Eliminate GPUI View, ViewContext, and WindowContext types (#22632)

There's still a bit more work to do on this, but this PR is compiling
(with warnings) after eliminating the key types. When the tasks below
are complete, this will be the new narrative for GPUI:

- `Entity<T>` - This replaces `View<T>`/`Model<T>`. It represents a unit
of state, and if `T` implements `Render`, then `Entity<T>` implements
`Element`.
- `&mut App` This replaces `AppContext` and represents the app.
- `&mut Context<T>` This replaces `ModelContext` and derefs to `App`. It
is provided by the framework when updating an entity.
- `&mut Window` Broken out of `&mut WindowContext` which no longer
exists. Every method that once took `&mut WindowContext` now takes `&mut
Window, &mut App` and every method that took `&mut ViewContext<T>` now
takes `&mut Window, &mut Context<T>`

Not pictured here are the two other failed attempts. It's been quite a
month!

Tasks:

- [x] Remove `View`, `ViewContext`, `WindowContext` and thread through
`Window`
- [x] [@cole-miller @mikayla-maki] Redraw window when entities change
- [x] [@cole-miller @mikayla-maki] Get examples and Zed running
- [x] [@cole-miller @mikayla-maki] Fix Zed rendering
- [x] [@mikayla-maki] Fix todo! macros and comments
- [x] Fix a bug where the editor would not be redrawn because of view
caching
- [x] remove publicness window.notify() and replace with
`AppContext::notify`
- [x] remove `observe_new_window_models`, replace with
`observe_new_models` with an optional window
- [x] Fix a bug where the project panel would not be redrawn because of
the wrong refresh() call being used
- [x] Fix the tests
- [x] Fix warnings by eliminating `Window` params or using `_`
- [x] Fix conflicts
- [x] Simplify generic code where possible
- [x] Rename types
- [ ] Update docs

### issues post merge

- [x] Issues switching between normal and insert mode
- [x] Assistant re-rendering failure
- [x] Vim test failures
- [x] Mac build issue



Release Notes:

- N/A

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>
Co-authored-by: Cole Miller <cole@zed.dev>
Co-authored-by: Mikayla <mikayla@zed.dev>
Co-authored-by: Joseph <joseph@zed.dev>
Co-authored-by: max <max@zed.dev>
Co-authored-by: Michael Sloan <michael@zed.dev>
Co-authored-by: Mikayla Maki <mikaylamaki@Mikaylas-MacBook-Pro.local>
Co-authored-by: Mikayla <mikayla.c.maki@gmail.com>
Co-authored-by: joão <joao@zed.dev>

crates/editor/src/display_map/block_map.rs

@@ -4,7 +4,7 @@ use super::{
 };
 use crate::{EditorStyle, GutterDimensions};
 use collections::{Bound, HashMap, HashSet};
-use gpui::{AnyElement, AppContext, EntityId, Pixels, WindowContext};
+use gpui::{AnyElement, App, EntityId, Pixels, Window};
 use language::{Chunk, Patch, Point};
 use multi_buffer::{
     Anchor, ExcerptId, ExcerptInfo, MultiBuffer, MultiBufferRow, MultiBufferSnapshot, RowInfo,
@@ -226,7 +226,8 @@ pub enum BlockStyle {
 }
 
 pub struct BlockContext<'a, 'b> {
-    pub context: &'b mut WindowContext<'a>,
+    pub window: &'a mut Window,
+    pub app: &'b mut App,
     pub anchor_x: Pixels,
     pub max_width: Pixels,
     pub gutter_dimensions: &'b GutterDimensions,
@@ -1232,22 +1233,12 @@ impl<'a> BlockMapWriter<'a> {
         self.remove(blocks_to_remove);
     }
 
-    pub fn fold_buffer(
-        &mut self,
-        buffer_id: BufferId,
-        multi_buffer: &MultiBuffer,
-        cx: &AppContext,
-    ) {
+    pub fn fold_buffer(&mut self, buffer_id: BufferId, multi_buffer: &MultiBuffer, cx: &App) {
         self.0.folded_buffers.insert(buffer_id);
         self.recompute_blocks_for_buffer(buffer_id, multi_buffer, cx);
     }
 
-    pub fn unfold_buffer(
-        &mut self,
-        buffer_id: BufferId,
-        multi_buffer: &MultiBuffer,
-        cx: &AppContext,
-    ) {
+    pub fn unfold_buffer(&mut self, buffer_id: BufferId, multi_buffer: &MultiBuffer, cx: &App) {
         self.0.folded_buffers.remove(&buffer_id);
         self.recompute_blocks_for_buffer(buffer_id, multi_buffer, cx);
     }
@@ -1256,7 +1247,7 @@ impl<'a> BlockMapWriter<'a> {
         &mut self,
         buffer_id: BufferId,
         multi_buffer: &MultiBuffer,
-        cx: &AppContext,
+        cx: &App,
     ) {
         let wrap_snapshot = self.0.wrap_snapshot.borrow().clone();
 
@@ -1934,16 +1925,16 @@ impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
 }
 
 impl<'a> Deref for BlockContext<'a, '_> {
-    type Target = WindowContext<'a>;
+    type Target = App;
 
     fn deref(&self) -> &Self::Target {
-        self.context
+        self.app
     }
 }
 
 impl DerefMut for BlockContext<'_, '_> {
     fn deref_mut(&mut self) -> &mut Self::Target {
-        self.context
+        self.app
     }
 }
 
@@ -2001,7 +1992,7 @@ mod tests {
     use crate::display_map::{
         fold_map::FoldMap, inlay_map::InlayMap, tab_map::TabMap, wrap_map::WrapMap,
     };
-    use gpui::{div, font, px, AppContext, Context as _, Element};
+    use gpui::{div, font, px, App, AppContext as _, Element};
     use itertools::Itertools;
     use language::{Buffer, Capability};
     use multi_buffer::{ExcerptRange, MultiBuffer};
@@ -2195,15 +2186,15 @@ mod tests {
     }
 
     #[gpui::test]
-    fn test_multibuffer_headers_and_footers(cx: &mut AppContext) {
+    fn test_multibuffer_headers_and_footers(cx: &mut App) {
         init_test(cx);
 
-        let buffer1 = cx.new_model(|cx| Buffer::local("Buffer 1", cx));
-        let buffer2 = cx.new_model(|cx| Buffer::local("Buffer 2", cx));
-        let buffer3 = cx.new_model(|cx| Buffer::local("Buffer 3", cx));
+        let buffer1 = cx.new(|cx| Buffer::local("Buffer 1", cx));
+        let buffer2 = cx.new(|cx| Buffer::local("Buffer 2", cx));
+        let buffer3 = cx.new(|cx| Buffer::local("Buffer 3", cx));
 
         let mut excerpt_ids = Vec::new();
-        let multi_buffer = cx.new_model(|cx| {
+        let multi_buffer = cx.new(|cx| {
             let mut multi_buffer = MultiBuffer::new(Capability::ReadWrite);
             excerpt_ids.extend(multi_buffer.push_excerpts(
                 buffer1.clone(),
@@ -3652,7 +3643,7 @@ mod tests {
         }
     }
 
-    fn init_test(cx: &mut gpui::AppContext) {
+    fn init_test(cx: &mut gpui::App) {
         let settings = SettingsStore::test(cx);
         cx.set_global(settings);
         theme::init(theme::LoadThemes::JustBase, cx);