Re: [web-animations] please, clarify "The current ready promise is initially a resolved Promise"

Hi Aleksei,

On 2015/01/16 20:16, Aleksei Semenov wrote:
> The Web Animations specification
> http://w3c.github.io/web-animations/#the-current-ready-promise
> reads:
>
>> Each player has a current ready promise.The current ready promise is
>> initiallya resolved Promise created using theprocedure to create a new
>> resolved Promise.
>
> Could you clarify what does "initially" mean?
> Does it mean that right after creation of AnimationPlayer instance
> its attribute 'ready' is a resolved Promise object?

Yes.

This is the same for all properties of all objects. For example, the 
start time and hold time of a player are described as "initially 
unresolved".

How would you like me to clarify this?

> AnimationPlayer instance can be created via AnimationPlayer constructor.
> The specification of the constructor
> http://w3c.github.io/web-animations/#dom-animationplayer-animationplayersource-timeline

That procedure builds on the definitions given in the first part of the 
spec. That is, the constructor creates a player object with all 
properties set to their initial values. After that it performs 
additional assignments based on the passed-in arguments.

I understand this separation may be somewhat confusing but it came about 
at the explicit request of Apple that we separate the abstract model 
from the script interface. The request was for two specs but we struck a 
compromise by simply separating the two within the one spec. I suppose 
that's not the way specs are being written these days but it's quite a 
bit of work to revert all that now.

> does not explicitly specify the value of attribute 'ready'.
> The procedures mentioned at steps 2 and 3 are quite complex
> and may or may not affect the attribute 'ready'.

Step 1 sets up the initial state (i.e. resolved) then the subsequent 
steps may modify that.

Best regards,

Brian

Received on Sunday, 18 January 2015 23:49:59 UTC