From 76560968149daf88a95d3f579be029dd54656a02 Mon Sep 17 00:00:00 2001
From: Marshall Bowers <elliott.codes@gmail.com>
Date: Mon, 29 Jan 2024 17:51:34 -0500
Subject: [PATCH] Rework access to `ThemeRegistry` global (#7023)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This PR reworks how we access the `ThemeRegistry` global.

Previously we were making calls directly on the context, like
`cx.global::<ThemeRegistry>`. However, one problem with this is that it
spreads out the knowledge of exactly what type is stored in the global.

In order to make it easier to adjust the type we store in the context
(e.g., wrapping the `ThemeRegistry` in an `Arc`), we now call methods on
the `ThemeRegistry` itself for accessing the global.

It would also be interesting to see how we could prevent access to the
`ThemeRegistry` without going through one of these dedicated methods 🤔

Release Notes:

- N/A
---
 crates/storybook/src/storybook.rs           |  2 +-
 crates/theme/src/registry.rs                | 19 ++++++++++++++++++-
 crates/theme/src/settings.rs                |  5 ++---
 crates/theme/src/theme.rs                   |  2 +-
 crates/theme_selector/src/theme_selector.rs |  4 ++--
 5 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/crates/storybook/src/storybook.rs b/crates/storybook/src/storybook.rs
index 47fc3b042a9ae5466c442ab9f79bdfea0b67eaf1..efbd46665ca312a6143c1e0358707c4aff8536e2 100644
--- a/crates/storybook/src/storybook.rs
+++ b/crates/storybook/src/storybook.rs
@@ -71,7 +71,7 @@ fn main() {
 
         let selector = story_selector;
 
-        let theme_registry = cx.global::<ThemeRegistry>();
+        let theme_registry = ThemeRegistry::global(cx);
         let mut theme_settings = ThemeSettings::get_global(cx).clone();
         theme_settings.active_theme = theme_registry.get(&theme_name).unwrap();
         ThemeSettings::override_global(theme_settings, cx);
diff --git a/crates/theme/src/registry.rs b/crates/theme/src/registry.rs
index c90b1c909e32867eebc3b01a7cb496296028f257..1fbee2449ee4f6eea08aa2f5aa2604231a99fd86 100644
--- a/crates/theme/src/registry.rs
+++ b/crates/theme/src/registry.rs
@@ -2,7 +2,7 @@ use std::collections::HashMap;
 use std::sync::Arc;
 
 use anyhow::{anyhow, Context, Result};
-use gpui::{AssetSource, HighlightStyle, SharedString};
+use gpui::{AppContext, AssetSource, HighlightStyle, SharedString};
 use refineable::Refineable;
 use util::ResultExt;
 
@@ -24,6 +24,23 @@ pub struct ThemeRegistry {
 }
 
 impl ThemeRegistry {
+    /// Returns the global [`ThemeRegistry`].
+    pub fn global(cx: &AppContext) -> &Self {
+        cx.global::<ThemeRegistry>()
+    }
+
+    /// Returns a mutable reference to the global [`ThemeRegistry`].
+    pub fn global_mut(cx: &mut AppContext) -> &mut Self {
+        cx.global_mut::<ThemeRegistry>()
+    }
+
+    /// Returns a mutable reference to the global [`ThemeRegistry`].
+    ///
+    /// Inserts a default [`ThemeRegistry`] if one does not yet exist.
+    pub fn default_global(cx: &mut AppContext) -> &mut Self {
+        cx.default_global::<ThemeRegistry>()
+    }
+
     pub fn new(assets: Box<dyn AssetSource>) -> Self {
         let mut registry = Self {
             assets,
diff --git a/crates/theme/src/settings.rs b/crates/theme/src/settings.rs
index 67e7e7a0d8da34494e88311bbeb1a4edc6a51550..828a2f5de535929dcf3868fa91f93ca28b8f9ece 100644
--- a/crates/theme/src/settings.rs
+++ b/crates/theme/src/settings.rs
@@ -164,7 +164,7 @@ impl settings::Settings for ThemeSettings {
         user_values: &[&Self::FileContent],
         cx: &mut AppContext,
     ) -> Result<Self> {
-        let themes = cx.default_global::<ThemeRegistry>();
+        let themes = ThemeRegistry::default_global(cx);
 
         let mut this = Self {
             ui_font_size: defaults.ui_font_size.unwrap().into(),
@@ -230,8 +230,7 @@ impl settings::Settings for ThemeSettings {
         cx: &AppContext,
     ) -> schemars::schema::RootSchema {
         let mut root_schema = generator.root_schema_for::<ThemeSettingsContent>();
-        let theme_names = cx
-            .global::<ThemeRegistry>()
+        let theme_names = ThemeRegistry::global(cx)
             .list_names(params.staff_mode)
             .map(|theme_name| Value::String(theme_name.to_string()))
             .collect();
diff --git a/crates/theme/src/theme.rs b/crates/theme/src/theme.rs
index 5018a72da0e22789039c2fb3ca5e9ec905c6b3f6..2686ffe62db325048692303da3295503dcc92f71 100644
--- a/crates/theme/src/theme.rs
+++ b/crates/theme/src/theme.rs
@@ -63,7 +63,7 @@ pub fn init(themes_to_load: LoadThemes, cx: &mut AppContext) {
     cx.set_global(ThemeRegistry::new(assets));
 
     if load_user_themes {
-        cx.global_mut::<ThemeRegistry>().load_user_themes();
+        ThemeRegistry::global_mut(cx).load_user_themes();
     }
 
     ThemeSettings::register(cx);
diff --git a/crates/theme_selector/src/theme_selector.rs b/crates/theme_selector/src/theme_selector.rs
index 14251c4a5353b7d0c088aee048bfdf0ee2c38c1a..d67ff9ba712b90da2c9fe7e051689c6ee74f6e02 100644
--- a/crates/theme_selector/src/theme_selector.rs
+++ b/crates/theme_selector/src/theme_selector.rs
@@ -102,7 +102,7 @@ impl ThemeSelectorDelegate {
         let original_theme = cx.theme().clone();
 
         let staff_mode = cx.is_staff();
-        let registry = cx.global::<ThemeRegistry>();
+        let registry = ThemeRegistry::global(cx);
         let mut themes = registry.list(staff_mode).collect::<Vec<_>>();
         themes.sort_unstable_by(|a, b| {
             a.appearance
@@ -135,7 +135,7 @@ impl ThemeSelectorDelegate {
 
     fn show_selected_theme(&mut self, cx: &mut ViewContext<Picker<ThemeSelectorDelegate>>) {
         if let Some(mat) = self.matches.get(self.selected_index) {
-            let registry = cx.global::<ThemeRegistry>();
+            let registry = ThemeRegistry::global(cx);
             match registry.get(&mat.string) {
                 Ok(theme) => {
                     Self::set_theme(theme, cx);