chore: audit all components (#2)

Reviewed-on: #2

crates/utils/src/lib.rs

@@ -1,9 +1,10 @@
 use gpui::prelude::FluentBuilder as _;
 use gpui::{
-    App, BoxShadow, Div, ElementId, FocusHandle, Hsla, IntoElement, Refineable as _,
-    StatefulInteractiveElement, StyleRefinement, Styled, Window, div, px,
+    App, Bounds, BoxShadow, Div, ElementId, FocusHandle, Global, Hsla, IntoElement, Pixels,
+    Refineable as _, StatefulInteractiveElement, StyleRefinement, Styled, Window, div, px,
 };
 use gpui_native_theme::ActiveTheme as _;
+use std::collections::HashMap;
 
 /// A row whose children center on the cross axis.
 pub fn h_flex() -> Div {
@@ -35,9 +36,45 @@ pub fn focus_handle(id: &ElementId, window: &mut Window, cx: &mut App) -> FocusH
         .clone()
 }
 
-/// Returns a focus ring shadow with the given color.
+/// The painted bounds of elements that tooltips anchor to, keyed by element id.
+#[derive(Clone, Default)]
+struct AnchorBoundsRegistry(HashMap<ElementId, Bounds<Pixels>>);
+
+impl Global for AnchorBoundsRegistry {}
+
+impl AnchorBoundsRegistry {
+    fn record(&mut self, id: ElementId, bounds: Bounds<Pixels>) {
+        self.0.insert(id, bounds);
+    }
+
+    fn get(&self, id: &ElementId) -> Option<Bounds<Pixels>> {
+        self.0.get(id).copied()
+    }
+}
+
+/// The last bounds an element painted at.
+pub fn anchor_bounds(id: &ElementId, cx: &mut App) -> Option<Bounds<Pixels>> {
+    cx.try_global::<AnchorBoundsRegistry>()
+        .and_then(|registry| registry.get(id))
+}
+
+/// A canvas prepaint closure recording the element's painted bounds.
+pub fn record_anchor_bounds(
+    id: ElementId,
+) -> impl Fn(Bounds<Pixels>, &mut Window, &mut App) + 'static {
+    move |bounds, _window, cx| {
+        let mut registry = cx
+            .try_global::<AnchorBoundsRegistry>()
+            .cloned()
+            .unwrap_or_default();
+        registry.record(id.clone(), bounds);
+        cx.set_global(registry);
+    }
+}
+
+/// Returns a focus ring shadow with the given color at half ink.
 pub fn focus_ring(color: Hsla) -> Vec<BoxShadow> {
-    vec![BoxShadow::new(px(0.), px(0.), color).spread_radius(px(3.))]
+    vec![BoxShadow::new(px(0.), px(0.), color.alpha(0.5)).spread_radius(px(3.))]
 }
 
 /// The next selectable row in the direction, or `None` at the ends.