topics.py

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"""
topics.py

Functions to do with topics
"""
import roslib
roslib.load_manifest('starmac_roshlib')
from rospy import loginfo, sleep
from rosh import nodes, info, topics

def is_publishing(node_name, topic_name):
    if nodes is None:
        return False
    else:
        topics_published = [info(s).name for s in info(nodes[node_name]).pubs]
        return True in [s.find(topic_name) >= 0 for s in topics_published]

def is_subscribing(node_name, topic_name):
    if nodes is None:
        return False
    else:
        topics_subscribed = [info(s).name for s in info(nodes[node_name]).subs]
        return True in [s.find(topic_name) >= 0 for s in topics_subscribed]

def wait_for_topic(node_name, topic_name, sleep_time=0.5):
    loginfo("Waiting for node %s to publish topic %s" % (node_name, topic_name))
    while not is_publishing(node_name, topic_name):
        #loginfo("Still waiting for topic %s from node %s" % (topic_name, node_name))
        sleep(sleep_time)
    loginfo("Node %s is now publishing topic %s" % (node_name, topic_name))
    
def wait_for_topic_sub(node_name, topic_name, sleep_time=0.5):
    loginfo("Waiting for node %s to subscribe to topic %s" % (node_name, topic_name))
    while not is_subscribing(node_name, topic_name):
        #loginfo("Still waiting for topic %s from node %s" % (topic_name, node_name))
        sleep(sleep_time)
    loginfo("Node %s is now subscribing to topic %s" % (node_name, topic_name))
    
def topics_list():
    all_topics = []
    for t in topics:
        all_topics.extend(list(t._list()))
    return all_topics

def wait_for_topic_existence(topic_name, sleep_time=0.5):
    loginfo("Waiting for topic %s to show up in topics list" % topic_name)
    while not topic_name in topics_list():
        sleep(sleep_time)
    loginfo("Topic %s is now in topics list" % topic_name)