Move all crates to a top-level crates folder

Co-Authored-By: Max Brunsfeld <maxbrunsfeld@gmail.com>

crates/gpui/src/elements/hook.rs

@@ -0,0 +1,79 @@
+use crate::{
+    geometry::{rect::RectF, vector::Vector2F},
+    json::json,
+    DebugContext, Element, ElementBox, Event, EventContext, LayoutContext, PaintContext,
+    SizeConstraint,
+};
+
+pub struct Hook {
+    child: ElementBox,
+    after_layout: Option<Box<dyn FnMut(Vector2F, &mut LayoutContext)>>,
+}
+
+impl Hook {
+    pub fn new(child: ElementBox) -> Self {
+        Self {
+            child,
+            after_layout: None,
+        }
+    }
+
+    pub fn on_after_layout(
+        mut self,
+        f: impl 'static + FnMut(Vector2F, &mut LayoutContext),
+    ) -> Self {
+        self.after_layout = Some(Box::new(f));
+        self
+    }
+}
+
+impl Element for Hook {
+    type LayoutState = ();
+    type PaintState = ();
+
+    fn layout(
+        &mut self,
+        constraint: SizeConstraint,
+        cx: &mut LayoutContext,
+    ) -> (Vector2F, Self::LayoutState) {
+        let size = self.child.layout(constraint, cx);
+        if let Some(handler) = self.after_layout.as_mut() {
+            handler(size, cx);
+        }
+        (size, ())
+    }
+
+    fn paint(
+        &mut self,
+        bounds: RectF,
+        visible_bounds: RectF,
+        _: &mut Self::LayoutState,
+        cx: &mut PaintContext,
+    ) {
+        self.child.paint(bounds.origin(), visible_bounds, cx);
+    }
+
+    fn dispatch_event(
+        &mut self,
+        event: &Event,
+        _: RectF,
+        _: &mut Self::LayoutState,
+        _: &mut Self::PaintState,
+        cx: &mut EventContext,
+    ) -> bool {
+        self.child.dispatch_event(event, cx)
+    }
+
+    fn debug(
+        &self,
+        _: RectF,
+        _: &Self::LayoutState,
+        _: &Self::PaintState,
+        cx: &DebugContext,
+    ) -> serde_json::Value {
+        json!({
+            "type": "Hooks",
+            "child": self.child.debug(cx),
+        })
+    }
+}