Get ROS examples to compile, add simple RC channels message

src/examples/subscriber/subscriber.cpp

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+/*
+ * Copyright (C) 2008, Morgan Quigley and Willow Garage, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the names of Stanford University or Willow Garage, Inc. nor the names of its
+ *     contributors may be used to endorse or promote products derived from
+ *     this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// %Tag(FULLTEXT)%
+#include "ros/ros.h"
+#include "std_msgs/String.h"
+
+/**
+ * This tutorial demonstrates simple receipt of messages over the ROS system.
+ */
+// %Tag(CALLBACK)%
+void chatterCallback(const std_msgs::String::ConstPtr& msg)
+{
+  ROS_INFO("I heard: [%s]", msg->data.c_str());
+}
+// %EndTag(CALLBACK)%
+
+int main(int argc, char **argv)
+{
+  /**
+   * The ros::init() function needs to see argc and argv so that it can perform
+   * any ROS arguments and name remapping that were provided at the command line. For programmatic
+   * remappings you can use a different version of init() which takes remappings
+   * directly, but for most command-line programs, passing argc and argv is the easiest
+   * way to do it.  The third argument to init() is the name of the node.
+   *
+   * You must call one of the versions of ros::init() before using any other
+   * part of the ROS system.
+   */
+  ros::init(argc, argv, "listener");
+
+  /**
+   * NodeHandle is the main access point to communications with the ROS system.
+   * The first NodeHandle constructed will fully initialize this node, and the last
+   * NodeHandle destructed will close down the node.
+   */
+  ros::NodeHandle n;
+
+  /**
+   * The subscribe() call is how you tell ROS that you want to receive messages
+   * on a given topic.  This invokes a call to the ROS
+   * master node, which keeps a registry of who is publishing and who
+   * is subscribing.  Messages are passed to a callback function, here
+   * called chatterCallback.  subscribe() returns a Subscriber object that you
+   * must hold on to until you want to unsubscribe.  When all copies of the Subscriber
+   * object go out of scope, this callback will automatically be unsubscribed from
+   * this topic.
+   *
+   * The second parameter to the subscribe() function is the size of the message
+   * queue.  If messages are arriving faster than they are being processed, this
+   * is the number of messages that will be buffered up before beginning to throw
+   * away the oldest ones.
+   */
+// %Tag(SUBSCRIBER)%
+  ros::Subscriber sub = n.subscribe("chatter", 1000, chatterCallback);
+// %EndTag(SUBSCRIBER)%
+
+  /**
+   * ros::spin() will enter a loop, pumping callbacks.  With this version, all
+   * callbacks will be called from within this thread (the main one).  ros::spin()
+   * will exit when Ctrl-C is pressed, or the node is shutdown by the master.
+   */
+// %Tag(SPIN)%
+  ros::spin();
+// %EndTag(SPIN)%
+
+  return 0;
+}
+// %EndTag(FULLTEXT)%