T13b Trees: Tree, TreeNode, TreeSelect, Outline, Disclosure (review pending: codex 401)

src/forms/options.rs

@@ -20,6 +20,7 @@ pub struct Choice {
     pub icon: Option<IconName>,
     pub note: Option<SharedString>,
     pub disabled: bool,
+    pub depth: usize,
 }
 
 impl Choice {
@@ -30,9 +31,16 @@ impl Choice {
             icon: None,
             note: None,
             disabled: false,
+            depth: 0,
         }
     }
 
+    /// How far it sits under a parent, for choices that come from a tree.
+    pub fn depth(mut self, depth: usize) -> Self {
+        self.depth = depth;
+        self
+    }
+
     pub fn icon(mut self, icon: IconName) -> Self {
         self.icon = Some(icon);
         self
@@ -108,6 +116,13 @@ pub(crate) fn option_row(
                     }),
             )
         })
+        .when(choice.depth > 0, |row| {
+            row.child(
+                div()
+                    .flex_none()
+                    .w(theme.tree_indent() * choice.depth as f32),
+            )
+        })
         .when_some(choice.icon, |row, icon| {
             row.child(Icon::new(icon).size(IconSize::Sm).color(colors.fg_muted))
         })