loses configuration on startup

[dirk-thomas]

From @trainman419 on May 23, 2014 3:12

When starting up, if rqt_plot can't find a topic, it silently ignores it and removes it from the configuration. This causes two problems:

• If you try to rely on the RQT framework to persist your plotting settings, they will silently be removed if the publisher isn't active when rqt_plot restarts
• If you start rqt_plot with a list of topics, any topics from the command line that don't exist are silently ignored

Note that any solution to this should also be aware of the changes that were made to fix #110

It might be worth trying:

• Maintaining internal configuration even if topics don't exist - possibly including topic types
• Not blocking startup on missing topics
• occasionally polling to see if missing topics have appeared
• failing startup if topics/fields specified on the command line don't exist

Copied from original issue: ros-visualization/rqt_common_plugins#229

[dirk-thomas]

From @ablasdel on May 28, 2014 21:4

I think the silently removing topics was a quick fix to solve the "block until it is published" bug.
The proposed "Occasional polling" seems like a more elegant solution to the issue.

[dirk-thomas]

From @DorianScholz on June 3, 2014 11:55

A possible solution to this problem and #106 might be to maintain a list of recently plotted topics.
These could be offered to the user in a drop down menu of the "+" button similar to the "-" button.
This list should contain previously plotted topics, which were not available at start up, as well as topics removed via the "-" button, thus allowing for easy toggling of topics.
But there needs to be an option to remove topics from this list, either manually maybe in the settings dialog, or automatically after a certain time that a topic has not been plotted (requiring a list with "last used" timestamps).

[dirk-thomas]

From @ablasdel on June 6, 2014 18:29

@trainman419 can you detail what you did in the demo you showed me here? It was pretty solid. possibly with screen shots?

[dirk-thomas]

From @trainman419 on June 6, 2014 18:33

@ablasdel I don't think I demo'd this issue for you. Perhaps you meant #236 or #239 ?

[dirk-thomas]

From @ablasdel on June 6, 2014 18:44

My mistake I thought this was covered by #239 as well since you handled switching between back-ends. My brain extended that to plug-in start-up which clearly isn't the case. Retracted!