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Re: [css3-transitions] Transitions from display:none

From: Boris Zbarsky <bzbarsky@MIT.EDU>
Date: Fri, 13 Jan 2012 15:10:13 -0500
Message-ID: <4F108FA5.5090904@mit.edu>
To: www-style@w3.org
On 1/13/12 2:47 PM, Tab Atkins Jr. wrote:
> Deciding whether an operation
> should or shouldn't flush styles is fairly easy, after all.

Two more issues here:

1) You speak of "flushing styles", but there is no such thing.  What 
there _is_, conceptually, is flushing value of particular style 
properties as they're needed.  Currently Gecko only computes the 
property values that matter (so e.g. if you're visibility:hidden we 
might not bother computing color).  I believe the transition code sort 
of works around that by computing values it decides it cares about after 
the fact, but that seems like an implementation detail.

2) _Forbidding_ flushes on operations is flat-out impossible, imo.  For 
example, a browser extension might notice your value change and do 
something that requires layout information.  Or a "core" part of the 
browser might do the same thing.  You, as the web page author, just 
don't control the code that will run as a result of various operations; 
neither do the spec writers and often enough browser vendors.

-Boris
Received on Friday, 13 January 2012 21:33:55 GMT

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