Add scoped overlay hosts

app-rust/examples/phone.rs

@@ -93,7 +93,7 @@ impl DefaultAppState for Client {
                     .pad(dp(16))
                     .add_strong(rsc)
                     .any();
-                ui_state.set_root(text);
+                ui_state.set_root(rsc, text);
                 None
             }
         };

app-rust/src/android/bench_client.rs

@@ -142,7 +142,7 @@ impl AndroidAppState for BenchClient {
             .span(Dir::DOWN)
             .add_strong(rsc)
             .any();
-        ui_state.set_root(tree);
+        ui_state.set_root(rsc, tree);
 
         let font = rsc.ui.text.font_diagnostics();
         log::info!(

app-rust/src/android/transcript_client.rs

@@ -99,7 +99,7 @@ impl AndroidAppState for TranscriptClient {
             .span(Dir::DOWN)
             .add_strong(rsc)
             .any();
-        ui_state.set_root(tree);
+        ui_state.set_root(rsc, tree);
 
         let mut client = Self {
             ui_state,

app-rust/src/ui/fixture.rs

@@ -99,12 +99,15 @@ where
     ))
 }
 
-pub fn open<Rsc: HasEvents>(rsc: &mut Rsc, ui_state: &mut impl HasRoot) -> Result<Opened, String>
+pub fn open<Rsc: HasEvents>(
+    rsc: &mut Rsc,
+    ui_state: &mut impl HasRoot<Rsc>,
+) -> Result<Opened, String>
 where
     Rsc::State: FocusHost + OpenUrl,
 {
     let (opened, tree) = build_screen(rsc)?;
-    ui_state.set_root(tree);
+    ui_state.set_root(rsc, tree);
     Ok(opened)
 }
 

app-rust/src/ui/mod.rs

@@ -224,14 +224,14 @@ impl TranscriptScreen {
 
 pub fn build<Rsc: HasEvents>(
     rsc: &mut Rsc,
-    ui_state: &mut impl HasRoot,
+    ui_state: &mut impl HasRoot<Rsc>,
     rows: Vec<FoldedRow>,
 ) -> TranscriptScreen
 where
     Rsc::State: FocusHost + OpenUrl,
 {
     let (screen, tree) = build_tree(rsc, rows);
-    ui_state.set_root(tree);
+    ui_state.set_root(rsc, tree);
     screen
 }
 
@@ -281,10 +281,9 @@ where
     {
         list.on(CursorSense::drag_senses(), move |ctx, rsc: &mut Rsc| {
             let input = &ctx.data;
-            rsc.with_nearest_controller::<SelectionController, _>(
-                list,
-                |id, selection, rsc| selection.drag(id, rsc, input),
-            );
+            rsc.with_nearest_controller::<SelectionController, _>(list, |id, selection, rsc| {
+                selection.drag(id, rsc, input)
+            });
         })
         .add(rsc);
     }

app-rust/src/ui/row.rs

@@ -214,10 +214,9 @@ where
             let (pos, size) = (ctx.data.pos, ctx.data.size);
             let input = &ctx.data;
             let outcome = rsc
-                .with_nearest_controller::<SelectionController, _>(
-                    field,
-                    |id, selection, rsc| selection.drag(id, rsc, input),
-                )
+                .with_nearest_controller::<SelectionController, _>(field, |id, selection, rsc| {
+                    selection.drag(id, rsc, input)
+                })
                 .unwrap_or(SelectionInput::Tapped);
             // A *tap*, decided by the same `DragArbiter` the pan and
             // the selection are: a gesture that panned the list past

app-rust/src/ui/tap.rs

@@ -11,10 +11,9 @@ pub(crate) fn on_tap<Rsc: HasEvents>(
     ptr.on(CursorSense::drag_senses(), move |ctx, rsc: &mut Rsc| {
         let input = &ctx.data;
         let outcome = rsc
-            .with_nearest_controller::<SelectionController, _>(
-                list,
-                |id, selection, rsc| selection.drag(id, rsc, input),
-            )
+            .with_nearest_controller::<SelectionController, _>(list, |id, selection, rsc| {
+                selection.drag(id, rsc, input)
+            })
             .unwrap_or(SelectionInput::Tapped);
         if outcome == SelectionInput::Tapped {
             f(rsc);

app-rust/tests/top_edge.rs

@@ -14,7 +14,7 @@ fn opened() -> (Harness, ai_app::ui::TranscriptScreen) {
         .span(Dir::DOWN)
         .add_strong(&mut h.rsc)
         .any();
-    h.state.set_root(root);
+    h.state.set_root(&mut h.rsc, root);
     h.frame(0);
     h.frame(PHONE_FRAME_MS);
     (h, opened.screen)