gpui: Add Global marker trait (#7095)

This should prevent a class of bugs where one queries the wrong type of
global, which results in oddities at runtime.

Release Notes:

- N/A

---------

Co-authored-by: Marshall <marshall@zed.dev>
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

crates/editor/src/editor.rs

@@ -104,7 +104,6 @@ use std::{
     ops::{ControlFlow, Deref, DerefMut, Range, RangeInclusive},
     path::Path,
     sync::Arc,
-    sync::Weak,
     time::{Duration, Instant},
 };
 pub use sum_tree::Bias;
@@ -241,7 +240,7 @@ pub fn init(cx: &mut AppContext) {
     .detach();
 
     cx.on_action(move |_: &workspace::NewFile, cx| {
-        let app_state = cx.global::<Weak<workspace::AppState>>();
+        let app_state = workspace::AppState::global(cx);
         if let Some(app_state) = app_state.upgrade() {
             workspace::open_new(&app_state, cx, |workspace, cx| {
                 Editor::new_file(workspace, &Default::default(), cx)
@@ -250,7 +249,7 @@ pub fn init(cx: &mut AppContext) {
         }
     });
     cx.on_action(move |_: &workspace::NewWindow, cx| {
-        let app_state = cx.global::<Weak<workspace::AppState>>();
+        let app_state = workspace::AppState::global(cx);
         if let Some(app_state) = app_state.upgrade() {
             workspace::open_new(&app_state, cx, |workspace, cx| {
                 Editor::new_file(workspace, &Default::default(), cx)

crates/editor/src/editor_tests.rs

@@ -7226,7 +7226,7 @@ async fn test_copilot(executor: BackgroundExecutor, cx: &mut gpui::TestAppContex
     init_test(cx, |_| {});
 
     let (copilot, copilot_lsp) = Copilot::fake(cx);
-    _ = cx.update(|cx| cx.set_global(copilot));
+    _ = cx.update(|cx| Copilot::set_global(copilot, cx));
     let mut cx = EditorLspTestContext::new_rust(
         lsp::ServerCapabilities {
             completion_provider: Some(lsp::CompletionOptions {
@@ -7479,7 +7479,7 @@ async fn test_copilot_completion_invalidation(
     init_test(cx, |_| {});
 
     let (copilot, copilot_lsp) = Copilot::fake(cx);
-    _ = cx.update(|cx| cx.set_global(copilot));
+    _ = cx.update(|cx| Copilot::set_global(copilot, cx));
     let mut cx = EditorLspTestContext::new_rust(
         lsp::ServerCapabilities {
             completion_provider: Some(lsp::CompletionOptions {
@@ -7543,7 +7543,7 @@ async fn test_copilot_multibuffer(executor: BackgroundExecutor, cx: &mut gpui::T
     init_test(cx, |_| {});
 
     let (copilot, copilot_lsp) = Copilot::fake(cx);
-    _ = cx.update(|cx| cx.set_global(copilot));
+    _ = cx.update(|cx| Copilot::set_global(copilot, cx));
 
     let buffer_1 = cx.new_model(|cx| {
         Buffer::new(
@@ -7660,7 +7660,7 @@ async fn test_copilot_disabled_globs(executor: BackgroundExecutor, cx: &mut gpui
     });
 
     let (copilot, copilot_lsp) = Copilot::fake(cx);
-    _ = cx.update(|cx| cx.set_global(copilot));
+    _ = cx.update(|cx| Copilot::set_global(copilot, cx));
 
     let fs = FakeFs::new(cx.executor());
     fs.insert_tree(

crates/editor/src/scroll.rs

@@ -10,7 +10,7 @@ use crate::{
     MultiBufferSnapshot, ToPoint,
 };
 pub use autoscroll::{Autoscroll, AutoscrollStrategy};
-use gpui::{point, px, AppContext, Entity, Pixels, Task, ViewContext};
+use gpui::{point, px, AppContext, Entity, Global, Pixels, Task, ViewContext};
 use language::{Bias, Point};
 pub use scroll_amount::ScrollAmount;
 use std::{
@@ -27,6 +27,8 @@ const SCROLLBAR_SHOW_INTERVAL: Duration = Duration::from_secs(1);
 #[derive(Default)]
 pub struct ScrollbarAutoHide(pub bool);
 
+impl Global for ScrollbarAutoHide {}
+
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct ScrollAnchor {
     pub offset: gpui::Point<f32>,