Add UI Event linking to DraggableColorbar

[ruuskas]

This change makes the DraggableColorbar class work with UI Events. Users can now link figures that contain topoplots or epoch/tfr images and manipulate the color scale and color map interactively.

Basic example based on the Using the event system to link figures tutorial.

import mne
from mne.viz.ui_events import link

# Turn on interactivity
plt.ion()
data_path = mne.datasets.sample.data_path()
evokeds_fname = data_path / "MEG" / "sample" / "sample_audvis-ave.fif"
evokeds = mne.read_evokeds(evokeds_fname)

left_auditory = evokeds[0]
right_auditory = evokeds[1]

fig1 = left_auditory.plot_topomap("interactive")
fig2 = right_auditory.plot_topomap("interactive")

link(fig1, fig2)

[larsoner]

Ideally every change should have an updated test. Can you look to see if _fake_click can be used to trigger a change in the colorbar and emit your new UIEvent?

[larsoner]

... also needs a doc/changes/devel.rst update to mention this enhancement

[wmvanvliet]

CI failure "Test Windows 3.11 pip pre" is not releated to this PR

[drammock]

CI failure "Test Windows 3.11 pip pre" is not releated to this PR

agreed, @larsoner snuck a fix into #12064

[wmvanvliet]

Looking great. Only a few nickpicks regarding kind

[ruuskas]

@wmvanvliet Any idea why the CI doctest fails?

[wmvanvliet]

seems unrelated. Let's try again with latest main merged in.

[ruuskas]

This should be good now @wmvanvliet

[wmvanvliet]

Thanks @ruuskas!