Added app icon

crates/platform-desktop/src/app.rs

@@ -0,0 +1,38 @@
+/// Applies the Furumi federation mark as the native application icon.
+///
+/// Slint forwards its window icon to Windows and X11. macOS deliberately
+/// ignores that window-level API, so its Dock icon is installed through
+/// `AppKit` from the same embedded SVG asset. On macOS this must be called
+/// from the main event loop after `applicationDidFinishLaunching`.
+pub fn set_application_icon() {
+    if let Err(error) = set_native_application_icon() {
+        eprintln!("failed to install the Furumi application icon: {error}");
+    }
+}
+
+#[cfg(target_os = "macos")]
+fn set_native_application_icon() -> Result<(), &'static str> {
+    use std::ffi::c_void;
+
+    use objc2::MainThreadMarker;
+    use objc2_app_kit::{NSApplication, NSImage};
+    use objc2_foundation::NSData;
+
+    let main_thread = MainThreadMarker::new().ok_or("not running on the macOS main thread")?;
+    let svg = include_bytes!("../../ui/assets/federation.svg");
+    // SAFETY: `dataWithBytes_length` copies `svg`; its pointer is valid for
+    // the complete duration of the Objective-C call.
+    let data = unsafe { NSData::dataWithBytes_length(svg.as_ptr().cast::<c_void>(), svg.len()) };
+    let icon = NSImage::initWithData(main_thread.alloc(), &data)
+        .ok_or("AppKit could not decode the embedded federation SVG")?;
+    let application = NSApplication::sharedApplication(main_thread);
+    // SAFETY: AppKit accepts a live NSImage here and retains it as the
+    // application's Dock icon. This function is restricted to the main thread.
+    unsafe { application.setApplicationIconImage(Some(&icon)) };
+    Ok(())
+}
+
+#[cfg(not(target_os = "macos"))]
+fn set_native_application_icon() -> Result<(), &'static str> {
+    Ok(())
+}

crates/platform-desktop/src/lib.rs

@@ -2,7 +2,9 @@
 
 use std::path::{Path, PathBuf};
 
+mod app;
 mod media;
+pub use app::set_application_icon;
 pub use media::{MediaCommand, MediaSession};
 
 /// Opens the platform-native directory picker.