Move all crates to a top-level crates folder

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

crates/gpui/src/elements/stack.rs

@@ -0,0 +1,85 @@
+use crate::{
+    geometry::{rect::RectF, vector::Vector2F},
+    json::{self, json, ToJson},
+    DebugContext, Element, ElementBox, Event, EventContext, LayoutContext, PaintContext,
+    SizeConstraint,
+};
+
+pub struct Stack {
+    children: Vec<ElementBox>,
+}
+
+impl Stack {
+    pub fn new() -> Self {
+        Stack {
+            children: Vec::new(),
+        }
+    }
+}
+
+impl Element for Stack {
+    type LayoutState = ();
+    type PaintState = ();
+
+    fn layout(
+        &mut self,
+        constraint: SizeConstraint,
+        cx: &mut LayoutContext,
+    ) -> (Vector2F, Self::LayoutState) {
+        let mut size = constraint.min;
+        for child in &mut self.children {
+            size = size.max(child.layout(constraint, cx));
+        }
+        (size, ())
+    }
+
+    fn paint(
+        &mut self,
+        bounds: RectF,
+        visible_bounds: RectF,
+        _: &mut Self::LayoutState,
+        cx: &mut PaintContext,
+    ) -> Self::PaintState {
+        for child in &mut self.children {
+            cx.scene.push_layer(None);
+            child.paint(bounds.origin(), visible_bounds, cx);
+            cx.scene.pop_layer();
+        }
+    }
+
+    fn dispatch_event(
+        &mut self,
+        event: &Event,
+        _: RectF,
+        _: &mut Self::LayoutState,
+        _: &mut Self::PaintState,
+        cx: &mut EventContext,
+    ) -> bool {
+        for child in self.children.iter_mut().rev() {
+            if child.dispatch_event(event, cx) {
+                return true;
+            }
+        }
+        false
+    }
+
+    fn debug(
+        &self,
+        bounds: RectF,
+        _: &Self::LayoutState,
+        _: &Self::PaintState,
+        cx: &DebugContext,
+    ) -> json::Value {
+        json!({
+            "type": "Stack",
+            "bounds": bounds.to_json(),
+            "children": self.children.iter().map(|child| child.debug(cx)).collect::<Vec<json::Value>>()
+        })
+    }
+}
+
+impl Extend<ElementBox> for Stack {
+    fn extend<T: IntoIterator<Item = ElementBox>>(&mut self, children: T) {
+        self.children.extend(children)
+    }
+}