Primitives · a raise keeps its state under its owner's id

A raise inside another was namespaced by its place in the layer's
queue, so one that came before it moved its id path and rebuilt its
keyed state and focus: an open date popup would lose its month when a
tip appeared. raise now takes its owner's id and draws under it, and
float and float_height pass the owner's id on from every call site.
A test holds a focused box in a raise while another comes before it.

src/primitives/tests.rs

@@ -1,6 +1,8 @@
+use std::{cell::RefCell, rc::Rc};
+
 use gpui::{
-    Context, IntoElement, Modifiers, ParentElement, Render, Styled, TestAppContext, Window,
-    anchored, div, point, prelude::*, px,
+    App, Context, Entity, FocusHandle, IntoElement, Modifiers, ParentElement, Render, RenderOnce,
+    Styled, TestAppContext, Window, anchored, div, point, prelude::*, px,
 };
 
 use super::raise;
@@ -27,11 +29,13 @@ impl Render for Stack {
             .size(px(200.0))
             .on_click(move |_, _, cx| cover.update(cx, |stack, _| stack.heard.push("cover")));
         div().size_full().child(raise(
+            "sheet",
             anchored().position(point(px(0.0), px(0.0))).child(
                 div()
                     .relative()
                     .size(px(200.0))
                     .child(raise(
+                        "button",
                         anchored().position(point(px(50.0), px(50.0))).child(button),
                     ))
                     .child(sheet),
@@ -51,3 +55,78 @@ fn what_is_raised_inside_a_raise_lies_over_it(cx: &mut TestAppContext) {
         ["inner"]
     );
 }
+
+/// A focusable box whose focus handle lives in keyed state; each draw tells the test which one it drew.
+#[derive(IntoElement)]
+struct Held {
+    seen: Rc<RefCell<Vec<Entity<FocusHandle>>>>,
+}
+
+impl RenderOnce for Held {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let kept = window.use_keyed_state("kept", cx, |_, cx| cx.focus_handle());
+        self.seen.borrow_mut().push(kept.clone());
+        let handle = kept.read(cx).clone();
+        div().id("held").size(px(40.0)).track_focus(&handle)
+    }
+}
+
+/// A raised sheet holding a raised tip that comes and goes, then a raised box that must stay itself.
+struct Nest {
+    tip: bool,
+    seen: Rc<RefCell<Vec<Entity<FocusHandle>>>>,
+}
+
+impl Render for Nest {
+    fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
+        let tip = self.tip.then(|| {
+            raise(
+                "tip",
+                anchored()
+                    .position(point(px(0.0), px(0.0)))
+                    .child(div().child("tip")),
+            )
+        });
+        let held = Held {
+            seen: self.seen.clone(),
+        };
+        div().size_full().child(raise(
+            "sheet",
+            anchored().position(point(px(0.0), px(0.0))).child(
+                div().size(px(200.0)).children(tip).child(raise(
+                    "held",
+                    anchored().position(point(px(50.0), px(50.0))).child(held),
+                )),
+            ),
+        ))
+    }
+}
+
+#[gpui::test]
+fn a_raise_keeps_its_state_while_another_comes_before_it(cx: &mut TestAppContext) {
+    cx.update(Theme::init);
+    let seen = Rc::new(RefCell::new(Vec::new()));
+    let (view, cx) = cx.add_window_view(|_, _| Nest {
+        tip: false,
+        seen: seen.clone(),
+    });
+    cx.run_until_parked();
+    let first = seen.borrow().last().cloned().expect("the box drew");
+    let handle = first.read_with(cx, |handle, _| handle.clone());
+    cx.update(|window, _| window.focus(&handle));
+    view.update(cx, |nest, cx| {
+        nest.tip = true;
+        cx.notify();
+    });
+    cx.run_until_parked();
+    let last = seen.borrow().last().cloned().expect("the box drew again");
+    assert_eq!(
+        last.entity_id(),
+        first.entity_id(),
+        "the box kept its state"
+    );
+    assert!(
+        cx.update(|window, _| handle.is_focused(window)),
+        "the box kept focus"
+    );
+}