Fix #290: hovering another menu title switches the open menu

On the in-window menu bar (Windows and Linux) each top-level menu needed
its own click: with File open, moving the pointer onto Edit or Object did
nothing. Now, as on a native menu bar, while one menu is open a moving
pointer that reaches another title opens that menu instead (ported from
PhotoCraft). A pointer resting on a title doesn't switch, and a tall menu
that covers the bar doesn't switch to the title underneath it. The native
macOS menu bar is unchanged.

Also adds a regression test for #292: the Simplify, Offset Path, Move,
Rotate, Split Into Grid and Average dialogs are 366 pt wide in a 1600 pt
window (already fixed by #239).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

ROADMAP.md

@@ -100,7 +100,7 @@ grade by behaviour against `plan/illustrator/`, not by whether a menu item exist
   - A canvas context menu: right-click selects the object under the pointer and lists what applies to the selection (Undo/Redo, clipboard, group, isolation, join, masks, compound paths, guides, Transform, Arrange, Select, Export Selection), or the view commands on empty canvas.
   - Save / Don't Save / Cancel before closing or quitting with unsaved documents (tabs, Close, Close All, Quit, window close).
   - Four brightness themes, persistent preferences.
-  - On Windows and Linux the app bar is the window's title bar (its own minimize, maximize and close buttons, drag to move, edges to resize), with the dragon app icon as the brand mark; dialogs and menus size to their content.
+  - On Windows and Linux the app bar is the window's title bar (its own minimize, maximize and close buttons, drag to move, edges to resize), with the dragon app icon as the brand mark; dialogs and menus size to their content. As on a native menu bar, once one menu is open, moving the pointer onto another title opens that one.
 - **Tools:**
   - **Selection:** Selection, Direct/Group Selection, Magic Wand, Lasso.
   - **Drawing:** Pen, Curvature, anchor tools, Pencil, Paintbrush, Blob Brush, Smooth, Path Eraser, Join.

crates/ui-egui/src/dialogs/tests.rs

@@ -274,6 +274,21 @@ fn a_form_dialog_is_as_wide_as_its_fields_not_the_window() {
     assert!(narrow.width() <= 360.0, "{:.0} wide in a 360-point window", narrow.width());
 }
 
+#[test]
+fn menu_parameter_dialogs_are_compact() {
+    // #292: Object › Path › Simplify (and its neighbours) spanned the whole window.
+    for id in ["object.path.simplify", "object.path.offsetPath", "object.move", "object.rotate", "object.path.splitIntoGrid", "path.average"] {
+        let mut app = app();
+        app.run("shape.rectangle", json!({"x": 10, "y": 10, "width": 50, "height": 50})).unwrap();
+        app.run("select.all", json!({})).unwrap();
+        crate::menus::invoke(&mut app, id, json!({}));
+        assert!(app.ui.dialog.is_some(), "{id} opened no dialog");
+        let wide = dialog_rect(&mut app, 1600.0);
+        eprintln!("{id}: {:.0} × {:.0} in a 1600-point window", wide.width(), wide.height());
+        assert!(wide.width() < 420.0, "{id} is {:.0} wide in a 1600-point window", wide.width());
+    }
+}
+
 /// A list mixing built-in labels with names translates only the built-in entries: names that
 /// happen to be catalog keys ("Black", "Regular") are shown as they are.
 #[test]

crates/ui-egui/src/menus.rs

@@ -2343,14 +2343,16 @@ pub fn menu_bar(app: &mut VectorcraftApp, ui: &mut egui::Ui) -> f32 {
     let tree = menu_tree();
     let end = egui::MenuBar::new()
         .ui(ui, |ui| {
+            let mut titles = Vec::with_capacity(tree.len());
             for (i, (title, items)) in tree.iter().enumerate() {
                 let text = if i == 0 {
                     egui::RichText::new(tl!(title)).font(theme::semibold(13.0)).color(t.text)
                 } else {
                     egui::RichText::new(tl!(title)).size(13.0).color(t.text)
                 };
-                ui.menu_button(text, |ui| menu_body(app, ui, items, &mut clicked));
+                titles.push(ui.menu_button(text, |ui| menu_body(app, ui, items, &mut clicked)).response);
             }
+            switch_on_hover(ui.ctx(), &titles);
             ui.cursor().min.x
         })
         .inner;
@@ -2360,6 +2362,39 @@ pub fn menu_bar(app: &mut VectorcraftApp, ui: &mut egui::Ui) -> f32 {
     end
 }
 
+/// Whether the pointer at `p` is really over the menu title `title`: inside it, and with no
+/// popup above it (a tall menu that egui moves up can cover the bar; hovering that menu must
+/// not switch to the title under it).
+fn pointer_reaches_title(ctx: &egui::Context, title: &egui::Response, p: egui::Pos2) -> bool {
+    title.interact_rect.contains(p) && ctx.layer_id_at(p) == Some(title.layer_id)
+}
+
+/// Like a native menu bar: while one top-level menu is open, moving the pointer onto another
+/// title opens that menu instead (egui alone needs a click on each title).
+fn switch_on_hover(ctx: &egui::Context, titles: &[egui::Response]) {
+    let ids: Vec<egui::Id> = titles.iter().map(egui::Popup::default_response_id).collect();
+    let Some(open) = ids.iter().position(|id| egui::Popup::is_id_open(ctx, *id)) else {
+        return;
+    };
+    // `Response::hovered` is false while a menu's popup is open, so hit-test the titles here.
+    let Some(p) = ctx.pointer_hover_pos() else {
+        return;
+    };
+    // Only a moving pointer switches: one resting on a title leaves the open menu alone.
+    if ctx.input(|i| i.pointer.delta() == egui::Vec2::ZERO) {
+        return;
+    }
+    let Some(i) = titles.iter().position(|title| pointer_reaches_title(ctx, title, p)) else {
+        return;
+    };
+    if i != open
+        && let Some(id) = ids.get(i)
+    {
+        egui::Popup::open_id(ctx, *id);
+        ctx.request_repaint();
+    }
+}
+
 /// A top-level menu's popup: as wide as its widest item (label plus shortcut), at least 230 pt;
 /// it scrolls when it is taller than the window.
 fn menu_body(app: &VectorcraftApp, ui: &mut egui::Ui, items: &[Item], clicked: &mut Option<(String, Value)>) {
@@ -2954,6 +2989,99 @@ pub fn menu_strings() -> std::collections::BTreeSet<String> {
 mod tests {
     use super::*;
 
+    /// One headless frame of the in-window menu bar; returns its titles (left to right) as
+    /// (rect, id of the title's popup).
+    fn bar_frame(app: &mut VectorcraftApp, ctx: &egui::Context, events: Vec<egui::Event>) -> Vec<(egui::Rect, egui::Id)> {
+        let screen = egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(1200.0, 700.0));
+        let mut layer = None;
+        let mut out = ctx.run_ui(egui::RawInput { screen_rect: Some(screen), events, ..Default::default() }, |ui| {
+            layer = Some(ui.layer_id());
+            menu_bar(app, ui);
+        });
+        out.textures_delta.clear();
+        let layer = layer.unwrap();
+        let mut titles: Vec<(egui::Rect, egui::Id)> = ctx.viewport(|vp| {
+            vp.prev_pass
+                .widgets
+                .get_layer(layer)
+                .filter(|w| w.sense.senses_click() && w.rect.top() < 30.0)
+                // `egui::Popup::default_response_id` of the title's response.
+                .map(|w| (w.rect, w.id.with("popup")))
+                .collect()
+        });
+        titles.sort_by(|a, b| a.0.left().total_cmp(&b.0.left()));
+        titles
+    }
+
+    fn open_titles(ctx: &egui::Context, titles: &[(egui::Rect, egui::Id)]) -> Vec<usize> {
+        (0..titles.len()).filter(|&i| egui::Popup::is_id_open(ctx, titles[i].1)).collect()
+    }
+
+    #[test]
+    fn hovering_another_title_switches_the_open_menu() {
+        let mut app = VectorcraftApp::new(vectorcraft_engine::Session::new(), crate::Services::default());
+        let ctx = egui::Context::default();
+        theme::install_fonts(&ctx);
+        theme::apply(&ctx, Default::default());
+        bar_frame(&mut app, &ctx, vec![]);
+        let titles = bar_frame(&mut app, &ctx, vec![]);
+        assert_eq!(titles.len(), menu_tree().len());
+        // 0 is the app menu, then File, Edit, Object.
+        let (file, edit, object) = (titles[1].0.center(), titles[2].0.center(), titles[3].0.center());
+        let frames = |app: &mut VectorcraftApp, events: Vec<egui::Event>| {
+            let mut t = bar_frame(app, &ctx, events);
+            for _ in 0..2 {
+                t = bar_frame(app, &ctx, vec![]);
+            }
+            t
+        };
+        let button = |pos, pressed| egui::Event::PointerButton { pos, button: egui::PointerButton::Primary, pressed, modifiers: Default::default() };
+
+        // Nothing open: hovering a title opens nothing.
+        let t = frames(&mut app, vec![egui::Event::PointerMoved(edit)]);
+        assert!(open_titles(&ctx, &t).is_empty());
+
+        // Click File, then move onto Edit and on to Object: each opens in turn, alone.
+        frames(&mut app, vec![egui::Event::PointerMoved(file)]);
+        frames(&mut app, vec![button(file, true)]);
+        let t = frames(&mut app, vec![button(file, false)]);
+        assert_eq!(open_titles(&ctx, &t), vec![1], "a click opens File");
+        let t = frames(&mut app, vec![egui::Event::PointerMoved(edit)]);
+        assert_eq!(open_titles(&ctx, &t), vec![2], "hovering Edit opens it and closes File");
+        let t = frames(&mut app, vec![egui::Event::PointerMoved(object)]);
+        assert_eq!(open_titles(&ctx, &t), vec![3], "hovering Object opens it and closes Edit");
+
+        // A pointer resting on a title doesn't switch: File opened another way (the keyboard)
+        // stays open while the pointer stays still over Object.
+        egui::Popup::open_id(&ctx, t[1].1);
+        let t = frames(&mut app, vec![]);
+        assert_eq!(open_titles(&ctx, &t), vec![1], "a still pointer leaves the open menu alone");
+    }
+
+    #[test]
+    fn a_popup_covering_a_title_does_not_switch_menus() {
+        let ctx = egui::Context::default();
+        let p = egui::pos2(90.0, 12.0);
+        let mut reaches = (true, false);
+        // The popup becomes hit-testable once egui has laid it out: draw a few frames.
+        for _ in 0..3 {
+            let raw =
+                egui::RawInput { screen_rect: Some(egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(300.0, 200.0))), ..Default::default() };
+            let mut out = ctx.run_ui(raw, |ui| {
+                let ctx = ui.ctx().clone();
+                let covered = ui.interact(egui::Rect::from_center_size(p, egui::vec2(80.0, 24.0)), egui::Id::new("covered"), egui::Sense::click());
+                let q = p + egui::vec2(0.0, 100.0);
+                let free = ui.interact(egui::Rect::from_center_size(q, egui::vec2(80.0, 24.0)), egui::Id::new("free"), egui::Sense::click());
+                egui::Area::new(egui::Id::new("popup")).order(egui::Order::Foreground).fixed_pos(p - egui::vec2(10.0, 10.0)).show(&ctx, |ui| {
+                    ui.allocate_space(egui::vec2(20.0, 20.0));
+                });
+                reaches = (pointer_reaches_title(&ctx, &covered, p), pointer_reaches_title(&ctx, &free, q));
+            });
+            out.textures_delta.clear();
+        }
+        assert_eq!(reaches, (false, true));
+    }
+
     #[test]
     fn names_in_menus_are_not_interface_labels() {
         for (id, label) in [