[whatwg] "canvas" tag and animations ?

Dean Edwards dean at edwards.name
Tue Jun 14 13:30:47 PDT 2005

Sjoerd Visscher wrote:
> Charles Iliya Krempeaux wrote:
>> IMO, it would be better to a have solution to this built into the API.
>>  Maybe with some kind of "drawing transaction".
>> (A "draw transaction" is a little higher level than "double
>> buffering", and allows you use other systems for this, other than
>> "double buffering".  And would probably be safer, considering much of
>> JavaScript is done via events.)
> This isn't needed. Just like in normal HTML a drawing transaction is 
> automatically started when the javascript code starts, and finished when 
> the javascript code is done. And this is how it is implemented in 
> Firefox (don't know about Safari).
> Maybe the spec should describe this somewhere? Not specifically for 
> canvas, but for script in general: Changes on the DOM must be performed 
> instantly, and values like offsetWidth etc. must be recalculated, but 
> only visible when the script is done.

What do you mean when you say "when the script is done" and "drawing 


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