Qt GUI messages not published when launched from launch file
Hi all,
So I'm quite experienced with ROS but I've never seen anything like this. I'm running a simulation of my mobile robot in gazebo and made a Qt GUI for building and publishing waypoint paths. I have one main launch file that launches everything and only new nodes are added once they have been determined to operate as expected.
So, during testing I would launch my all encompassing launch file and then in another terminal I would rosrun my gui with no messaging issues or publishing issues. Then when I added my GUI to the launch file, messages would not come through the topics. However, if I did rostopic list or rosnode info gui_node all the appropriate topics with the correct types appeared.
The only way I've found a work around for this issue currently is to make a shell script that does rosrun my_pkg gui_node and then do <node type="rosrun.sh" name="gui_node" pkg="my_pkg" />.
I do not really know how launch files work so anyone with deeper knowledge on that would be a great help. Also another factor in this might be that I'm using an async spinner in my gui so that both gui callbacks and subscriber callbacks can both occur without a problem. I'm also happy to provide more details if needed.
Thanks!
is it possible that you have a timeout for subscribers in your GUI? the launch file does not guarantee which node runs first, so your GUI may be running first, before any topics are available to it.