GCS_MAVLINK: move sending of optical flow status up to base class

libraries/GCS_MAVLink/GCS.h

@@ -183,7 +183,7 @@ public:
     void send_ahrs();
     void send_battery2();
 #if AP_AHRS_NAVEKF_AVAILABLE
-    void send_opticalflow(const OpticalFlow &optflow);
+    void send_opticalflow();
 #endif
     virtual void send_attitude() const;
     void send_autopilot_version() const;

libraries/GCS_MAVLink/GCS_Common.cpp

@@ -1481,16 +1481,19 @@ MAV_RESULT GCS_MAVLINK::_set_mode_common(const MAV_MODE _base_mode, const uint32
 /*
   send OPTICAL_FLOW message
  */
-void GCS_MAVLINK::send_opticalflow(const OpticalFlow &optflow)
+void GCS_MAVLINK::send_opticalflow()
 {
+    const OpticalFlow *optflow = AP::opticalflow();
+
     // exit immediately if no optical flow sensor or not healthy
-    if (!optflow.healthy()) {
+    if (optflow == nullptr ||
+        !optflow->healthy()) {
         return;
     }
 
     // get rates from sensor
-    const Vector2f &flowRate = optflow.flowRate();
-    const Vector2f &bodyRate = optflow.bodyRate();
+    const Vector2f &flowRate = optflow->flowRate();
+    const Vector2f &bodyRate = optflow->bodyRate();
 
     const AP_AHRS &ahrs = AP::ahrs();
     float hagl = 0;
@@ -1509,7 +1512,7 @@ void GCS_MAVLINK::send_opticalflow(const OpticalFlow &optflow)
         flowRate.y,
         bodyRate.x,
         bodyRate.y,
-        optflow.quality(),
+        optflow->quality(),
         hagl,  // ground distance (in meters) set to zero
         flowRate.x,
         flowRate.y);
@@ -3203,6 +3206,11 @@ bool GCS_MAVLINK::try_send_message(const enum ap_message id)
         send_mount_status();
         break;
 
+    case MSG_OPTICAL_FLOW:
+        CHECK_PAYLOAD_SIZE(OPTICAL_FLOW);
+        send_opticalflow();
+        break;
+
     case MSG_POSITION_TARGET_GLOBAL_INT:
         CHECK_PAYLOAD_SIZE(POSITION_TARGET_GLOBAL_INT);
         send_position_target_global_int();