fix(ui): apply compact density to title bar and tabs (#194)

Apply compact density consistently to the title bar, tabs, sidebar scrolling and drag geometry. Keep native title-bar dimensions and align the command overlay with the effective title-bar height.

Includes layout, hit-target and density-transition regressions.

Fixes #327.

nebula_app/src/gpui_shell/workspace.rs

@@ -363,10 +363,6 @@ fn dock_tree(target: SplitTree<u64>, source: SplitTree<u64>, nav: SplitNav) -> S
     target.joined(source, nav)
 }
 
-/// 侧栏 tab 行高与行距（与 `render_sidebar` 的 `h(px(TAB_ROW_H))`、
-/// `gap_2`(8px) 同源）；受约束拖拽按此步距换算让位槽位。
-pub(super) const TAB_ROW_H: f32 = 34.0;
-pub(super) const TAB_ROW_PITCH: f32 = TAB_ROW_H + 8.0;
 /// 右侧抽屉槽位宽度 = 抽屉自身宽度。抽屉贴满右侧整条竖带（上下右都不留卡缝，
 /// 左侧直接抵住终端卡），所以槽位里不再有额外的卡缝要算进来。
 
@@ -628,8 +624,9 @@ pub struct NebulaWorkspace {
     sidebar_collapsed: bool,
     /// 只折叠 TABS 分区，不影响整个左栏；与旧壳分区标题的 chevron 同义。
     tabs_section_collapsed: bool,
-    /// 标签栏布局：默认沿用左侧栏；Top 将同一组 tab 放进 48px 标题栏。
+    /// 标签栏布局：默认沿用左侧栏；Top 将同一组 tab 放进标题栏。
     tabs_position: nebula_settings::TabsPositionName,
+    density: nebula_settings::DensityName,
     /// 运行时持久化的侧栏逻辑宽；布局、初始窗口和折叠动画必须同源。
     sidebar_width: f32,
     /// 首次手动切换后才启用折叠动画：启动帧保持静止落位（旧壳同感，
@@ -930,6 +927,7 @@ impl NebulaWorkspace {
             sidebar_collapsed: false,
             tabs_section_collapsed: false,
             tabs_position: runtime.tabs_position,
+            density: runtime.density,
             sidebar_width,
             sidebar_fold_armed: false,
             tabs_fold_armed: false,
@@ -1139,6 +1137,8 @@ impl NebulaWorkspace {
         crate::gpui_shell::apply_app_icon(runtime.app_icon, cx);
         self.sidebar_width = runtime.sidebar_width;
         self.tabs_position = runtime.tabs_position;
+        self.density = runtime.density;
+        self.reveal_active_tab();
         self.sync_settings_layout();
         self.sidebar_resizing = None;
         self.reveal_if_tray_disabled(cx);

nebula_app/src/gpui_shell/workspace/command_manager.rs

@@ -16,8 +16,6 @@ const PANEL_EMPTY_HEIGHT: f32 = 196.0;
 const PANEL_FIXED_HEIGHT: f32 = 146.0;
 const GROUP_NAV_HEIGHT: f32 = 36.0;
 const PANEL_MARGIN: f32 = 8.0;
-// 覆盖层从自绘标题栏下沿开始；固定组件依赖当前将该区域定义为 34px。
-const WINDOW_TITLE_BAR_HEIGHT: f32 = 34.0;
 const PANEL_FOOTER_HEIGHT: f32 = 44.0;
 const ROW_HEIGHT: f32 = 62.0;
 const ROW_ICON_SIZE: f32 = 16.0;
@@ -559,8 +557,12 @@ impl NebulaWorkspace {
         let viewport = window.viewport_size();
         let panel_width =
             PANEL_MAX_WIDTH.min((f32::from(viewport.width) - PANEL_MARGIN * 2.0).max(0.0));
+        let title_bar_height = super::window_titlebar::effective_title_bar_height(
+            self.density,
+            crate::platform::window_chrome::layout(window),
+        );
         let available_height =
-            (f32::from(viewport.height) - WINDOW_TITLE_BAR_HEIGHT - PANEL_MARGIN * 2.0).max(0.0);
+            (f32::from(viewport.height) - title_bar_height - PANEL_MARGIN * 2.0).max(0.0);
 
         let rows = self.command_manager_rows(cx);
         self.command_manager_selected =
@@ -688,7 +690,7 @@ impl NebulaWorkspace {
             .child(
                 v_flex()
                     .absolute()
-                    .top(px(WINDOW_TITLE_BAR_HEIGHT + PANEL_MARGIN))
+                    .top(px(title_bar_height + PANEL_MARGIN))
                     .right(px(PANEL_MARGIN))
                     .w(px(panel_width))
                     .h(px(panel_height))

nebula_app/src/gpui_shell/workspace/settings_navigation/ui_tests.rs

@@ -160,3 +160,53 @@ fn closing_last_regular_tab_keeps_settings_until_it_is_closed(cx: &mut TestAppCo
     cx.simulate_keystrokes("ctrl-shift-w");
     assert!(cx.read(|cx| cx.windows().is_empty()));
 }
+
+#[gpui::test]
+fn density_changes_real_tab_bounds_and_sidebar_drag_pitch(cx: &mut TestAppContext) {
+    use nebula_settings::{DensityName, TabsPositionName};
+
+    let (_directory, workspace, mut cx) = open_workspace(8, cx);
+    click_tab("top-tab-0", &mut cx);
+    for position in [TabsPositionName::Sidebar, TabsPositionName::Top] {
+        for (density, height, gap, title_height) in [
+            (DensityName::Standard, 34.0, 8.0, 48.0),
+            (DensityName::Compact, 32.0, 4.0, 40.0),
+            (DensityName::Standard, 34.0, 8.0, 48.0),
+        ] {
+            workspace.update(&mut cx, |workspace, cx| {
+                workspace.tabs_position = position;
+                workspace.density = density;
+                workspace.sync_settings_layout();
+                workspace.reveal_active_tab();
+                cx.notify();
+            });
+            cx.run_until_parked();
+            let sidebar = position == TabsPositionName::Sidebar;
+            let first = tab_bounds(if sidebar { "sidebar-tab-0" } else { "top-tab-0" }, &mut cx);
+            let second = tab_bounds(if sidebar { "sidebar-tab-1" } else { "top-tab-1" }, &mut cx);
+            assert_eq!(f32::from(first.size.height), height);
+            assert_eq!(f32::from(second.size.height), height);
+            if sidebar {
+                assert_eq!(f32::from(second.top() - first.top()), height + gap);
+            }
+            let native = cx.update(|window, _| crate::platform::window_chrome::layout(window));
+            let title = tab_bounds("workspace-titlebar", &mut cx);
+            assert_eq!(
+                f32::from(title.size.height),
+                native.map_or(title_height, |layout| layout.0)
+            );
+
+            // Padding belongs to the tab's actual click target in either density.
+            let point = gpui::point(second.left() + px(8.0), second.bottom() - px(2.0));
+            cx.simulate_click(point, Modifiers::default());
+            workspace.read_with(&cx, |workspace, _| assert_eq!(workspace.active, 1));
+            if sidebar {
+                cx.simulate_mouse_down(point, gpui::MouseButton::Left, Modifiers::default());
+                workspace.read_with(&cx, |workspace, _| {
+                    assert_eq!(workspace.tab_drag.as_ref().unwrap().pitch, height + gap);
+                });
+                cx.simulate_mouse_up(point, gpui::MouseButton::Left, Modifiers::default());
+            }
+        }
+    }
+}

nebula_app/src/gpui_shell/workspace/sidebar.rs

@@ -187,6 +187,8 @@ impl NebulaWorkspace {
     }
 
     fn render_sidebar(&self, window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let row_height = tab_scroll::tab_row_height(self.density);
+        let row_pitch = self.tab_row_pitch();
         let theme = cx.theme();
         let muted = theme.muted_foreground;
         // 数量 chip 数字：旧壳独用 ink_faint（比 ink_dim 再暗一档），chip 背
@@ -330,10 +332,10 @@ impl NebulaWorkspace {
                 let (dragged, shift) = match drag {
                     Some((src, _, _)) if ix == src => (true, 0.0),
                     Some((src, tgt, _)) if src < tgt && ix > src && ix <= tgt => {
-                        (false, -TAB_ROW_PITCH)
+                        (false, -row_pitch)
                     },
                     Some((src, tgt, _)) if src > tgt && ix >= tgt && ix < src => {
-                        (false, TAB_ROW_PITCH)
+                        (false, row_pitch)
                     },
                     _ => (false, 0.0),
                 };
@@ -359,7 +361,7 @@ impl NebulaWorkspace {
                 .overflow_hidden()
                 .gap_2()
                 .px_2()
-                .h(px(TAB_ROW_H))
+                .h(px(row_height))
                 .items_center()
                 // 旧壳 pill 圆角 = UI_CORNER_RADIUS_LOGICAL(8)，rounded_md(6)
                 // 偏小一圈，选中水洗的轮廓形状会不一样。
@@ -389,7 +391,7 @@ impl NebulaWorkspace {
                             press_x: f32::from(event.position.x),
                             press_y: f32::from(event.position.y),
                             axis: TabDragAxis::Vertical,
-                            pitch: TAB_ROW_PITCH,
+                            pitch: row_pitch,
                             offset: 0.0,
                             active: false,
                             dock: None,
@@ -415,7 +417,7 @@ impl NebulaWorkspace {
                             .left(px(4.0))
                             .top(px(7.0))
                             .w(px(2.5))
-                            .h(px(TAB_ROW_H - 14.0))
+                            .h(px(row_height - 14.0))
                             .rounded_full()
                             .bg(color),
                     )
@@ -621,7 +623,7 @@ impl NebulaWorkspace {
             // 仍是旧壳的 8px。
             .px_2()
             .pb_2()
-            .gap_2()
+            .gap(px(tab_scroll::tab_row_gap(self.density)))
             // 待命阶段（未过阈值）的指针跟踪；激活后由根部罩层独占接管。
             .on_mouse_move(cx.listener(|this, event, window, cx| {
                 this.update_tab_drag(event, window, cx);
@@ -631,7 +633,7 @@ impl NebulaWorkspace {
                     .id("sidebar-tabs-toggle")
                     .group(header_group.clone())
                     .w_full()
-                    .h(px(34.0))
+                    .h(px(row_height))
                     .pb_1()
                     // 旧壳标题文字从 panel_x + 16px 起；侧栏根已有 8px
                     // padding，这里再补 8px，箭头不会贴住左边缘。
@@ -1042,7 +1044,7 @@ mod tests {
                     .id("status-probe-row")
                     .debug_selector(|| "status-probe-row".to_owned())
                     .w(px(200.0))
-                    .h(px(TAB_ROW_H))
+                    .h(px(tab_scroll::tab_row_height(nebula_settings::DensityName::Standard)))
                     .px_2()
                     .overflow_hidden()
                     .child(div().flex_1())

nebula_app/src/gpui_shell/workspace/tab_scroll.rs

@@ -14,10 +14,25 @@ use gpui::{
 use crate::display::ui::widgets::{self, OverlayScrollbar};
 use crate::gpui_shell::prelude::*;
 
-use super::{NebulaWorkspace, TAB_ROW_H, TAB_ROW_PITCH};
+use nebula_settings::DensityName;
+
+use super::NebulaWorkspace;
+
+pub(super) fn tab_row_height(density: DensityName) -> f32 {
+    match density {
+        DensityName::Standard => 34.0,
+        DensityName::Compact => crate::display::ui::tokens::control::MIN_HIT_TARGET,
+    }
+}
+
+pub(super) fn tab_row_gap(density: DensityName) -> f32 {
+    use crate::display::ui::tokens::space;
+    match density {
+        DensityName::Standard => space::XS,
+        DensityName::Compact => space::XXS,
+    }
+}
 
-/// 行间距（pitch − 行高）。旧壳 `gap = s(8)`。
-const TAB_ROW_GAP: f32 = TAB_ROW_PITCH - TAB_ROW_H;
 /// 旧壳 `tab_right_pad`：给覆盖式滚动条留的恒定沟槽，出现与否都不改行宽。
 pub(super) const TAB_SCROLL_GUTTER: f32 = 9.0;
 
@@ -97,9 +112,18 @@ struct TabsWindow {
 }
 
 impl NebulaWorkspace {
+    pub(super) fn tab_row_pitch(&self) -> f32 {
+        tab_row_height(self.density) + tab_row_gap(self.density)
+    }
+
     fn tabs_window(&self) -> TabsWindow {
         let want = self.tabs.len();
-        let show = visible_count(want, self.tabs_viewport_h, TAB_ROW_PITCH, TAB_ROW_GAP);
+        let show = visible_count(
+            want,
+            self.tabs_viewport_h,
+            self.tab_row_pitch(),
+            tab_row_gap(self.density),
+        );
         let max = max_scroll(want, show);
         let scroll = clamp_scroll(self.tabs_scroll, max);
         TabsWindow { scroll, show, max, want }
@@ -137,15 +161,16 @@ impl NebulaWorkspace {
         if window.show == 0 || window.want <= window.show {
             return None;
         }
-        let viewport = rows_h(window.show, TAB_ROW_PITCH, TAB_ROW_GAP).max(1.0);
+        let viewport =
-        let content = rows_h(window.want, TAB_ROW_PITCH, TAB_ROW_GAP);
+            rows_h(window.show, self.tab_row_pitch(), tab_row_gap(self.density)).max(1.0);
+        let content = rows_h(window.want, self.tab_row_pitch(), tab_row_gap(self.density));
         let width = self.tabs_list_width.max(1.0);
         let height = self.tabs_viewport_h.max(viewport);
         widgets::overlay_scrollbar(
             (0.0, 0.0, width, height),
             viewport,
             content,
-            window.scroll as f32 * TAB_ROW_PITCH,
+            window.scroll as f32 * self.tab_row_pitch(),
             1.0,
         )
     }
@@ -191,7 +216,7 @@ impl NebulaWorkspace {
         _window: &mut Window,
         cx: &mut Context<Self>,
     ) {
-        let delta_y = f32::from(event.delta.pixel_delta(px(TAB_ROW_PITCH)).y);
+        let delta_y = f32::from(event.delta.pixel_delta(px(self.tab_row_pitch())).y);
         let rows = wheel_rows(delta_y);
         if rows == 0 {
             return;
@@ -254,7 +279,7 @@ impl NebulaWorkspace {
                 .absolute()
                 .size_full(),
             )
-            .child(v_flex().w_full().gap_2().children(items))
+            .child(v_flex().w_full().gap(px(tab_row_gap(self.density))).children(items))
             .when_some(bar.filter(|_| show_thumb), |list, bar| {
                 list.child(
                     div()
@@ -304,7 +329,10 @@ impl NebulaWorkspace {
         }
         // 折叠中/已折叠：裁剪高度不是 `tabs_avail`。写回去会让
         // `visible_count` 按 20–40px 算出 0/1 行，展开后整列锁死。
-        if !self.tabs_section_collapsed && !self.tabs_fold_frozen && h >= TAB_ROW_H {
+        if !self.tabs_section_collapsed
+            && !self.tabs_fold_frozen
+            && h >= tab_row_height(self.density)
+        {
             self.tabs_viewport_h = h;
         }
         self.tabs_list_width = w;
@@ -349,6 +377,24 @@ mod tests {
         wheel_rows,
     };
 
+    #[test]
+    fn compact_rows_fit_more_tabs_without_shrinking_hit_targets() {
+        use super::{DensityName, tab_row_gap, tab_row_height};
+        for (density, expected_height, expected_show) in
+            [(DensityName::Standard, 34.0, 2), (DensityName::Compact, 32.0, 3)]
+        {
+            let height = tab_row_height(density);
+            let gap = tab_row_gap(density);
+            let pitch = height + gap;
+            assert_eq!(height, expected_height);
+            assert!(height >= crate::display::ui::tokens::control::MIN_HIT_TARGET);
+            assert_eq!(rows_h(1, pitch, gap), height);
+            let show = visible_count(10, 104.0, pitch, gap);
+            assert_eq!(show, expected_show);
+            assert_eq!(reveal_index(9, 0, show), max_scroll(10, show));
+        }
+    }
+
     const PITCH: f32 = 42.0;
     const GAP: f32 = 8.0;
 

nebula_app/src/gpui_shell/workspace/tests.rs

@@ -77,7 +77,7 @@ mod title_bar_panel_control_tests {
     }
 
     #[derive(Default)]
-    struct TopTabGeometryProbe;
+    struct TopTabGeometryProbe(nebula_settings::DensityName);
 
     impl Render for TopTabGeometryProbe {
         fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
@@ -89,9 +89,10 @@ mod title_bar_panel_control_tests {
                     div()
                         .debug_selector(|| "top-tab-geometry-probe".to_owned())
                         .w(px(160.0))
-                        .h(px(super::top_tabs::TOP_TAB_H)),
+                        .h(px(super::tab_scroll::tab_row_height(self.0))),
                 )
                 .child(super::top_tabs::top_tab_action_slot(
+                    self.0,
                     super::top_tabs::top_new_tab_control(
                         crate::i18n::UiLanguage::EnUs,
                         |_, _, _| {},
@@ -99,6 +100,7 @@ mod title_bar_panel_control_tests {
                     .debug_selector(|| "top-new-tab-geometry-probe".to_owned()),
                 ))
                 .child(super::top_tabs::top_tab_action_slot(
+                    self.0,
                     h_flex().debug_selector(|| "top-tabs-menu-geometry-probe".to_owned()).child(
                         super::top_tabs::top_tabs_menu_button(false, crate::i18n::UiLanguage::EnUs),
                     ),
@@ -113,16 +115,27 @@ mod title_bar_panel_control_tests {
     #[gpui::test]
     fn top_tab_action_buttons_share_the_tab_vertical_center(cx: &mut TestAppContext) {
         cx.update(gpui_component::init);
-        let (_, cx) = cx.add_window_view(|_, _| TopTabGeometryProbe);
+        let (probe, cx) = cx.add_window_view(|_, _| TopTabGeometryProbe::default());
-        let tab = cx.debug_bounds("top-tab-geometry-probe").expect("tab bounds");
+        for (density, height) in [
-        let new_tab = cx.debug_bounds("top-new-tab-geometry-probe").expect("new-tab bounds");
+            (nebula_settings::DensityName::Standard, 34.0),
-        let menu = cx.debug_bounds("top-tabs-menu-geometry-probe").expect("menu bounds");
+            (nebula_settings::DensityName::Compact, 32.0),
+            (nebula_settings::DensityName::Standard, 34.0),
+        ] {
+            probe.update(cx, |probe, cx| {
+                probe.0 = density;
+                cx.notify();
+            });
+            cx.run_until_parked();
+            let tab = cx.debug_bounds("top-tab-geometry-probe").expect("tab bounds");
+            let new_tab = cx.debug_bounds("top-new-tab-geometry-probe").expect("new-tab bounds");
+            let menu = cx.debug_bounds("top-tabs-menu-geometry-probe").expect("menu bounds");
 
-        assert_eq!(f32::from(tab.size.height), 34.0);
+            assert_eq!(f32::from(tab.size.height), height);
-        assert_eq!(f32::from(new_tab.size.height), 32.0);
+            assert_eq!(f32::from(new_tab.size.height), 32.0);
-        assert_eq!(f32::from(menu.size.height), 32.0);
+            assert_eq!(f32::from(menu.size.height), 32.0);
-        assert_eq!(vertical_center(new_tab), vertical_center(tab));
+            assert_eq!(vertical_center(new_tab), vertical_center(tab));
-        assert_eq!(vertical_center(menu), vertical_center(tab));
+            assert_eq!(vertical_center(menu), vertical_center(tab));
+        }
     }
 }
 

nebula_app/src/gpui_shell/workspace/top_tabs.rs

@@ -1,4 +1,4 @@
-//! 48px 自定义标题栏里的横向标签布局。
+//! 自定义标题栏里的横向标签布局。
 //!
 //! 这里只负责同一组 workspace tab 的第二种呈现；激活、关闭、重命名、排序
 //! 与 dock 都调用 `NebulaWorkspace` 既有动作，不维护平行状态。
@@ -23,7 +23,6 @@ use super::{
     TabDragAxis, TabPresentation, ToggleShellPicker, pane_header, title_bar_panel_controls,
 };
 
-pub(super) const TOP_TAB_H: f32 = 34.0;
 /// 与顶部模式正文卡片的 `px_2` 左边距同源，让首个 tab 和终端左缘对齐。
 pub(super) const TOP_TAB_LEFT_INSET: f32 = 8.0;
 /// 单个 tab 的最小宽。WT 的 TabView 同一条取舍：标签**不压到读不出来**，
@@ -110,10 +109,13 @@ pub(super) fn top_tabs_menu_button(settings_active: bool, language: UiLanguage)
         .tooltip(language.text(Message::ChromeMore))
 }
 
-/// 紧邻 TabView 的操作按钮占满同一条 34px 行，再在槽内居中 32px 按钮。
+/// 紧邻 TabView 的操作按钮占满同一条标签行，再在槽内居中 32px 按钮。
 /// 外层仍贴标题栏底边，tab 与正文相接的既有布局不变。
-pub(super) fn top_tab_action_slot(child: impl gpui::IntoElement) -> gpui::Div {
+pub(super) fn top_tab_action_slot(
-    h_flex().h(px(TOP_TAB_H)).items_center().child(child)
+    density: nebula_settings::DensityName,
+    child: impl gpui::IntoElement,
+) -> gpui::Div {
+    h_flex().h(px(super::tab_scroll::tab_row_height(density))).items_center().child(child)
 }
 
 impl NebulaWorkspace {
@@ -130,6 +132,7 @@ impl NebulaWorkspace {
         window: &mut Window,
         cx: &mut Context<Self>,
     ) -> gpui::AnyElement {
+        let row_height = super::tab_scroll::tab_row_height(self.density);
         let language = crate::gpui_shell::config::ui_language(cx);
         let theme = cx.theme();
         let muted = theme.muted_foreground;
@@ -276,7 +279,7 @@ impl NebulaWorkspace {
                     .group(hover_group.clone())
                     .relative()
                     .w(px(tab_w))
-                    .h(px(TOP_TAB_H))
+                    .h(px(row_height))
                     .flex_shrink_0()
                     .min_w_0()
                     .overflow_hidden()
@@ -552,7 +555,7 @@ impl NebulaWorkspace {
                     // 看不见的入口——tab 一多，用户根本不知道右边还有东西。
                     .when(overflow, |bar| {
                         bar.child(
-                            div().h(px(TOP_TAB_H)).flex().items_center().child(
+                            div().h(px(row_height)).flex().items_center().child(
                                 title_bar_panel_controls().h_auto().child(
                                     Button::new("top-tabs-prev")
                                         .icon(IconName::ChevronLeft)
@@ -580,7 +583,7 @@ impl NebulaWorkspace {
                             .w(px(tab_viewport_w))
                             .flex_shrink(1.0)
                             .min_w_0()
-                            .h(px(TOP_TAB_H))
+                            .h(px(row_height))
                             .overflow_hidden()
                             // 待命拖拽在越过 4px 前由此接收移动；激活后根罩层接管。
                             .on_mouse_move(cx.listener(|this, event, window, cx| {
@@ -600,7 +603,7 @@ impl NebulaWorkspace {
                     )
                     .when(overflow, |bar| {
                         bar.child(
-                            div().h(px(TOP_TAB_H)).flex().items_center().child(
+                            div().h(px(row_height)).flex().items_center().child(
                                 title_bar_panel_controls().h_auto().child(
                                     Button::new("top-tabs-next")
                                         .icon(IconName::ChevronRight)
@@ -622,7 +625,7 @@ impl NebulaWorkspace {
                         )
                     })
                     .child(
-                        top_tab_action_slot(top_new_tab_control(language, cx.listener(
+                        top_tab_action_slot(self.density, top_new_tab_control(language, cx.listener(
                             |this, _, window, cx| {
                                 this.add_terminal(window, cx);
                             },
@@ -630,6 +633,7 @@ impl NebulaWorkspace {
                     )
                     .child(
                         top_tab_action_slot(
+                            self.density,
                             top_tabs_menu_button(settings_active, language).dropdown_menu_with_anchor(
                                 gpui::Anchor::TopRight,
                                 move |menu, _, _| {

nebula_app/src/gpui_shell/workspace/window_titlebar.rs

@@ -1,5 +1,19 @@
 use super::*;
 
+fn title_bar_height(density: nebula_settings::DensityName) -> f32 {
+    match density {
+        nebula_settings::DensityName::Standard => 48.0,
+        nebula_settings::DensityName::Compact => 40.0,
+    }
+}
+
+pub(super) fn effective_title_bar_height(
+    density: nebula_settings::DensityName,
+    native_layout: Option<(f32, f32)>,
+) -> f32 {
+    native_layout.map_or_else(|| title_bar_height(density), |(height, _)| height)
+}
+
 /// Prepaint records the actual pane column before any titlebar paint runs. Keep
 /// this cell for the workspace lifetime, so resizing and panel animations do not
 /// allocate a new shared slot or duplicate the body's layout calculations.
@@ -93,9 +107,9 @@ impl NebulaWorkspace {
     ) -> gpui::Div {
         let top_tabs = self.tabs_position == nebula_settings::TabsPositionName::Top;
         let native_layout = crate::platform::window_chrome::layout(window);
+        let title_bar_height = effective_title_bar_height(self.density, native_layout);
         let bar = TitleBar::new()
-            // Leave 8px above and below the existing 32px controls.
+            .h(px(title_bar_height))
-            .h(px(48.0))
             .when(!settings_active, |bar| bar.bg(gpui::transparent_black()).border_b_0())
             .when(settings_active, |bar| {
                 bar.border_b_1().border_color(crate::gpui_shell::theme::settings_hairline(cx))
@@ -103,29 +117,15 @@ impl NebulaWorkspace {
             .when(top_tabs && native_layout.is_none(), |bar| {
                 bar.pl(px(top_tabs::TOP_TAB_LEFT_INSET))
             })
-            .when(top_tabs, |bar| {
+            .when(top_tabs, |bar| bar.child(self.render_top_title_bar(settings_active, window, cx)))
-                bar.child(self.render_top_title_bar(
+            .when(!top_tabs, |bar| bar.child(self.render_sidebar_title_bar(settings_active, cx)));
-                    settings_active,
-                    window,
-                    cx,
-                ))
-            })
-            .when(!top_tabs, |bar| {
-                bar.child(self.render_sidebar_title_bar(
-                    settings_active,
-                    cx,
-                ))
-            });
 
         // AppKit owns both the control group and its geometry. Read the live
         // frames so system layout, resize and full-screen transitions agree.
-        let bar = if let Some((height, inset)) = native_layout {
+        let bar = if let Some((_, inset)) = native_layout { bar.pl(px(inset)) } else { bar };
-            bar.h(px(height)).pl(px(inset))
-        } else {
-            bar
-        };
 
         title_bar_frame()
+            .debug_selector(|| "workspace-titlebar".to_owned())
             .when(!settings_active, |title| title.child(self.titlebar_background.element()))
             .child(bar)
     }
@@ -175,3 +175,19 @@ mod tests {
         assert!(!cx.update(|window, cx| window.selected_text(cx).is_empty()));
     }
 }
+
+#[cfg(test)]
+mod density_tests {
+    use super::{effective_title_bar_height, title_bar_height};
+    use nebula_settings::DensityName;
+
+    #[test]
+    fn compact_title_bar_retains_space_around_controls() {
+        assert_eq!(title_bar_height(DensityName::Standard), 48.0);
+        assert_eq!(title_bar_height(DensityName::Compact), 40.0);
+        assert_eq!(effective_title_bar_height(DensityName::Standard, None), 48.0);
+        assert_eq!(effective_title_bar_height(DensityName::Compact, None), 40.0);
+        assert_eq!(effective_title_bar_height(DensityName::Compact, Some((34.0, 7.0))), 34.0);
+        assert!(title_bar_height(DensityName::Compact) >= 32.0 + 2.0 * 4.0);
+    }
+}