Use rosdep (#32)

* Add Cyclone DDS build dependencies for rosdep

* Update README.md

Change apt install commands to rosdep install.

* build_depend -> buildtool_depend for maven and java

* Add vendor package to build cyclonedds from source

Remove maven and java dependency (thanks, @eboasson)

* remove --symlink-build flag

this obscures the intention of the code and sophisticated users can choose whether to use it or not.

* add rosdep to readme

README.md

@@ -6,26 +6,25 @@ implementation.
 
 ## Getting, building and using it
    
-All it takes to get Cyclone DDS support into ROS2 is to clone this repository and the Cyclone DDS
+All it takes to get Cyclone DDS support into ROS2 is to clone this repository into the ROS2 workspace
-one in the ROS2 workspace source directory, and then run colcon build in the usual manner:
+source directory, and then run colcon build in the usual manner:
 
     cd ros2_ws/src
     git clone https://github.com/atolab/rmw_cyclonedds
-    git clone https://github.com/eclipse-cyclonedds/cyclonedds
     cd ..
-    colcon build --symlink-install --cmake-args -DCMAKE_BUILD_TYPE=RelWithDebInfo
+    rosdep install --from src -i
+    colcon build --cmake-args -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCYCLONEDDS_FROM_SOURCE=ON
     export RMW_IMPLEMENTATION=rmw_cyclonedds_cpp
 
+If you prefer to install CycloneDDS yourself, set `-DCYCLONEDDS_FROM_SOURCE=OFF`. CMake caches this
+value, so you can omit it between builds
+
 This seems to work fine on Linux with a binary ROS2 installation as well as when building ROS2 from
 source.  On macOS it has only been tested in a source build on a machine in an "unsupported"
 configuration (macOS 10.14 with SIP enabled, instead of 10.12 with SIP disabled), and apart from a
 few details that are caused by the machine configuration, that works fine, too.  There is no reason
 why it wouldn't work the same on Windows, but I haven't tried.
 
-That said, Cyclone DDS has some prerequisites because it currently relies on Java and Maven to build
-its IDL preprocessor, and so it is probably advisable to check its README for details.  On an Ubuntu
-18.04 system, ``sudo apt-get install maven default-jdk`` will likely address that.
-
 If you want to use a pre-existing installation of Cyclone DDS, you don't need to clone it, but you
 may have to tell CMake where to look for it using the CycloneDDS\_DIR variable.  That also appears
 to be the case if there are other packages in the ROS2 workspace that you would like to use Cyclone

cyclonedds_vendor/CMakeLists.txt

@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.5)
+project(cyclonedds_vendor)
+find_package(ament_cmake REQUIRED)
+
+include(ExternalProject)
+ExternalProject_Add(cyclonedds
+  GIT_REPOSITORY "https://github.com/eclipse-cyclonedds/cyclonedds.git"
+  CMAKE_ARGS
+   -DBUILD_CONFTOOL:BOOL=OFF
+   -DBUILD_IDLC:BOOL=OFF
+   -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
+  )
+
+ament_package()

cyclonedds_vendor/package.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0"?>
+<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="3">
+    <name>cyclonedds_vendor</name>
+    <version>0.4.0</version>
+    <description>Wrapper package for Eclipse CycloneDDS.</description>
+    <maintainer email="erik.boasson@adlinktech.com">Erik Boasson</maintainer>
+    <license>Apache License 2.0</license>
+
+    <buildtool_depend>ament_cmake</buildtool_depend>
+
+    <export>
+        <build_type>ament_cmake</build_type>
+    </export>
+</package>

rmw_cyclonedds_cpp/CMakeLists.txt

@@ -16,6 +16,8 @@ cmake_minimum_required(VERSION 3.5)
 
 project(rmw_cyclonedds_cpp)
 
+set(CYCLONEDDS_FROM_SOURCE CACHE BOOL "Should we download and build cycloneDDS from source?")
+
 link_directories(/usr/local/lib)
 
 # Default to C++14
@@ -31,7 +33,13 @@ find_package(ament_cmake_ros REQUIRED)
 
 find_package(rcutils REQUIRED)
 
+if (CYCLONEDDS_FROM_SOURCE)
+  message("Building CycloneDDS from source")
+  find_package(cyclonedds_vendor REQUIRED)
+else()
   find_package(cyclonedds_cmake_module REQUIRED)
+  message("Using installed CycloneDDS")
+endif()
 find_package(CycloneDDS REQUIRED CONFIG)
 
 find_package(rmw REQUIRED)

rmw_cyclonedds_cpp/package.xml

@@ -14,6 +14,8 @@
 
   <build_depend>cyclonedds</build_depend>
   <build_depend>cyclonedds_cmake_module</build_depend>
+  <build_depend>cyclonedds_vendor</build_depend>
+
   <build_depend>rcutils</build_depend>
   <build_depend>rmw</build_depend>
   <build_depend>rosidl_generator_c</build_depend>