Astrowidgets.set_colormap does not handle Monochromatic switch gracefully

[Jdaviz-Triage-Bot]

Reporter: pllim

Workflow:

1. Fire up Imviz example notebook and load the images.
2. In Plot Options, change Color Mode to Monochromatic (make sure you select the second image, which is what you will be seeing first).
3. In the notebook cell, run imviz.default_viewer.set_colormap('Viridis') and then observe the state of Plot Options.

@kecnry and I apparently observed different behavior, both which were a little counter-intuitive (either the image does not change back to colormap or it did but Plot Options didn't).

What should be the desired behavior? Kyle presented 3 possible solutions:

1. Change the colormode on the viewer to colormap and the colormap on the top layer (or all layers?) to whatever is requested
2. Set the underlying state, but require manually changing the mode. This is what I’d expect, but that’s probably because I know what happens at the low level with the state objects
3. Raise an error requiring mode to be changed first (or perhaps passing an additional argument to set_colormap)

Kyle: I’d probably vote for 3, because I like error messages and being very clear when some magic is happening. But if 1 is consistent with astrowidget API, then we can make that happen… although its odd that you’re seeing it happen now and I don’t. Nowhere in astrowidgets does that logic exist, so is glue triggering a change to the mode somewhere? Do you actually see the mode dropdown change to "colormaps"?

POs should decide which option would make most sense to a typical scientist user.

Related issues:

• Imviz API to change Monochromatic color #1504
• Imviz set_colormap does not update Plot Options correctly #1506

🐱

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DISCLAIMER: This issue was autocreated by the Jdaviz Issue Creation Bot on behalf of the reporter. If any information is incorrect, please contact Duy Nguyen