From 9babaeaa6a7b8daef5e7773c0191d5530d176c8f Mon Sep 17 00:00:00 2001
From: Kenji Brameld <kenjibrameld@gmail.com>
Date: Sun, 21 Aug 2022 07:16:32 +0900
Subject: [PATCH] add code to deprecate barcode topic

Signed-off-by: Kenji Brameld <kenjibrameld@gmail.com>
---
 README.md                                      |  3 ++-
 .../include/zbar_ros/barcode_reader_node.hpp   |  4 +++-
 zbar_ros/package.xml                           |  1 +
 zbar_ros/src/barcode_reader_node.cpp           | 18 +++++++++++++-----
 zbar_ros_interfaces/msg/Symbol.msg             |  2 +-
 5 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index e1f2e48..18379be 100644
--- a/README.md
+++ b/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
diff --git a/zbar_ros/include/zbar_ros/barcode_reader_node.hpp b/zbar_ros/include/zbar_ros/barcode_reader_node.hpp
index 7669e84..a80b4fb 100644
--- a/zbar_ros/include/zbar_ros/barcode_reader_node.hpp
+++ b/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_;
diff --git a/zbar_ros/package.xml b/zbar_ros/package.xml
index 4c55d75..b9ed5c3 100644
--- a/zbar_ros/package.xml
+++ b/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>
diff --git a/zbar_ros/src/barcode_reader_node.cpp b/zbar_ros/src/barcode_reader_node.cpp
index 3fa5235..59f8aa7 100644
--- a/zbar_ros/src/barcode_reader_node.cpp
+++ b/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);
 }
 
diff --git a/zbar_ros_interfaces/msg/Symbol.msg b/zbar_ros_interfaces/msg/Symbol.msg
index 9b4e98d..11dae92 100644
--- a/zbar_ros_interfaces/msg/Symbol.msg
+++ b/zbar_ros_interfaces/msg/Symbol.msg
@@ -1,2 +1,2 @@
 string data
-geometry_msgs/Point[] points
\ No newline at end of file
+geometry_msgs/Point[] points