Stability attribute should not be displayed as just color

[rodrigorc]

In rustdoc documentation, the stability attribute is shown as a little vertical bar to the left of the item. In the main window of crates, types, etc. it is also shown as text in the header of the window. But some items, as impl member functions do not have a proper window, so the stability is never seen in plain text.

It is a well known usability rule that relevant information should never be revealed with color only, as the sensibility to color varies highly between individuals.

I would like stability to be shown as a letter, icon or something other than color alone, so that color-blind people will see what they are doing.

[steveklabnik]

We chose the current colors to be decent for color-blind people, IIRC.

[killercup]

The colored bars have tooltips (like "stable" or "deprecated").

This reminds me: many stability attributes contain further information that is only "visible" in that little tooltip if you hover above that small colored bar, e.g. "Unstable: should ideally be implemented for all fixed-sized arrays". (rustdoc just writes this to the title attribute of the a.stability element).

This doesn't work for touch devices. Should that information be displayed more prominently? (Might be another issue, sorry of this is too off-topic.)

[steveklabnik]

We have an issue for that already, @killercup

[rodrigorc]

There are a lot of color-blindness types. Choosing a set of about 5 colors easy to differentiate for everybody is practically impossible.

See for example this image:

I can barely see the difference between the orange and the green ones, unless they are just next to each other. And I'm just slightly color-blind. (The magenta one is fine for me though.)

The problem with the tooltip is double: 1. you cannot see it in touchscreens. 2. You have to move the mouse over it for every function, and there may be a lot of functions to check, if you want to use only stable functions you have to step through all of them.

[steveklabnik]

I'm not saying that it's perfect, just trying to add some context.

[rodrigorc]

Don't worry, we color-blind people are not very sensitive about this ;-p

However, the rule of not using only color for conveying information stands: any combination other than black / gray / white will be confusing for somebody. And imagine the situation with real blind people and screen readers!

For me adding an icon, or even a simple uppercase letter (S for stable, U for unstable, D deprecated) would be more than welcomed.

[killercup]

I couldn't help but think of icons for this.

state	icon
stable	😃
unstable	⚠️
deprecated	💀

[steveklabnik]

@killercup that is.... amazing

[vogon]

some prior art: developer.mozilla.org uses icons for "deprecated" and "unstable", as well:

[killercup]

@steveklabnik, thanks. I was gonna go with ❄️ for "deprecated", but then stable APIs are kinda frozen…

I'd prefer to use a monochrome icon font, though, using the old colors ;)

[lilyball]

I like the icons idea. They'd also provide good touch targets for revealing the stability info (which is important for non-touch devices as well; users may not know to expect a tooltip, and you can't copy text from a tooltip).

[aturon]

I also really like the idea of icons; I think we should remove the little color blobs altogether. I also think that stable APIs should have no marking (they should be the default), and the icons should go to the right as in the above comment. That would help with some other alignment issues as well.

[rodrigorc]

@aturon: Agreed. I like the mozilla style best. Profesional and easy to see from a distance.

About the tooltip information, I would keep it as tooltip in content lists, such as members of a crate, but promote it to full paragraph when viewing the details. After all, the reason for unstability is IMO quite important.