All entries from August 2010

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  1. Web Fonts, Dingbats, Icons, and Unicode

    Yesterday, Cameron Koczon shared a link to the dingbat font, Pictos, by the talented, Drew Wilson. Cameron predicted that dingbats will soon be everywhere. Symbol fonts, yes, I thought. Dingbats? No, thanks. Jason Santa Maria replied:

    @FictiveCameron I hope not, dingbat fonts sort of spit in the face of accessibility and semantics at the moment. We need better options.

    Jason rightly pointed out the accessibility and semantic problems with dingbats. By mapping icons to letters or numbers in the character map, they are represented on the page by that icon. That’s what Pictos does. For example, by typing an ‘a’ on your keyboard, and setting Pictos as the font-face for that letter, the Pictos anchor icon is displayed.

    Other folks suggested SVG and JS might be better, and other more novel workarounds to hide content from assistive technology like screen readers. All interesting, but either not workable in my view, or just a bit awkward.

    Ralf Herrmann has an elegant CSS example that works well in Safari.

    Falling down with CSS text-replacement

    A CSS solution in an article from Pictos creator, Drew Wilson, relies on the fact that most of his icons are mapped to a character that forms part of the common name for that symbol. The article uses the delete icon as an example which is mapped to ‘d’. Using :before and :after pseudo-elements, Drew suggests you can kind-of wrangle the markup into something sort-of semantic. However, it starts to fall down fast. For example, a check mark (tick) is mapped to ‘3’. There’s nothing semantic about that. Clever replacement techniques just hide the evidence. It’s a hack. There’s nothing wrong with a hack here and there (as box model veterans well know) but the ends have to justify the means. The end of this story is not good as a VoiceOver test by Scott at Filament Group shows. In fairness to Drew Wilson, though, he goes on to say if in doubt, do it the old way, using his font to create a background image and deploy with a negative text-indent.

    I agreed with Jason, and mentioned a half-formed idea:

    @jasonsantamaria that’s exactly what I was thinking. Proper unicode mapping if possible, perhaps?

    The conversation continued, and thanks to Jason, helped me refine the idea into this post.

    Jon Hicks flagged a common problem for some Windows users where certain Unicode characters are displayed as ‘missing character’ glyphs depending on what character it is. I think most of the problems with dingbats or missing Unicode characters can be solved with web fonts and Unicode.

    Rising with Unicode and web fonts

    I’d love to be able to use custom icons via optimised web fonts. I want to do so accessibly and semantically, and have optimised font files. This is how it could be done:

    1. Map the icons in the font to the existing Unicode code points for those symbols wherever possible.

      Unicode code points already exist for many common symbols. Fonts could be tiny, fast, stand-alone symbol fonts. Existing typefaces could also be extended to contain symbols that match the style of individual widths, variants, slopes, and weights. Imagine a set of Clarendon or Gotham symbols for a moment. Wouldn’t that be a joy to behold?

      There may be a possibility that private code points could be used if a code-point does not exist for a symbol we need. Type designers, iconographers, and foundries might agree a common set of extended symbols. Alternatively, they could be proposed for inclusion in Unicode.

    2. Include the font with font-face.

      This assumes ubiquitous support (as any use of dingbats does) — we’re very nearly there. WOFF is coming to Safari and with a bit more campaigning we may even see WOFF on iPad soon.

    3. In HTML, reference the Unicode code points in UTF-8 using numeric character references.

      Unicode characters have corresponding numerical references. Named entities may not be rendered by XML parsers. Sean Coates reminded me that in many Cocoa apps in OS X the character map is accessible via a simple CMD+ALT+t shortcut. Ralf Herrmann mentioned that unicode characters ‘…have “speaking” descriptions (like Leftwards Arrow) and fall back nicely to system fonts.’

    Limitations

    1. Accessibility: Limited Unicode / entity support in assistive devices.

      My friend and colleague, Jon Gibbins’s old tests in JAWS 7 show some of the inconsistencies. It seems some characters are read out, some ignored completely, and some read as a question mark. Not great, but perhaps Jon will post more about this in the future.

      Elizabeth Pyatt at Penn State university did some dingbat tests in screen readers. For real Unicode symbols, there are pronunciation files that increase the character repertoire of screen readers, like this file for phonetic characters. Symbols would benefit from one.

    2. Web fonts: font-face not supported.

      If font-face is not supported on certain devices like mobile phones, falling back to system fonts is problematic. Unicode symbols may not be present in any system fonts. If they are, for many designers, they will almost certainly be stylistically suboptimal. It is possible to detect font-face using the Paul Irish technique. Perhaps there could be a way to swap Unicode for images if font-face is not present.

    Now, next, and a caveat

    I can’t recommend using dingbats like Pictos, but the icons sure are useful as images. Beautifully crafted icon sets as carefully crafted fonts could be very useful for rapidly creating image icons for different resolution devices like the iPhone 4, and iPad.

    Perhaps we could try and formulate a standard set of commonly used icons using the Unicode symbols range as a starting point. I’ve struggled to find a better visual list of the existing symbols than this Unicode symbol chart from Johannes Knabe.

    Icons in fonts as Unicode symbols needs further testing in assistive devices and using font-face.

    Last, but not least, I feel a bit cheeky making these suggestions. A little knowledge is a dangerous thing. Combine it with a bit of imagination, and it can be lethal. I have a limited knowledge about how fonts are created, and about Unicode. The real work would be done by others with deeper knowledge than I. I’d be fascinated to hear from Unicode, accessibility, or font experts to see if this is possible. I hope so. It feels to me like a much more elegant and sustainable solution for scalable icons than dingbat fonts.

    For more on Unicode, read this long, but excellent, article recommended by my colleague, Andrei, the architect of Unicode and internationalization support in PHP 6: The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets.

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