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Re: Making pt a non-physical unit

From: Jonathan Kew <jonathan@jfkew.plus.com>
Date: Thu, 7 Jan 2010 14:53:09 +0000
Cc: rfink@readableweb.com
Message-Id: <4C9F7B92-932A-4A3C-813E-3D8D50BD88F0@jfkew.plus.com>
To: www-style list <www-style@w3.org>
On 7 Jan 2010, at 14:22, Richard Fink wrote:

> Wednesday, January 06, 2010 7:10 PM <jonathan@jfkew.plus.com>:
>> As for truept: I should be able to specify a touch-screen interface element
> as being 8 truemm high,
>> and put some text inside it using a font-size of 14 truept.
> Jonathan,
> Does what you're saying mean that such an element - set using truept - will
> exist in a sort of "no zoom" zone? And remain at the size specified by the
> author no matter what?

I'd be interested to know what the people who actually want to use true physical dimensions to create such interface elements would say.

My own (perhaps rather vague) thinking is that "true" dimensions would still zoom - along with everything else - in scenarios where the overall display is being zoomed, like when you use pinch gestures on an iPhone, or the accessibility features on Mac OS X. But they would not be affected by "text zoom" features that change the root em unit, and they would resolve to correct physical distances at the default ("100% zoom") display size. In this respect, they'd be unlike "non-true" dimensions, which in the case of very small (or large) devices might be resolved to something quite different from their nominal real-world size.

So, for example, on a desktop or a printed document, 12pt might be a reasonable default text size. On a phone, text specified as "12pt" would actually be rendered substantially smaller, corresponding to the smaller size of "px" on this device. Text specified as "12truept", however, would remain at 12 real-world points at the standard default zoom level. If the user then pinches to zoom the entire display, then the 12truept text (and the 8truemm high box surrounding it, or whatever) will still all zoom together.

Does that make some kind of sense.....?

Received on Thursday, 7 January 2010 14:53:57 UTC

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