ROS Resources: Documentation | Support | Discussion Forum | Index | Service Status | Q&A
Ask Your Question

Explain RosTextView

asked 2012-08-30 11:58:45 -0500

Srogacki gravatar image

updated 2014-01-28 17:13:30 -0500

ngrennan gravatar image

I am working with the android_tutorial_pubsub package and have built an app that publishes to a node and subscribes to another. I also have two RosTextView widgets, which I want to display activity over my "publishing" rostopic and my "subscribing" rostopic. the tutorial has built-in functionality to display the publisher's messages on the RosTextView, but I cannot seem to get the subscriber messages to do the same. All the nodes and topics are set up correctly [per rxgraph], but I do not understand RosTextView enough to know how it gets its information or if subscriber should be pushing new messages to it.

Any help is appreciated.

edit retag flag offensive close merge delete

1 Answer

Sort by » oldest newest most voted

answered 2012-12-18 14:19:03 -0500


I know this is a little late and you've already probably worked it out, but the RosTextView widget is a subscriber attached to a TextView. As per the basic ROS concepts a subscriber must be subscribed to a the message generated by a Publisher. As such any subscriber doesn't generate any messages but only listens to those made by a Publisher. I guess a better description of a RosTopic is a message channel between at least one publisher and one subscriber.

As this is the case, the subscriber in the RosTextView cannot subscribe to the messages from another subscriber, because your "subscribing" node does not generate any. The only way to see the messages your "subscribing" node might be listening to is to have your RosTextView subscribe to the same publisher over the same topic.

Hope this helps


edit flag offensive delete link more


Now I got it, but still a question: can I put the rosTextView subscriber listening to a server Publisher? if Yes, Why in the android_core/ android_tutorial_pubsub it didn't work ( keeping in mind that the only thing I've changed is the topic name of rosTextView of of the pubsub tutorial inside android_core.

サイトダニエロ gravatar image サイトダニエロ  ( 2020-06-02 13:34:45 -0500 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools


Asked: 2012-08-30 11:58:45 -0500

Seen: 943 times

Last updated: Dec 18 '12