feat(core): OS Accent color

.github/workflows/rust_android.yml

@@ -33,14 +33,20 @@ jobs:
       - name: Install Rust toolchain
         uses: actions-rust-lang/setup-rust-toolchain@2b1f5e9b395427c92ee4e3331786ca3c37afe2d7 # v1
         with:
-          target: aarch64-linux-android
+          target: aarch64-linux-android, x86_64-linux-android
       - name: Install cargo-ndk
         run: cargo install cargo-ndk
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: "17"
       - name: Set up cargo cache
         uses: Swatinem/rust-cache@c19371144df3bb44fab255c43d04cbc2ab54d1c4 # v2.9.1
         if: github.ref != 'refs/heads/main'
         with:
           shared-key: "rust-android"
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: Build Android example
-        run: cargo ndk -t arm64-v8a build -p android --lib
+        working-directory: examples/android/AndroidApp
+        run: ./gradlew buildRelease

Cargo.toml

@@ -84,6 +84,11 @@ freya-code-editor = { path = "./crates/freya-code-editor", version = "0.4.0-rc.1
   "rust",
 ] }
 freya-android = { path = "./crates/freya-android", version = "0.4.0-rc.19" }
+mundy = { version = "0.2.3", default-features = false, features = [
+  "async-io",
+  "callback",
+  "accent-color",
+] }
 
 # core
 generational-box = "0.7"

crates/freya-components/src/theming/themes.rs

@@ -637,15 +637,35 @@ fn register_base_component_themes(theme: &mut Theme) {
 }
 
 /// Light theme with all built-in component themes registered.
+///
+/// The primary color tracks the OS-level [`AccentColor`] when available; the
+/// secondary and tertiary colors are derived from it (lightened / darkened).
 pub fn light_theme() -> Theme {
-    let mut theme = Theme::new("light", LIGHT_COLORS);
-    register_base_component_themes(&mut theme);
-    theme
+    build_theme("light", LIGHT_COLORS)
 }
 
 /// Dark theme with all built-in component themes registered.
+///
+/// The primary color tracks the OS-level [`AccentColor`] when available; the
+/// secondary and tertiary colors are derived from it (lightened / darkened).
 pub fn dark_theme() -> Theme {
-    let mut theme = Theme::new("dark", DARK_COLORS);
+    build_theme("dark", DARK_COLORS)
+}
+
+fn build_theme(name: &'static str, mut colors: ColorsSheet) -> Theme {
+    if let Some(primary) = current_accent_color() {
+        colors.primary = primary;
+        colors.secondary = Color::lerp(primary, Color::WHITE, 0.65);
+        colors.tertiary = Color::lerp(primary, Color::BLACK, 0.23);
+    }
+    let mut theme = Theme::new(name, colors);
     register_base_component_themes(&mut theme);
     theme
 }
+
+fn current_accent_color() -> Option<Color> {
+    let platform: Platform = try_consume_root_context()?;
+    let accent = platform.accent_color.read().0?;
+    let [r, g, b, _] = accent.to_u8_array();
+    Some(Color::from_rgb(r, g, b))
+}

crates/freya-core/Cargo.toml

@@ -37,6 +37,9 @@ keyboard-types = { workspace = true }
 torin = { workspace = true }
 smallvec = "1.15.1"
 
+# OS preferences
+mundy = { workspace = true }
+
 # Layers
 itertools = { workspace = true }
 

crates/freya-core/src/platform.rs

@@ -1,5 +1,9 @@
 use std::rc::Rc;
 
+pub use mundy::{
+    AccentColor,
+    Srgba,
+};
 use torin::prelude::Size2D;
 
 use crate::{
@@ -41,6 +45,8 @@ pub struct Platform {
     pub navigation_mode: State<NavigationMode>,
     /// The OS-level [`PreferredTheme`].
     pub preferred_theme: State<PreferredTheme>,
+    /// The OS-level [`AccentColor`].
+    pub accent_color: State<AccentColor>,
     /// Sender used to dispatch [`UserEvent`]s to the active renderer.
     pub sender: Rc<dyn Fn(UserEvent)>,
 }

crates/freya-core/src/style/color.rs

@@ -236,4 +236,17 @@ impl Color {
     pub fn pretty(&self) -> String {
         self.to_rgb_string()
     }
+
+    /// Linearly interpolates between two colors per channel. `t` is clamped
+    /// to `0.0..=1.0`; `0.0` returns `start`, `1.0` returns `end`.
+    pub fn lerp(start: Color, end: Color, t: f32) -> Color {
+        let t = t.clamp(0.0, 1.0);
+        let mix = |a: u8, b: u8| (a as f32 + (b as f32 - a as f32) * t).round() as u8;
+        Color::from_argb(
+            mix(start.a(), end.a()),
+            mix(start.r(), end.r()),
+            mix(start.g(), end.g()),
+            mix(start.b(), end.b()),
+        )
+    }
 }

crates/freya-testing/src/lib.rs

@@ -203,6 +203,7 @@ impl TestingRunner {
                 root_size: State::create(size),
                 navigation_mode: State::create(NavigationMode::NotKeyboard),
                 preferred_theme: State::create(PreferredTheme::Light),
+                accent_color: State::create(AccentColor::default()),
                 sender: Rc::new(move |user_event| {
                     match user_event {
                         UserEvent::RequestRedraw => {

crates/freya-winit/Cargo.toml

@@ -31,6 +31,9 @@ raw-window-handle = { workspace = true }
 winit = { workspace = true }
 freya-engine = { workspace = true }
 
+# OS preferences
+mundy = { workspace = true }
+
 # Events
 ragnarok = { workspace = true }
 keyboard-types = { workspace = true }

crates/freya-winit/src/renderer.rs

@@ -247,6 +247,7 @@ pub enum NativeEvent {
     #[cfg(feature = "tray")]
     Tray(NativeTrayEvent),
     Generic(NativeGenericEvent),
+    Preferences(mundy::Preferences),
 }
 
 impl From<accesskit_winit::Event> for NativeEvent {
@@ -300,6 +301,8 @@ impl ApplicationHandler<NativeEvent> for WinitRenderer {
             }
             self.resumed = true;
 
+            subscribe_preferences(self.proxy.clone());
+
             let _ = self
                 .proxy
                 .send_event(NativeEvent::Generic(NativeGenericEvent::PollFutures));
@@ -353,6 +356,13 @@ impl ApplicationHandler<NativeEvent> for WinitRenderer {
                 self.futures
                     .retain_mut(|fut| fut.poll(&mut cx).is_pending());
             }
+            NativeEvent::Preferences(prefs) => {
+                for app in self.windows.values_mut() {
+                    app.platform
+                        .accent_color
+                        .set_if_modified(prefs.accent_color);
+                }
+            }
             #[cfg(feature = "tray")]
             NativeEvent::Tray(NativeTrayEvent { action }) => {
                 let renderer_context = RendererContext {
@@ -1178,3 +1188,10 @@ impl ApplicationHandler<NativeEvent> for WinitRenderer {
         }
     }
 }
+
+fn subscribe_preferences(proxy: EventLoopProxy<NativeEvent>) {
+    let subscription = mundy::Preferences::subscribe(mundy::Interest::AccentColor, move |prefs| {
+        let _ = proxy.send_event(NativeEvent::Preferences(prefs));
+    });
+    std::mem::forget(subscription);
+}

crates/freya-winit/src/window.rs

@@ -182,6 +182,7 @@ impl AppWindow {
         let mut tree = Tree::default();
 
         let window_size = window.inner_size();
+        let accent_color_preference = accent_color_preference();
         let platform = runner.provide_root_context({
             let event_loop_proxy = event_loop_proxy.clone();
             let window_id = window.id();
@@ -200,6 +201,7 @@ impl AppWindow {
                 )),
                 navigation_mode: State::create(NavigationMode::NotKeyboard),
                 preferred_theme: State::create(theme),
+                accent_color: State::create(accent_color_preference.accent_color),
                 sender: Rc::new(move |user_event| {
                     event_loop_proxy
                         .send_event(NativeEvent::Window(NativeWindowEvent {
@@ -365,3 +367,15 @@ impl AppWindow {
         &mut self.window
     }
 }
+
+fn accent_color_preference() -> mundy::Preferences {
+    use std::sync::OnceLock;
+    static PREFERENCE: OnceLock<mundy::Preferences> = OnceLock::new();
+    *PREFERENCE.get_or_init(|| {
+        mundy::Preferences::once_blocking(
+            mundy::Interest::AccentColor,
+            std::time::Duration::from_millis(200),
+        )
+        .unwrap_or_default()
+    })
+}

examples/android/AndroidApp/app/build.gradle.kts

@@ -41,10 +41,14 @@ android {
 
 tasks.register<Exec>("buildRustLibrary") {
     workingDir("../..")
+    val androidHome = System.getenv("ANDROID_HOME") ?: System.getenv("ANDROID_SDK_ROOT") ?: ""
+    environment("ANDROID_HOME", androidHome)
+    environment("ANDROID_JAR", "$androidHome/platforms/android-36/android.jar")
     commandLine("cargo", "ndk",
         "-o", "AndroidApp/app/src/main/jniLibs/",
         "-t", "arm64-v8a",
         "-t", "x86_64-linux-android",
+        "--platform", "31",
         "build", "--lib", "--release")
 }