Add theme mode toggle action

Fixes #35552

crates/theme_selector/src/theme_selector.rs

@@ -7,9 +7,9 @@ use gpui::{
     Window, actions,
 };
 use picker::{Picker, PickerDelegate};
-use settings::{SettingsStore, update_settings_file};
+use settings::{Settings as _, SettingsStore, update_settings_file};
 use std::sync::Arc;
-use theme::{Appearance, Theme, ThemeMeta, ThemeRegistry, ThemeSettings};
+use theme::{Appearance, Theme, ThemeMeta, ThemeMode, ThemeRegistry, ThemeSelection, ThemeSettings};
 use ui::{ListItem, ListItemSpacing, prelude::*, v_flex};
 use util::ResultExt;
 use workspace::{ModalView, Workspace, ui::HighlightedLabel, with_active_or_new_workspace};
@@ -38,6 +38,11 @@ pub fn init(cx: &mut App) {
             toggle_icon_theme_selector(workspace, &action, window, cx);
         });
     });
+    cx.on_action(|_: &zed_actions::theme_selector::ToggleMode, cx| {
+        with_active_or_new_workspace(cx, |workspace, window, cx| {
+            toggle_theme_mode(workspace, window, cx);
+        });
+    });
 }
 
 fn toggle_theme_selector(
@@ -76,6 +81,35 @@ fn toggle_icon_theme_selector(
     });
 }
 
+fn toggle_theme_mode(
+    workspace: &mut Workspace,
+    _window: &mut Window,
+    cx: &mut Context<Workspace>,
+) {
+    let current_settings = ThemeSettings::get_global(cx);
+    let current_selection = current_settings.theme_selection.as_ref();
+    
+    let new_mode = match current_selection {
+        Some(ThemeSelection::Dynamic { mode, .. }) => {
+            match mode {
+                ThemeMode::Light => ThemeMode::Dark,
+                ThemeMode::Dark => ThemeMode::System,
+                ThemeMode::System => ThemeMode::Light,
+            }
+        }
+        Some(ThemeSelection::Static(_)) => ThemeMode::Light,
+        None => ThemeMode::Light
+    };
+    
+    let fs = workspace.app_state().fs.clone();
+    
+    update_settings_file::<ThemeSettings>(fs, cx, move |settings, _| {
+        settings.set_mode(new_mode);
+    });
+    
+    ThemeSettings::reload_current_theme(cx);
+}
+
 impl ModalView for ThemeSelector {}
 
 struct ThemeSelector {

crates/zed/src/zed/app_menus.rs

@@ -32,6 +32,10 @@ pub fn app_menus() -> Vec<Menu> {
                             "Select Theme...",
                             zed_actions::theme_selector::Toggle::default(),
                         ),
+                        MenuItem::action(
+                            "Toggle Theme Mode",
+                            zed_actions::theme_selector::ToggleMode,
+                        ),
                     ],
                 }),
                 MenuItem::separator(),

crates/zed_actions/src/lib.rs

@@ -243,6 +243,12 @@ pub mod theme_selector {
         /// A list of theme names to filter the theme selector down to.
         pub themes_filter: Option<Vec<String>>,
     }
+
+    /// Toggles between light, dark, and system theme modes.
+    #[derive(PartialEq, Clone, Default, Debug, Deserialize, JsonSchema, Action)]
+    #[action(namespace = theme_selector)]
+    #[serde(deny_unknown_fields)]
+    pub struct ToggleMode;
 }
 
 pub mod icon_theme_selector {