Add/map U+2236 RATIO (raised colon) for GNOME/MS Windows Clock compatibility

[Sam Hakala]

I don't know the priority of this issue, but I love the Ubuntu font, and I set it to the native font for my windows (10) machine, and now the clock in the taskbar shows the rectangular 'unknown character' character where the colon is supposed to be (something like this: 23▯45).

[Adolfo Jayme Barrientos (fitojb)]

That would be because the Ubuntu family lacks the RATIO character (U+2236).

[Matthew Paul Thomas (mpt)]

I’m glad you love the Ubuntu font! Unfortunately this problem is a bit complicated and probably can’t be fixed in the font.

A colon usually has its lower dot on the baseline, for consistency with the period (full stop).

.:.:.

In digital clocks, however, many people prefer the colons to be centered on the height of the numerals.

Apple’s San Francisco font achieves this using a “contextual alternate”, where the colon character switches to a different glyph whenever it is surrounded by numerals. <http://graphicdesign.stackexchange.com/questions/68203/vertically-centered-colon-for-time> <https://fontsinuse.com/uses/9788/apple-watch-os-watchos>

From your screenshot, it seems that Windows achieves the same effect by a different method: the clock software uses a different character altogether. It is not a colon, it just looks like one in the Windows standard Segoe UI font. Unfortunately, whichever character that is, it is not one that is present in the Ubuntu font.

People who customize their Android UI have had the same problem with other fonts, apparently because the Android lock screen clock uses the same technique.
<https://www.reddit.com/r/nexus6/comments/3zbh6a/colon_on_lock_screen_not_appearing_after_changing/>
<https://forum.xda-developers.com/nexus-4/help/replaced-stock-font-lock-screen-clock-t3110488>
<https://androidforums.com/threads/lock-screen-clock-has-slash-in-place-of-colon-after-marshmallow-upgrade.1009826/>

I assume the Windows clock isn’t open source, so it would be difficult to tell which character it’s using. One way of doing it would be to switch temporarily to a fallback font <https://en.wikipedia.org/wiki/Fallback_font> that shows the number of the codepoint, rather than just a box.

[Matthew Paul Thomas (mpt)]

Ah, it seems Adolfo posted that comment while I was writing mine. It should be possible to test whether U+2236 is indeed the codepoint being used, by copying the colon character into that slot in a font editor.

[Adolfo Jayme Barrientos (fitojb)]

Note that GNOME Shell also uses U+2236 for its clock…

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.