Feature request: `legend.title.position` argument added to `theme`

[davidhodge931]

Would the title.position argument from the guide_legend/guide_colourbar/guide_coloursteps functionality be able to be added as an argument (or arguments) to theme?

I always like the all my legends to have the title on top, so it'd be super helpful if I could do this via the theme

[teunbrand]

I like this suggestion, it also bothered me sometimes that this wasn't a theme option.

[teunbrand]

Quick thought: In principle, we could treat legend.text.position the same for the label.position argument in guides. However, sometimes these are incompatible with the guide's direction: we cannot have a vertical colourbar with labels at the bottom side of the bar. So to avoid incompatible arguments, we probably shouldn't direct the label positions from the theme.

[davidhodge931]

It looks like at present in theme, the arguments prefixed legend relate also to the colourbar and coloursteps.

An idea is to add colourbar. and coloursteps. prefixed arguments into theme. These could inherit from the equivalent legend. prefixed argument where there is one.

[teunbrand]

It looks like at present in theme, the arguments prefixed legend relate also to the colourbar and coloursteps.

It does, mostly through historical quirks I think. They apply to any non-position guide (i.e. not axes).

An idea is to add colourbar. and coloursteps. prefixed arguments into theme

I'm not an enormous fan of this, partly because the guides are opened for extensions now and setting that precedent (and expecting extension developers to follow it) would make themes even more unmanageable than they already are. The other half is that colourbars/coloursteps/binned guides are implemented as legends with 1 key, so most of what applies to legends also applies to the others.

[davidhodge931]

The non-position guides are awesome for flexibility, but I think using theme is much better for ease. So I think it'd be great to get as much as possible of the additional style stuff from the non-position guides into the theme. But, I can understand that you have to prioritise where you put your effort

[teunbrand]

Probably makes most sense to implement this after #5512 is merged.