From d8871078ffdded97036c65c092b3d064c0283f56 Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Mon, 21 May 2018 22:34:22 +1000
Subject: [PATCH] GCS_MAVLink: create persist_streamrates() callback to
 indicate persistence

Removes the catching of the message in each vehicle separately.
---
 libraries/GCS_MAVLink/GCS.h          | 3 ++-
 libraries/GCS_MAVLink/GCS_Common.cpp | 4 ++++
 libraries/GCS_MAVLink/GCS_Param.cpp  | 6 +++---
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/libraries/GCS_MAVLink/GCS.h b/libraries/GCS_MAVLink/GCS.h
index 4c897b4d6e..e87dd34b68 100644
--- a/libraries/GCS_MAVLink/GCS.h
+++ b/libraries/GCS_MAVLink/GCS.h
@@ -278,7 +278,8 @@ protected:
     // saveable rate of each stream
     AP_Int16        streamRates[NUM_STREAMS];
 
-    void handle_request_data_stream(mavlink_message_t *msg, bool save);
+    virtual bool persist_streamrates() const { return false; }
+    void handle_request_data_stream(mavlink_message_t *msg);
 
     virtual void handle_command_ack(const mavlink_message_t* msg);
     void handle_set_mode(mavlink_message_t* msg);
diff --git a/libraries/GCS_MAVLink/GCS_Common.cpp b/libraries/GCS_MAVLink/GCS_Common.cpp
index 6ef9f131c0..ba6abae538 100644
--- a/libraries/GCS_MAVLink/GCS_Common.cpp
+++ b/libraries/GCS_MAVLink/GCS_Common.cpp
@@ -2349,6 +2349,10 @@ void GCS_MAVLINK::handle_common_message(mavlink_message_t *msg)
         handle_common_rally_message(msg);
         break;
 
+    case MAVLINK_MSG_ID_REQUEST_DATA_STREAM:
+        handle_request_data_stream(msg);
+        break;
+
     case MAVLINK_MSG_ID_DATA96:
         handle_data_packet(msg);
         break;        
diff --git a/libraries/GCS_MAVLink/GCS_Param.cpp b/libraries/GCS_MAVLink/GCS_Param.cpp
index b54103d26a..884b3c0311 100644
--- a/libraries/GCS_MAVLink/GCS_Param.cpp
+++ b/libraries/GCS_MAVLink/GCS_Param.cpp
@@ -124,7 +124,7 @@ bool GCS_MAVLINK::have_flow_control(void)
   save==false so we don't want the save to happen when the user connects the
   ground station.
  */
-void GCS_MAVLINK::handle_request_data_stream(mavlink_message_t *msg, bool save)
+void GCS_MAVLINK::handle_request_data_stream(mavlink_message_t *msg)
 {
     mavlink_request_data_stream_t packet;
     mavlink_msg_request_data_stream_decode(msg, &packet);
@@ -143,7 +143,7 @@ void GCS_MAVLINK::handle_request_data_stream(mavlink_message_t *msg, bool save)
     case MAV_DATA_STREAM_ALL:
         // note that we don't set STREAM_PARAMS - that is internal only
         for (uint8_t i=0; i<STREAM_PARAMS; i++) {
-            if (save) {
+            if (persist_streamrates()) {
                 streamRates[i].set_and_save_ifchanged(freq);
             } else {
                 streamRates[i].set(freq);
@@ -177,7 +177,7 @@ void GCS_MAVLINK::handle_request_data_stream(mavlink_message_t *msg, bool save)
     }
 
     if (rate != nullptr) {
-        if (save) {
+        if (persist_streamrates()) {
             rate->set_and_save_ifchanged(freq);
         } else {
             rate->set(freq);