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/assistant2/src/thread_store.rs

@@ -9,7 +9,7 @@ use context_server::manager::ContextServerManager;
 use context_server::{ContextServerFactoryRegistry, ContextServerTool};
 use futures::future::{self, BoxFuture, Shared};
 use futures::FutureExt as _;
-use gpui::{prelude::*, AppContext, BackgroundExecutor, Model, ModelContext, SharedString, Task};
+use gpui::{prelude::*, App, BackgroundExecutor, Context, Entity, SharedString, Task};
 use heed::types::SerdeBincode;
 use heed::Database;
 use language_model::Role;
@@ -21,9 +21,9 @@ use crate::thread::{MessageId, Thread, ThreadId};
 
 pub struct ThreadStore {
     #[allow(unused)]
-    project: Model<Project>,
+    project: Entity<Project>,
     tools: Arc<ToolWorkingSet>,
-    context_server_manager: Model<ContextServerManager>,
+    context_server_manager: Entity<ContextServerManager>,
     context_server_tool_ids: HashMap<Arc<str>, Vec<ToolId>>,
     threads: Vec<SavedThreadMetadata>,
     database_future: Shared<BoxFuture<'static, Result<Arc<ThreadsDatabase>, Arc<anyhow::Error>>>>,
@@ -31,15 +31,15 @@ pub struct ThreadStore {
 
 impl ThreadStore {
     pub fn new(
-        project: Model<Project>,
+        project: Entity<Project>,
         tools: Arc<ToolWorkingSet>,
-        cx: &mut AppContext,
-    ) -> Task<Result<Model<Self>>> {
+        cx: &mut App,
+    ) -> Task<Result<Entity<Self>>> {
         cx.spawn(|mut cx| async move {
-            let this = cx.new_model(|cx: &mut ModelContext<Self>| {
+            let this = cx.new(|cx: &mut Context<Self>| {
                 let context_server_factory_registry =
                     ContextServerFactoryRegistry::default_global(cx);
-                let context_server_manager = cx.new_model(|cx| {
+                let context_server_manager = cx.new(|cx| {
                     ContextServerManager::new(context_server_factory_registry, project.clone(), cx)
                 });
 
@@ -88,15 +88,15 @@ impl ThreadStore {
         self.threads().into_iter().take(limit).collect()
     }
 
-    pub fn create_thread(&mut self, cx: &mut ModelContext<Self>) -> Model<Thread> {
-        cx.new_model(|cx| Thread::new(self.tools.clone(), cx))
+    pub fn create_thread(&mut self, cx: &mut Context<Self>) -> Entity<Thread> {
+        cx.new(|cx| Thread::new(self.tools.clone(), cx))
     }
 
     pub fn open_thread(
         &self,
         id: &ThreadId,
-        cx: &mut ModelContext<Self>,
-    ) -> Task<Result<Model<Thread>>> {
+        cx: &mut Context<Self>,
+    ) -> Task<Result<Entity<Thread>>> {
         let id = id.clone();
         let database_future = self.database_future.clone();
         cx.spawn(|this, mut cx| async move {
@@ -107,16 +107,12 @@ impl ThreadStore {
                 .ok_or_else(|| anyhow!("no thread found with ID: {id:?}"))?;
 
             this.update(&mut cx, |this, cx| {
-                cx.new_model(|cx| Thread::from_saved(id.clone(), thread, this.tools.clone(), cx))
+                cx.new(|cx| Thread::from_saved(id.clone(), thread, this.tools.clone(), cx))
             })
         })
     }
 
-    pub fn save_thread(
-        &self,
-        thread: &Model<Thread>,
-        cx: &mut ModelContext<Self>,
-    ) -> Task<Result<()>> {
+    pub fn save_thread(&self, thread: &Entity<Thread>, cx: &mut Context<Self>) -> Task<Result<()>> {
         let (metadata, thread) = thread.update(cx, |thread, _cx| {
             let id = thread.id().clone();
             let thread = SavedThread {
@@ -144,11 +140,7 @@ impl ThreadStore {
         })
     }
 
-    pub fn delete_thread(
-        &mut self,
-        id: &ThreadId,
-        cx: &mut ModelContext<Self>,
-    ) -> Task<Result<()>> {
+    pub fn delete_thread(&mut self, id: &ThreadId, cx: &mut Context<Self>) -> Task<Result<()>> {
         let id = id.clone();
         let database_future = self.database_future.clone();
         cx.spawn(|this, mut cx| async move {
@@ -161,7 +153,7 @@ impl ThreadStore {
         })
     }
 
-    fn reload(&self, cx: &mut ModelContext<Self>) -> Task<Result<()>> {
+    fn reload(&self, cx: &mut Context<Self>) -> Task<Result<()>> {
         let database_future = self.database_future.clone();
         cx.spawn(|this, mut cx| async move {
             let threads = database_future
@@ -177,7 +169,7 @@ impl ThreadStore {
         })
     }
 
-    fn register_context_server_handlers(&self, cx: &mut ModelContext<Self>) {
+    fn register_context_server_handlers(&self, cx: &mut Context<Self>) {
         cx.subscribe(
             &self.context_server_manager.clone(),
             Self::handle_context_server_event,
@@ -187,9 +179,9 @@ impl ThreadStore {
 
     fn handle_context_server_event(
         &mut self,
-        context_server_manager: Model<ContextServerManager>,
+        context_server_manager: Entity<ContextServerManager>,
         event: &context_server::manager::Event,
-        cx: &mut ModelContext<Self>,
+        cx: &mut Context<Self>,
     ) {
         let tool_working_set = self.tools.clone();
         match event {