fix: set default steering angle to N/A when not received and check for msg_ptr instead of float value

Signed-off-by: KhalilSelyan <khalil@leodrive.ai>

Author: KhalilSelyan

Diff for: common/autoware_overlay_rviz_plugin/autoware_overlay_rviz_plugin/include/steering_wheel_display.hpp

@@ -47,6 +47,7 @@ class SteeringWheelDisplay
   QImage wheelImage;
   QImage scaledWheelImage;
   QImage coloredImage(const QImage & source, const QColor & color);
+  autoware_vehicle_msgs::msg::SteeringReport::ConstSharedPtr last_msg_ptr_;
 };
 
 }  // namespace autoware_overlay_rviz_plugin

Diff for: common/autoware_overlay_rviz_plugin/autoware_overlay_rviz_plugin/src/steering_wheel_display.cpp

@@ -59,6 +59,8 @@ void SteeringWheelDisplay::updateSteeringData(
   const autoware_vehicle_msgs::msg::SteeringReport::ConstSharedPtr & msg)
 {
   try {
+    last_msg_ptr_ = msg;
+
     steering_angle_ = msg->steering_tire_angle;
   } catch (const std::exception & e) {
     // Log the error
@@ -96,11 +98,11 @@ void SteeringWheelDisplay::drawSteeringWheel(
   painter.drawImage(drawPoint.x(), drawPoint.y(), rotatedWheel);
 
   std::ostringstream steering_angle_ss;
-  if (steering_angle_) {
+  if (last_msg_ptr_) {
     steering_angle_ss << std::fixed << std::setprecision(1) << steering_angle_ * 180.0 / M_PI
                       << "°";
   } else {
-    steering_angle_ss << "0.0°";
+    steering_angle_ss << "N/A";
   }
 
   QString steeringAngleString = QString::fromStdString(steering_angle_ss.str());