Remove cx from ThemeSettings (#38836)

Before this change the active theme and icon theme were retrofitted onto
the ThemeSettings.

Now they're in their own new global (GlobalTheme::theme(cx) and
GlobalTheme::icon_theme(cx))

This lets us remove cx from the settings traits, and tidy up a few other
things along the way.

Release Notes:

- N/A

crates/workspace/src/item.rs

@@ -65,7 +65,7 @@ pub struct PreviewTabsSettings {
 }
 
 impl Settings for ItemSettings {
-    fn from_settings(content: &settings::SettingsContent, _cx: &mut App) -> Self {
+    fn from_settings(content: &settings::SettingsContent) -> Self {
         let tabs = content.tabs.as_ref().unwrap();
         Self {
             git_status: tabs.git_status.unwrap(),
@@ -113,7 +113,7 @@ impl Settings for ItemSettings {
 }
 
 impl Settings for PreviewTabsSettings {
-    fn from_settings(content: &settings::SettingsContent, _cx: &mut App) -> Self {
+    fn from_settings(content: &settings::SettingsContent) -> Self {
         let preview_tabs = content.preview_tabs.as_ref().unwrap();
         Self {
             enabled: preview_tabs.enabled.unwrap(),

crates/workspace/src/workspace.rs

@@ -103,7 +103,7 @@ use std::{
     time::Duration,
 };
 use task::{DebugScenario, SpawnInTerminal, TaskContext};
-use theme::{ActiveTheme, SystemAppearance, ThemeSettings};
+use theme::{ActiveTheme, GlobalTheme, SystemAppearance, ThemeSettings};
 pub use toolbar::{Toolbar, ToolbarItemEvent, ToolbarItemLocation, ToolbarItemView};
 pub use ui;
 use ui::{Window, prelude::*};
@@ -1435,8 +1435,8 @@ impl Workspace {
 
                 *SystemAppearance::global_mut(cx) = SystemAppearance(window_appearance.into());
 
-                ThemeSettings::reload_current_theme(cx);
-                ThemeSettings::reload_current_icon_theme(cx);
+                GlobalTheme::reload_theme(cx);
+                GlobalTheme::reload_icon_theme(cx);
             }),
             cx.on_release(move |this, cx| {
                 this.app_state.workspace_store.update(cx, move |store, _| {

crates/workspace/src/workspace_settings.rs

@@ -2,7 +2,6 @@ use std::num::NonZeroUsize;
 
 use crate::DockPosition;
 use collections::HashMap;
-use gpui::App;
 use serde::Deserialize;
 pub use settings::AutosaveSetting;
 use settings::Settings;
@@ -62,7 +61,7 @@ pub struct TabBarSettings {
 }
 
 impl Settings for WorkspaceSettings {
-    fn from_settings(content: &settings::SettingsContent, _cx: &mut App) -> Self {
+    fn from_settings(content: &settings::SettingsContent) -> Self {
         let workspace = &content.workspace;
         Self {
             active_pane_modifiers: ActivePanelModifiers {
@@ -197,7 +196,7 @@ impl Settings for WorkspaceSettings {
 }
 
 impl Settings for TabBarSettings {
-    fn from_settings(content: &settings::SettingsContent, _cx: &mut App) -> Self {
+    fn from_settings(content: &settings::SettingsContent) -> Self {
         let tab_bar = content.tab_bar.clone().unwrap();
         TabBarSettings {
             show: tab_bar.show.unwrap(),
@@ -231,7 +230,7 @@ pub struct StatusBarSettings {
 }
 
 impl Settings for StatusBarSettings {
-    fn from_settings(content: &settings::SettingsContent, _cx: &mut App) -> Self {
+    fn from_settings(content: &settings::SettingsContent) -> Self {
         let status_bar = content.status_bar.clone().unwrap();
         StatusBarSettings {
             show: status_bar.show.unwrap(),