consistent text mode

[nicolaskruchten]

We need a simple way to guarantee that the text displayed within/across traces of the same type is in the same size and orientation. For example if I have two bar traces in a plot with text visible, the text should all be of the same size and either all vertical or all horizontal. Likely this will mean making it all as small as necessary to fit the largest bit of text.

We likely want this to work within treemaps as well: being able to guarantee that short labels aren't being displayed bigger than long labels.

For pies and sunbursts obviously orientation is a bit trickier because it's relative to the sector but for size the logic should be the same. I would expect that below a certain size the text could all be horizontal and above a certain size the text would all just be oriented radially or something.

I don't think we need this to work across trace types (although it should work across traces), e.g. same font size for bars and treemaps in the same figure (but different bar traces should coordinate).

We should probably provide a min/max font size along with some kind of defined fallback if the required size to make it fit is outside of those bounds.

[etpinard]

For pies and sunbursts obviously orientation is a bit trickier

Related: #3590

[archmoj]

Any idea for attribute names?

[nicolaskruchten]

maybe layout.tracetext = {min, max, mode}
where mode can be clamp or hide ?
maxmode and minmode?
so if the text is smaller than min and the minmode is clamp then you set the size to min and overflow
otherwise you hide?

[archmoj]

I am thinking of adding a module called crossTracePlot.

[archmoj]

How this should operate between subplots?

[nicolaskruchten]

It should operate across subplots please.

[archmoj]

So with traces in two different subplots should they use an identical minimum or two minimum values?

[nicolaskruchten]

identical.