Desktop: Buffer web messages until connection is initialized (#3082)

Buffer web messages until connection is initialized

Author: timon-schelling

desktop/src/app.rs

@@ -35,6 +35,8 @@ pub(crate) struct WinitApp {
 	last_ui_update: Instant,
 	avg_frame_time: f32,
 	start_render_sender: SyncSender<()>,
+	web_communication_initialized: bool,
+	web_communication_startup_buffer: Vec<Vec<u8>>,
 }
 
 impl WinitApp {
@@ -61,6 +63,8 @@ impl WinitApp {
 			last_ui_update: Instant::now(),
 			avg_frame_time: 0.,
 			start_render_sender,
+			web_communication_initialized: false,
+			web_communication_startup_buffer: Vec::new(),
 		}
 	}
 
@@ -71,7 +75,7 @@ impl WinitApp {
 					tracing::error!("Failed to serialize frontend messages");
 					return;
 				};
-				self.cef_context.send_web_message(bytes);
+				self.send_or_queue_web_message(bytes);
 			}
 			DesktopFrontendMessage::OpenFileDialog { title, filters, context } => {
 				let event_loop_proxy = self.event_loop_proxy.clone();
@@ -161,6 +165,14 @@ impl WinitApp {
 		let responses = self.desktop_wrapper.dispatch(message);
 		self.handle_desktop_frontend_messages(responses);
 	}
+
+	fn send_or_queue_web_message(&mut self, message: Vec<u8>) {
+		if self.web_communication_initialized {
+			self.cef_context.send_web_message(message);
+		} else {
+			self.web_communication_startup_buffer.push(message);
+		}
+	}
 }
 
 impl ApplicationHandler<CustomEvent> for WinitApp {
@@ -215,6 +227,12 @@ impl ApplicationHandler<CustomEvent> for WinitApp {
 
 	fn user_event(&mut self, _: &ActiveEventLoop, event: CustomEvent) {
 		match event {
+			CustomEvent::WebCommunicationInitialized => {
+				self.web_communication_initialized = true;
+				for message in self.web_communication_startup_buffer.drain(..) {
+					self.cef_context.send_web_message(message);
+				}
+			}
 			CustomEvent::DesktopWrapperMessage(message) => self.dispatch_desktop_wrapper_message(message),
 			CustomEvent::NodeGraphExecutionResult(result) => match result {
 				NodeGraphExecutionResult::HasRun(texture) => {

desktop/src/cef.rs

@@ -46,6 +46,7 @@ pub(crate) trait CefEventHandler: Clone {
 	/// Scheudule the main event loop to run the cef event loop after the timeout
 	///  [`_cef_browser_process_handler_t::on_schedule_message_pump_work`] for more documentation.
 	fn schedule_cef_message_loop_work(&self, scheduled_time: Instant);
+	fn initialized_web_communication(&self);
 	fn receive_web_message(&self, message: &[u8]);
 }
 
@@ -145,6 +146,10 @@ impl CefEventHandler for CefHandler {
 		let _ = self.event_loop_proxy.send_event(CustomEvent::ScheduleBrowserWork(scheduled_time));
 	}
 
+	fn initialized_web_communication(&self) {
+		let _ = self.event_loop_proxy.send_event(CustomEvent::WebCommunicationInitialized);
+	}
+
 	fn receive_web_message(&self, message: &[u8]) {
 		let Some(desktop_wrapper_message) = deserialize_editor_message(message) else {
 			tracing::error!("Failed to deserialize web message");

desktop/src/cef/internal/browser_process_client.rs

@@ -32,6 +32,10 @@ impl<H: CefEventHandler> ImplClient for BrowserProcessClientImpl<H> {
 	) -> ::std::os::raw::c_int {
 		let unpacked_message = unsafe { message.and_then(|m| m.unpack()) };
 		match unpacked_message {
+			Some(UnpackedMessage {
+				message_type: MessageType::Initialized,
+				data: _,
+			}) => self.event_handler.initialized_web_communication(),
 			Some(UnpackedMessage {
 				message_type: MessageType::SendToNative,
 				data,

desktop/src/cef/internal/render_process_handler.rs

@@ -76,24 +76,30 @@ impl ImplRenderProcessHandler for RenderProcessHandlerImpl {
 	}
 
 	fn on_context_created(&self, _browser: Option<&mut cef::Browser>, _frame: Option<&mut cef::Frame>, context: Option<&mut cef::V8Context>) {
-		let function_name = "sendNativeMessage";
+		let register_js_function = |context: &mut cef::V8Context, name: &'static str| {
+			let mut v8_handler = V8Handler::new(BrowserProcessV8HandlerImpl::new());
+			let Some(mut function) = v8_value_create_function(Some(&CefString::from(name)), Some(&mut v8_handler)) else {
+				tracing::error!("Failed to create V8 function {name}");
+				return;
+			};
+
+			let Some(global) = context.global() else {
+				tracing::error!("Global object is not available in V8 context");
+				return;
+			};
+			global.set_value_bykey(Some(&CefString::from(name)), Some(&mut function), V8Propertyattribute::default());
+		};
 
 		let Some(context) = context else {
 			tracing::error!("V8 context is not available");
 			return;
 		};
 
-		let mut v8_handler = V8Handler::new(BrowserProcessV8HandlerImpl::new());
-		let Some(mut function) = v8_value_create_function(Some(&CefString::from(function_name)), Some(&mut v8_handler)) else {
-			tracing::error!("Failed to create V8 function {function_name}");
-			return;
-		};
+		let initialized_function_name = "initializeNativeCommunication";
+		let send_function_name = "sendNativeMessage";
 
-		let Some(global) = context.global() else {
-			tracing::error!("Global object is not available in V8 context");
-			return;
-		};
-		global.set_value_bykey(Some(&CefString::from(function_name)), Some(&mut function), V8Propertyattribute::default());
+		register_js_function(context, initialized_function_name);
+		register_js_function(context, send_function_name);
 	}
 
 	fn get_raw(&self) -> *mut _cef_render_process_handler_t {

desktop/src/cef/internal/render_process_v8_handler.rs

@@ -21,8 +21,11 @@ impl ImplV8Handler for BrowserProcessV8HandlerImpl {
 		_retval: Option<&mut Option<V8Value>>,
 		_exception: Option<&mut cef::CefString>,
 	) -> ::std::os::raw::c_int {
-		if let Some(name) = name {
-			if name.to_string() == "sendNativeMessage" {
+		match name.map(|s| s.to_string()).unwrap_or_default().as_str() {
+			"initializeNativeCommunication" => {
+				v8_context_get_current_context().send_message(MessageType::Initialized, vec![0u8].as_slice());
+			}
+			"sendNativeMessage" => {
 				let Some(args) = arguments else {
 					tracing::error!("No arguments provided to sendNativeMessage");
 					return 0;
@@ -48,6 +51,9 @@ impl ImplV8Handler for BrowserProcessV8HandlerImpl {
 
 				return 1;
 			}
+			name => {
+				tracing::error!("Unknown V8 function called: {}", name);
+			}
 		}
 		1
 	}

desktop/src/cef/ipc.rs

@@ -1,12 +1,17 @@
 use cef::{CefString, Frame, ImplBinaryValue, ImplFrame, ImplListValue, ImplProcessMessage, ImplV8Context, ProcessId, V8Context, sys::cef_process_id_t};
 
 pub(crate) enum MessageType {
+	Initialized,
 	SendToJS,
 	SendToNative,
 }
 impl From<MessageType> for MessageInfo {
 	fn from(val: MessageType) -> Self {
 		match val {
+			MessageType::Initialized => MessageInfo {
+				name: "initialized".to_string(),
+				target: cef_process_id_t::PID_BROWSER.into(),
+			},
 			MessageType::SendToJS => MessageInfo {
 				name: "send_to_js".to_string(),
 				target: cef_process_id_t::PID_RENDERER.into(),
@@ -22,6 +27,7 @@ impl TryFrom<String> for MessageType {
 	type Error = ();
 	fn try_from(value: String) -> Result<Self, Self::Error> {
 		match value.as_str() {
+			"initialized" => Ok(MessageType::Initialized),
 			"send_to_js" => Ok(MessageType::SendToJS),
 			"send_to_native" => Ok(MessageType::SendToNative),
 			_ => Err(()),

desktop/src/main.rs

@@ -21,6 +21,7 @@ use graphite_desktop_wrapper::{NodeGraphExecutionResult, WgpuContext};
 pub(crate) enum CustomEvent {
 	UiUpdate(wgpu::Texture),
 	ScheduleBrowserWork(Instant),
+	WebCommunicationInitialized,
 	DesktopWrapperMessage(DesktopWrapperMessage),
 	NodeGraphExecutionResult(NodeGraphExecutionResult),
 }

frontend/wasm/src/editor_api.rs

@@ -242,6 +242,9 @@ impl EditorHandle {
 
 	#[wasm_bindgen(js_name = initAfterFrontendReady)]
 	pub fn init_after_frontend_ready(&self, platform: String) {
+		#[cfg(feature = "native")]
+		crate::native_communcation::initialize_native_communication();
+
 		// Send initialization messages
 		let platform = match platform.as_str() {
 			"Windows" => Platform::Windows,

frontend/wasm/src/native_communcation.rs

@@ -20,6 +20,17 @@ pub fn receive_native_message(buffer: ArrayBuffer) {
 	}
 }
 
+pub fn initialize_native_communication() {
+	let global = js_sys::global();
+
+	// Get the function by name
+	let func = js_sys::Reflect::get(&global, &JsValue::from_str("initializeNativeCommunication")).expect("Function not found");
+	let func = func.dyn_into::<js_sys::Function>().expect("Not a function");
+
+	// Call it
+	func.call0(&JsValue::NULL).expect("Function call failed");
+}
+
 pub fn send_message_to_cef(message: String) {
 	let global = js_sys::global();