M8: join and round layer hierarchy highlights

crates/ui-egui/src/layers_behaviour_tests.rs

@@ -51,6 +51,115 @@ fn sorted(mut v: Vec<NodeId>) -> Vec<NodeId> {
     v
 }
 
+#[test]
+fn selected_hierarchies_have_continuous_rounded_backgrounds() {
+    let mut s = Session::new();
+    let frame = id(s.execute("frame.create", &json!({"name": "Selected frame"})).unwrap());
+    let child = rect(&mut s, "child", 0.0, Some(frame));
+    let group = id(s.execute("object.group", &json!({"ids": [child]})).unwrap());
+    rect(&mut s, "sibling", 30.0, Some(frame));
+    let other = id(s.execute("frame.create", &json!({"name": "Other frame"})).unwrap());
+    rect(&mut s, "other child", 0.0, Some(other));
+    s.execute("select.set", &json!({"ids": [frame, group, other]})).unwrap();
+    let mut u = Ui::new(s);
+    u.app.ui.expanded.extend([frame, group, other]);
+    let selected_rows = [frame, group, other].map(|id| u.row_at(id));
+    let out = u.frame_output(vec![Event::PointerGone]);
+    let t = crate::theme::Tokens::get(&u.ctx);
+    for pos in selected_rows {
+        let rect_at = |fill| {
+            out.shapes.iter().enumerate().find_map(|(i, s)| match &s.shape {
+                egui::Shape::Rect(r) if r.fill == fill && r.rect.contains(pos) => Some(i),
+                _ => None,
+            })
+        };
+        let background = rect_at(t.selected_row_child).expect("the selected row belongs to the hierarchy background");
+        let highlight = rect_at(t.selected_row).expect("each selected frame or group has its own highlight");
+        assert!(highlight > background, "the selected highlight is painted above the hierarchy background");
+    }
+    let backgrounds: Vec<_> = out
+        .shapes
+        .iter()
+        .filter_map(|s| match &s.shape {
+            egui::Shape::Rect(r) if r.fill == t.selected_row_child => Some(r),
+            _ => None,
+        })
+        .collect();
+    // Other frame + child, then selected frame + sibling + selected group + child.
+    assert_eq!(backgrounds.len(), 6);
+    for band in [&backgrounds[..2], &backgrounds[2..]] {
+        assert_eq!(band.first().unwrap().corner_radius.nw, 5);
+        assert_eq!(band.last().unwrap().corner_radius.sw, 5);
+        for pair in band.windows(2) {
+            assert_eq!(pair[0].rect.bottom(), pair[1].rect.top(), "the highlight fills the inter-row spacing");
+            assert_eq!(pair[0].corner_radius.sw, 0, "no rounded seams inside the hierarchy");
+            assert_eq!(pair[1].corner_radius.nw, 0, "a selected nested group stays in the same block");
+        }
+    }
+    assert!(backgrounds[1].rect.bottom() < backgrounds[2].rect.top(), "separate selected hierarchies stay separate");
+    // A collapsed frame and a filtered leaf each have all four corners rounded.
+    u.app.ui.expanded.clear();
+    let out = u.frame_output(vec![]);
+    let collapsed: Vec<_> = out
+        .shapes
+        .iter()
+        .filter_map(|s| match &s.shape {
+            egui::Shape::Rect(r) if r.fill == t.selected_row_child => Some(r),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(collapsed.len(), 2);
+    assert!(collapsed.iter().all(|r| r.corner_radius == egui::CornerRadius::same(5)));
+    u.app.ui.layer_filter = "child".into();
+    let out = u.frame_output(vec![]);
+    assert!(out.shapes.iter().any(|s| matches!(&s.shape,
+        egui::Shape::Rect(r) if r.fill == t.selected_row_child && r.corner_radius.sw == 5
+    )));
+}
+
+#[test]
+fn selected_hierarchy_keeps_square_seams_when_scrolled() {
+    let mut s = Session::new();
+    let frame = id(s.execute("frame.create", &json!({"name": "Long hierarchy"})).unwrap());
+    for i in 0..70 {
+        rect(&mut s, &format!("Child {i}"), 0.0, Some(frame));
+    }
+    s.execute("select.set", &json!({"ids": [frame]})).unwrap();
+    let mut u = Ui::new(s);
+    u.app.ui.expanded.insert(frame);
+    let fill = crate::theme::Tokens::get(&u.ctx).selected_row_child;
+    let corners = |out: &egui::FullOutput| {
+        out.shapes
+            .iter()
+            .filter_map(|s| match &s.shape {
+                egui::Shape::Rect(r) if r.fill == fill && r.rect.intersects(s.clip_rect) => Some(r.corner_radius),
+                _ => None,
+            })
+            .collect::<Vec<_>>()
+    };
+    let wheel = |y| Event::MouseWheel {
+        unit: egui::MouseWheelUnit::Point,
+        delta: egui::vec2(0.0, y),
+        modifiers: Modifiers::NONE,
+        phase: egui::TouchPhase::Move,
+        source: egui::MouseWheelSource::Unknown,
+    };
+    u.frame(vec![Event::PointerMoved(egui::pos2(150.0, 500.0)), wheel(-700.0)]);
+    for _ in 0..30 {
+        u.frame(vec![]);
+    }
+    let middle = corners(&u.frame_output(vec![]));
+    assert!(!middle.is_empty());
+    assert!(middle.iter().all(|c| *c == egui::CornerRadius::ZERO), "viewport edges inside a subtree are square seams");
+    u.frame(vec![wheel(-10000.0)]);
+    for _ in 0..30 {
+        u.frame(vec![]);
+    }
+    let end = corners(&u.frame_output(vec![]));
+    assert_eq!(end.first().unwrap().nw, 0, "the hierarchy starts above the viewport");
+    assert_eq!(end.last().unwrap().sw, 5, "the hierarchy's real end stays rounded");
+}
+
 #[test]
 fn clicking_rows_selects_by_the_documented_rules() {
     let (mut u, [a, b, c, d]) = four();

crates/ui-egui/src/panels/layers.rs

@@ -956,15 +956,33 @@ fn reveal_selection(app: &mut FigApp, doc: &Document, page: NodeId, sel: &[NodeI
     reveal
 }
 
+/// The outermost selected layer owning a row's continuous hierarchy highlight.
+fn selection_root(doc: &Document, sel: &[NodeId], id: NodeId) -> Option<NodeId> {
+    doc.ancestors(id).into_iter().rev().find(|a| sel.contains(a)).or_else(|| sel.contains(&id).then_some(id))
+}
+
+fn hierarchy_bg(doc: &Document, sel: &[NodeId], rows: &[Row], i: usize, mut rr: Rect, gap: f32) -> Option<(Rect, CornerRadius)> {
+    let root = selection_root(doc, sel, rows.get(i)?.id)?;
+    // Look beyond the viewport too: scrolling must not round an edge in the
+    // middle of a selected subtree. Separate selected subtrees keep their corners.
+    let joins = |neighbor: &Row| selection_root(doc, sel, neighbor.id) == Some(root);
+    let above = i.checked_sub(1).and_then(|j| rows.get(j)).is_some_and(joins);
+    let below = rows.get(i + 1).is_some_and(joins);
+    if below {
+        rr.max.y += gap;
+    }
+    let top = if above { 0 } else { 5 };
+    let bottom = if below { 0 } else { 5 };
+    Some((rr, CornerRadius { nw: top, ne: top, sw: bottom, se: bottom }))
+}
+
 /// A row's background: selected, inside a selected layer, or outlined when hovered.
 /// `state` is [selected, in_selected, component].
 fn paint_row_bg(ui: &Ui, t: &Tokens, rr: Rect, state: [bool; 3], hovered: bool) {
     let [selected, in_selected, is_comp] = state;
     if selected {
         ui.painter().rect_filled(rr, CornerRadius::same(5), if is_comp { t.component_row } else { t.selected_row });
-    } else if in_selected {
-        ui.painter().rect_filled(rr, CornerRadius::ZERO, t.selected_row_child);
-    } else if hovered {
+    } else if !in_selected && hovered {
         ui.painter().rect_stroke(rr, CornerRadius::same(5), Stroke::new(1.0, if is_comp { COMPONENT } else { ACCENT }), egui::StrokeKind::Inside);
     }
 }
@@ -1070,7 +1088,7 @@ fn layers(app: &mut FigApp, ui: &mut Ui) {
         // Stable widget ids for a row wherever the list is scrolled.
         band_ui.skip_ahead_auto_ids(first);
         let ui = &mut band_ui;
-        for row in rows.iter().take(last).skip(first) {
+        for (i, row) in rows.iter().enumerate().take(last).skip(first) {
             let Some(n) = doc.node(row.id) else { continue };
             let (r, resp) = ui.allocate_exact_size(vec2(w, ROW), Sense::click_and_drag());
             let selected = sel.contains(&row.id);
@@ -1087,9 +1105,13 @@ fn layers(app: &mut FigApp, ui: &mut Ui) {
                 locked: n.locked,
             };
             a11y::tree_item(&resp, if n.name.is_empty() { tr(n.kind.label()) } else { &n.name }, &info);
-            let in_selected = !selected && doc.ancestors(row.id).iter().any(|a| sel.contains(a));
             let is_comp = matches!(n.kind, NodeKind::Component { .. } | NodeKind::ComponentSet { .. } | NodeKind::Instance { .. });
             let rr = r.shrink2(vec2(8.0, 0.0));
+            let bg = hierarchy_bg(&doc, &sel, &rows, i, rr, pitch - ROW);
+            let in_selected = !selected && bg.is_some();
+            if let Some((rect, corners)) = bg {
+                ui.painter().rect_filled(rect, corners, t.selected_row_child);
+            }
             a11y::ring_around(ui, rr, &resp);
             // Over the row, its eye and padlock included (they sit on top of it).
             let over = resp.contains_pointer();

crates/ui-egui/src/theme.rs

@@ -493,7 +493,7 @@ mod tests {
             let theme = if t.dark { "dark" } else { "light" };
             // Disabled text (a disabled button's label, placeholders) on panels, fields and
             // selected rows, still dimmer than secondary text.
-            for bg in [t.panel, t.field, t.hover, t.selected_row] {
+            for bg in [t.panel, t.field, t.hover, t.selected_row, t.selected_row_child] {
                 let ratio = c(t.text_tertiary).contrast(c(bg));
                 assert!(ratio >= 3.0, "{theme}: dim text {:?} on {bg:?} is {ratio:.2}:1", t.text_tertiary);
                 assert!(ratio < c(t.text_secondary).contrast(c(bg)), "{theme}: dim text reads dimmer than secondary text");