WIP: Refs

[larsoner]

@GuillaumeFavelier on pyvista/pyvista#958 and pyvista/pyvistaqt#66 using pytest mne/viz/_brain I get:

Traceback (most recent call last):
  File "/home/larsoner/python/mne-python/mne/viz/_brain/_brain.py", line 45, in safe_event
    return fun(*args, **kwargs)
  File "/home/larsoner/python/mne-python/mne/viz/_brain/_brain.py", line 432, in _clean
    self.clear_points()
  File "/home/larsoner/python/mne-python/mne/viz/_brain/_brain.py", line 1245, in clear_points
    self.remove_point(sphere)
  File "/home/larsoner/python/mne-python/mne/viz/_brain/_brain.py", line 1235, in remove_point
    self.plotter.remove_actor(sphere._actors)
  File "/home/larsoner/python/pyvista/pyvista/plotting/plotting.py", line 616, in remove_actor
    renderer.remove_actor(actor, reset_camera)
  File "/home/larsoner/python/pyvista/pyvista/plotting/renderer.py", line 1174, in remove_actor
    rv = self.remove_actor(a, reset_camera=reset_camera)
  File "/home/larsoner/python/pyvista/pyvista/plotting/renderer.py", line 1182, in remove_actor
    _remove_mapper_from_plotter(self.parent, actor, False)
  File "/home/larsoner/python/pyvista/pyvista/plotting/renderer.py", line 1462, in _remove_mapper_from_plotter
    for name in list(plotter._scalar_bar_mappers.keys()):
AttributeError: 'NoneType' object has no attribute '_scalar_bar_mappers'

Can you look and push commits to fix?

[GuillaumeFavelier]

Okay, I'm on it

[GuillaumeFavelier]

This is my report for pytest mne/viz/_brain on mne-python/ref:

1. pyvista/master, pyvistaqt/master:
   all tests are green

2. pyvista/mem, pyvistaqt/master:
   Segmentation fault in test_brain_init
   Does not crash if I use -k init and the test is green

3. pyvista/master, pyvistaqt/mem:
   MemoryError in test_brain_traces for volume and mixed, test_brain_linkviewer

4. pyvista/mem, pyvistaqt/mem:
   Segmentation fault in test_brain_traces
   Does not crash if I use -k traces and I got the same MemoryError as in 3)

I think the MemoryError is related to your traceback, I'll investigate

[GuillaumeFavelier]

I identified the issue with MemoryError on 3). BasePlotter.deep_clean() is forced in pyvistaqt/mem

deep_clean() will set self.parent = None which is used to remove the actors in our function clear_points().

I would recommend to proceed with caution here. PyVista made the difference between 'close' and 'clean'. I suggest that we stick to it until we can have a proper discussion or plan in pyvista/pyvista#959

The way I see it, Brain -> BackgroundPlotter -> BasePlotter (-> : depends on) so the sequence should be (in this order):

Brain.close(), BackgroundPlotter.close(), BasePlotter.close(), Brain.clean(), BackgroundPlotter.clean(), BasePlotter.clean()

[GuillaumeFavelier]

I identified the issue with the segfault on 2). On our code, the patch to remove lights should be removed and self.plotter.interactor=None needs to removed. The refs to vtkXOpenGLRenderWindow will remain though.

EDIT: I can work something out, it's just some cleaning to do

[larsoner]

Brain.close(), BackgroundPlotter.close(), BasePlotter.close(), Brain.clean(), BackgroundPlotter.clean(), BasePlotter.clean()

Do you mean BasePlotter.deep_clean?

[GuillaumeFavelier]

Do you mean BasePlotter.deep_clean?

Yes. I used 'clean' just to give the idea

[larsoner]

I reverted the deep_clean in pyvistaqt and now things pass there and on this PR!

I'll go ahead and merge this since it has a fix for latest matplotlib