Add a native Nodes switcher and keep the launch screen gated through session handoff

Hop-State: A_06FPGHN5480G5QDY6X262B0
Hop-Proposal: R_06FPGHM5F6DNCB08QXQS5ER
Hop-Task: T_06FPGDYGAF0D1M389636J4G
Hop-Attempt: AT_06FPGDYGAF0KT0QDZXYQS1R

src-tauri/Cargo.lock

@@ -2267,9 +2267,17 @@ checksum = "d49e936b501e5c5bf01fda3a9452ff86dc3ea98ad5f283e1455153142d97518c"
 dependencies = [
  "bitflags 2.13.1",
  "block2",
+ "libc",
  "objc2",
+ "objc2-cloud-kit",
+ "objc2-core-data",
  "objc2-core-foundation",
+ "objc2-core-graphics",
+ "objc2-core-image",
+ "objc2-core-text",
+ "objc2-core-video",
  "objc2-foundation",
+ "objc2-quartz-core",
 ]
 
 [[package]]
@@ -2289,6 +2297,7 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b402a653efbb5e82ce4df10683b6b28027616a2715e90009947d50b8dd298fa"
 dependencies = [
+ "bitflags 2.13.1",
  "objc2",
  "objc2-foundation",
 ]
@@ -2349,6 +2358,19 @@ dependencies = [
  "objc2-core-graphics",
 ]
 
+[[package]]
+name = "objc2-core-video"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d425caf1df73233f29fd8a5c3e5edbc30d2d4307870f802d18f00d83dc5141a6"
+dependencies = [
+ "bitflags 2.13.1",
+ "objc2",
+ "objc2-core-foundation",
+ "objc2-core-graphics",
+ "objc2-io-surface",
+]
+
 [[package]]
 name = "objc2-encode"
 version = "4.1.0"
@@ -3677,6 +3699,9 @@ name = "synapsis-desktop"
 version = "0.1.0"
 dependencies = [
  "http",
+ "objc2",
+ "objc2-app-kit",
+ "objc2-foundation",
  "reqwest 0.12.28",
  "serde",
  "serde_json",

src-tauri/Cargo.toml

@@ -24,5 +24,23 @@ serde_json = "1"
 reqwest = { version = "0.12", features = ["cookies", "json", "rustls-tls"] }
 tauri-plugin-notification = "2"
 
+[target.'cfg(target_os = "macos")'.dependencies]
+objc2 = "0.6"
+objc2-app-kit = { version = "0.3", features = [
+  "NSButton",
+  "NSCell",
+  "NSControl",
+  "NSLayoutConstraint",
+  "NSMenu",
+  "NSMenuItem",
+  "NSPopUpButton",
+  "NSResponder",
+  "NSTitlebarAccessoryViewController",
+  "NSView",
+  "NSViewController",
+  "NSWindow",
+] }
+objc2-foundation = { version = "0.3", features = ["NSArray", "NSString"] }
+
 [dev-dependencies]
 http = "1"

src-tauri/src/lib.rs

@@ -1,5 +1,7 @@
 use reqwest::{Client, Method, StatusCode, Url};
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
+use std::fs;
+use std::path::{Path, PathBuf};
 use std::sync::atomic::{AtomicU64, Ordering};
 use std::sync::Mutex;
 use std::time::Duration;
@@ -10,6 +12,15 @@ struct AppState {
     client: Client,
     notification_capability_sequence: AtomicU64,
     entry_url: Mutex<Option<Url>>,
+    node_registry: Mutex<NodeRegistry>,
+    node_registry_path: Mutex<Option<PathBuf>>,
+}
+
+#[derive(Clone, Debug, Default, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct NodeRegistry {
+    nodes: Vec<String>,
+    active: Option<String>,
 }
 
 #[derive(Debug, Default, Deserialize, Serialize)]
@@ -98,6 +109,56 @@ fn endpoint(base: &Url, path: &str) -> Result<Url, String> {
         .map_err(|_| "The selected node address is invalid.".into())
 }
 
+fn load_node_registry(path: &Path) -> NodeRegistry {
+    fs::read(path)
+        .ok()
+        .and_then(|bytes| serde_json::from_slice(&bytes).ok())
+        .unwrap_or_default()
+}
+
+fn persist_node_registry(state: &AppState, registry: &NodeRegistry) -> Result<(), String> {
+    let path = state
+        .node_registry_path
+        .lock()
+        .map_err(|_| "Couldn’t access the saved node list.".to_string())?
+        .clone();
+    let Some(path) = path else {
+        return Ok(());
+    };
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent)
+            .map_err(|error| format!("Couldn’t save the node list: {error}"))?;
+    }
+    let bytes = serde_json::to_vec_pretty(registry)
+        .map_err(|error| format!("Couldn’t encode the node list: {error}"))?;
+    fs::write(path, bytes).map_err(|error| format!("Couldn’t save the node list: {error}"))
+}
+
+fn remember_node(state: &AppState, node: &Url) -> Result<NodeRegistry, String> {
+    let node_url = node.as_str().to_owned();
+    let snapshot = {
+        let mut registry = state
+            .node_registry
+            .lock()
+            .map_err(|_| "Couldn’t access the saved node list.".to_string())?;
+        registry.nodes.retain(|saved| saved != &node_url);
+        registry.nodes.push(node_url.clone());
+        registry.active = Some(node_url);
+        registry.clone()
+    };
+    persist_node_registry(state, &snapshot)?;
+    Ok(snapshot)
+}
+
+#[tauri::command]
+fn get_saved_nodes(state: State<'_, AppState>) -> Result<NodeRegistry, String> {
+    state
+        .node_registry
+        .lock()
+        .map(|registry| registry.clone())
+        .map_err(|_| "Couldn’t access the saved node list.".to_string())
+}
+
 async fn decode_response<T: DeserializeOwned>(response: reqwest::Response) -> Result<T, String> {
     let status = response.status();
     let bytes = response.bytes().await.map_err(|error| error.to_string())?;
@@ -282,6 +343,13 @@ async fn open_web_app(
             );
         }
     }
+    let registry = remember_node(&state, &base)?;
+    #[cfg(target_os = "macos")]
+    macos_titlebar::install(&webview, &registry)?;
+    navigate_to_node(&state, &webview, &base)
+}
+
+fn navigate_to_node(state: &AppState, webview: &WebviewWindow, base: &Url) -> Result<(), String> {
     let origin = base.origin().ascii_serialization();
     let capability_id = state
         .notification_capability_sequence
@@ -291,7 +359,7 @@ async fn open_web_app(
         .add_capability(capability)
         .map_err(|error| format!("Couldn’t enable native notifications for this node: {error}"))?;
     webview
-        .navigate(base)
+        .navigate(base.clone())
         .map_err(|error| format!("Couldn’t open the Synapsis web app: {error}"))
 }
 
@@ -309,6 +377,145 @@ fn remote_notification_capability(origin: &str, sequence: u64) -> String {
     .to_string()
 }
 
+#[cfg(target_os = "macos")]
+mod macos_titlebar {
+    use super::*;
+    use objc2::rc::Retained;
+    use objc2::runtime::AnyObject;
+    use objc2::{define_class, msg_send, sel, MainThreadOnly};
+    use objc2_app_kit::{
+        NSControlStateValueOn, NSLayoutAttribute, NSMenu, NSMenuItem, NSPopUpButton,
+        NSTitlebarAccessoryViewController, NSView, NSWindow,
+    };
+    use objc2_foundation::{MainThreadMarker, NSObjectProtocol, NSPoint, NSRect, NSSize, NSString};
+    use std::sync::OnceLock;
+
+    static APP_HANDLE: OnceLock<tauri::AppHandle> = OnceLock::new();
+
+    define_class!(
+        #[unsafe(super = NSTitlebarAccessoryViewController)]
+        #[thread_kind = MainThreadOnly]
+        #[ivars = ()]
+        struct NodeTitlebarController;
+
+        impl NodeTitlebarController {
+            #[unsafe(method(selectNode:))]
+            fn select_node(&self, sender: &NSMenuItem) {
+                let Some(value) = sender
+                    .representedObject()
+                    .and_then(|object| object.downcast::<NSString>().ok())
+                    .map(|string| string.to_string())
+                else {
+                    return;
+                };
+                let Some(app) = APP_HANDLE.get() else {
+                    return;
+                };
+                let Some(webview) = app.get_webview_window("main") else {
+                    return;
+                };
+                let state = app.state::<AppState>();
+
+                if value == "__add_node__" {
+                    let Ok(saved_entry_url) = state.entry_url.lock() else {
+                        return;
+                    };
+                    let Some(mut entry_url) = saved_entry_url.clone() else {
+                        return;
+                    };
+                    entry_url.set_query(Some("addNode=1"));
+                    let _ = webview.navigate(entry_url);
+                    return;
+                }
+
+                let Ok(base) = normalize_node(&value) else {
+                    return;
+                };
+                let Ok(registry) = remember_node(&state, &base) else {
+                    return;
+                };
+                let _ = install(&webview, &registry);
+                let _ = navigate_to_node(&state, &webview, &base);
+            }
+        }
+
+        unsafe impl NSObjectProtocol for NodeTitlebarController {}
+    );
+
+    impl NodeTitlebarController {
+        fn new(mtm: MainThreadMarker) -> Retained<Self> {
+            let this = Self::alloc(mtm).set_ivars(());
+            unsafe { msg_send![super(this), init] }
+        }
+    }
+
+    pub fn initialize(app: &tauri::AppHandle) {
+        let _ = APP_HANDLE.set(app.clone());
+    }
+
+    pub fn install(webview: &WebviewWindow, registry: &NodeRegistry) -> Result<(), String> {
+        let mtm = MainThreadMarker::new()
+            .ok_or_else(|| "The node switcher must be created on the main thread.".to_string())?;
+        let controller = NodeTitlebarController::new(mtm);
+        let menu = NSMenu::initWithTitle(NSMenu::alloc(mtm), &NSString::from_str("Nodes"));
+
+        for node_url in &registry.nodes {
+            let Ok(url) = Url::parse(node_url) else {
+                continue;
+            };
+            let title = url.host_str().unwrap_or(node_url);
+            let item = unsafe {
+                menu.addItemWithTitle_action_keyEquivalent(
+                    &NSString::from_str(title),
+                    Some(sel!(selectNode:)),
+                    &NSString::new(),
+                )
+            };
+            unsafe {
+                item.setTarget(Some(&*controller as &AnyObject));
+                item.setRepresentedObject(Some(&*NSString::from_str(node_url) as &AnyObject));
+            }
+            if registry.active.as_deref() == Some(node_url) {
+                item.setState(NSControlStateValueOn);
+            }
+        }
+
+        if !registry.nodes.is_empty() {
+            menu.addItem(&NSMenuItem::separatorItem(mtm));
+        }
+        let add_item = unsafe {
+            menu.addItemWithTitle_action_keyEquivalent(
+                &NSString::from_str("Add Node…"),
+                Some(sel!(selectNode:)),
+                &NSString::new(),
+            )
+        };
+        unsafe {
+            add_item.setTarget(Some(&*controller as &AnyObject));
+            add_item.setRepresentedObject(Some(&*NSString::from_str("__add_node__") as &AnyObject));
+        }
+        let button =
+            NSPopUpButton::pullDownButtonWithTitle_menu(&NSString::from_str("Nodes"), &menu);
+        button.setBordered(false);
+        button.setFrame(NSRect::new(NSPoint::new(0.0, 0.0), NSSize::new(86.0, 28.0)));
+        controller.setView(unsafe { &*(&*button as *const NSPopUpButton as *const NSView) });
+        controller.setLayoutAttribute(NSLayoutAttribute::Right);
+        controller.setAutomaticallyAdjustsSize(false);
+
+        let window = unsafe {
+            let pointer = webview
+                .ns_window()
+                .map_err(|error| format!("Couldn’t access the desktop title bar: {error}"))?;
+            &*(pointer as *const NSWindow)
+        };
+        while window.titlebarAccessoryViewControllers().count() > 0 {
+            window.removeTitlebarAccessoryViewControllerAtIndex(0);
+        }
+        window.addTitlebarAccessoryViewController(&controller);
+        Ok(())
+    }
+}
+
 #[tauri::command]
 async fn logout(state: State<'_, AppState>, node_url: String) -> Result<(), String> {
     let base = normalize_node(&node_url)?;
@@ -341,6 +548,41 @@ pub fn run() {
             client,
             notification_capability_sequence: AtomicU64::new(0),
             entry_url: Mutex::new(None),
+            node_registry: Mutex::new(NodeRegistry::default()),
+            node_registry_path: Mutex::new(None),
+        })
+        .setup(|app| {
+            let webview = app
+                .get_webview_window("main")
+                .ok_or_else(|| "Couldn’t find the main Synapsis window.".to_string())?;
+            let registry_path = app
+                .path()
+                .app_data_dir()
+                .map_err(|error| format!("Couldn’t find the app data folder: {error}"))?
+                .join("nodes.json");
+            let registry = load_node_registry(&registry_path);
+            let state = app.state::<AppState>();
+            *state
+                .entry_url
+                .lock()
+                .map_err(|_| "Couldn’t remember the app entry screen.".to_string())? =
+                Some(webview.url()?);
+            *state
+                .node_registry_path
+                .lock()
+                .map_err(|_| "Couldn’t prepare the saved node list.".to_string())? =
+                Some(registry_path);
+            *state
+                .node_registry
+                .lock()
+                .map_err(|_| "Couldn’t prepare the saved node list.".to_string())? =
+                registry.clone();
+            #[cfg(target_os = "macos")]
+            {
+                macos_titlebar::initialize(app.handle());
+                macos_titlebar::install(&webview, &registry)?;
+            }
+            Ok(())
         })
         .on_page_load(|webview, payload| {
             if payload.event() != PageLoadEvent::Finished
@@ -390,7 +632,8 @@ pub fn run() {
             register,
             logout,
             has_web_session,
-            open_web_app
+            open_web_app,
+            get_saved_nodes
         ])
         .run(tauri::generate_context!())
         .expect("error while running Synapsis");

src/App.tsx

@@ -27,6 +27,7 @@ type Connection = {
 };
 
 type AuthResponse = { user: User };
+type NodeRegistry = { nodes: string[]; active?: string };
 
 const DEFAULT_NODE = "synapsis.social";
 const SAVED_NODE_KEY = "synapsis.nodeUrl";
@@ -246,25 +247,29 @@ function App() {
 
   useEffect(() => {
     const launchParams = new URLSearchParams(window.location.search);
-    if (launchParams.has("signedOut")) {
-      localStorage.removeItem(SAVED_NODE_KEY);
+    if (launchParams.has("signedOut") || launchParams.has("addNode")) {
+      if (launchParams.has("signedOut")) localStorage.removeItem(SAVED_NODE_KEY);
       window.history.replaceState({}, "", window.location.pathname);
       setScreen("node");
       setBootstrapping(false);
       return;
     }
 
-    const savedNode = localStorage.getItem(SAVED_NODE_KEY);
-    if (!savedNode || !isTauri()) {
+    if (!isTauri()) {
       setBootstrapping(false);
       return;
     }
-    const savedNodeUrl = savedNode;
+
     async function restore() {
+      let handedOffToWebApp = false;
       try {
+        const registry = await invoke<NodeRegistry>("get_saved_nodes");
+        const savedNodeUrl = registry.active || localStorage.getItem(SAVED_NODE_KEY);
+        if (!savedNodeUrl) return;
         const hasWebSession = await invoke<boolean>("has_web_session", { nodeUrl: savedNodeUrl });
         if (hasWebSession) {
           await openNodeWebApp(savedNodeUrl);
+          handedOffToWebApp = true;
           return;
         }
 
@@ -275,13 +280,14 @@ function App() {
         setUser(connection.user);
         if (connection.user) {
           await openNodeWebApp(connection.nodeUrl);
+          handedOffToWebApp = true;
         } else {
           setScreen("login");
         }
       } catch {
         setScreen("node");
       } finally {
-        setBootstrapping(false);
+        if (!handedOffToWebApp) setBootstrapping(false);
       }
     }
     void restore();