00001 #!/usr/bin/env python 00002 # Software License Agreement (BSD License) 00003 # 00004 # Copyright (c) 2008, Willow Garage, Inc. 00005 # All rights reserved. 00006 # 00007 # Redistribution and use in source and binary forms, with or without 00008 # modification, are permitted provided that the following conditions 00009 # are met: 00010 # 00011 # * Redistributions of source code must retain the above copyright 00012 # notice, this list of conditions and the following disclaimer. 00013 # * Redistributions in binary form must reproduce the above 00014 # copyright notice, this list of conditions and the following 00015 # disclaimer in the documentation and/or other materials provided 00016 # with the distribution. 00017 # * Neither the name of Willow Garage, Inc. nor the names of its 00018 # contributors may be used to endorse or promote products derived 00019 # from this software without specific prior written permission. 00020 # 00021 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 00022 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 00023 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 00024 # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 00025 # COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 00026 # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 00027 # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00028 # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 00029 # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00030 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 00031 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 00032 # POSSIBILITY OF SUCH DAMAGE. 00033 # 00034 # Revision $Id: listener_with_user_data.py 5152 2009-07-08 21:33:24Z sfkwc $ 00035 00036 ## Simple listener demo that demonstrates how to register additional 00037 ## arguments to be passed to a subscription callback 00038 00039 PKG = 'rospy_tutorials' # this package name 00040 NAME = 'listener_with_user_data' 00041 00042 import roslib; roslib.load_manifest(PKG) 00043 00044 import sys 00045 00046 import rospy 00047 from std_msgs.msg import * 00048 00049 def callback(data, args): 00050 if args == 1: 00051 print "#1: I heard [%s]"%data.data 00052 elif args == 2: 00053 print "#2: I heard [%s]"%data.data 00054 else: 00055 print "I heard [%s] with userdata [%s]"%(data.data, str(args)) 00056 00057 def listener_with_user_data(): 00058 # Callback arguments (aka user data) allow you to reuse the same 00059 # callback for different topics, or they can even allow you to use 00060 # the same callback for the same topic, but have it do something 00061 # different based on the arguments. 00062 rospy.Subscriber("chatter", String, callback, 1) 00063 rospy.Subscriber("chatter", String, callback, 2) 00064 rospy.Subscriber("chatter", String, callback, ("chatter1", 4)) 00065 rospy.Subscriber("chatter2", String, callback, "This is from chatter2") 00066 rospy.init_node(NAME, anonymous=True) 00067 rospy.spin() 00068 00069 if __name__ == '__main__': 00070 try: 00071 listener_with_user_data() 00072 except KeyboardInterrupt, e: 00073 pass 00074 print "exiting"