Re: Set Window Size

On 18/05/16 13:06, Andreas Tolfsen wrote:
> Clay Martin <clmartin@microsoft.com> writes:
>
>> Sam Uong <samuong@google.com> writes:
>>
>>> Does this look at the content of the page, or does it wait for
>>> (something like) window.outerHeight/Width to change?
>>
>> We currently just set the frame to resize and the rest propagates but
>> we plan to change that to verify content also resizes as we've seen
>> issues related to screenshot because of it (user resizes, takes a
>> screenshot and the height/width is incorrect because the resize hasn't
>> finished, adding a sleep fixed it for the user).
>
> I feel the specification in its current form implies
> that the command should be performed synchronously in
> http://w3c.github.io/webdriver/webdriver-spec.html#set-window-size,
> although it uses a rather hand-wavy language to achieve it.
>
> Previously we had a paragraph near the top of the document stating that
> WebDriver provided a (mostly) blocking and synchronous API. Do you feel
> it is worth pointing this out as something applying to the spec as a
> whole?
>
> Related to Set Window Size directly, do we feel it is necessary to add a
> provision to wait for the window to change its size before returning?
>

The window may never change its size e.g. if you have a tiling wm it may 
ignore windows' requests to change their own size. Or the size may 
change multiple times e.g. if there is a transition animation that 
exposes intermediate states to the window.

In general I doubt we can make strong guarantees about the behaviour 
across different OSes here. For Servo we have considered implementing 
some logic to wait for a quiescent state in the window size e.g. no size 
changes recorded within 200ms, and then returning whatever the window 
size is at that point. In the case of the WM blocking the size change 
one would therefore incur a mandatory delay before this command returns. 
But I think it should be a rare enough command that making it 
super-performant isn't that important.

Received on Wednesday, 18 May 2016 12:15:56 UTC