feat: Minimal reactive volume viewer

[manzt]

Implements proposed API in niivue/ipyniivue#51 using the example from basic multi-planar as an example.

from ipyniivue_experimental import AnyNiivue, SliceType

volumes = [
  { "path": "images/mni152.nii.gz", "colormap": "gray", "visible": True, "opacity": 1.0 },
  { "path": "images/hippo.nii.gz", "colormap": "red", "visible": True, "opacity": 1 },
]
nv = AnyNiivue(slice_type=SliceType.MULTIPLANAR)
nv.load_volumes(volumes)
nv

The volumes are reactive for colormap and opacity. Meaning the above will change interactively with:

v.volumes[0].colormap = "blue"
nv.volumes[0].opacity = 0.2

Finally, I added a script in script/generate_options_mixin.py to generate the _options_mixin.py file. This takes the defaults for all the viewer options and exposes reactive getters/setters for the values.

Thus, you can change viewer-level properties like slice_type programatically:

nv.slice_type = SliceType.SAGITTAL # updates view

[manzt]

this file is automatically generated with getters/setters for the front-end properties.

[manzt]

[manzt]

The default values for the OptionsMixin come from niivue DEFAULT_OPTIONS. I think that several of these properties don't really make sense on the Python side. One thing that would be nice is to annotate those options on the JS comments with extra metadata if we should ignore, and then this whole process can be automated (deriving from the JS as the source of truth).

[kolibril13]

Just tested this notebook, and I'm impressed with what you implemented here!

Also, the auto-generated generate_options_mixin works nicely, I've tried a few options from there.

As this pr is quite large, I suggest that we merge this one soon, and then discuss further steps on discord.

Feel free to also delete the current notebooks and add the Untitled1.ipynb that you show in the demo.

[manzt]

I think we can add the demo later. I prefer not to check in notebooks right now as they cause many issues with version control. Ideally, we should have the examples from niivue/ipyniivue#50 organized nicely into some notebooks like (examples, etc).

[manzt]

@kolibril13 I don't have write access to this repo so I cannot merge.

[kolibril13]

Nice, Ive merged this pr now from the GitHub app. I will add you as a repo admin once I am back home