Moving rqt to pure python (#169)

[mlautman]

re-opening #169

[brawner]

@dirk-thomas Addressing your comments from #169 (comment)

The Python packages need to register themselves at the resource index as well as install their manifest file: see https://github.com/ros2/demos/blob/f2a1d9f5fe694a11fb42f3c036dacd130141ac0e/demo_nodes_py/setup.py#L10-L14 for an example.

Addressed

Also since the patch removed all CMake based linters the Python packages need linter tests instead: see https://github.com/ros2/demos/tree/f2a1d9f5fe694a11fb42f3c036dacd130141ac0e/demo_nodes_py/test

Test files were added to rqt_gui and rqt_gui_py

I haven't checked the entry points myself but it looks weird that they reference a main function in the rqt_gui.main module which doesn't exist - only a Main and a check for main?

A main function was added to main.py. I couldn't figure out how to get entry_points to call a script without a function as its entry point, nor could I figure out how to call the Main class method main.

rqt/rqt_gui/src/rqt_gui/main.py

Line 86 in 0e54f9f

def main():

The information in the setup.py files should match the existing information in the package.xml files: e.g. description, license, authors.

Addressed

[dirk-thomas]

I don't know what the recommended approach for setuptools is but currently it only list a single author (see previous comment).

[brawner]

It looks like as many names and emails can be added in the author name field, email address field can only be one though.

[dirk-thomas]

Also in ROS 1 rqt can be invoked without rosrun since it is on the PATH. That should be the same in ROS 2. Since there can be only a single install destination for scripts the rqt entry point should go to bin and the rqt_gui one can stay a script which is is installed without being an entry point.

[dirk-thomas]

This file should removed to place the rqt executable into bin.

[brawner]

Tested on windows, and it has the expected effects. rqt can be run directly as a command, but ros2 run rqt_gui rqt_gui fails

[brawner]

Linux CI https://ci.ros2.org/job/ci_linux/5859

[dirk-thomas]

@ros-pull-request-builder retest this please

[dirk-thomas]

See #179.