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Re: [css-device-adaptation] New draft

From: Charles Pritchard <chuck@jumis.com>
Date: Mon, 18 Oct 2010 08:50:29 -0700
Message-ID: <4CBC6CC5.7090208@jumis.com>
To: timeless <timeless@gmail.com>
CC: Rune Lillesveen <rune@opera.com>, www-style@w3.org
  On 10/18/2010 6:50 AM, timeless wrote:
> On Mon, Oct 18, 2010 at 4:31 PM, Rune Lillesveen<rune@opera.com>  wrote:
>>> It might be the case that user agents need to implement a zoom which
>>> lets users know about events that happen beyond the zoomed area or
>>> something, but I don't think it's ever reasonable to assume that
>>> allowing zooming would be user unfriendly.
>> I was thinking about cases where the user accidentally changes the zoom
>> factor making it somewhat inconvenient to get back to a zoom factor where
>> the app is usable.
> This is a UA failing. I've been talking to colleagues about things
> like this recently. It's important to provide something like an undo,
> especially for devices where the input surface is flaky and it's easy
> to accidentally do something (like ruin the zoom).
> The fix is to improve the UA, not to tell the UA not to support the feature.
The fix, for some time, has been to allow authors to disable zoom in the 
UA: this is a standard on mobile devices.
In this case, I think it's important to recognize that there are 
use-cases where zoom becomes a usability issue, and "magnify" is more 

On the topic of zoom in web-apps:
I recently did some quirk-work, using window.outerWidth and 
window.innerWidth  to guesstimate the current zoom factor.
It seems to me that the UA should alter window.devicePixelRatio upon 
zoom actions -- the one I was working in does not.

Anyway, my point there: zoom is actually quite useful for web apps -- 
we've made our GUI respond appropriately.

It seems again, that there is still a question of zoom vs magnify. Zoom 
is intended to enlarge the UI and shrink window.innerWidth.
Magnify is intended to display a portion of the window, at a larger 
magnification level, without altering the model.

Within the context of our web app, both modalities are valid/useful. 
And, so is the option of disabling zoom, on small screens (like the iPhone).

I think, as discussion goes on around viewport, magnify should be 
further reviewed.

Received on Monday, 18 October 2010 15:50:57 UTC

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