M2: shut padding pair fields edit their own axis

The closed Spacing row paired each icon with the other axis: the
side-bars field wrote top/bottom and the top/bottom-bars field wrote
left/right. The H field now binds paddingHorizontal (left+right) and the
V field paddingVertical (top+bottom); the PaddingH/PaddingV paintings
were swapped to match so every icon is pixel-identical.
(shut_pair_fields_edit_their_own_axis).

crates/ui-egui/src/icons.rs

@@ -938,17 +938,17 @@ fn draw(p: &P, icon: Icon) {
             p.line(3.0, 7.5, 13.0, 7.5);
         }
         PaddingH => {
-            // The horizontal axis: bars across the top and bottom in their frame.
-            p.rect(2.5, 2.5, 13.5, 13.5, 1.0);
-            p.fill_rect(2.5, 2.5, 13.5, 5.5, 1.0);
-            p.fill_rect(2.5, 10.5, 13.5, 13.5, 1.0);
-        }
-        PaddingV => {
-            // The vertical axis: bars down the left and right in their frame.
+            // Horizontal padding: bars down the padded left and right sides in their frame.
             p.rect(2.5, 2.5, 13.5, 13.5, 1.0);
             p.fill_rect(2.5, 2.5, 5.5, 13.5, 1.0);
             p.fill_rect(10.5, 2.5, 13.5, 13.5, 1.0);
         }
+        PaddingV => {
+            // Vertical padding: bars across the padded top and bottom in their frame.
+            p.rect(2.5, 2.5, 13.5, 13.5, 1.0);
+            p.fill_rect(2.5, 2.5, 13.5, 5.5, 1.0);
+            p.fill_rect(2.5, 10.5, 13.5, 13.5, 1.0);
+        }
         PaddingTop => {
             p.rect(2.5, 2.5, 13.5, 13.5, 1.0);
             p.fill_rect(2.5, 2.5, 13.5, 5.5, 1.0);

crates/ui-egui/src/layout_panel.rs

@@ -456,21 +456,6 @@ fn spacing(app: &mut FigApp, ui: &mut Ui, ids: &[NodeId], l: &AutoLayout) {
     }
     row(ui, 32.0, |ui| {
         // Sides that disagree show both values ("16,54") instead of "Mixed".
-        let v_pair = format!("{},{}", widgets::fmt_num(pt), widgets::fmt_num(pb));
-        let v_empty = if pt == pb { tr("Mixed") } else { v_pair.as_str() };
-        let e = crate::variable_ui::number_field_or(
-            app,
-            ui,
-            ids,
-            "paddingVertical",
-            Id::new("al_padv"),
-            (pt == pb).then_some(pt),
-            col,
-            v_empty,
-            Lead::Icon(Icon::PaddingV, tr("Vertical padding")),
-            "",
-        );
-        app.field(ids, "paddingVertical", e, |v| json!(v.max(0.0)));
         let h_pair = format!("{},{}", widgets::fmt_num(pl), widgets::fmt_num(pr));
         let h_empty = if pl == pr { tr("Mixed") } else { h_pair.as_str() };
         let e = crate::variable_ui::number_field_or(
@@ -486,6 +471,21 @@ fn spacing(app: &mut FigApp, ui: &mut Ui, ids: &[NodeId], l: &AutoLayout) {
             "",
         );
         app.field(ids, "paddingHorizontal", e, |v| json!(v.max(0.0)));
+        let v_pair = format!("{},{}", widgets::fmt_num(pt), widgets::fmt_num(pb));
+        let v_empty = if pt == pb { tr("Mixed") } else { v_pair.as_str() };
+        let e = crate::variable_ui::number_field_or(
+            app,
+            ui,
+            ids,
+            "paddingVertical",
+            Id::new("al_padv"),
+            (pt == pb).then_some(pt),
+            col,
+            v_empty,
+            Lead::Icon(Icon::PaddingV, tr("Vertical padding")),
+            "",
+        );
+        app.field(ids, "paddingVertical", e, |v| json!(v.max(0.0)));
         if icons::button(ui, Icon::IndependentPadding, 24.0, false, tr("Individual padding")).clicked() {
             ui.data_mut(|d| d.insert_temp(Id::new("indep_padding"), true));
         }

crates/ui-egui/src/padding_individual_tests.rs

@@ -73,3 +73,35 @@ fn side_fields_show_only_once_the_toggle_opens_and_set_one_side() {
     u.app.run("edit.undo", json!({}));
     assert_eq!(padding(&u, f), [10.0; 4]);
 }
+
+/// The middle of the shut pair field with accessible name `label`.
+fn named_field(u: &mut Ui, label: &str) -> Pos2 {
+    u.ctx.enable_accesskit();
+    u.frame(vec![]);
+    let out = u.frame_output(vec![]);
+    let nodes = out.platform_output.accesskit_update.expect("an AccessKit update").nodes;
+    let n = nodes.iter().map(|(_, n)| n).find(|n| n.role() != Role::Button && n.label() == Some(label)).expect(label);
+    let b = n.bounds().expect("bounds");
+    pos2(((b.x0 + b.x1) / 2.0) as f32, ((b.y0 + b.y1) / 2.0) as f32)
+}
+
+/// The shut pair fields edit their own axis: horizontal touches left and right
+/// only, vertical touches top and bottom only.
+#[test]
+fn shut_pair_fields_edit_their_own_axis() {
+    let (mut u, f) = scene();
+    u.app.run("node.set", json!({"ids": [f], "props": {"paddingLeft": 16.0, "paddingRight": 54.0}}));
+    assert_eq!(padding(&u, f), [10.0, 54.0, 10.0, 16.0]);
+    let h = named_field(&mut u, "Horizontal padding");
+    click(&mut u, h);
+    u.frame(vec![Event::Text("20".into())]);
+    enter(&mut u);
+    u.frame(vec![]);
+    assert_eq!(padding(&u, f), [10.0, 20.0, 10.0, 20.0]);
+    let v = named_field(&mut u, "Vertical padding");
+    click(&mut u, v);
+    u.frame(vec![Event::Text("7".into())]);
+    enter(&mut u);
+    u.frame(vec![]);
+    assert_eq!(padding(&u, f), [7.0, 20.0, 7.0, 20.0]);
+}