[whatwg] Proposal for a tab visibility API

[Boris Zbarsky]

On 12/9/10 3:19 AM, Markus Ernst wrote:
> Am 09.12.2010 00:12 schrieb Boris Zbarsky:
>> On 12/8/10 5:29 PM, Markus Ernst wrote:
>>> Thus, I'd consider an api for detecting the visibility state of every
>>> HTML element useful (totally visible, partially visible, hidden - or a
>>> percentage value).
>>
>> This is pretty hard to implement, in general. For example, if I put
>> another window over the browser window then whether the content in the
>> browser is visible depends on the exact app running in that window, and
>> on the parts of it overlapping the browser content, right?
>
> Sure. Some applications might even be partially transparent, like some
> fancy-skinned media players.

Yes, that's precisely what I was saying above.  And it's not just 
"fancy-skinned media players".  It's every single app on Windows 7 by 
default (see "Aero glass").  It's a commonly tweaked setting for 
Terminal on Mac.  It's a common setting for terminal windows on Linux.

The fact is, at this point _most_ windows are partially transparent.

-Boris