feat(statusbar): selection cycling shows a pick list, adds to selection

Replace the repeat-click cycling with a list box: when a click lands on
two or more overlapping objects (cycling on), a small list of the
candidates opens at the cursor. Picking a row adds that object to the
current selection (accumulate); clicking outside dismisses it. A single
object under the cursor falls through to the normal click.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/mod.rs

@@ -183,11 +183,11 @@ pub(super) struct OpenCADStudio {
     clean_screen: bool,
     /// Quick Properties: show a compact floating property panel on selection.
     quick_properties: bool,
-    /// Selection cycling: repeated clicks at one spot step through the
-    /// overlapping objects there instead of accumulating the selection.
+    /// Selection cycling: clicking where objects overlap opens a list box
+    /// to pick which one; the pick is added to the current selection.
     selection_cycling: bool,
-    /// Cycling cursor: (screen point, ordered candidates, current index).
-    cycle_state: Option<(iced::Point, Vec<acadrust::Handle>, usize)>,
+    /// When set, the cycling list box is open: (canvas point, candidates).
+    cycle_candidates: Option<(iced::Point, Vec<acadrust::Handle>)>,
     /// Which status-bar pills the user has chosen to show (persisted).
     statusbar_config: crate::ui::statusbar_config::StatusBarConfig,
     /// Whether Tangent snap was enabled before a tangent-pick command started.
@@ -765,6 +765,10 @@ pub enum Message {
     ToggleQuickProperties,
     /// Toggle selection cycling for overlapping objects.
     ToggleSelectionCycling,
+    /// Add an object from the selection-cycling list box to the selection.
+    CycleSelect(acadrust::Handle),
+    /// Dismiss the selection-cycling list box without picking.
+    CycleCancel,
     /// Toggle the selection-filter type picker open/closed.
     ToggleSelectionFilterPopup,
     /// Close the selection-filter type picker.
@@ -1245,7 +1249,7 @@ impl OpenCADStudio {
             clean_screen: false,
             quick_properties: false,
             selection_cycling: false,
-            cycle_state: None,
+            cycle_candidates: None,
             pre_cmd_tangent: None,
             ortho_mode: false,
             polar_mode: false,

src/app/update.rs

@@ -2910,9 +2910,11 @@ impl OpenCADStudio {
                             let all_wires = self.tabs[i].scene.hit_test_wires();
                             let vp_mat = self.tabs[i].scene.camera.borrow().view_proj(bounds);
 
-                            // Selection cycling: step through overlapping objects
-                            // under the cursor on repeated clicks at the same spot.
-                            // Gated behind the toggle, so default picking is unchanged.
+                            // Selection cycling: where two or more objects
+                            // overlap, open a list box to pick which one; a
+                            // single object falls through to the normal click.
+                            // Gated behind the toggle, so default picking is
+                            // unchanged when off.
                             let mut handled_by_cycling = false;
                             if self.selection_cycling {
                                 let cands: Vec<Handle> = scene::hit_test::click_hits_all(
@@ -2925,25 +2927,9 @@ impl OpenCADStudio {
                                 .filter_map(|s| Scene::handle_from_wire_name(s))
                                 .filter(|&h| self.tabs[i].scene.passes_selection_filter(h))
                                 .collect();
-                                if !cands.is_empty() {
-                                    let same =
-                                        self.cycle_state.as_ref().map_or(false, |(pt, list, _)| {
-                                            (pt.x - p.x).abs() < 3.0
-                                                && (pt.y - p.y).abs() < 3.0
-                                                && *list == cands
-                                        });
-                                    let idx = if same {
-                                        (self.cycle_state.as_ref().unwrap().2 + 1) % cands.len()
-                                    } else {
-                                        0
-                                    };
-                                    let handle = cands[idx];
-                                    self.cycle_state = Some((p, cands, idx));
-                                    self.tabs[i].scene.deselect_all();
-                                    self.tabs[i].scene.select_entity(handle, false);
-                                    self.tabs[i].scene.expand_selection_for_groups(&[handle]);
-                                    self.refresh_properties();
-                                    selection_just_completed = true;
+                                if cands.len() >= 2 {
+                                    // Overlap: open the list box at the cursor.
+                                    self.cycle_candidates = Some((p_full, cands));
                                     handled_by_cycling = true;
                                 }
                             }
@@ -3644,7 +3630,20 @@ impl OpenCADStudio {
             }
             Message::ToggleSelectionCycling => {
                 self.selection_cycling ^= true;
-                self.cycle_state = None;
+                self.cycle_candidates = None;
+                Task::none()
+            }
+            Message::CycleSelect(handle) => {
+                // Add the picked object to the current selection (accumulate).
+                self.cycle_candidates = None;
+                let i = self.active_tab;
+                self.tabs[i].scene.select_entity(handle, false);
+                self.tabs[i].scene.expand_selection_for_groups(&[handle]);
+                self.refresh_properties();
+                Task::none()
+            }
+            Message::CycleCancel => {
+                self.cycle_candidates = None;
                 Task::none()
             }
             Message::ToggleSelectionFilterPopup => {

src/app/view.rs

@@ -1014,6 +1014,24 @@ impl OpenCADStudio {
             }
         }
 
+        // Selection-cycling list box: pick among overlapping objects.
+        if let Some((pt, cands)) = &self.cycle_candidates {
+            if !tab.is_start {
+                let items: Vec<(acadrust::Handle, String)> = cands
+                    .iter()
+                    .filter_map(|&h| {
+                        tab.scene.document.get_entity(h).map(|e| {
+                            (h, crate::entities::traits::entity_type_name(e).to_string())
+                        })
+                    })
+                    .collect();
+                if !items.is_empty() {
+                    viewport_stack = viewport_stack
+                        .push(crate::ui::cycle_popup::cycle_popup_overlay(*pt, items));
+                }
+            }
+        }
+
         // Right-click context menu. Lives inside the viewport stack so
         // the cursor position (canvas-relative) anchors the menu under
         // the cursor instead of drifting into window-relative space.

src/ui/cycle_popup.rs

@@ -0,0 +1,87 @@
+//! Selection-cycling list box — shown at the cursor when a click lands on
+//! two or more overlapping objects. Each row names a candidate; clicking it
+//! adds that object to the current selection. Clicking outside dismisses it.
+
+use iced::widget::{button, column, container, mouse_area, opaque, row, text, Space};
+use iced::{Background, Border, Color, Element, Fill, Length, Theme};
+
+use crate::app::Message;
+
+/// Full-canvas overlay: the list box anchored at `anchor` (canvas
+/// coordinates) plus a transparent click-catcher that cancels.
+pub fn cycle_popup_overlay(
+    anchor: iced::Point,
+    items: Vec<(acadrust::Handle, String)>,
+) -> Element<'static, Message> {
+    let rows: Vec<Element<'static, Message>> = items
+        .into_iter()
+        .map(|(handle, label)| item_row(label, Message::CycleSelect(handle)))
+        .collect();
+
+    let panel = container(column(rows))
+        .style(|_: &Theme| container::Style {
+            background: Some(Background::Color(PANEL_BG)),
+            border: Border {
+                color: PANEL_BORDER,
+                width: 1.0,
+                radius: 3.0.into(),
+            },
+            ..Default::default()
+        })
+        .width(Length::Fixed(150.0));
+
+    let positioned = column![
+        Space::new().height(Length::Fixed(anchor.y.max(0.0))),
+        row![
+            Space::new().width(Length::Fixed(anchor.x.max(0.0))),
+            opaque(panel),
+        ],
+    ]
+    .width(Fill)
+    .height(Fill);
+
+    mouse_area(positioned).on_press(Message::CycleCancel).into()
+}
+
+fn item_row(label: String, msg: Message) -> Element<'static, Message> {
+    let content = text(label).size(11).color(LABEL).align_y(iced::Center);
+    button(content)
+        .on_press(msg)
+        .style(|_: &Theme, status| button::Style {
+            background: Some(Background::Color(match status {
+                button::Status::Hovered => ROW_HOVER,
+                _ => Color::TRANSPARENT,
+            })),
+            ..Default::default()
+        })
+        .width(Fill)
+        .padding([4, 10])
+        .into()
+}
+
+// ── Colours ───────────────────────────────────────────────────────────────
+
+const PANEL_BG: Color = Color {
+    r: 0.15,
+    g: 0.15,
+    b: 0.15,
+    a: 1.0,
+};
+const PANEL_BORDER: Color = Color {
+    r: 0.32,
+    g: 0.32,
+    b: 0.32,
+    a: 1.0,
+};
+const ROW_HOVER: Color = Color {
+    r: 0.22,
+    g: 0.45,
+    b: 0.62,
+    a: 1.0,
+};
+const LABEL: Color = Color {
+    r: 0.92,
+    g: 0.92,
+    b: 0.92,
+    a: 1.0,
+};

src/ui/mod.rs

@@ -7,6 +7,7 @@ pub mod app_menu;
 pub mod isolate_popup;
 pub mod update_notice;
 pub mod command_line;
+pub mod cycle_popup;
 pub mod dimstyle;
 pub mod layers;
 pub mod layout_manager;