hoverlabel config

[nicolaskruchten]

This exists in layout and in data but right now it looks like bgcolor etc aren't populated in fulldata?

[nicolaskruchten]

Blocked by plotly/plotly.js#2964

[nicolaskruchten]

OK, not blocked. Let's work around this at the editor level...

Here's what we need:

1. ColorPicker needs to be able to handle null or missing values by showing some text saying "this color is computed from other parts of the figure but you can 'click here' to override it" at which point it shows the normal picker and forces a value into the field
2. We add this capability to the editor for both the trace and layout-level variants, and tie its visibility to hoverlabel.font or something so that it shows up even when the value isn't in fullData, and then the 'empty state' kicks in.

[dmt0]

Would be great to know exactly from which "other parts of the figure" do they actually get colors, so I could prepopulate them with whatever is visually there, and not just black/white.
bgcolor is clearly from marker.color, bordercolor and font are white, but where did white come from?