Reland "Remove cx from ThemeSettings" (#39720)

- **Reapply "Remove cx from ThemeSettings (#38836)" (#39691)**
- **Fix theme loading races**

Closes #ISSUE

Release Notes:

- N/A

crates/zed/src/main.rs

@@ -12,7 +12,6 @@ use crashes::InitCrashHandler;
 use db::kvp::{GLOBAL_KEY_VALUE_STORE, KEY_VALUE_STORE};
 use editor::Editor;
 use extension::ExtensionHostProxy;
-use extension_host::ExtensionStore;
 use fs::{Fs, RealFs};
 use futures::{StreamExt, channel::oneshot, future};
 use git::GitHostingProviderRegistry;
@@ -40,10 +39,7 @@ use std::{
     process,
     sync::Arc,
 };
-use theme::{
-    ActiveTheme, IconThemeNotFoundError, SystemAppearance, ThemeNotFoundError, ThemeRegistry,
-    ThemeSettings,
-};
+use theme::{ActiveTheme, GlobalTheme, ThemeRegistry};
 use util::{ResultExt, TryFutureExt, maybe};
 use uuid::Uuid;
 use workspace::{
@@ -57,7 +53,7 @@ use zed::{
     initialize_workspace, open_paths_with_positions,
 };
 
-use crate::zed::OpenRequestKind;
+use crate::zed::{OpenRequestKind, eager_load_active_theme_and_icon_theme};
 
 #[cfg(feature = "mimalloc")]
 #[global_allocator]
@@ -543,11 +539,18 @@ pub fn main() {
             system_id.as_ref().map(|id| id.to_string()),
             cx,
         );
-
-        SystemAppearance::init(cx);
-        theme::init(theme::LoadThemes::All(Box::new(Assets)), cx);
-        theme_extension::init(
+        extension_host::init(
             extension_host_proxy.clone(),
+            app_state.fs.clone(),
+            app_state.client.clone(),
+            app_state.node_runtime.clone(),
+            cx,
+        );
+
+        theme::init(theme::LoadThemes::All(Box::new(Assets)), cx);
+        eager_load_active_theme_and_icon_theme(fs.clone(), cx);
+        theme_extension::init(
+            extension_host_proxy,
             ThemeRegistry::global(cx),
             cx.background_executor().clone(),
         );
@@ -581,18 +584,10 @@ pub fn main() {
         );
         assistant_tools::init(app_state.client.http_client(), cx);
         repl::init(app_state.fs.clone(), cx);
-        extension_host::init(
-            extension_host_proxy,
-            app_state.fs.clone(),
-            app_state.client.clone(),
-            app_state.node_runtime.clone(),
-            cx,
-        );
         recent_projects::init(cx);
 
         load_embedded_fonts(cx);
 
-        app_state.languages.set_theme(cx.theme().clone());
         editor::init(cx);
         image_viewer::init(cx);
         repl::notebook::init(cx);
@@ -638,8 +633,6 @@ pub fn main() {
         json_schema_store::init(cx);
 
         cx.observe_global::<SettingsStore>({
-            let fs = fs.clone();
-            let languages = app_state.languages.clone();
             let http = app_state.client.http_client();
             let client = app_state.client.clone();
             move |cx| {
@@ -652,9 +645,6 @@ pub fn main() {
                         .ok();
                 }
 
-                eager_load_active_theme_and_icon_theme(fs.clone(), cx);
-
-                languages.set_theme(cx.theme().clone());
                 let new_host = &client::ClientSettings::get_global(cx).server_url;
                 if &http.base_url() != new_host {
                     http.set_base_url(new_host);
@@ -665,6 +655,14 @@ pub fn main() {
             }
         })
         .detach();
+        app_state.languages.set_theme(cx.theme().clone());
+        cx.observe_global::<GlobalTheme>({
+            let languages = app_state.languages.clone();
+            move |cx| {
+                languages.set_theme(cx.theme().clone());
+            }
+        })
+        .detach();
         telemetry::event!(
             "Settings Changed",
             setting = "theme",
@@ -1354,63 +1352,6 @@ fn load_embedded_fonts(cx: &App) {
         .unwrap();
 }
 
-/// Eagerly loads the active theme and icon theme based on the selections in the
-/// theme settings.
-///
-/// This fast path exists to load these themes as soon as possible so the user
-/// doesn't see the default themes while waiting on extensions to load.
-fn eager_load_active_theme_and_icon_theme(fs: Arc<dyn Fs>, cx: &App) {
-    let extension_store = ExtensionStore::global(cx);
-    let theme_registry = ThemeRegistry::global(cx);
-    let theme_settings = ThemeSettings::get_global(cx);
-    let appearance = SystemAppearance::global(cx).0;
-
-    if let Some(theme_selection) = theme_settings.theme_selection.as_ref() {
-        let theme_name = theme_selection.theme(appearance);
-        if matches!(theme_registry.get(theme_name), Err(ThemeNotFoundError(_)))
-            && let Some(theme_path) = extension_store.read(cx).path_to_extension_theme(theme_name)
-        {
-            cx.spawn({
-                let theme_registry = theme_registry.clone();
-                let fs = fs.clone();
-                async move |cx| {
-                    theme_registry.load_user_theme(&theme_path, fs).await?;
-
-                    cx.update(|cx| {
-                        ThemeSettings::reload_current_theme(cx);
-                    })
-                }
-            })
-            .detach_and_log_err(cx);
-        }
-    }
-
-    if let Some(icon_theme_selection) = theme_settings.icon_theme_selection.as_ref() {
-        let icon_theme_name = icon_theme_selection.icon_theme(appearance);
-        if matches!(
-            theme_registry.get_icon_theme(icon_theme_name),
-            Err(IconThemeNotFoundError(_))
-        ) && let Some((icon_theme_path, icons_root_path)) = extension_store
-            .read(cx)
-            .path_to_extension_icon_theme(icon_theme_name)
-        {
-            cx.spawn({
-                let fs = fs.clone();
-                async move |cx| {
-                    theme_registry
-                        .load_icon_theme(&icon_theme_path, &icons_root_path, fs)
-                        .await?;
-
-                    cx.update(|cx| {
-                        ThemeSettings::reload_current_icon_theme(cx);
-                    })
-                }
-            })
-            .detach_and_log_err(cx);
-        }
-    }
-}
-
 /// Spawns a background task to load the user themes from the themes directory.
 fn load_user_themes_in_background(fs: Arc<dyn fs::Fs>, cx: &mut App) {
     cx.spawn({
@@ -1435,7 +1376,7 @@ fn load_user_themes_in_background(fs: Arc<dyn fs::Fs>, cx: &mut App) {
                     }
                 }
                 theme_registry.load_user_themes(themes_dir, fs).await?;
-                cx.update(ThemeSettings::reload_current_theme)?;
+                cx.update(GlobalTheme::reload_theme)?;
             }
             anyhow::Ok(())
         }
@@ -1461,7 +1402,7 @@ fn watch_themes(fs: Arc<dyn fs::Fs>, cx: &mut App) {
                         .await
                         .log_err()
                 {
-                    cx.update(ThemeSettings::reload_current_theme).log_err();
+                    cx.update(GlobalTheme::reload_theme).log_err();
                 }
             }
         }

crates/zed/src/zed.rs

@@ -20,7 +20,9 @@ use collections::VecDeque;
 use debugger_ui::debugger_panel::DebugPanel;
 use editor::ProposedChangesEditorToolbar;
 use editor::{Editor, MultiBuffer};
+use extension_host::ExtensionStore;
 use feature_flags::{FeatureFlagAppExt, PanicFeatureFlag};
+use fs::Fs;
 use futures::future::Either;
 use futures::{StreamExt, channel::mpsc, select_biased};
 use git_ui::git_panel::GitPanel;
@@ -68,7 +70,10 @@ use std::{
     sync::atomic::{self, AtomicBool},
 };
 use terminal_view::terminal_panel::{self, TerminalPanel};
-use theme::{ActiveTheme, ThemeSettings};
+use theme::{
+    ActiveTheme, GlobalTheme, IconThemeNotFoundError, SystemAppearance, ThemeNotFoundError,
+    ThemeRegistry, ThemeSettings,
+};
 use ui::{PopoverMenuHandle, prelude::*};
 use util::markdown::MarkdownString;
 use util::rel_path::RelPath;
@@ -2012,6 +2017,55 @@ fn capture_recent_audio(workspace: &mut Workspace, _: &mut Window, cx: &mut Cont
     );
 }
 
+/// Eagerly loads the active theme and icon theme based on the selections in the
+/// theme settings.
+///
+/// This fast path exists to load these themes as soon as possible so the user
+/// doesn't see the default themes while waiting on extensions to load.
+pub(crate) fn eager_load_active_theme_and_icon_theme(fs: Arc<dyn Fs>, cx: &mut App) {
+    let extension_store = ExtensionStore::global(cx);
+    let theme_registry = ThemeRegistry::global(cx);
+    let theme_settings = ThemeSettings::get_global(cx);
+    let appearance = SystemAppearance::global(cx).0;
+
+    let theme_name = theme_settings.theme.name(appearance);
+    if matches!(
+        theme_registry.get(&theme_name.0),
+        Err(ThemeNotFoundError(_))
+    ) && let Some(theme_path) = extension_store
+        .read(cx)
+        .path_to_extension_theme(&theme_name.0)
+    {
+        if cx
+            .background_executor()
+            .block(theme_registry.load_user_theme(&theme_path, fs.clone()))
+            .log_err()
+            .is_some()
+        {
+            GlobalTheme::reload_theme(cx);
+        }
+    }
+
+    let theme_settings = ThemeSettings::get_global(cx);
+    let icon_theme_name = theme_settings.icon_theme.name(appearance);
+    if matches!(
+        theme_registry.get_icon_theme(&icon_theme_name.0),
+        Err(IconThemeNotFoundError(_))
+    ) && let Some((icon_theme_path, icons_root_path)) = extension_store
+        .read(cx)
+        .path_to_extension_icon_theme(&icon_theme_name.0)
+    {
+        if cx
+            .background_executor()
+            .block(theme_registry.load_icon_theme(&icon_theme_path, &icons_root_path, fs))
+            .log_err()
+            .is_some()
+        {
+            GlobalTheme::reload_icon_theme(cx);
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -2031,8 +2085,11 @@ mod tests {
         path::{Path, PathBuf},
         time::Duration,
     };
-    use theme::{ThemeRegistry, ThemeSettings};
-    use util::{path, rel_path::rel_path};
+    use theme::ThemeRegistry;
+    use util::{
+        path,
+        rel_path::{RelPath, rel_path},
+    };
     use workspace::{
         NewFile, OpenOptions, OpenVisible, SERIALIZATION_THROTTLE_TIME, SaveIntent, SplitDirection,
         WorkspaceHandle,
@@ -4632,7 +4689,7 @@ mod tests {
         for theme_name in themes.list().into_iter().map(|meta| meta.name) {
             let theme = themes.get(&theme_name).unwrap();
             assert_eq!(theme.name, theme_name);
-            if theme.name == ThemeSettings::get(None, cx).active_theme.name {
+            if theme.name.as_ref() == "One Dark" {
                 has_default_theme = true;
             }
         }