Repeat isolation: draw the isolated repeat undimmed; test exit, undo and groups

A live object reached the renderer without passing the isolated-object check that groups go
through, so an isolated repeat was dimmed with the art around it. Tests cover leaving isolation
(double-click outside, exitIsolation), undo/redo of an edit inside, and a repeat of a group.

crates/engine/src/tests/repeat_edit.rs

@@ -39,3 +39,102 @@ fn a_double_click_on_a_repeat_isolates_it_to_edit_its_text() {
     assert_eq!(spec(&s)["kind"], before["kind"], "the repeat keeps its settings (rows, columns, spacing)");
     assert!(before["kind"].is_object(), "the settings are read: {before}");
 }
+
+/// A text repeat isolated by a double-click on it: returns (session, text, repeat, point on the text).
+fn isolated_text_repeat() -> (Session, NodeId, NodeId, (f64, f64)) {
+    let mut s = Session::new();
+    s.execute("file.new", &json!({"width": 600, "height": 400})).unwrap();
+    let text = NodeId(s.execute("text.create", &json!({"x": 50, "y": 60, "text": "Alice", "size": 24})).unwrap()["id"].as_u64().unwrap());
+    s.execute("select.set", &json!({"ids": [text.0]})).unwrap();
+    let repeat = NodeId(s.execute("object.repeat.grid", &json!({})).unwrap()["id"].as_u64().unwrap());
+    s.select_tool("selection", ViewInfo::default()).unwrap();
+    let b = s.doc().unwrap().doc.node(text).unwrap().geometric_bounds().unwrap();
+    let at = (b.center().x, b.center().y);
+    click(&mut s, PointerKind::DoubleClick, at.0, at.1);
+    assert_eq!(s.doc().unwrap().isolation, Some(repeat));
+    (s, text, repeat, at)
+}
+
+fn plain_text(s: &Session, id: NodeId) -> String {
+    let NodeKind::Text(t) = &s.doc().unwrap().doc.node(id).unwrap().kind else { panic!("not type") };
+    t.plain_text()
+}
+
+/// #5054 review: a double-click outside the repeat leaves isolation mode, and so does
+/// `object.exitIsolation` (what Escape and Exit Isolation Mode run); the repeat stays a repeat.
+#[test]
+fn isolation_on_a_repeat_ends_by_double_click_outside_or_exit() {
+    let (mut s, _, repeat, _) = isolated_text_repeat();
+    click(&mut s, PointerKind::DoubleClick, 580.0, 380.0);
+    assert_eq!(s.doc().unwrap().isolation, None, "a double-click on empty canvas leaves isolation mode");
+    let (mut s, _, repeat2, at) = isolated_text_repeat();
+    assert_eq!(repeat, repeat2);
+    s.execute("object.exitIsolation", &json!({})).unwrap();
+    assert_eq!(s.doc().unwrap().isolation, None, "Escape's command leaves isolation mode");
+    assert!(matches!(s.doc().unwrap().doc.node(repeat).unwrap().kind, NodeKind::Repeat(_)), "still a repeat");
+    // And a double-click on it isolates it again.
+    click(&mut s, PointerKind::DoubleClick, at.0, at.1);
+    assert_eq!(s.doc().unwrap().isolation, Some(repeat));
+}
+
+/// #5054 review: an edit made in a repeat's isolation mode undoes in one step and the repeat
+/// keeps drawing its source; isolating it adds no undo step of its own.
+#[test]
+fn an_edit_inside_an_isolated_repeat_undoes() {
+    let (mut s, text, repeat, _) = isolated_text_repeat();
+    let steps = s.doc().unwrap().history.undo.len();
+    s.execute("text.setText", &json!({"id": text.0, "text": "Bob"})).unwrap();
+    assert_eq!(s.doc().unwrap().history.undo.len(), steps + 1);
+    s.execute("edit.undo", &json!({})).unwrap();
+    assert_eq!(plain_text(&s, text), "Alice");
+    assert_eq!(s.doc().unwrap().doc.position(text).and_then(|(p, ..)| p), Some(repeat), "still the repeat's source");
+    s.execute("edit.redo", &json!({})).unwrap();
+    assert_eq!(plain_text(&s, text), "Bob");
+}
+
+/// #5054 review: a repeat of a group isolates on a double-click, and a double-click on the group
+/// inside it goes one level further, into the group, where its art can be selected alone.
+#[test]
+fn a_repeat_of_a_group_isolates_then_enters_the_group() {
+    let mut s = Session::new();
+    s.execute("file.new", &json!({"width": 600, "height": 400})).unwrap();
+    let a = s.execute("shape.rectangle", &json!({"x": 40, "y": 40, "width": 30, "height": 30})).unwrap()["id"].as_u64().unwrap();
+    let b = s.execute("shape.rectangle", &json!({"x": 80, "y": 40, "width": 30, "height": 30})).unwrap()["id"].as_u64().unwrap();
+    s.execute("select.set", &json!({"ids": [a, b]})).unwrap();
+    let group = NodeId(s.execute("object.group", &json!({})).unwrap()["id"].as_u64().unwrap());
+    s.execute("select.set", &json!({"ids": [group.0]})).unwrap();
+    let repeat = NodeId(s.execute("object.repeat.grid", &json!({})).unwrap()["id"].as_u64().unwrap());
+    s.select_tool("selection", ViewInfo::default()).unwrap();
+    click(&mut s, PointerKind::DoubleClick, 55.0, 55.0);
+    assert_eq!(s.doc().unwrap().isolation, Some(repeat), "the first double-click isolates the repeat");
+    click(&mut s, PointerKind::DoubleClick, 55.0, 55.0);
+    assert_eq!(s.doc().unwrap().isolation, Some(group), "the second enters the group inside it");
+    click(&mut s, PointerKind::Down, 55.0, 55.0);
+    click(&mut s, PointerKind::Up, 55.0, 55.0);
+    assert_eq!(s.doc().unwrap().selection.objects, [NodeId(a)], "inside the group a click selects one rectangle");
+}
+
+/// #5054: in a repeat's isolation mode the repeat itself draws as usual (its source and every
+/// copy); only the art around it is dimmed, as for an isolated group.
+#[test]
+fn an_isolated_repeat_is_not_dimmed() {
+    let mut s = Session::new();
+    s.execute("file.new", &json!({"width": 200, "height": 200})).unwrap();
+    let r = s.execute("shape.rectangle", &json!({"x": 10, "y": 10, "width": 20, "height": 20})).unwrap()["id"].as_u64().unwrap();
+    s.execute("paint.setFill", &json!({"ids": [r], "color": "#000000"})).unwrap();
+    s.execute("select.set", &json!({"ids": [r]})).unwrap();
+    let repeat = s.execute("object.repeat.grid", &json!({})).unwrap()["id"].as_u64().unwrap();
+    let other = s.execute("shape.rectangle", &json!({"x": 150, "y": 150, "width": 30, "height": 30})).unwrap()["id"].as_u64().unwrap();
+    s.execute("paint.setFill", &json!({"ids": [other], "color": "#000000"})).unwrap();
+    let doc = s.doc().unwrap().doc.clone();
+    let render = |iso: Option<u64>| {
+        let opts = vectorcraft_render::RenderOptions { isolated: iso.map(NodeId), ..Default::default() };
+        vectorcraft_render::Renderer::new().render(&doc, 200, 200, vectorcraft_geom::Affine::IDENTITY, &opts)
+    };
+    let alpha = |img: &vectorcraft_render::Rendered, x: usize, y: usize| img.pixels[(y * 200 + x) * 4 + 3];
+    let plain = render(None);
+    let iso = render(Some(repeat));
+    assert_eq!(alpha(&plain, 20, 20), 255, "the source");
+    assert_eq!(alpha(&iso, 20, 20), 255, "the isolated repeat's source is not dimmed");
+    assert!(alpha(&iso, 165, 165) < 200, "the art around it is: {}", alpha(&iso, 165, 165));
+}

crates/render/src/renderer/nodes.rs

@@ -273,7 +273,14 @@ impl Renderer {
             return;
         }
         if vectorcraft_doc::live::is_live(a) || effects::has_pathfinder(a) {
-            return self.draw_live(ctx, f, a);
+            // The isolated object itself (a repeat isolated to edit its source, #5054) draws its
+            // art as usual, as an isolated group does in `draw_layer_node`.
+            let settle = f.opts.isolated == Some(a.id) && f.doc.mask_edit.is_none();
+            let outer = self.isolation_settled;
+            self.isolation_settled = outer || settle;
+            self.draw_live(ctx, f, a);
+            self.isolation_settled = outer;
+            return;
         }
         // Its live-effect geometry depends on the node alone, and for plug-in effects on the
         // plug-ins installed (`check_plugins`), so it can be kept across frames.