Start work on expanding and collapsing directories in project panel

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

gpui/src/elements/uniform_list.rs

@@ -5,7 +5,7 @@ use crate::{
         vector::{vec2f, Vector2F},
     },
     json::{self, json},
-    ElementBox, MutableAppContext,
+    ElementBox,
 };
 use json::ToJson;
 use parking_lot::Mutex;
@@ -38,7 +38,7 @@ pub struct LayoutState {
 
 pub struct UniformList<F>
 where
-    F: Fn(Range<usize>, &mut Vec<ElementBox>, &mut MutableAppContext),
+    F: Fn(Range<usize>, &mut Vec<ElementBox>, &mut LayoutContext),
 {
     state: UniformListState,
     item_count: usize,
@@ -47,7 +47,7 @@ where
 
 impl<F> UniformList<F>
 where
-    F: Fn(Range<usize>, &mut Vec<ElementBox>, &mut MutableAppContext),
+    F: Fn(Range<usize>, &mut Vec<ElementBox>, &mut LayoutContext),
 {
     pub fn new(state: UniformListState, item_count: usize, append_items: F) -> Self {
         Self {
@@ -102,7 +102,7 @@ where
 
 impl<F> Element for UniformList<F>
 where
-    F: Fn(Range<usize>, &mut Vec<ElementBox>, &mut MutableAppContext),
+    F: Fn(Range<usize>, &mut Vec<ElementBox>, &mut LayoutContext),
 {
     type LayoutState = LayoutState;
     type PaintState = ();
@@ -124,7 +124,7 @@ where
         let mut scroll_max = 0.;
 
         let mut items = Vec::new();
-        (self.append_items)(0..1, &mut items, cx.app);
+        (self.append_items)(0..1, &mut items, cx);
         if let Some(first_item) = items.first_mut() {
             let mut item_size = first_item.layout(item_constraint, cx);
             item_size.set_x(size.x());
@@ -146,7 +146,7 @@ where
                 self.item_count,
                 start + (size.y() / item_height).ceil() as usize + 1,
             );
-            (self.append_items)(start..end, &mut items, cx.app);
+            (self.append_items)(start..end, &mut items, cx);
             for item in &mut items {
                 item.layout(item_constraint, cx);
             }

gpui/src/presenter.rs

@@ -7,7 +7,7 @@ use crate::{
     platform::Event,
     text_layout::TextLayoutCache,
     Action, AnyAction, AssetCache, ElementBox, Entity, FontSystem, ModelHandle, ReadModel,
-    ReadView, Scene, View, ViewHandle,
+    ReadView, Scene, UpdateView, View, ViewHandle,
 };
 use pathfinder_geometry::vector::{vec2f, Vector2F};
 use serde_json::json;
@@ -264,6 +264,16 @@ impl<'a> ReadView for LayoutContext<'a> {
     }
 }
 
+impl<'a> UpdateView for LayoutContext<'a> {
+    fn update_view<T, F, S>(&mut self, handle: &ViewHandle<T>, update: F) -> S
+    where
+        T: View,
+        F: FnOnce(&mut T, &mut crate::ViewContext<T>) -> S,
+    {
+        self.app.update_view(handle, update)
+    }
+}
+
 impl<'a> ReadModel for LayoutContext<'a> {
     fn read_model<T: Entity>(&self, handle: &ModelHandle<T>) -> &T {
         self.app.read_model(handle)

gpui/src/views/select.rs

@@ -126,7 +126,7 @@ impl View for Select {
                             UniformList::new(
                                 self.list_state.clone(),
                                 self.item_count,
-                                move |mut range, items, mut cx| {
+                                move |mut range, items, cx| {
                                     let handle = handle.upgrade(cx).unwrap();
                                     let this = handle.read(cx);
                                     let selected_item_ix = this.selected_item_ix;
@@ -134,9 +134,9 @@ impl View for Select {
                                     items.extend(range.map(|ix| {
                                         MouseEventHandler::new::<Item, _, _, _>(
                                             (handle.id(), ix),
-                                            &mut cx,
+                                            cx,
                                             |mouse_state, cx| {
-                                                (handle.read(*cx).render_item)(
+                                                (handle.read(cx).render_item)(
                                                     ix,
                                                     if ix == selected_item_ix {
                                                         ItemType::Selected