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 <[email protected]>

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;