T12: sessions: new (+, Cmd-T), close (row x, Cmd-W), select (press, Cmd-1 to 8, Cmd-9 last, Ctrl-Tab, Ctrl-Shift-Tab), Ghostty's keys off macOS; rows show the title and the folder with ~; an ended program closes its row, the last row the window, and the app quits; a bell marks a hidden row; new sessions follow the Shell and Start in settings

src/sessions.rs

@@ -0,0 +1,112 @@
+use std::path::{MAIN_SEPARATOR, Path, PathBuf};
+
+use ely_gpui_component::{
+    buttons::{ButtonVariant, IconButton},
+    lists::ListItem,
+    primitives::{Icon, IconName},
+    theme::{ActiveTheme, ControlSize},
+};
+use gpui::{App, Entity, Subscription};
+
+use crate::{
+    term::TerminalView,
+    workspace::{TITLE, Workspace},
+};
+
+/// A program on its own terminal, as the sessions column lists it.
+pub struct Session {
+    pub terminal: Entity<TerminalView>,
+    /// The program's title; empty while it names none.
+    pub title: String,
+    /// The folder it reports, else the one it started in.
+    pub folder: PathBuf,
+    /// A bell rang while it was hidden.
+    pub bell: bool,
+    pub _events: Subscription,
+}
+
+/// `folder` as a row shows it: the home folder as `~`.
+pub fn shown(folder: &Path, home: Option<&Path>) -> String {
+    match home.and_then(|home| folder.strip_prefix(home).ok()) {
+        Some(rest) if rest.as_os_str().is_empty() => "~".into(),
+        Some(rest) => format!("~{MAIN_SEPARATOR}{}", rest.display()),
+        None => folder.display().to_string(),
+    }
+}
+
+/// The session shown once session `closed` of `left + 1` is gone, `active` having been shown.
+pub fn after_close(active: usize, closed: usize, left: usize) -> usize {
+    if closed < active || active == left {
+        active - 1
+    } else {
+        active
+    }
+}
+
+/// Session `index`'s row: its title and folder, a bell while one rang unseen, a button that closes it.
+pub fn row(
+    workspace: &Entity<Workspace>,
+    index: usize,
+    session: &Session,
+    active: bool,
+    home: Option<&Path>,
+    cx: &App,
+) -> ListItem {
+    let pid = session.terminal.read(cx).pid() as usize;
+    let title = if session.title.is_empty() {
+        TITLE
+    } else {
+        &session.title
+    };
+    let (select, close) = (workspace.clone(), workspace.clone());
+    let item = ListItem::new(("session", pid), title.to_string())
+        .description(shown(&session.folder, home))
+        .selected(active)
+        .strong(session.bell)
+        .on_click(move |_, window, cx| select.update(cx, |this, cx| this.select(index, window, cx)))
+        .trailing(
+            IconButton::new(("close-session", pid), IconName::X)
+                .variant(ButtonVariant::Ghost)
+                .size(ControlSize::Sm)
+                .tooltip("Close session")
+                .on_click(move |_, window, cx| {
+                    cx.stop_propagation();
+                    close.update(cx, |this, cx| this.close(index, window, cx))
+                }),
+        );
+    if session.bell {
+        item.leading(Icon::new(IconName::Bell).color(cx.theme().colors.warning))
+    } else {
+        item
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn folders_under_home_read_from_a_tilde() {
+        let home = PathBuf::from("/Users/ely");
+        let shown = |folder: &str| shown(Path::new(folder), Some(&home));
+        assert_eq!(shown("/Users/ely"), "~");
+        assert_eq!(
+            shown("/Users/ely/src/app"),
+            format!("~{MAIN_SEPARATOR}src/app")
+        );
+        assert_eq!(
+            shown("/Users/elyse"),
+            "/Users/elyse",
+            "a sibling is no child"
+        );
+        assert_eq!(shown("/tmp"), "/tmp");
+    }
+
+    #[test]
+    fn closing_shows_the_next_session_or_keeps_the_shown_one() {
+        assert_eq!(after_close(2, 0, 3), 1, "one before it went");
+        assert_eq!(after_close(1, 1, 3), 1, "it went: the next one");
+        assert_eq!(after_close(3, 3, 3), 2, "the last went: the one before");
+        assert_eq!(after_close(1, 2, 3), 1, "one after it went");
+    }
+}