improve styling in relation to windows theme

src/gui/app.rs

@@ -1,6 +1,10 @@
 use crate::{
     features,
-    gui::{settings::Settings, tools, ui_ext::UiExt},
+    gui::{
+        settings::{Settings, Theme},
+        tools,
+        ui_ext::UiExt,
+    },
     util::{consts::game::WINDOW_TITLE, meta::Meta, persistent_state::PersistentState, win},
 };
 use eframe::egui;
@@ -201,6 +205,13 @@ impl App {
             if selection != self.settings.theme {
                 catppuccin_egui::set_theme(ctx, self.settings.theme.into());
             }
+            if ui
+                .add_visible(self.settings.theme == Theme::Auto, egui::Button::new("⟲"))
+                .on_hover_text("Refresh theme")
+                .clicked()
+            {
+                catppuccin_egui::set_theme(ctx, self.settings.theme.into());
+            }
         });
         ui.checkbox(&mut self.settings.start_elevated, "Always start elevated");
     }

src/gui/run.rs

@@ -50,10 +50,12 @@ fn app_creator(
     app.sysinfo.refresh_all();
     // enable image loading support in egui
     egui_extras::install_image_loaders(&cc.egui_ctx);
-    // set our initial theme, from earlier loaded settings
+    // set our initial theme, from earlier loaded settings. we set the egui theme
+    // to dark here to work around system theme based switching of the egui style
+    cc.egui_ctx.set_theme(egui::Theme::Dark);
     catppuccin_egui::set_theme(&cc.egui_ctx, app.settings.theme.into());
     // apply some global styling that we like
-    cc.egui_ctx.style_mut(|style| {
+    cc.egui_ctx.all_styles_mut(|style| {
         style.spacing.item_spacing = egui::vec2(4.0, 4.0);
         style.interaction.selectable_labels = false;
     });

src/gui/settings.rs

@@ -1,8 +1,11 @@
+use crate::util::win;
 use serde::{Deserialize, Serialize};
 use strum::{Display, EnumIter};
 
 #[derive(Clone, Copy, Debug, Display, PartialEq, Eq, Serialize, Deserialize, EnumIter)]
 pub enum Theme {
+    #[strum(to_string = "Auto")]
+    Auto,
     #[strum(to_string = "Catppuccin Latte")]
     CatppuccinLatte,
     #[strum(to_string = "Catppuccin Frappe")]
@@ -16,6 +19,13 @@ pub enum Theme {
 impl From<Theme> for catppuccin_egui::Theme {
     fn from(val: Theme) -> Self {
         match val {
+            Theme::Auto => {
+                if win::is_system_theme_dark() {
+                    catppuccin_egui::MOCHA
+                } else {
+                    catppuccin_egui::LATTE
+                }
+            }
             Theme::CatppuccinLatte => catppuccin_egui::LATTE,
             Theme::CatppuccinFrappe => catppuccin_egui::FRAPPE,
             Theme::CatppuccinMacchiato => catppuccin_egui::MACCHIATO,
@@ -33,7 +43,7 @@ pub struct Settings {
 impl Default for Settings {
     fn default() -> Self {
         Self {
-            theme: Theme::CatppuccinMocha,
+            theme: Theme::Auto,
             start_elevated: false,
         }
     }

src/util/win.rs

@@ -83,3 +83,17 @@ pub fn is_elevated() -> bool {
         result.is_ok() && elevation.TokenIsElevated != 0
     }
 }
+
+pub fn is_system_theme_dark() -> bool {
+    use winreg::RegKey;
+    let hkcu = RegKey::predef(winreg::enums::HKEY_CURRENT_USER);
+    let Ok(subkey) =
+        hkcu.open_subkey("Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize")
+    else {
+        return true;
+    };
+    let Ok(dword): Result<u32, std::io::Error> = subkey.get_value("AppsUseLightTheme") else {
+        return true;
+    };
+    dword != 1
+}