feat(maestro): add draft-pane widget with its own field focus

crates/maestro-tui/src/draft.rs

@@ -0,0 +1,272 @@
+//! Draft pane — the spawn form living in an ordinary pane (issue #63).
+//!
+//! An empty pane renders a [`DraftPane`] instead of nothing; submitting hands
+//! the caller a built request and the pane is replaced with the new session,
+//! matching the web client's inline draft panes (#57). Field editing goes
+//! through [`crate::text_input::TextInput`]; Tab / BackTab walk the fields.
+//!
+//! Scope note: presets, the project list, generated names, and the worktree
+//! section land with issues #64/#65 — this is cwd + command only.
+
+use ratatui::layout::{Constraint, Layout, Rect};
+use ratatui::style::{Modifier, Style};
+use ratatui::text::{Line, Span};
+use ratatui::widgets::{Block, Borders, Paragraph};
+use ratatui::Frame;
+
+use crate::input::InputKey;
+
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
+pub enum DraftField {
+    #[default]
+    Cwd,
+    Command,
+    Submit,
+}
+
+#[derive(Debug, Default, Clone)]
+pub struct DraftPane {
+    pub cwd: crate::text_input::TextInput,
+    pub command: crate::text_input::TextInput,
+    pub focused_field: DraftField,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum DraftInputResult {
+    Consumed,
+    Submit,
+}
+
+impl DraftPane {
+    pub fn next_field(&mut self) {
+        self.focused_field = match self.focused_field {
+            DraftField::Cwd => DraftField::Command,
+            DraftField::Command => DraftField::Submit,
+            DraftField::Submit => DraftField::Cwd,
+        };
+    }
+
+    pub fn prev_field(&mut self) {
+        self.focused_field = match self.focused_field {
+            DraftField::Cwd => DraftField::Submit,
+            DraftField::Command => DraftField::Cwd,
+            DraftField::Submit => DraftField::Command,
+        };
+    }
+
+    /// Handle one keystroke while this draft owns input (Insert mode, pane
+    /// focused). Returns [`DraftInputResult::Submit`] when the user accepts;
+    /// the caller fires the POST and replaces the draft with the session.
+    pub fn on_input(&mut self, key: &InputKey) -> DraftInputResult {
+        match key {
+            InputKey::Tab => {
+                self.next_field();
+                DraftInputResult::Consumed
+            }
+            InputKey::BackTab => {
+                self.prev_field();
+                DraftInputResult::Consumed
+            }
+            InputKey::Enter => match self.focused_field {
+                DraftField::Submit => DraftInputResult::Submit,
+                _ => {
+                    self.next_field();
+                    DraftInputResult::Consumed
+                }
+            },
+            // Everything else — characters, motion, editing, paste — goes to
+            // the focused field's text input.
+            other => {
+                match self.focused_field {
+                    DraftField::Cwd => self.cwd.handle_key(other),
+                    DraftField::Command => self.command.handle_key(other),
+                    DraftField::Submit => {}
+                }
+                DraftInputResult::Consumed
+            }
+        }
+    }
+
+    /// Draw into the pane area. `pane_focused` gates the field highlight and
+    /// cursor placement the same way a session pane hides its cursor when
+    /// unfocused.
+    pub fn render(&self, f: &mut Frame, area: Rect, pane_focused: bool) {
+        let block = Block::default().title(" draft ").borders(Borders::ALL);
+        let inner = block.inner(area);
+        f.render_widget(block, area);
+        let rows = Layout::vertical([
+            Constraint::Length(2),
+            Constraint::Length(2),
+            Constraint::Length(1),
+        ])
+        .split(inner);
+
+        let style_for = |field: DraftField| {
+            if pane_focused && self.focused_field == field {
+                Style::default().add_modifier(Modifier::REVERSED)
+            } else {
+                Style::default()
+            }
+        };
+
+        // Each text field renders through the shared `TextInput`, which
+        // handles horizontal scrolling and reports where the terminal cursor
+        // belongs. Label is fixed-width 8 chars + 1 space = column 9.
+        let label = |text: &str| Paragraph::new(Line::from(Span::raw(format!("{text:8} "))));
+        f.render_widget(label("cwd:"), rows[0]);
+        f.render_widget(label("command:"), rows[1]);
+        let draw_field =
+            |f: &mut Frame, input: &crate::text_input::TextInput, row: Rect, style: Style| -> u16 {
+                let area = Rect {
+                    x: row.x.saturating_add(9),
+                    y: row.y,
+                    width: row.width.saturating_sub(9),
+                    height: 1,
+                };
+                input.render(area, f.buffer_mut(), style)
+            };
+        let cwd_col = draw_field(f, &self.cwd, rows[0], style_for(DraftField::Cwd));
+        let cmd_col = draw_field(f, &self.command, rows[1], style_for(DraftField::Command));
+
+        f.render_widget(
+            Paragraph::new(Line::from(vec![Span::styled(
+                "[ Spawn ]",
+                style_for(DraftField::Submit),
+            )])),
+            rows[2],
+        );
+
+        if pane_focused {
+            match self.focused_field {
+                DraftField::Cwd => f.set_cursor_position((cwd_col, rows[0].y)),
+                DraftField::Command => f.set_cursor_position((cmd_col, rows[1].y)),
+                DraftField::Submit => {
+                    // The submit button is indicated by the REVERSED style; no
+                    // cursor placement.
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use ratatui::backend::TestBackend;
+    use ratatui::Terminal;
+
+    fn render_to_string(w: u16, h: u16, draw: impl FnOnce(&mut Frame)) -> String {
+        let backend = TestBackend::new(w, h);
+        let mut terminal = Terminal::new(backend).unwrap();
+        terminal.draw(draw).unwrap();
+        let buf = terminal.backend().buffer().clone();
+        let mut out = String::new();
+        for y in 0..buf.area.height {
+            for x in 0..buf.area.width {
+                out.push_str(buf[(x, y)].symbol());
+            }
+            out.push('\n');
+        }
+        out
+    }
+
+    #[test]
+    fn draft_pane_renders_field_labels_and_values() {
+        let draft = DraftPane {
+            cwd: crate::text_input::TextInput::with_value("/x"),
+            command: crate::text_input::TextInput::with_value("bash"),
+            focused_field: DraftField::Cwd,
+        };
+        let rendered = render_to_string(80, 20, |f| draft.render(f, f.area(), true));
+        for s in ["cwd", "command", "draft", "Spawn", "/x", "bash"] {
+            assert!(rendered.contains(s), "missing {s:?}:\n{rendered}");
+        }
+    }
+
+    #[test]
+    fn field_rotation_wraps_in_both_directions() {
+        let mut draft = DraftPane::default();
+        assert_eq!(draft.focused_field, DraftField::Cwd);
+        draft.next_field();
+        assert_eq!(draft.focused_field, DraftField::Command);
+        draft.next_field();
+        assert_eq!(draft.focused_field, DraftField::Submit);
+        draft.next_field();
+        assert_eq!(draft.focused_field, DraftField::Cwd);
+        draft.prev_field();
+        assert_eq!(draft.focused_field, DraftField::Submit);
+
+        draft.on_input(&InputKey::BackTab);
+        assert_eq!(draft.focused_field, DraftField::Command);
+        draft.on_input(&InputKey::Tab);
+        draft.on_input(&InputKey::Tab);
+        assert_eq!(draft.focused_field, DraftField::Cwd);
+    }
+
+    /// Editing keys must reach the focused field's text input, not a bare
+    /// String — this is what gives the operator cursor motion and word ops.
+    #[test]
+    fn editing_keys_reach_the_focused_text_input() {
+        let mut draft = DraftPane::default();
+        assert_eq!(draft.focused_field, DraftField::Cwd);
+        for k in [
+            InputKey::char('/'),
+            InputKey::char('t'),
+            InputKey::char('m'),
+            InputKey::char('p'),
+        ] {
+            draft.on_input(&k);
+        }
+        draft.on_input(&InputKey::Left);
+        draft.on_input(&InputKey::Backspace);
+        assert_eq!(draft.cwd.value(), "/tp");
+
+        // Tab to command, then a paste and ctrl-w land there, not in cwd.
+        draft.on_input(&InputKey::Tab);
+        assert_eq!(draft.focused_field, DraftField::Command);
+        draft.on_input(&InputKey::Paste("/tmp/foo".into()));
+        assert_eq!(draft.command.value(), "/tmp/foo");
+        draft.on_input(&InputKey::ctrl_char('w'));
+        assert_eq!(draft.command.value(), "");
+        assert_eq!(draft.cwd.value(), "/tp", "cwd untouched while unfocused");
+    }
+
+    /// Enter walks forward until the submit field, where it submits.
+    #[test]
+    fn enter_walks_fields_then_submits_from_submit() {
+        let mut draft = DraftPane::default();
+        assert_eq!(draft.on_input(&InputKey::Enter), DraftInputResult::Consumed);
+        assert_eq!(draft.focused_field, DraftField::Command);
+        assert_eq!(draft.on_input(&InputKey::Enter), DraftInputResult::Consumed);
+        assert_eq!(draft.focused_field, DraftField::Submit);
+        assert_eq!(draft.on_input(&InputKey::Enter), DraftInputResult::Submit);
+    }
+
+    /// The terminal cursor must sit right after the typed text in the focused
+    /// field (label is 8 chars + 1 space, block border takes column 0).
+    #[test]
+    fn render_places_the_cursor_after_the_typed_text_when_focused() {
+        let draft = DraftPane {
+            cwd: crate::text_input::TextInput::with_value("abc"),
+            ..DraftPane::default()
+        };
+        let backend = TestBackend::new(80, 20);
+        let mut terminal = Terminal::new(backend).unwrap();
+        terminal.draw(|f| draft.render(f, f.area(), true)).unwrap();
+        let pos = terminal.get_cursor_position().unwrap();
+        assert_eq!(pos, ratatui::layout::Position::new(1 + 9 + 3, 1));
+
+        // Unfocused pane: no field highlight either.
+        let rendered_unfocused = render_to_string(80, 20, |f| draft.render(f, f.area(), false));
+        let backend = TestBackend::new(80, 20);
+        let mut terminal = Terminal::new(backend).unwrap();
+        terminal.draw(|f| draft.render(f, f.area(), false)).unwrap();
+        let buf = terminal.backend().buffer();
+        assert!(
+            !buf.content()
+                .iter()
+                .any(|c| c.modifier.contains(ratatui::style::Modifier::REVERSED)),
+            "unfocused draft must not highlight fields:\n{rendered_unfocused}"
+        );
+    }
+}

crates/maestro-tui/src/lib.rs

@@ -7,6 +7,7 @@ pub mod app;
 pub mod catalog;
 pub mod cli;
 pub mod config;
+pub mod draft;
 pub mod emulators;
 pub mod input;
 pub mod keymap;