWNLOADS: usize = 10;
+
+type DownloadId = usize;
+type WorkerId = usize;
+
+enum Event {
+    Input(crossterm::event::KeyEvent),
+    Tick,
+    Resize,
+    DownloadUpdate(WorkerId, DownloadId, f64),
+    DownloadDone(WorkerId, DownloadId),
+}
+
+struct Downloads {
+    pending: VecDeque<Download>,
+    in_progress: BTreeMap<WorkerId, DownloadInProgress>,
+}
+
+impl Downloads {
+    fn next(&mut self, worker_id: WorkerId) -> Option<Download> {
+        match self.pending.pop_front() {
+            Some(d) => {
+                self.in_progress.insert(
+                    worker_id,
+                    DownloadInProgress {
+                        id: d.id,
+                        started_at: Instant::now(),
+                        progress: 0.0,
+                    },
+                );
+                Some(d)
+            }
+            None => None,
+        }
+    }
+}
+
+struct DownloadInProgress {
+    id: DownloadId,
+    started_at: Instant,
+    progress: f64,
+}
+
+struct Download {
+    id: DownloadId,
+    size: usize,
+}
+
+struct Worker {
+    id: WorkerId,
+    tx: mpsc::Sender<Download>,
+}
+
+fn main() -> Result<(), Box<dyn Error>> {
+    tracing_subscriber::fmt()
+        .with_env_filter(tracing_subscriber::EnvFilter::from_default_env())
+        .with_writer(io::stderr)
+        .init();
+
+    crossterm::terminal::enable_raw_mode()?;
+    let stdout = io::stdout();
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::with_options(
+        backend,
+        TerminalOptions {
+            viewport: ViewportVariant::Inline(8),
+        },
+    )?;
+
+    let (tx, rx) = mpsc::channel();
+    input_handling(tx.clone());
+    let workers = workers(tx);
+    let mut downloads = downloads();
+
+    for w in &workers {
+        let d = downloads.next(w.id).unwrap();
+        w.tx.send(d).unwrap();
+    }
+
+    let mut redraw = true;
+    loop {
+        if redraw {
+            ui(&mut terminal);
+        }
+        redraw = true;
+
+        let span = span!(Level::INFO, "recv");
+        let _guard = span.enter();
+        match rx.recv()? {
+            Event::Input(event) => {
+                if event.code == crossterm::event::KeyCode::Char('q') {
+                    break;
+                }
+            }
+            Event::Resize => {
+                event!(Level::INFO, "resize");
+                terminal.resize()?;
+            }
+            Event::Tick => {
+                event!(Level::INFO, "tick");
+            }
+            Event::DownloadUpdate(worker_id, download_id, progress) => {
+                event!(
+                    Level::INFO,
+                    worker_id,
+                    download_id,
+                    progress,
+                    "download update"
+                );
+                let download = downloads.in_progress.get_mut(&worker_id).unwrap();
+                download.progress = progress;
+                redraw = false
+            }
+            Event::DownloadDone(worker_id, download_id) => {
+                event!(Level::INFO, worker_id, download_id, "download done");
+                let download = downloads.in_progress.remove(&worker_id).unwrap();
+                terminal.insert_before(1, |buf| {
+                    Paragraph::new(Spans::from(vec![
+                        Span::from("Finished "),
+                        Span::styled(
+                            format!("download {}", download_id),
+                            Style::default().add_modifier(Modifier::BOLD),
+                        ),
+                        Span::from(format!(
+                            " in {}ms",
+                            download.started_at.elapsed().as_millis()
+                        )),
+                    ]))
+                    .render(area, buf);
+                })?;
+                match downloads.next(worker_id) {
+                    Some(d) => workers[worker_id].tx.send(d).unwrap(),
+                    None => {
+                        if downloads.in_progress.is_empty() {
+                            terminal.insert_before(1, |area, buffer| {
+                                Paragraph::new("Done !").render(area, buffer);
+                            })?;
+                            break;
+                        }
+                    }
+                };
+            }
+        };
+    }
+
+    crossterm::terminal::disable_raw_mode()?;
+    terminal.clear()?;
+
+    Ok(())
+}
+
+fn input_handling(tx: mpsc::Sender<Event>) {
+    let tick_rate = Duration::from_millis(200);
+    thread::spawn(move || {
+        let mut last_tick = Instant::now();
+        loop {
+            // poll for tick rate duration, if no events, sent tick event.
+            let timeout = tick_rate
+                .checked_sub(last_tick.elapsed())
+                .unwrap_or_else(|| Duration::from_secs(0));
+            if crossterm::event::poll(timeout).unwrap() {
+                match crossterm::event::read().unwrap() {
+                    crossterm::event::Event::Key(key) => tx.send(Event::Input(key)).unwrap(),
+                    crossterm::event::Event::Resize(_, _) => tx.send(Event::Resize).unwrap(),
+                    _ => {}
+                };
+            }
+            if last_tick.elapsed() >= tick_rate {
+                tx.send(Event::Tick).unwrap();
+                last_tick = Instant::now();
+            }
+        }
+    });
+}
+
+fn workers(tx: mpsc::Sender<Event>) -> Vec<Worker> {
+    (0..4)
+        .map(|id| {
+            let (worker_tx, worker_rx) = mpsc::channel::<Download>();
+            let tx = tx.clone();
+            thread::spawn(move || {
+                while let Ok(download) = worker_rx.recv() {
+                    let mut remaining = download.size;
+                    while remaining > 0 {
+                        let wait = (remaining as u64).min(10);
+                        thread::sleep(Duration::from_millis(wait * 10));
+                        remaining = remaining.saturating_sub(10);
+                        let progress = (download.size - remaining) * 100 / download.size;
+                        tx.send(Event::DownloadUpdate(id, download.id, progress as f64))
+                            .unwrap();
+                    }
+                    tx.send(Event::DownloadDone(id, download.id)).unwrap();
+                }
+            });
+            Worker { id, tx: worker_tx }
+        })
+        .collect()
+}
+
+fn downloads() -> Downloads {
+    let distribution = Uniform::new(0, 1000);
+    let mut rng = rand::thread_rng();
+    let pending = (0..NUM_DOWNLOADS)
+        .map(|id| {
+            let size = distribution.sample(&mut rng);
+            Download { id, size }
+        })
+        .collect();
+    Downloads {
+        pending,
+        in_progress: BTreeMap::new(),
+    }
+}
+
+fn ui(terminal: &mut Terminal<CrosstermBackend>) {
+    terminal.draw(|f| {
+        let size = f.size();
+
+        let block = Block::default()
+            .title("Progress")
+            .title_alignment(Alignment::Center);
+        f.render_widget(block, size);
+
+        let chunks = Layout::default()
+            .constraints(vec![Constraint::Length(2), Constraint::Length(4)])
+            .margin(1)
+            .split(size);
+
+        // total progress
+        let done = NUM_DOWNLOADS - downloads.pending.len() - downloads.in_progress.len();
+        let progress = LineGauge::default()
+            .gauge_style(Style::default().fg(Color::Blue))
+            .label(format!("{}/{}", done, NUM_DOWNLOADS))
+            .ratio(done as f64 / NUM_DOWNLOADS as f64);
+        f.render_widget(progress, chunks[0]);
+
+        let chunks = Layout::default()
+            .direction(Direction::Horizontal)
+            .constraints(vec![Constraint::Percentage(20), Constraint::Percentage(80)])
+            .split(chunks[1]);
+
+        // in progress downloads
+        let items: Vec<ListItem> = downloads
+            .in_progress
+            .iter()
+            .map(|(worker_id, download)| {
+                ListItem::new(Spans::from(vec![
+                    Span::raw(symbols::DOT),
+                    Span::styled(
+                        format!(" download {:>2}", download.id),
+                        Style::default()
+                            .fg(Color::LightGreen)
+                            .add_modifier(Modifier::BOLD),
+                    ),
+                    Span::raw(format!(
+                        " ({}ms)",
+                        download.started_at.elapsed().as_millis()
+                    )),
+                ]))
+            })
+            .collect();
+        let list = List::new(items);
+        f.render_widget(list, chunks[0]);
+
+        for (i, (_, download)) in downloads.in_progress.iter().enumerate() {
+            let gauge = Gauge::default()
+                .gauge_style(Style::default().fg(Color::Yellow))
+                .ratio(download.progress / 100.0);
+            if chunks[1].top().saturating_add(i as u16) > size.bottom() {
+                continue;
+            }
+            f.render_widget(
+                gauge,
+                Rect {
+                    x: chunks[1].left(),
+                    y: chunks[1].top().saturating_add(i as u16),
+                    width: chunks[1].width,
+                    height: 1,
+                },
+            );
+        }
+    })?;
+}