[whatwg] "canvas" tag and animations ?

Sjoerd Visscher sjoerd at w3future.com
Tue Jun 14 14:50:53 PDT 2005

Dean Edwards wrote:
> Charles Iliya Krempeaux wrote:
>>> From what I undestood (from what Sjoerd Visscher was saying), is that
>> there is no need for "drawing transactions" because of the way things
>> are done with JavaScript and the DOM.
> Thanks for the very good explanation of "drawing transaction". I wasn't 
> entirely sure what Sjoerd meant and wanted some clarity. I'd still like 
> to know what is meant by "when the script is done". This seems to imply 
> that there is a transaction of some sort. I think it really depends on 
> what he means by "script" in this context. The reason I ask for 
> clarification of these terms is because I'm thinking of how it might be 
> implemented on Internet Explorer. So I'm interested when changes should 
> be applied. I assumed that changes were applied immediately any of the 
> drawing methods were called. Am I missing something?

They are applied immediately (internally in some kind of buffer), but 
not visible.

About "when script is done", most cases are easy. But as always with 
HTML there are hard edge cases.

Script from a script block is done when the last statement in that block 
has been executed. The same goes for onevent attributes.

Another possibility is calling a script function from an internal event, 
like what happens with setTimeout or addEventHandler. Then the script is 
done when the function has been executed. I'm not sure what happens when 
there are more event handlers for the same event.

(I'll leave aside what this means for expression() in CSS in IE)

Sjoerd Visscher

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