clean up examples to make a bare `cargo test` work

1 files changed, 379 insertions, 0 deletions

diff --git a/examples/tmux_impl/mod.rs b/examples/tmux_impl/mod.rs
new file mode 100644
index 0000000..de026e4
--- /dev/null
+++ b/examples/tmux_impl/mod.rs
@@ -0,0 +1,379 @@
+use pty_process::Command as _;
+use smol::io::{AsyncReadExt as _, AsyncWriteExt as _};
+use textmode::Textmode as _;
+
+enum Command {
+    NewWindow,
+    NextWindow,
+}
+
+enum Event {
+    Input(textmode::Key),
+    Output,
+    WindowExit(usize),
+    Command(Command),
+    Notification,
+}
+
+struct Window {
+    child: std::sync::Arc<pty_process::smol::Child>,
+    vt: std::sync::Arc<smol::lock::Mutex<vt100::Parser>>,
+    screen: vt100::Screen,
+}
+
+#[derive(Clone)]
+struct Notification {
+    text: String,
+    expiry: std::time::Instant,
+}
+
+struct State {
+    windows: std::collections::BTreeMap<usize, Window>,
+    current_window: usize,
+    next_window_id: usize,
+    notifications: std::collections::BTreeMap<usize, Notification>,
+    next_notification_id: usize,
+    wevents: smol::channel::Sender<Event>,
+    revents: smol::channel::Receiver<Event>,
+}
+
+impl State {
+    fn new() -> Self {
+        let (sender, receiver) = smol::channel::unbounded();
+        Self {
+            windows: std::collections::BTreeMap::new(),
+            current_window: 0,
+            next_window_id: 0,
+            notifications: std::collections::BTreeMap::new(),
+            next_notification_id: 0,
+            wevents: sender,
+            revents: receiver,
+        }
+    }
+
+    fn current_window(&self) -> &Window {
+        &self.windows[&self.current_window]
+    }
+
+    fn current_window_mut(&mut self) -> &mut Window {
+        self.windows.get_mut(&self.current_window).unwrap()
+    }
+
+    fn next_window(&mut self, ex: &smol::Executor<'_>) {
+        self.current_window = self
+            .windows
+            .keys()
+            .copied()
+            .cycle()
+            .skip_while(|&id| id < self.current_window)
+            .nth(1)
+            .unwrap();
+        self.notify(
+            ex,
+            &format!("switched to window {}", self.current_window),
+        );
+    }
+
+    fn notify(&mut self, ex: &smol::Executor<'_>, text: &str) {
+        let now = std::time::Instant::now();
+        let expiry = now + std::time::Duration::from_secs(5);
+        let text = text.to_string();
+        let notification = Notification { text, expiry };
+        let id = self.next_notification_id;
+        self.next_notification_id += 1;
+        self.notifications.insert(id, notification);
+        let notify = self.wevents.clone();
+        ex.spawn(async move {
+            smol::Timer::at(expiry).await;
+            notify.send(Event::Notification).await.unwrap();
+        })
+        .detach();
+    }
+
+    fn spawn_input_task(
+        &self,
+        ex: &smol::Executor<'_>,
+        mut input: textmode::Input,
+    ) {
+        let notify = self.wevents.clone();
+        ex.spawn(async move {
+            let mut waiting_for_command = false;
+            input.parse_utf8(false);
+            input.parse_meta(false);
+            input.parse_special_keys(false);
+            loop {
+                input.parse_single(waiting_for_command);
+                match input.read_key().await {
+                    Ok(Some(key)) => {
+                        if waiting_for_command {
+                            waiting_for_command = false;
+                            match key {
+                                textmode::Key::Ctrl(b'n') => {
+                                    notify
+                                        .send(Event::Input(key))
+                                        .await
+                                        .unwrap();
+                                }
+                                textmode::Key::Byte(b'c') => {
+                                    notify
+                                        .send(Event::Command(
+                                            Command::NewWindow,
+                                        ))
+                                        .await
+                                        .unwrap();
+                                }
+                                textmode::Key::Byte(b'n') => {
+                                    notify
+                                        .send(Event::Command(
+                                            Command::NextWindow,
+                                        ))
+                                        .await
+                                        .unwrap();
+                                }
+                                _ => {} // ignore
+                            }
+                        } else {
+                            match key {
+                                textmode::Key::Ctrl(b'n') => {
+                                    waiting_for_command = true;
+                                }
+                                _ => {
+                                    notify
+                                        .send(Event::Input(key))
+                                        .await
+                                        .unwrap();
+                                }
+                            }
+                        }
+                    }
+                    Ok(None) => {
+                        break;
+                    }
+                    Err(e) => {
+                        eprintln!("{}", e);
+                        break;
+                    }
+                }
+            }
+        })
+        .detach();
+    }
+
+    fn new_window(
+        &mut self,
+        ex: &smol::Executor<'_>,
+        notify: smol::channel::Sender<Event>,
+    ) {
+        let child = smol::process::Command::new("zsh")
+            .spawn_pty(Some(&pty_process::Size::new(24, 80)))
+            .unwrap();
+        let child = std::sync::Arc::new(child);
+        let vt = vt100::Parser::default();
+        let screen = vt.screen().clone();
+        let vt = std::sync::Arc::new(smol::lock::Mutex::new(vt));
+        let id = self.next_window_id;
+        self.next_window_id += 1;
+        let window = Window {
+            child: child.clone(),
+            vt: vt.clone(),
+            screen,
+        };
+        self.windows.insert(id, window);
+        self.current_window = id;
+        self.notify(ex, &format!("created window {}", id));
+        ex.spawn(async move {
+            let mut buf = [0_u8; 4096];
+            loop {
+                match child.pty().read(&mut buf).await {
+                    Ok(bytes) => {
+                        vt.lock_arc().await.process(&buf[..bytes]);
+                        notify.send(Event::Output).await.unwrap();
+                    }
+                    Err(e) => {
+                        // EIO means that the process closed the other
+                        // end of the pty
+                        if e.raw_os_error() != Some(libc::EIO) {
+                            eprintln!("pty read failed: {:?}", e);
+                        }
+                        notify.send(Event::WindowExit(id)).await.unwrap();
+                        break;
+                    }
+                }
+            }
+        })
+        .detach();
+    }
+
+    async fn redraw_current_window(&mut self, tm: &mut textmode::Output) {
+        let window = self.current_window();
+        tm.clear();
+        let new_screen = window.vt.lock_arc().await.screen().clone();
+        tm.write(&new_screen.state_formatted());
+        self.draw_notifications(tm, &new_screen);
+        tm.refresh().await.unwrap();
+    }
+
+    async fn update_current_window(&mut self, tm: &mut textmode::Output) {
+        let window = self.current_window();
+        let old_screen = window.screen.clone();
+        let new_screen = window.vt.lock_arc().await.screen().clone();
+        let diff = new_screen.state_diff(&old_screen);
+        self.clear_notifications(tm, &old_screen);
+        tm.write(&diff);
+        self.draw_notifications(tm, &new_screen);
+        tm.refresh().await.unwrap();
+        self.current_window_mut().screen = new_screen;
+    }
+
+    fn clear_notifications(
+        &mut self,
+        tm: &mut textmode::Output,
+        screen: &vt100::Screen,
+    ) {
+        if self.notifications.is_empty() {
+            return;
+        }
+
+        let reset_attrs = screen.attributes_formatted();
+        let pos = screen.cursor_position();
+        for (i, row) in screen
+            .rows_formatted(0, 80)
+            .enumerate()
+            .take(self.notifications.len())
+        {
+            tm.move_to(i as u16, 0);
+            tm.reset_attributes();
+            tm.clear_line();
+            tm.write(&row);
+        }
+        tm.move_to(pos.0, pos.1);
+        tm.write(&reset_attrs);
+    }
+
+    fn draw_notifications(
+        &mut self,
+        tm: &mut textmode::Output,
+        screen: &vt100::Screen,
+    ) {
+        if self.notifications.is_empty() {
+            return;
+        }
+
+        let now = std::time::Instant::now();
+        self.notifications = self
+            .notifications
+            .iter()
+            .map(|(k, v)| (*k, v.clone()))
+            .filter(|(_, v)| v.expiry >= now)
+            .collect();
+
+        if self.notifications.is_empty() {
+            return;
+        }
+
+        let reset_attrs = screen.attributes_formatted();
+        let pos = screen.cursor_position();
+        tm.reset_attributes();
+        tm.set_bgcolor(textmode::color::CYAN);
+        tm.set_fgcolor(textmode::color::WHITE);
+        for (i, notification) in self.notifications.values().enumerate() {
+            tm.move_to(i as u16, 0);
+            tm.clear_line();
+            let str_len = notification.text.len();
+            let spaces = 80 - str_len;
+            let prefix_spaces = spaces / 2;
+            tm.write(&vec![b' '; prefix_spaces]);
+            tm.write_str(&notification.text);
+        }
+        tm.move_to(pos.0, pos.1);
+        tm.write(&reset_attrs);
+    }
+}
+
+#[must_use]
+pub struct Tmux {
+    input: textmode::Input,
+    tm: textmode::Output,
+    state: State,
+}
+
+impl Tmux {
+    pub async fn new() -> Self {
+        let input = textmode::Input::new().await.unwrap();
+        let tm = textmode::Output::new().await.unwrap();
+        let state = State::new();
+        Self { input, tm, state }
+    }
+
+    pub async fn run(self, ex: &smol::Executor<'_>) {
+        let Self {
+            input,
+            mut tm,
+            mut state,
+        } = self;
+
+        state.spawn_input_task(ex, input);
+
+        ex.run(async {
+            state.new_window(ex, state.wevents.clone());
+
+            loop {
+                match state.revents.recv().await {
+                    Ok(Event::Output) => {
+                        state.update_current_window(&mut tm).await;
+                    }
+                    Ok(Event::Input(key)) => {
+                        state
+                            .current_window()
+                            .child
+                            .pty()
+                            .write_all(&key.into_bytes())
+                            .await
+                            .unwrap();
+                    }
+                    Ok(Event::WindowExit(id)) => {
+                        // do this first because next_window breaks if
+                        // current_window is greater than all existing windows
+                        if state.current_window == id {
+                            state.next_window(ex)
+                        }
+                        let mut dropped_window =
+                            state.windows.remove(&id).unwrap();
+                        // i can get_mut because at this point the future
+                        // holding the other copy of child has already been
+                        // dropped
+                        std::sync::Arc::get_mut(&mut dropped_window.child)
+                            .unwrap()
+                            .status()
+                            .await
+                            .unwrap();
+                        if state.windows.is_empty() {
+                            break;
+                        }
+                        state.notify(ex, &format!("window {} exited", id));
+
+                        state.redraw_current_window(&mut tm).await;
+                    }
+                    Ok(Event::Command(c)) => match c {
+                        Command::NewWindow => {
+                            state.new_window(ex, state.wevents.clone());
+                            state.redraw_current_window(&mut tm).await;
+                        }
+                        Command::NextWindow => {
+                            state.next_window(ex);
+                            state.redraw_current_window(&mut tm).await;
+                        }
+                    },
+                    Ok(Event::Notification) => {
+                        state.update_current_window(&mut tm).await;
+                    }
+                    Err(e) => {
+                        eprintln!("{}", e);
+                        break;
+                    }
+                }
+            }
+        })
+        .await;
+    }
+}