Support QoS override parameters in depth_image_proc/register (backport …

…#1043) (#1044)

This PR adds support to the `depth_image_proc` - `register` node for
setting External QoS Configuration on topic _subscriptions_.

Signed-off-by: Alejandro Hernández Cordero <[email protected]>
Co-authored-by: Stuart Alldritt <[email protected]>
Co-authored-by: Alejandro Hernández Cordero <[email protected]>

depth_image_proc/src/register.cpp

@@ -133,14 +133,21 @@ RegisterNode::RegisterNode(const rclcpp::NodeOptions & options)
         sub_depth_info_.unsubscribe();
         sub_rgb_info_.unsubscribe();
       } else if (!sub_depth_image_.getSubscriber()) {
+        // Allow overriding QoS settings (history, depth, reliability)
+        rclcpp::SubscriptionOptions sub_options;
+        sub_options.qos_overriding_options = rclcpp::QosOverridingOptions::with_default_policies();
+
         // For compressed topics to remap appropriately, we need to pass a
         // fully expanded and remapped topic name to image_transport
         auto node_base = this->get_node_base_interface();
         std::string topic = node_base->resolve_topic_or_service_name("depth/image_rect", false);
         image_transport::TransportHints hints(this, "raw", "depth_image_transport");
-        sub_depth_image_.subscribe(this, topic, hints.getTransport());
-        sub_depth_info_.subscribe(this, "depth/camera_info");
-        sub_rgb_info_.subscribe(this, "rgb/camera_info");
+        sub_depth_image_.subscribe(this, topic, hints.getTransport(), rmw_qos_profile_default,
+          sub_options);
+        auto qos = rmw_qos_profile_default;
+        qos.depth = 10;
+        sub_depth_info_.subscribe(this, "depth/camera_info", qos, sub_options);
+        sub_rgb_info_.subscribe(this, "rgb/camera_info", qos, sub_options);
       }
     };
   // For compressed topics to remap appropriately, we need to pass a