From 8c44a35398abdacd5521e4726db3093fa3fee1b6 Mon Sep 17 00:00:00 2001
From: "Wyatt J. Miller" <wyatt@wyattjmiller.com>
Date: Thu, 27 Aug 2026 22:50:40 -0400
Subject: [PATCH] mod: adjustments

---
 resources/appmenu.xml | 17 ++++++++++++
 resources/style.css   | 17 ++++++++----
 src/main.rs           | 62 ++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 90 insertions(+), 6 deletions(-)

diff --git a/resources/appmenu.xml b/resources/appmenu.xml
index 683d574..7777d12 100644
--- a/resources/appmenu.xml
+++ b/resources/appmenu.xml
@@ -2,6 +2,23 @@
 <interface>
   <requires lib="gtk" version="4.0"/>
       <menu id="app-menu">
+        <section>
+          <submenu>
+            <attribute name="label" translatable="yes">_Appearance</attribute>
+            <section>
+              <item>
+                <attribute name="label" translatable="yes">Follow _System</attribute>
+                <attribute name="action">app.theme</attribute>
+                <attribute name="target">system</attribute>
+              </item>
+              <item>
+                <attribute name="label" translatable="yes">_Dark</attribute>
+                <attribute name="action">app.theme</attribute>
+                <attribute name="target">dark</attribute>
+              </item>
+            </section>
+          </submenu>
+        </section>
         <section>
           <item>
             <attribute name="label" translatable="yes">_About SNES Patcher</attribute>
diff --git a/resources/style.css b/resources/style.css
index 370c1f3..831e67e 100644
--- a/resources/style.css
+++ b/resources/style.css
@@ -2,11 +2,6 @@
     min-width: 356px;
 }
 
-.title {
-    font-size: 1.5rem;
-    font-weight: 700;
-}
-
 .heading {
     font-weight: 600;
 }
@@ -21,3 +16,15 @@
     min-height: 48px;
     padding: 10px 12px;
 }
+
+.intro-title {
+    font-size: 1.5rem;
+    font-weight: 700;
+}
+
+headerbar.titlebar {
+    background-color: transparent;
+    background-image: none;
+    border-bottom: none;
+    box-shadow: none;
+}
diff --git a/src/main.rs b/src/main.rs
index eb574dc..bb32dc9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -7,6 +7,7 @@ use std::rc::Rc;
 
 use gtk4::gio;
 use gtk4::glib;
+use gtk4::glib::ToVariant;
 use gtk4::pango::EllipsizeMode;
 use gtk4::prelude::*;
 use gtk4::{
@@ -17,6 +18,8 @@ use gtk4::{
 
 const APP_ID: &str = "com.wyattjmiller.snespatcher";
 const APP_NAME: &str = "SNES Patcher";
+const THEME_SYSTEM: &str = "system";
+const THEME_DARK: &str = "dark";
 
 #[derive(Clone)]
 struct SelectionState {
@@ -71,7 +74,7 @@ fn build_ui(app: &Application) {
 
     let introduction = GtkBox::new(Orientation::Vertical, 8);
     let heading = Label::new(Some("Patch a Super Nintendo ROM"));
-    heading.add_css_class("title");
+    heading.add_css_class("intro-title");
     heading.set_justify(Justification::Center);
     heading.set_wrap(true);
 
@@ -192,6 +195,8 @@ fn build_header_bar(
     header_bar.pack_start(rom_info_button);
     header_bar.pack_end(&menu_button);
 
+    add_theme_action(app);
+
     let about = gio::SimpleAction::new("about", None);
     about.connect_activate(glib::clone!(@weak window => move |_, _| {
         let dialog = AboutDialog::builder()
@@ -219,6 +224,61 @@ fn build_header_bar(
     header_bar
 }
 
+fn add_theme_action(app: &Application) {
+    let preference = load_theme_preference();
+    let settings = gtk4::Settings::default().expect("Could not access GTK settings");
+    apply_theme_preference(&settings, &preference);
+
+    let theme = gio::SimpleAction::new_stateful(
+        "theme",
+        Some(glib::VariantTy::STRING),
+        &preference.to_variant(),
+    );
+    theme.connect_activate(move |action, parameter| {
+        let Some(preference) = parameter.and_then(|value| value.get::<String>()) else {
+            return;
+        };
+        if preference != THEME_SYSTEM && preference != THEME_DARK {
+            return;
+        }
+
+        apply_theme_preference(&settings, &preference);
+        action.set_state(&preference.to_variant());
+        save_theme_preference(&preference);
+    });
+    app.add_action(&theme);
+}
+
+fn apply_theme_preference(settings: &gtk4::Settings, preference: &str) {
+    settings.set_gtk_application_prefer_dark_theme(preference == THEME_DARK);
+}
+
+fn theme_preference_path() -> PathBuf {
+    glib::user_config_dir().join(APP_ID).join("theme")
+}
+
+fn load_theme_preference() -> String {
+    match std::fs::read_to_string(theme_preference_path()) {
+        Ok(preference) if preference.trim() == THEME_DARK => THEME_DARK.to_string(),
+        _ => THEME_SYSTEM.to_string(),
+    }
+}
+
+fn save_theme_preference(preference: &str) {
+    let path = theme_preference_path();
+    let Some(parent) = path.parent() else {
+        return;
+    };
+
+    if let Err(error) = std::fs::create_dir_all(parent) {
+        eprintln!("Could not create the preferences directory: {error}");
+        return;
+    }
+    if let Err(error) = std::fs::write(path, preference) {
+        eprintln!("Could not save the theme preference: {error}");
+    }
+}
+
 fn selection_row(title: &str, placeholder: &str, icon_name: &str) -> SelectionRow {
     let icon = Image::from_icon_name(icon_name);
     icon.set_pixel_size(24);