Implement fgopacity, fgcolor & "overlay" fillmode for bars, fix bar legend and pattern with marker colorscale

[archmoj]

Resolves #5728 and fixes #5285.
Also fixes drawing bar pattern when the marker get a colorscale.

@plotly/plotly_js

[nicolaskruchten]

Behaviour looks pretty good at first glance! Will dig more tomorrow but nice job :)

[nicolaskruchten]

The legend items get hard to identify when the size goes up... could we offset the "+" and "." patterns so they're centered?

[nicolaskruchten]

I'm thinking that we need to tune things a little bit because for the same size/solidity, the different patterns feel quite different to my eye.

Also I'm thinking we need to either make the overlay semi-transparent or add pattern.opacity to make the patterns vibrate a little less strongly IMO.

[nicolaskruchten]

I'm thinking that we need to tune things a little bit because for the same size/solidity, the different patterns feel quite different to my eye.

Well, playing with it a bit I can see this will be a rabbit-hole so let's leave this alone for now :)

so my asks are:

1. Can we fix the legend items for + and . patterns
2. Can we add pattern.opacity and set it to like 0.8 when fillmode=overlay, to make things a bit less intense?

[archmoj]

2. Can we add pattern.opacity and set it to like 0.8 when fillmode=overlay, to make things a bit less intense?

What about pattern.fgopacity which won't impact the background opacity?

[nicolaskruchten]

sounds good.

[nicolaskruchten]

oooh that's nice:

[archmoj]

1. Can we fix the legend items for + and . patterns

Good call. The scale for all shapes of legends is now reduced by fd89e23.

[nicolaskruchten]

OK, this behaviour is all good for me 🌟

@alexcjohnson just need a dancer :)

[alexcjohnson]

Can we adjust the size from the legend side, rather than detecting the legend inside here? Also do we need to scale down all these sizes? I'd rather we just restrict the maximum size to something we know will work, and perhaps when we have an array for pattern size just use the default size instead of the first one.

[archmoj]

Good calls.
See 5f5561f, a2a66e7 and 69f91e2.

[alexcjohnson]

Again though, do we need to scale down to 0.7 here? In the legend style we already limit the size to 12, can't we keep the same scale as on the graph, but if 12 is too big just reduce that limit?

[archmoj]

Today in 38bd5ec I did try to avoid this scale reduction. But the problem is that the default size of 8 does not fit nicely in the legend icons and lose their identity.
So again in 178e0a6 I scaled down the patterns for icons using a greater ratio at 0.8.

[nicolaskruchten]

I think the current legend items are "ok" ... better than on master, and we can always tweak them a bit more later. I really do need to get this merged and released so unless there's a hard blocker/pathological case here, can we defer the remaining work @alexcjohnson ?

[alexcjohnson]

OK

[alexcjohnson]

💃

[archmoj]

The image test does not show a green light this branch at the moment.
While we updated flaky list on the master in #5737, let's see is we need to adjust it once again after the merge.
Merging...