Scaffold signals

api/lua/pinnacle/grpc/client.lua

@@ -162,4 +162,10 @@ function client.server_streaming_request(grpc_request_params, callback)
     end)
 end
 
+---@param grpc_request_params GrpcRequestParams
+---@param callback fun(response: table)
+---
+---@return H2Stream
+function client.bidirectional_streaming_request(grpc_request_params, callback) end
+
 return client

api/protocol/pinnacle/signal/v0alpha1/signal.proto

@@ -0,0 +1,53 @@
+syntax = "proto2";
+
+package pinnacle.signal.v0alpha1;
+
+import "google/protobuf/empty.proto";
+
+enum StreamControl {
+  STREAM_CONTROL_UNSPECIFIED = 0;
+  // The client is ready to receive the next signal.
+  STREAM_CONTROL_READY = 1;
+  // The client wishes to disconnect a signal connection.
+  STREAM_CONTROL_DISCONNECT = 2;
+}
+
+message OutputConnectRequest {
+  optional StreamControl control = 1;
+}
+message OutputConnectResponse {
+  optional string output_name = 1;
+}
+
+message LayoutRequest {
+  optional StreamControl control = 1;
+}
+message LayoutResponse {
+  // The windows that need to be laid out.
+  repeated uint32 window_ids = 1;
+  // The tag that is being laid out.
+  optional uint32 tag_id = 2;
+}
+
+message WindowPointerEnterRequest {
+  optional StreamControl control = 1;
+}
+message WindowPointerEnterResponse {
+  // The window that the pointer entered.
+  optional uint32 window_id = 1;
+}
+
+message WindowPointerLeaveRequest {
+  optional StreamControl control = 1;
+}
+message WindowPointerLeaveResponse {
+  // The window that the pointer left.
+  optional uint32 window_id = 1;
+}
+
+service SignalService {
+  rpc OutputConnect(stream OutputConnectRequest) returns (stream OutputConnectResponse);
+  rpc Layout(stream LayoutRequest) returns (stream LayoutResponse);
+  rpc WindowPointerEnter(stream WindowPointerEnterRequest) returns (stream WindowPointerEnterResponse);
+  rpc WindowPointerLeave(stream WindowPointerLeaveRequest) returns (stream WindowPointerLeaveResponse);
+}

pinnacle-api-defs/build.rs

@@ -13,6 +13,7 @@ fn main() {
         formatcp!("../api/protocol/pinnacle/process/{VERSION}/process.proto"),
         formatcp!("../api/protocol/pinnacle/tag/{VERSION}/tag.proto"),
         formatcp!("../api/protocol/pinnacle/window/{VERSION}/window.proto"),
+        formatcp!("../api/protocol/pinnacle/signal/{VERSION}/signal.proto"),
     ];
 
     let descriptor_path = PathBuf::from(std::env::var("OUT_DIR").unwrap()).join("pinnacle.bin");

pinnacle-api-defs/src/lib.rs

@@ -33,6 +33,12 @@ pub mod pinnacle {
             tonic::include_proto!("pinnacle.process.v0alpha1");
         }
     }
+
+    pub mod signal {
+        pub mod v0alpha1 {
+            tonic::include_proto!("pinnacle.signal.v0alpha1");
+        }
+    }
 }
 
 pub const FILE_DESCRIPTOR_SET: &[u8] = tonic::include_file_descriptor_set!("pinnacle");

src/api.rs

@@ -1,3 +1,5 @@
+pub mod signal;
+
 use std::{ffi::OsString, num::NonZeroU32, pin::Pin, process::Stdio};
 
 use pinnacle_api_defs::pinnacle::{
@@ -45,8 +47,8 @@ use tokio::{
     io::AsyncBufReadExt,
     sync::mpsc::{unbounded_channel, UnboundedSender},
 };
-use tokio_stream::Stream;
-use tonic::{Request, Response, Status};
+use tokio_stream::{Stream, StreamExt};
+use tonic::{Request, Response, Status, Streaming};
 
 use crate::{
     config::ConnectorSavedState,
@@ -58,6 +60,8 @@ use crate::{
     window::{window_state::WindowId, WindowElement},
 };
 
+use self::signal::SignalData;
+
 type ResponseStream<T> = Pin<Box<dyn Stream<Item = Result<T, Status>> + Send>>;
 pub type StateFnSender = calloop::channel::Sender<Box<dyn FnOnce(&mut State) + Send>>;
 
@@ -122,6 +126,44 @@ where
     Ok(Response::new(Box::pin(receiver_stream)))
 }
 
+fn run_bidirectional_streaming<F1, F2, I, O>(
+    fn_sender: StateFnSender,
+    mut in_stream: Streaming<I>,
+    with_client_item: F1,
+    with_out_stream: F2,
+) -> Result<Response<ResponseStream<O>>, Status>
+where
+    F1: Fn(&mut State, Result<I, Status>) + Clone + Send + 'static,
+    F2: FnOnce(&mut State, UnboundedSender<Result<O, Status>>) + Send + 'static,
+    I: Send + 'static,
+    O: Send + 'static,
+{
+    let (sender, receiver) = unbounded_channel::<Result<O, Status>>();
+
+    let with_out_stream = Box::new(|state: &mut State| {
+        with_out_stream(state, sender);
+    });
+
+    fn_sender
+        .send(with_out_stream)
+        .map_err(|_| Status::internal("failed to execute request"))?;
+
+    let with_in_stream = async move {
+        while let Some(t) = in_stream.next().await {
+            let with_client_item = with_client_item.clone();
+            // TODO: handle error
+            let _ = fn_sender.send(Box::new(move |state: &mut State| {
+                with_client_item(state, t);
+            }));
+        }
+    };
+
+    tokio::spawn(with_in_stream);
+
+    let receiver_stream = tokio_stream::wrappers::UnboundedReceiverStream::new(receiver);
+    Ok(Response::new(Box::pin(receiver_stream)))
+}
+
 pub struct PinnacleService {
     sender: StateFnSender,
 }

src/api/signal.rs

@@ -0,0 +1,188 @@
+use pinnacle_api_defs::pinnacle::signal::v0alpha1::{
+    signal_service_server, LayoutRequest, LayoutResponse, OutputConnectRequest,
+    OutputConnectResponse, StreamControl, WindowPointerEnterRequest, WindowPointerEnterResponse,
+    WindowPointerLeaveRequest, WindowPointerLeaveResponse,
+};
+use tokio::sync::mpsc::UnboundedSender;
+use tonic::{Request, Response, Status, Streaming};
+
+use crate::state::State;
+
+use super::{run_bidirectional_streaming, ResponseStream, StateFnSender};
+
+#[derive(Debug, Default)]
+pub struct SignalState {
+    pub output_connect: SignalData<OutputConnectResponse>,
+    pub layout: SignalData<LayoutResponse>,
+    pub window_pointer_enter: SignalData<WindowPointerEnterResponse>,
+    pub window_pointer_leave: SignalData<WindowPointerLeaveResponse>,
+}
+
+#[derive(Debug, Default)]
+pub struct SignalData<T> {
+    sender: Option<UnboundedSender<Result<T, Status>>>,
+    ready: bool,
+    value: Option<T>,
+}
+
+impl<T> SignalData<T> {
+    pub fn signal(&mut self, with_data: impl FnOnce(Option<T>) -> T) {
+        let Some(sender) = self.sender.as_ref() else {
+            return;
+        };
+
+        if self.ready {
+            sender
+                .send(Ok(with_data(self.value.take())))
+                .expect("failed to send signal");
+            self.ready = false;
+        } else {
+            self.value = Some(with_data(self.value.take()));
+        }
+    }
+
+    pub fn connect(&mut self, sender: UnboundedSender<Result<T, Status>>) {
+        self.sender.replace(sender);
+    }
+
+    fn disconnect(&mut self) {
+        self.sender.take();
+        self.ready = false;
+        self.value.take();
+    }
+
+    fn ready(&mut self) {
+        let Some(sender) = self.sender.as_ref() else {
+            return;
+        };
+
+        if let Some(value) = self.value.take() {
+            sender.send(Ok(value)).expect("failed to send signal");
+            self.ready = false;
+        } else {
+            self.ready = true;
+        }
+    }
+}
+
+trait SignalRequest {
+    fn control(&self) -> StreamControl;
+}
+
+macro_rules! impl_signal_request {
+    ( $( $request:ident ),* ) => {
+        $(
+            impl SignalRequest for $request {
+                fn control(&self) -> StreamControl {
+                    self.control()
+                }
+            }
+        )*
+    };
+}
+
+impl_signal_request!(
+    OutputConnectRequest,
+    LayoutRequest,
+    WindowPointerEnterRequest,
+    WindowPointerLeaveRequest
+);
+
+fn start_signal_stream<I: SignalRequest, O>(
+    sender: StateFnSender,
+    in_stream: Streaming<I>,
+    signal: impl Fn(&mut State) -> &mut SignalData<O> + Clone + Send + 'static,
+) -> Result<Response<ResponseStream<O>>, Status>
+where
+    I: Send + 'static,
+    O: Send + 'static,
+{
+    let signal_clone = signal.clone();
+
+    run_bidirectional_streaming(
+        sender,
+        in_stream,
+        move |state, request| {
+            let request = match request {
+                Ok(request) => request,
+                Err(status) => {
+                    tracing::error!("Error in output_connect signal in stream: {status}");
+                    return;
+                }
+            };
+
+            let signal = signal(state);
+            match request.control() {
+                StreamControl::Ready => signal.ready(),
+                StreamControl::Disconnect => signal.disconnect(),
+                StreamControl::Unspecified => tracing::warn!("Received unspecified stream control"),
+            }
+        },
+        move |state, sender| {
+            let signal = signal_clone(state);
+            signal.connect(sender);
+        },
+    )
+}
+
+pub struct SignalService {
+    sender: StateFnSender,
+}
+
+impl SignalService {
+    pub fn new(sender: StateFnSender) -> Self {
+        Self { sender }
+    }
+}
+
+#[tonic::async_trait]
+impl signal_service_server::SignalService for SignalService {
+    type OutputConnectStream = ResponseStream<OutputConnectResponse>;
+    type LayoutStream = ResponseStream<LayoutResponse>;
+    type WindowPointerEnterStream = ResponseStream<WindowPointerEnterResponse>;
+    type WindowPointerLeaveStream = ResponseStream<WindowPointerLeaveResponse>;
+
+    async fn output_connect(
+        &self,
+        request: Request<Streaming<OutputConnectRequest>>,
+    ) -> Result<Response<Self::OutputConnectStream>, Status> {
+        let in_stream = request.into_inner();
+
+        start_signal_stream(self.sender.clone(), in_stream, |state| {
+            &mut state.signal_state.output_connect
+        })
+    }
+
+    async fn layout(
+        &self,
+        request: Request<Streaming<LayoutRequest>>,
+    ) -> Result<Response<Self::LayoutStream>, Status> {
+        let in_stream = request.into_inner();
+
+        start_signal_stream(self.sender.clone(), in_stream, |state| {
+            &mut state.signal_state.layout
+        })
+    }
+
+    async fn window_pointer_enter(
+        &self,
+        request: Request<Streaming<WindowPointerEnterRequest>>,
+    ) -> Result<Response<Self::WindowPointerEnterStream>, Status> {
+        let in_stream = request.into_inner();
+
+        start_signal_stream(self.sender.clone(), in_stream, |state| {
+            &mut state.signal_state.window_pointer_enter
+        })
+    }
+
+    async fn window_pointer_leave(
+        &self,
+        request: Request<Streaming<WindowPointerLeaveRequest>>,
+    ) -> Result<Response<Self::WindowPointerLeaveStream>, Status> {
+        let in_stream = request.into_inner();
+
+        start_signal_stream(self.sender.clone(), in_stream, |state| {
+            &mut state.signal_state.window_pointer_leave
+        })
+    }
+}

src/config.rs

@@ -1,6 +1,7 @@
 use crate::{
     api::{
-        InputService, OutputService, PinnacleService, ProcessService, TagService, WindowService,
+        signal::SignalService, InputService, OutputService, PinnacleService, ProcessService,
+        TagService, WindowService,
     },
     input::ModifierMask,
     output::OutputName,
@@ -18,6 +19,7 @@ use pinnacle_api_defs::pinnacle::{
     input::v0alpha1::input_service_server::InputServiceServer,
     output::v0alpha1::{output_service_server::OutputServiceServer, ConnectForAllResponse},
     process::v0alpha1::process_service_server::ProcessServiceServer,
+    signal::v0alpha1::signal_service_server::SignalServiceServer,
     tag::v0alpha1::tag_service_server::TagServiceServer,
     v0alpha1::pinnacle_service_server::PinnacleServiceServer,
     window::v0alpha1::window_service_server::WindowServiceServer,
@@ -447,6 +449,7 @@ impl State {
         let tag_service = TagService::new(grpc_sender.clone());
         let output_service = OutputService::new(grpc_sender.clone());
         let window_service = WindowService::new(grpc_sender.clone());
+        let signal_service = SignalService::new(grpc_sender.clone());
 
         let refl_service = tonic_reflection::server::Builder::configure()
             .register_encoded_file_descriptor_set(pinnacle_api_defs::FILE_DESCRIPTOR_SET)
@@ -464,7 +467,8 @@ impl State {
             .add_service(ProcessServiceServer::new(process_service))
             .add_service(TagServiceServer::new(tag_service))
             .add_service(OutputServiceServer::new(output_service))
-            .add_service(WindowServiceServer::new(window_service));
+            .add_service(WindowServiceServer::new(window_service))
+            .add_service(SignalServiceServer::new(signal_service));
 
         match self.xdisplay.as_ref() {
             Some(_) => {

src/state.rs

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 use crate::{
-    backend::Backend, config::Config, cursor::Cursor, focus::FocusState,
+    api::signal::SignalState, backend::Backend, config::Config, cursor::Cursor, focus::FocusState,
     grab::resize_grab::ResizeSurfaceState, window::WindowElement,
 };
 use anyhow::Context;
@@ -93,6 +93,8 @@ pub struct State {
     pub grpc_server_join_handle: Option<tokio::task::JoinHandle<()>>,
 
     pub xdg_base_dirs: BaseDirectories,
+
+    pub signal_state: SignalState,
 }
 
 impl State {
@@ -269,6 +271,8 @@ impl State {
 
             xdg_base_dirs: BaseDirectories::with_prefix("pinnacle")
                 .context("couldn't create xdg BaseDirectories")?,
+
+            signal_state: SignalState::default(),
         };
 
         Ok(state)