Bug 2970

Summary:	restore vertical flow labels for PyViz flow monitor
Product:	ns-3	Reporter:	Tom Henderson <tomh>
Component:	visualizer	Assignee:	Gustavo J. A. M. Carneiro <gjcarneiro>
Status:	PATCH WANTED ---
Severity:	normal	CC:	ns-bugs
Priority:	P3
Version:	ns-3.29
Hardware:	All
OS:	All

Description Tom Henderson 2018-08-15 16:26:37 EDT

There is an upstream bug in PyGObject that prevents the flow labels from being rendered vertically:  https://gitlab.gnome.org/GNOME/pygobject/issues/16

Gustavo has committed a workaround with a warning:

/ns-3-dev/src/visualizer/visualizer/core.py:1351: UserWarning: PyGobject bug causing label position error; should be fixed in PyGObject >= 3.29.1
  warnings.warn("PyGobject bug causing label position error; "

Attached image gives an example of the problem.  The two flow labels overlap horizontally instead of being placed one to the left, one to the right of the vertical flow line (at 90 degree angle).

An alternate solution is desired, or some way for users to start seeing the benefits of the upstream fix if it is fixed and the libraries propagate to Linux distributions.