LR-LIB-RATING: one Tab stop per rating row, visible-only favourite registration, true docs

The star row is a single Tab stop (the current rating's star, or the first) with the arrow keys
stepping inside it and the focus following. favorite_button registers its automation id only while
on screen again. The module and test docs no longer mention a size/read-only API that doesn't exist.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/rating.rs

@@ -4,12 +4,13 @@
 //! badges, the compare caption and the filter bar.
 //!
 //! ```ignore
-//! if let Some(r) = Rating::new("bottom", photo.rating).size(RatingSize::Large).show(ui) { … }
-//! Rating::new("row", 3).size(RatingSize::Small).read_only().show(ui);
+//! if let Some(r) = Rating::new("bottom", photo.rating).show(ui) { … }
+//! paint_rating(ui.painter(), pos, 3, RatingSize::Small, color);
 //! ```
 //!
 //! Hovering a star previews the rating a click would set; clicking the current rating clears it.
-//! With a star focused, ← and → lower and raise the rating (0 to 5).
+//! The row is one Tab stop (the star of the current rating, or the first when unrated); inside it, ← and →
+//! lower and raise the rating (0 to 5) and the focus follows.
 
 use egui::{Color32, Key, Modifiers, Painter, Pos2, Rect, Sense, Ui, pos2, vec2};
 
@@ -120,6 +121,10 @@ impl Rating {
         }
     }
 
+    fn star_id(&self, ui: &Ui, i: u8) -> egui::Id {
+        ui.id().with(("rating-star", &self.id, i))
+    }
+
     /// Draw the row. Returns the new rating when a click or an arrow key changed it.
     pub fn show(self, ui: &mut Ui) -> Option<u8> {
         let t = Tokens::get(ui.ctx());
@@ -128,8 +133,14 @@ impl Rating {
         let mut hover_n = None;
         let mut focused = false;
         let mut cells = [Rect::NOTHING; STARS as usize];
+        // One Tab stop for the row, like a radio group: the star of the current rating (the first when
+        // unrated), plus whichever star already has the focus so it keeps it
+        let stop = self.rating.max(1) - 1;
         for (i, slot) in (0..STARS).zip(cells.iter_mut()) {
-            let (r, resp) = ui.allocate_exact_size(vec2(cell, cell), Sense::click());
+            let id = self.star_id(ui, i);
+            let (r, _) = ui.allocate_exact_size(vec2(cell, cell), Sense::hover());
+            let sense = if i == stop || ui.memory(|m| m.has_focus(id)) { Sense::click() } else { Sense::CLICK };
+            let resp = ui.interact(r, id, sense);
             announce_selected(&resp, format!("{} ★", i + 1), i < self.rating);
             register(ui.ctx(), self.widget_id(i + 1), r);
             if resp.hovered() {
@@ -156,6 +167,11 @@ impl Rating {
                 ui.memory_mut(|m| m.move_focus(egui::FocusDirection::None));
             }
             out = nudged_rating(self.rating, left, right);
+            if let Some(n) = out {
+                // keep the focus on the star that is now the row's Tab stop
+                let to = self.star_id(ui, n.max(1) - 1);
+                ui.memory_mut(|m| m.request_focus(to));
+            }
         }
         // The hovered star also gets the icon-button hover square, so hovering the current rating (where
         // the preview looks the same) still shows feedback.
@@ -178,7 +194,10 @@ pub fn favorite_button(ui: &mut Ui, widget: String, favorite: bool, name: &str)
     let side = ui.spacing().interact_size.y;
     let (r, resp) = ui.allocate_exact_size(vec2(side, side), Sense::click());
     announce_selected(&resp, name, favorite);
-    register(ui.ctx(), widget, r);
+    // (rows scrolled out of view can't be clicked)
+    if ui.is_rect_visible(r) {
+        register(ui.ctx(), widget, r);
+    }
     if resp.hovered() {
         ui.painter().rect_filled(r, 4.0, t.hover.gamma_multiply(0.7));
     }
@@ -211,4 +230,21 @@ mod tests {
         assert_eq!(nudged_rating(3, false, true), Some(4));
         assert_eq!(nudged_rating(3, true, true), None);
     }
+
+    #[test]
+    fn rows_scrolled_out_of_view_are_not_registered() {
+        let ctx = egui::Context::default();
+        crate::theme::install_fonts(&ctx);
+        let mut out = ctx.run_ui(egui::RawInput { screen_rect: Some(Rect::from_min_size(Pos2::ZERO, vec2(300.0, 100.0))), ..Default::default() }, |ui| {
+            egui::ScrollArea::vertical().max_height(60.0).show(ui, |ui| {
+                for i in 0..30 {
+                    favorite_button(ui, format!("effectStar:{i}"), false, "Favorite");
+                }
+            });
+        });
+        out.textures_delta.clear();
+        let ids: Vec<String> = crate::widgets::take_registry(&ctx).into_iter().map(|(id, _)| id).collect();
+        assert!(ids.contains(&"effectStar:0".to_string()), "{ids:?}");
+        assert!(!ids.contains(&"effectStar:29".to_string()), "{ids:?}");
+    }
 }

crates/ui-egui/src/tests_rating.rs

@@ -1,5 +1,5 @@
-//! The star rating: clicking sets the rating, clicking the current one clears it, a read-only or
-//! disabled row ignores clicks, the arrow keys step it, and screen readers hear every star.
+//! The star rating: clicking sets the rating, clicking the current one clears it, the row is one
+//! Tab stop, the arrow keys step it, and screen readers hear every star.
 
 use egui::{Pos2, Rect, vec2};
 
@@ -134,3 +134,32 @@ fn arrows_keep_stepping_between_other_focusable_widgets() {
     let seen = step_with_neighbours(0, &[Tab, Tab, ArrowRight, ArrowRight, ArrowRight, ArrowRight, ArrowRight, ArrowLeft]);
     assert_eq!(seen.last(), Some(&4), "{seen:?}");
 }
+
+#[test]
+fn a_rating_row_is_one_tab_stop() {
+    use egui::Key::Tab;
+    // left neighbour, one stop for the five stars, right neighbour: the third Tab is already past the row
+    let ctx = egui::Context::default();
+    crate::theme::install_fonts(&ctx);
+    let mut focused = Vec::new();
+    for frame in 0..5 {
+        let events = if frame >= 1 {
+            vec![egui::Event::Key { key: Tab, physical_key: Some(Tab), pressed: true, repeat: false, modifiers: Default::default() }]
+        } else {
+            Vec::new()
+        };
+        let raw = egui::RawInput { screen_rect: Some(Rect::from_min_size(Pos2::ZERO, vec2(600.0, 200.0))), events, ..Default::default() };
+        let mut right = None;
+        let mut out = ctx.run_ui(raw, |ui| {
+            ui.horizontal(|ui| {
+                let _ = ui.button("left neighbour");
+                let _ = row(3).show(ui);
+                right = Some(ui.button("right neighbour").id);
+            });
+        });
+        out.textures_delta.clear();
+        focused.push(right.is_some_and(|id| ctx.memory(|m| m.has_focus(id))));
+    }
+    // frames 1 to 3 press Tab: left neighbour, the row, right neighbour
+    assert_eq!(focused, vec![false, false, false, true, false], "{focused:?}");
+}