Re: [PageVisibility] Need to define interaction with page navigation

On 10/5/11 7:10 PM, Jatinder Mann wrote:
> I don't know if there is value in changing the visibility state properties when the page is unloaded - developers should key off of the unload event to save state and do cleanup work instead. From the UA point of view, to support this behavior might be a lot of work with limited usefulness to the developer. Do you have a scenario in mind where this could be useful?

Well, as I see it we have the following options:

1)  Have .visibilityState/.hidden continue to return "visible" for
     documents that used to be visible and then were unloaded.  Note
     that this is pretty easy to observe, since script can have
     references to unloaded documents.
2)  Have the visibility/hidden state change during unload or load from
     document cache without actually firing an event.
3)  Do what I implemented in Gecko for now, and actually update the
     state and fire the event when pageshow/pagehide fire.

#3 seems like the most self-consistent behavior to me.  Which one of the 
other two are you proposing we specify if you don't like #3?  Or do you 
have a fourth option in mind?

Note, by the way, that documents going into the document cache as well 
as those that are unloaded, end up with a null defaultView in at least 
some UAs, so current spec with agreed-on modifications says that #1 is 
not OK for those UAs.


Received on Thursday, 6 October 2011 03:38:39 UTC