From 8184c0488859bdfcdda4aa88efa46acccd9c204c Mon Sep 17 00:00:00 2001
From: Julian Oes <julian@oes.ch>
Date: Fri, 3 Nov 2023 13:45:05 +1300
Subject: [PATCH] param_server: add subscription for changed params

Signed-off-by: Julian Oes <julian@oes.ch>
---
 protos/param_server/param_server.proto | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/protos/param_server/param_server.proto b/protos/param_server/param_server.proto
index 0790d7320..b44c1d958 100644
--- a/protos/param_server/param_server.proto
+++ b/protos/param_server/param_server.proto
@@ -49,6 +49,15 @@ service ParamServerService {
      * Retrieve all parameters.
      */
     rpc RetrieveAllParams(RetrieveAllParamsRequest) returns(RetrieveAllParamsResponse) { option (mavsdk.options.async_type) = SYNC; }
+
+    // Subscribe to changed int param.
+    rpc SubscribeChangedParamInt(SubscribeChangedParamIntRequest) returns(stream ChangedParamIntResponse) { option (mavsdk.options.async_type) = ASYNC; }
+
+    // Subscribe to changed float param.
+    rpc SubscribeChangedParamFloat(SubscribeChangedParamFloatRequest) returns(stream ChangedParamFloatResponse) { option (mavsdk.options.async_type) = ASYNC; }
+
+    // Subscribe to changed custom param.
+    rpc SubscribeChangedParamCustom(SubscribeChangedParamCustomRequest) returns(stream ChangedParamCustomResponse) { option (mavsdk.options.async_type) = ASYNC; }
 }
 
 message RetrieveParamIntRequest {
@@ -108,6 +117,21 @@ message RetrieveAllParamsResponse {
     AllParams params = 1; // Collection of all parameters
 }
 
+message SubscribeChangedParamIntRequest {}
+message ChangedParamIntResponse {
+    IntParam param = 1; // Param that changed
+}
+
+message SubscribeChangedParamFloatRequest {}
+message ChangedParamFloatResponse {
+    FloatParam param = 1; // Param that changed
+}
+
+message SubscribeChangedParamCustomRequest {}
+message ChangedParamCustomResponse {
+    CustomParam param = 1; // Param that changed
+}
+
 /*
  * Type for integer parameters.
  */