Move layout metrics into theme and apply audit cleanups

crates/data/src/sidebar.rs

@@ -197,16 +197,31 @@ impl RenderOnce for Sidebar {
 
         let scroll_area_id = (self.id.clone(), "entries");
 
-        // Entry paint reads the theme through this borrow.
+        let row_count = entries
+            .iter()
+            .filter(|entry| matches!(entry, SidebarEntry::Row { .. }))
+            .count();
+
+        let mut row_position = 0usize;
         let children: Vec<AnyElement> = entries
             .iter()
             .enumerate()
             .map(|(index, entry)| {
+                let is_row = matches!(entry, SidebarEntry::Row { .. });
+                if is_row {
+                    row_position += 1;
+                }
+                let (position_in_set, size_of_set) = if is_row {
+                    (row_position, row_count)
+                } else {
+                    (0, 0)
+                };
                 render_entry(
                     cx,
                     entry,
                     index,
-                    entries.len(),
+                    position_in_set,
+                    size_of_set,
                     self.selected == Some(index),
                     material,
                     &self.on_change,
@@ -258,7 +273,8 @@ fn render_entry(
     cx: &App,
     entry: &SidebarEntry,
     index: usize,
-    count: usize,
+    position_in_set: usize,
+    size_of_set: usize,
     selected: bool,
     material: bool,
     on_change: &Option<ChangeHandler>,
@@ -294,8 +310,8 @@ fn render_entry(
                 .rounded(theme.radius.sm)
                 .role(Role::ListItem)
                 .aria_selected(selected)
-                .aria_position_in_set(index + 1)
-                .aria_size_of_set(count)
+                .aria_position_in_set(position_in_set)
+                .aria_size_of_set(size_of_set)
                 .map(|row| {
                     if material && !*row_disabled {
                         if selected {

crates/data/src/tabs.rs

@@ -214,7 +214,6 @@ impl RenderOnce for Tabs {
                     cx,
                     tab,
                     index,
-                    self.selected == index,
                     self.selected,
                     self.variant,
                     &self.on_change,
@@ -272,7 +271,6 @@ fn render_tab(
     cx: &App,
     tab: Tab,
     index: usize,
-    selected: bool,
     selected_index: usize,
     variant: TabsVariant,
     on_change: &Option<ChangeHandler>,
@@ -280,6 +278,7 @@ fn render_tab(
     focus: &gpui::FocusHandle,
 ) -> AnyElement {
     let mut tab = tab;
+    let selected = index == selected_index;
 
     let theme = cx.theme();
     let metrics = theme.sizes.resolve(Size::default());

crates/data/src/tree.rs

@@ -166,14 +166,49 @@ impl RenderOnce for Tree {
             .clone()
             .unwrap_or_else(|| SharedString::from(self.id.to_string()));
 
+        let sibling_sets: Vec<(usize, usize)> = {
+            let mut sets = vec![(0usize, 0usize); items.len()];
+            let mut start = 0usize;
+
+            while start < items.len() {
+                let depth = items[start].depth;
+
+                let mut end = start + 1;
+                while end < items.len() && items[end].depth > depth {
+                    end += 1;
+                }
+
+                let mut position = 0usize;
+                for index in start..end {
+                    if items[index].depth == depth {
+                        position += 1;
+                        sets[index] = (position, 0);
+                    }
+                }
+
+                for index in start..end {
+                    if items[index].depth == depth {
+                        sets[index].1 = position;
+                    }
+                }
+
+                start = end;
+            }
+
+            sets
+        };
+
         let rows: Vec<AnyElement> = items
             .iter()
             .enumerate()
             .map(|(index, _item)| {
+                let (position_in_set, size_of_set) = sibling_sets[index];
                 render_row(
                     cx,
-                    &items,
+                    &items[index],
                     index,
+                    position_in_set,
+                    size_of_set,
                     self.selected == Some(index),
                     &self.on_change,
                     &self.on_disclosure,
@@ -228,21 +263,21 @@ impl RenderOnce for Tree {
     }
 }
 
+#[allow(clippy::too_many_arguments)]
 fn render_row(
     cx: &App,
-    items: &[TreeItem],
+    item: &TreeItem,
     index: usize,
+    position_in_set: usize,
+    size_of_set: usize,
     selected: bool,
     on_change: &Option<ChangeHandler>,
     on_disclosure: &Option<DisclosureHandler>,
     focus: &FocusHandle,
 ) -> AnyElement {
     let theme = cx.theme();
-    let item = &items[index];
-    let count = items.len();
     let label_color = selectable_label_color(cx, selected, item.disabled);
     let disabled = item.disabled;
-
     // One indent step per depth level, on the theme's horizontal padding.
     let indent = theme.sizes.medium.padding_x * (item.depth as f32 + 1.0);
 
@@ -258,7 +293,8 @@ fn render_row(
         .role(Role::TreeItem)
         .aria_selected(selected)
         .aria_level(item.depth + 1)
-        .aria_size_of_set(count)
+        .aria_position_in_set(position_in_set)
+        .aria_size_of_set(size_of_set)
         .when(item.expandable, |row| row.aria_expanded(item.expanded))
         .map(|row| paint_selectable_row(cx, row, selected, disabled))
         .when(!disabled, |row| {