Make python

This was an attempt at making the ROS2 launch files work with the Python
samples on Windows. The issue is that, if we simply try to launch the
python script directly, we get the following error:

```
OSError: [WinError 193] %1 is not a valid Win32 application
```

In this commit, we try to make a Python module out of the samples,
install them using `ament_cmake_python`, and use a `setup.cfg` to add a
console script entry point. This way, we can launch the samples using
both `ros2 run` and `ros2 launch` commands.

This approach was modeled after: ros/xacro#304

This seemed to work. However, a new issue emerged. While `ros2 run`
still works fine, now we are not getting any log output when launching
it with `ros2 launch`. We seem to be encountering this issue:

MISC-2024-06-19-ros2-testing

README.md

@@ -351,14 +351,16 @@ This sample performs single-acquisition 3D captures in a loop. This sample shows
 the capture settings, how to subscribe to the [points/xyzrgba](#pointsxyzrgba) topic, and how to invoke the
 [capture](#capture) service.
 
-Source code: [C++](./zivid_samples/src/sample_capture.cpp)
+Source code: [C++](./zivid_samples/src/sample_capture.cpp) [Python](./zivid_samples/scripts/sample_capture.py)
 
 ```bash
 ros2 launch zivid_samples sample.launch sample:=sample_capture_cpp
+ros2 launch zivid_samples sample.launch sample:=sample_capture_py
 ```
 Using ros2 run (when `zivid_camera` node is already running):
 ```bash
 ros2 run zivid_samples sample_capture_cpp
+ros2 run zivid_samples sample_capture_py
 ```
 
 ### Sample Capture 2D

zivid_samples/CMakeLists.txt

@@ -12,6 +12,7 @@ if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
 endif()
 
 find_package(ament_cmake REQUIRED)
+find_package(ament_cmake_python REQUIRED)
 find_package(ament_index_cpp REQUIRED)
 find_package(rclcpp REQUIRED)
 find_package(zivid_interfaces REQUIRED)
@@ -34,7 +35,9 @@ add_executable(sample_capture_and_save_cpp src/sample_capture_and_save.cpp)
 ament_target_dependencies(sample_capture_and_save_cpp rclcpp zivid_interfaces)
 install(TARGETS sample_capture_and_save_cpp DESTINATION lib/${PROJECT_NAME})
 
-install(PROGRAMS scripts/sample_capture.py DESTINATION lib/${PROJECT_NAME})
+ament_python_install_package(${PROJECT_NAME} SCRIPTS_DESTINATION lib/${PROJECT_NAME})
+#install(PROGRAMS scripts/zivid_samples DESTINATION bin)
+#install(PROGRAMS scripts/zivid_samples DESTINATION lib/${PROJECT_NAME})
 
 if(BUILD_TESTING)
   # TODO enable linting of the samples

zivid_samples/launch/sample.launch

@@ -2,4 +2,4 @@
   <arg name="sample" default=""/>
   <node pkg="zivid_camera" exec="zivid_camera" name="zivid_camera" />
   <node pkg="zivid_samples" exec="$(var sample)" name="$(var sample)" />
-</launch>
+</launch>

zivid_samples/launch/sample_py_launch.py

@@ -0,0 +1,22 @@
+from launch import LaunchDescription
+from launch_ros.actions import Node
+
+
+def generate_launch_description():
+    launch_description = LaunchDescription()
+
+    launch_description.add_action(
+        Node(package="zivid_camera", executable="zivid_camera", name="zivid_camera")
+    )
+
+    launch_description.add_action(
+        Node(
+            package="zivid_samples",
+            executable="sample_capture_py",
+            name="zivid_sample",
+            output="screen",
+            emulate_tty=True,
+        ),
+    )
+
+    return launch_description

zivid_samples/package.xml

@@ -10,6 +10,7 @@
   <url type="repository">https://github.com/zivid/zivid-ros</url>
   <url type="bugtracker">https://github.com/zivid/zivid-ros/issues</url>
   <buildtool_depend>ament_cmake</buildtool_depend>
+  <buildtool_depend>ament_cmake_python</buildtool_depend>
   <depend>rclcpp</depend>
   <depend>rclcpp_components</depend>
   <depend>sensor_msgs</depend>

zivid_samples/setup.cfg

@@ -0,0 +1,3 @@
+[options.entry_points]
+console_scripts =
+    sample_capture_py = zivid_samples.sample_capture:main

zivid_samples/scripts/sample_capture.py → zivid_samples/zivid_samples/sample_capture.py

@@ -15,6 +15,8 @@ class Sample(Node):
     def __init__(self):
         super().__init__("sample_capture_py")
 
+        self.get_logger().info("Starting sample_capture_py")
+
         self.capture_service = self.create_client(Trigger, "capture")
         while not self.capture_service.wait_for_service(timeout_sec=3.0):
             self.get_logger().info("Capture service not available, waiting again...")