feat(window): add configurable default cursor_style

CHANGELOG.md

@@ -6,6 +6,7 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ## [Unreleased]
 
 ### Added
+- add `window.cursor_style` to set the default cursor shape (block, beam, or underline)
 - add `--maximized` and `--fullscreen` flags to start the window in that mode
 - persist and restore window size, maximized, and fullscreen state per session
 - REP (`CSI Ps b`): repeat the last printed character `Ps` times

README.md

@@ -159,6 +159,7 @@ width           = 800
 height          = 600
 title           = "mmterm"
 cursor_blink_ms = 500
+cursor_style    = "block"   # default cursor shape: block | beam | underline
 
 [shell]
 # program = "/bin/zsh"   # defaults to $SHELL

assets/config.toml

@@ -11,6 +11,8 @@ title           = "mmterm"
 cursor_blink_ms = 500
 inactive_dim    = 0.55
 detect_urls     = true
+# default cursor shape: block | beam | underline
+cursor_style    = "block"
 
 [shell]
 # program = "/bin/zsh"

doc/SPEC.md

@@ -221,6 +221,7 @@ Screenshot capture is a two-step flow: region selection followed by a name promp
 | window | cursor_blink_ms | uint | `500` |
 | window | inactive_dim | float | `0.55` |
 | window | detect_urls | bool | `true` |
+| window | cursor_style | string | `"block"` (block, beam, or underline) |
 | terminal | scrollback_lines | uint | `10000` (min 100) |
 | shell | program | string? | `$SHELL` |
 | logging | auto_log | bool | `false` |

src/config/config_test.rs

@@ -157,6 +157,44 @@ palette = []
     assert!(cfg.window.detect_urls);
 }
 
+#[test]
+fn default_cursor_style_value() {
+    assert_eq!(default_cursor_style(), "block");
+    assert_eq!(Config::default().window.cursor_style, "block");
+}
+
+#[test]
+fn cursor_style_default_applied_when_missing() {
+    let toml = r###"
+[font]
+family = "Mono"
+size = 14.0
+[window]
+width = 800
+height = 600
+title = "t"
+cursor_blink_ms = 500
+[shell]
+[colors]
+background = "#000000"
+foreground = "#ffffff"
+cursor = "#ffffff"
+selection = "#333333"
+palette = []
+"###;
+    let cfg: Config = toml::from_str(toml).expect("parse failed");
+    assert_eq!(cfg.window.cursor_style, "block");
+}
+
+#[test]
+fn config_roundtrip_preserves_cursor_style() {
+    let mut cfg = Config::default();
+    cfg.window.cursor_style = "beam".into();
+    let s = toml::to_string_pretty(&cfg).expect("serialize failed");
+    let restored: Config = toml::from_str(&s).expect("deserialize failed");
+    assert_eq!(restored.window.cursor_style, "beam");
+}
+
 #[test]
 fn save_does_not_panic() {
     Config::default().save();

src/config/mod.rs

@@ -147,6 +147,9 @@ fn default_inactive_dim() -> f32 {
 fn default_detect_urls() -> bool {
     true
 }
+fn default_cursor_style() -> String {
+    "block".into()
+}
 
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct WindowConfig {
@@ -158,6 +161,8 @@ pub struct WindowConfig {
     pub inactive_dim: f32,
     #[serde(default = "default_detect_urls")]
     pub detect_urls: bool,
+    #[serde(default = "default_cursor_style")]
+    pub cursor_style: String,
 }
 
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]

src/config/tui_config.rs

@@ -33,6 +33,7 @@ const F_AUTO_UPDATE_CHECK: usize = 37;
 const F_AUTO_UPDATE_INSTALL: usize = 38;
 const F_SHELL_INTEGRATION: usize = 39;
 const F_DESKTOP_NOTIFICATIONS: usize = 40;
+const F_CURSOR_STYLE: usize = 41;
 
 const PALETTE_LABELS: [&str; 16] = [
     "Palette 0  black",
@@ -301,6 +302,13 @@ impl ConfigPanel {
             kind: FieldKind::Bool,
             section: None,
         });
+        fields.push(Field {
+            label: "Cursor Style",
+            hint: "← / → to cycle: block, beam, underline",
+            value: cfg.window.cursor_style.clone(),
+            kind: FieldKind::Select(vec!["block".into(), "beam".into(), "underline".into()]),
+            section: None,
+        });
 
         let mut collapsed = HashSet::new();
         collapsed.insert("Palette");
@@ -577,7 +585,13 @@ impl ConfigPanel {
         let next = ((cur as i32 + delta).rem_euclid(len as i32)) as usize;
         let name = options[next].clone();
         field.value = name.clone();
-        ConfigAction::PreviewTheme(name)
+        // Only the Theme field triggers a live preview; other Select fields
+        // (e.g. Cursor Style) just update their value.
+        if self.selected == F_THEME_NAME {
+            ConfigAction::PreviewTheme(name)
+        } else {
+            ConfigAction::None
+        }
     }
 
     fn validate(&self, val: &str) -> bool {
@@ -678,6 +692,8 @@ impl ConfigPanel {
             .parse::<bool>()
             .map_err(|_| "Invalid desktop_notifications — use true or false")?;
 
+        let cursor_style = get(F_CURSOR_STYLE);
+
         Ok(Config {
             font: FontConfig { family, size },
             window: WindowConfig {
@@ -687,6 +703,7 @@ impl ConfigPanel {
                 cursor_blink_ms: blink_ms,
                 inactive_dim,
                 detect_urls,
+                cursor_style,
             },
             shell: ShellConfig { program: shell },
             terminal: TerminalConfig { scrollback_lines },

src/config/tui_config_test.rs

@@ -10,8 +10,8 @@ fn make_panel() -> ConfigPanel {
 #[test]
 fn from_config_has_correct_field_count() {
     let panel = make_panel();
-    // 9 base + 1 scrollback + 2 logging + 1 theme + 4 colors + 16 palette + 1 status_bar + 3 general + 2 updates + 2 shell/notify = 41
-    assert_eq!(panel.fields.len(), 41);
+    // 9 base + 1 scrollback + 2 logging + 1 theme + 4 colors + 16 palette + 1 status_bar + 3 general + 2 updates + 2 shell/notify + 1 cursor style = 42
+    assert_eq!(panel.fields.len(), 42);
 }
 
 #[test]
@@ -305,6 +305,7 @@ fn distinct_config() -> Config {
             cursor_blink_ms: 523,
             inactive_dim: 0.42,
             detect_urls: true,
+            cursor_style: "beam".into(),
         },
         shell: ShellConfig {
             program: Some("/bin/xyzsh".into()),
@@ -375,6 +376,7 @@ fn field_index_sanity() {
         F_AUTO_UPDATE_INSTALL,
         F_SHELL_INTEGRATION,
         F_DESKTOP_NOTIFICATIONS,
+        F_CURSOR_STYLE,
     ];
     occupied.extend((0..16).map(|i| F_PALETTE + i));
     occupied.sort_unstable();
@@ -611,6 +613,33 @@ fn field_select_cycles_forward_wraps_at_end() {
     assert!(matches!(action, ConfigAction::PreviewTheme(ref n) if n == "alpha"));
 }
 
+#[test]
+fn cursor_style_cycles_without_previewing_theme() {
+    let mut panel = make_panel();
+    panel.selected = F_CURSOR_STYLE;
+    assert_eq!(panel.fields[F_CURSOR_STYLE].value, "block");
+    // Cycling a non-theme Select must update the value but emit no PreviewTheme.
+    let action = panel.handle_right();
+    assert!(matches!(action, ConfigAction::None));
+    assert_eq!(panel.fields[F_CURSOR_STYLE].value, "beam");
+    let action = panel.handle_right();
+    assert!(matches!(action, ConfigAction::None));
+    assert_eq!(panel.fields[F_CURSOR_STYLE].value, "underline");
+    // Wrap back to the first option.
+    let action = panel.handle_right();
+    assert!(matches!(action, ConfigAction::None));
+    assert_eq!(panel.fields[F_CURSOR_STYLE].value, "block");
+}
+
+#[test]
+fn build_config_roundtrip_preserves_cursor_style() {
+    let mut cfg = Config::default();
+    cfg.window.cursor_style = "underline".into();
+    let panel = ConfigPanel::from_config(&cfg);
+    let rebuilt = panel.build_config().expect("must rebuild");
+    assert_eq!(rebuilt.window.cursor_style, "underline");
+}
+
 #[test]
 fn handle_right_on_non_select_field_returns_none() {
     let mut panel = make_panel();
@@ -680,8 +709,8 @@ fn palette_collapsed_by_default() {
 #[test]
 fn visible_indices_hides_palette_body() {
     let panel = make_panel();
-    // 41 total - 15 palette body fields = 26 visible
-    assert_eq!(panel.visible_indices().len(), 26);
+    // 42 total - 15 palette body fields = 27 visible
+    assert_eq!(panel.visible_indices().len(), 27);
 }
 
 #[test]
@@ -690,7 +719,7 @@ fn toggle_on_palette_header_expands() {
     panel.selected = F_PALETTE;
     panel.toggle_collapse();
     assert!(!panel.collapsed.contains("Palette"));
-    assert_eq!(panel.visible_indices().len(), 41);
+    assert_eq!(panel.visible_indices().len(), 42);
 }
 
 #[test]
@@ -700,7 +729,7 @@ fn toggle_twice_restores_collapsed() {
     panel.toggle_collapse();
     panel.toggle_collapse();
     assert!(panel.collapsed.contains("Palette"));
-    assert_eq!(panel.visible_indices().len(), 26);
+    assert_eq!(panel.visible_indices().len(), 27);
 }
 
 #[test]
@@ -755,10 +784,10 @@ fn move_up_skips_collapsed_palette() {
 #[test]
 fn move_down_at_last_visible_clamps() {
     let mut panel = make_panel();
-    // F_DESKTOP_NOTIFICATIONS is the last field and is always visible
-    panel.selected = F_DESKTOP_NOTIFICATIONS;
+    // F_CURSOR_STYLE is the last field and is always visible
+    panel.selected = F_CURSOR_STYLE;
     panel.handle_down();
-    assert_eq!(panel.selected, F_DESKTOP_NOTIFICATIONS);
+    assert_eq!(panel.selected, F_CURSOR_STYLE);
 }
 
 #[test]

src/pane_ops.rs

@@ -33,7 +33,7 @@ impl App {
         let pad2 = self.scale.chrome(crate::ui::layout::PANE_PADDING) * 2;
         let (cols, rows) = metrics.grid_size_for(w.saturating_sub(pad2), h.saturating_sub(pad2));
         let t = &self.state.theme;
-        let grid = Arc::new(RwLock::new(Grid::with_colors(
+        let mut grid = Grid::with_colors(
             cols,
             rows,
             GridColors {
@@ -44,7 +44,12 @@ impl App {
                 palette: t.palette,
             },
             self.state.config.terminal.scrollback_lines,
-        )));
+        );
+        let shape =
+            crate::terminal::grid::cursor_shape_from_str(&self.state.config.window.cursor_style);
+        grid.default_cursor_shape = shape;
+        grid.cursor_shape = shape;
+        let grid = Arc::new(RwLock::new(grid));
         let pane = Pane::new(grid.clone(), rect);
         // Bounded channel caps PTY output backlog at ~1 MB (256 × 4 KB chunks),
         // matching WezTerm's socketpair size. Provides natural backpressure:

src/terminal/grid.rs

@@ -15,6 +15,20 @@ pub enum CursorShape {
     Beam,
 }
 
+/// Map a config string to a [`CursorShape`] (case-insensitive).
+/// Unknown values fall back to `Block` with a warning.
+pub fn cursor_shape_from_str(s: &str) -> CursorShape {
+    match s.to_ascii_lowercase().as_str() {
+        "block" => CursorShape::Block,
+        "beam" => CursorShape::Beam,
+        "underline" => CursorShape::Underline,
+        other => {
+            log::warn!("unknown cursor_style {other:?}, falling back to \"block\"");
+            CursorShape::Block
+        }
+    }
+}
+
 /// OSC 133 shell integration state.
 #[derive(Clone, Copy, Debug, PartialEq, Default)]
 pub enum ShellState {
@@ -195,6 +209,8 @@ pub struct Grid {
     pub cursor_visible: bool,
     // DECSCUSR: cursor shape set by the running program
     pub cursor_shape: CursorShape,
+    // Configured default cursor shape; restored on reset and `CSI 0 SP q`.
+    pub default_cursor_shape: CursorShape,
     // Bracketed paste mode (?2004)
     pub bracketed_paste: bool,
     // Mouse reporting mode: 0=off, 1000=click, 1002=button-motion, 1003=any-motion
@@ -282,6 +298,7 @@ impl Grid {
             application_cursor_keys: false,
             cursor_visible: true,
             cursor_shape: CursorShape::Block,
+            default_cursor_shape: CursorShape::Block,
             bracketed_paste: false,
             mouse_mode: 0,
             mouse_sgr: false,
@@ -337,7 +354,7 @@ impl Grid {
         self.cursor_col = 0;
         self.cursor_row = 0;
         self.cursor_visible = true;
-        self.cursor_shape = CursorShape::Block;
+        self.cursor_shape = self.default_cursor_shape;
         self.scroll_top = 0;
         self.scroll_bottom = self.max_row();
         self.reset_sgr();
@@ -1036,7 +1053,7 @@ impl Grid {
         self.current_url = None;
         self.osc_title = None;
         self.cursor_visible = true;
-        self.cursor_shape = CursorShape::Block;
+        self.cursor_shape = self.default_cursor_shape;
         self.bracketed_paste = false;
         self.mouse_mode = 0;
         self.mouse_sgr = false;

src/terminal/grid_test.rs

@@ -1224,3 +1224,34 @@ fn reset_clears_shell_integration_state() {
     assert_eq!(g.shell_state, ShellState::Unknown);
     assert_eq!(g.last_exit_code, None);
 }
+
+#[test]
+fn reset_restores_configured_default_cursor_shape() {
+    let mut g = make_grid(10, 5);
+    g.default_cursor_shape = CursorShape::Beam;
+    g.cursor_shape = CursorShape::Underline;
+    g.reset();
+    assert_eq!(g.cursor_shape, CursorShape::Beam);
+}
+
+#[test]
+fn alternate_screen_restores_configured_default_cursor_shape() {
+    let mut g = make_grid(10, 5);
+    g.default_cursor_shape = CursorShape::Beam;
+    g.cursor_shape = CursorShape::Underline;
+    g.enter_alternate_screen();
+    assert_eq!(g.cursor_shape, CursorShape::Beam);
+}
+
+#[test]
+fn cursor_shape_from_str_maps_all_variants() {
+    assert_eq!(cursor_shape_from_str("block"), CursorShape::Block);
+    assert_eq!(cursor_shape_from_str("Block"), CursorShape::Block);
+    assert_eq!(cursor_shape_from_str("beam"), CursorShape::Beam);
+    assert_eq!(cursor_shape_from_str("BEAM"), CursorShape::Beam);
+    assert_eq!(cursor_shape_from_str("underline"), CursorShape::Underline);
+    assert_eq!(cursor_shape_from_str("Underline"), CursorShape::Underline);
+    // Unknown values fall back to Block.
+    assert_eq!(cursor_shape_from_str("nonsense"), CursorShape::Block);
+    assert_eq!(cursor_shape_from_str(""), CursorShape::Block);
+}

src/terminal/parser.rs

@@ -321,7 +321,12 @@ impl Perform for Performer<'_> {
             'c' if p0 == 0 => self.grid.pending_responses.extend_from_slice(b"\x1b[?1;0c"),
             // DECSCUSR: cursor shape (CSI Ps SP q)
             'q' if intermediates == b" " => {
-                self.grid.cursor_shape = cursor_shape_from_param(p0);
+                // `CSI 0 SP q` resets to the configured default shape.
+                self.grid.cursor_shape = if p0 == 0 {
+                    self.grid.default_cursor_shape
+                } else {
+                    cursor_shape_from_param(p0)
+                };
             }
             // Set scroll region
             'r' => self.handle_scroll_region(p0, p1),