Custom background feature

[LittleBigThing]

The theme has no Customizer setting to add a custom background image. It is, however, tagged as having the custom background feature.

Is there a reason that the custom background feature is not supported? This is a core feature that is fairly easily added. It is supported by all default themes, except for Twenty Seventeen and Twenty Thirteen.

[joyously]

Look at the history, but I think someone already tried to add it and it wasn't accepted because of accessibility concerns on the color scheme. (managing contrast)

[LittleBigThing]

It is indeed a feature that can be used in ‘surprising ways’, creating potential problems for accessibility or issues by adding large images as a background.

But the use of a custom background can be versatile: one could add a subtle background pattern or a (repeated) background image on the bottom to customize the look of her/his site. These do not affect accessibility.

The core feature works out-of-the-box. I seems to work fine with the theme. But it is a decision we need to make and it's about controlling the user's freedom. I think that one can also mess up things in the editor, maybe even more than before Gutenberg, by setting way too large fonts sizes, font and background colors, ...

I am not sure either. :-)
Adding the feature is not really a bloat, so see PR #709.

And if we don't use it, we should remove the tag.

[LittleBigThing]

A thought against adding the feature:

• The custom background image won’t be visible in the editor (at least, by default).

[kjellr]

Thanks, @LittleBigThing! This was left out intentionally since it opens the door to accessibility issues. It's true that users could upload images/use colors that work fine accessibility-wise, but on the other hand... we can't guarantee that'll be the case. If someone wanted to add this option, I could definitely see it in a simple child theme or plugin, but I'd like to avoid including it by default.

[LittleBigThing]

Thanks, @kjellr.
But don't forget to remove the 'custom-background' tag then, because that may be confusing. I don't think it can stand for any other feature of the theme?

[LittleBigThing]

Or is it meant for the background colors added in the editor? Hm...

[allancole]

That custom-background tag was left in there by mistake @LittleBigThing. It gets removed in ready-for-merge PR here: https://github.com/WordPress/twentynineteen/pull/710/files#diff-82af3a992dd99d43d1fccbf4380772adL13