Query regarding creating a custom display plugin.

[suchetanrs]

Hello!

I had a question while writing a custom display plugin to visualize my custom messages.

I have the following custom message

std_msgs/Header header
geometry_msgs/PointStamped point
geometry_msgs/PolygonStamped polygon
geometry_msgs/PoseStamped pose

In my display plugin, I thought it would be simpler to directly use the processMessage function from rviz_default_plugins individually for the point, polygon and the pose.
I've got the PointStamped section and the PolygonStamped section of my custom message to work fine because the processMessage function was public and protected respectively and hence accessible by my custom display plugin. However, it's not the case with the default PoseStamped rviz display plugin. The processMessage is made private here.

Any suggestions on how I should proceed in this case? Was this function supposed to be protected / public?

Thanks for your help in advance!

[suchetanrs]

After looking at the codebase further, I observe that the access control doesn't seem to be consistent across different messages that inherit from rviz_common::MessageFilterDisplay.

Message Type	Status
AccelStamped	processMsg is private
DepthCloudDisplay	processMsg is public
Effort	processMsg is private
GridCells	processMsg is public
Map	processMsg is public
Odometry	processMsg is public
Path	processMsg is public
PointStamped	processMsg is public
PoseArray	processMsg is public
Range	processMsg is public
Twist	processMsg is private
Wrench	processMsg is public

In use cases such as mine, I feel like it is best to leave it public / protected for all of them. Will a PR help here? Please let me know.

[clalancette]

I'm fine with switching them all to protected. If you'd like to make a PR to switch all of them, please go ahead.

[suchetanrs]

Great! Thanks. I'll raise a PR for this.

[suchetanrs]

Hello @clalancette !
There were a few errors in the table above. I've updated it.
I have raised a PR #1311 which moves the private ones to protected.
I was not able to move the public ones to protected because doing that would not allow me to compile the unit tests for those displays. Please let me know what I can do in this case :)