add code to deprecate barcode topic

Signed-off-by: Kenji Brameld <kenjibrameld@gmail.com>

README.md

@@ -37,7 +37,8 @@ Subscriptions:
 * `image` (`sensor_msgs/msg/Image.msg`)
 
 Publisher:
-* `barcode` (`zbar_ros_interfaces/msg/Symbol`)
+* `barcode` (`std_msgs/msg/String`) - **DEPRECATED**
+* `symbol` (`zbar_ros_interfaces/msg/Symbol`)
 
 
 ### (Optional) Debugging the barcode_reader node

zbar_ros/include/zbar_ros/barcode_reader_node.hpp

@@ -37,6 +37,7 @@
 #include "rclcpp/timer.hpp"
 #include "./zbar.h"
 #include "sensor_msgs/msg/image.hpp"
+#include "std_msgs/msg/string.hpp"
 #include "zbar_ros_interfaces/msg/symbol.hpp"
 
 namespace zbar_ros
@@ -52,7 +53,8 @@ class BarcodeReaderNode : public rclcpp::Node
  void cleanCb();
 
  rclcpp::Subscription<sensor_msgs::msg::Image>::SharedPtr camera_sub_;
- rclcpp::Publisher<zbar_ros_interfaces::msg::Symbol>::SharedPtr barcode_pub_;
+ rclcpp::Publisher<std_msgs::msg::String>::SharedPtr barcode_pub_; // DEPRECATED
+ rclcpp::Publisher<zbar_ros_interfaces::msg::Symbol>::SharedPtr symbol_pub_;
  zbar::ImageScanner scanner_;
 
  rclcpp::TimerBase::SharedPtr clean_timer_;

zbar_ros/package.xml

@@ -15,6 +15,7 @@
  <depend>zbar</depend>
  <depend>cv_bridge</depend>
  <depend>sensor_msgs</depend>
+ <depend>std_msgs</depend>
  <depend>zbar_ros_interfaces</depend>
 
  <test_depend>ament_lint_auto</test_depend>

zbar_ros/src/barcode_reader_node.cpp

@@ -44,12 +44,11 @@ BarcodeReaderNode::BarcodeReaderNode()
 {
  scanner_.set_config(zbar::ZBAR_NONE, zbar::ZBAR_CFG_ENABLE, 1);
 
-
  camera_sub_ = this->create_subscription<sensor_msgs::msg::Image>(
  "image", 10, std::bind(&BarcodeReaderNode::imageCb, this, std::placeholders::_1));
 
  barcode_pub_ = this->create_publisher<std_msgs::msg::String>("barcode", 10);
- barcode_pub_ = this->create_publisher<zbar_ros_interfaces::msg::Symbol>("symbol", 10);
+ symbol_pub_ = this->create_publisher<zbar_ros_interfaces::msg::Symbol>("symbol", 10);
 
  throttle_ = this->declare_parameter<double>("throttle_repeated_barcodes", 0.0);
  RCLCPP_DEBUG(get_logger(), "throttle_repeated_barcodes : %f", throttle_);
@@ -77,7 +76,6 @@ void BarcodeReaderNode::imageCb(sensor_msgs::msg::Image::ConstSharedPtr image)
  // If there are barcodes in the image, iterate over all barcode readings from image
  for (zbar::Image::SymbolIterator symbol_it = it_start; symbol_it != it_end; ++symbol_it) {
  zbar_ros_interfaces::msg::Symbol symbol;
-
  symbol.data = symbol_it->get_data();
  RCLCPP_DEBUG(get_logger(), "Barcode detected with data: '%s'", symbol.data.c_str());
 
@@ -98,6 +96,7 @@ void BarcodeReaderNode::imageCb(sensor_msgs::msg::Image::ConstSharedPtr image)
  if (throttle_ > 0.0) {
  const std::lock_guard<std::mutex> lock(memory_mutex_);
 
+ std::string barcode = symbol.data;
  // check if barcode has been recorded as seen, and skip detection
  if (barcode_memory_.count(barcode) > 0) {
  // check if time reached to forget barcode
@@ -119,17 +118,26 @@ void BarcodeReaderNode::imageCb(sensor_msgs::msg::Image::ConstSharedPtr image)
  // publish barcode
  RCLCPP_DEBUG(get_logger(), "Publishing data as string");
  std_msgs::msg::String barcode_string;
- barcode_string.data = barcode;
+ barcode_string.data = symbol.data;
  barcode_pub_->publish(barcode_string);
 
  // publish symbol
  RCLCPP_DEBUG(get_logger(), "Publishing Symbol");
- barcode_pub_->publish(symbol);
+ symbol_pub_->publish(symbol);
  }
  } else {
  RCLCPP_DEBUG(get_logger(), "No barcode detected in image");
  }
 
+ // Warn if there are subscriptions on barcode topic, because it's deprecated.
+ static bool alreadyWarnedDeprecation = false;
+ if (!alreadyWarnedDeprecation && count_subscribers("barcode") > 0) {
+ alreadyWarnedDeprecation = true;
+ RCLCPP_WARN(get_logger(), "A subscription was detected on the deprecated 'barcode'"
+ "topic. Please subscribe to the new 'symbol' topic with type"
+ "'zbar_ros_interfaces::msg::Symbol'.");
+ }
+
  zbar_image.set_data(NULL, 0);
 }
 

zbar_ros_interfaces/msg/Symbol.msg

@@ -1,2 +1,2 @@
 string data
-geometry_msgs/Point[] points
+geometry_msgs/Point[] points