[whatwg] Proposal for a tab visibility API

[Boris Zbarsky]

On 12/8/10 5:55 PM, Alex Komoroske wrote:
>     1) "background tab" is pretty narrow.  Minimized windows, windows that
>         aren't on the current desktop, etc, have all the same problems.
>
> In general this can be very challenging to do correctly, as you allude
> to, and others later in the thread mention.  What about windows on a
> second monitor that are partially obscured by another window?  Fully
> obscured?

I explicitly left those out of my list, yes, because they are rather 
difficult to detect.

> This initial API aims to allow developers to detect the obvious cases
> where they are guaranteed that their content is not visible at all.

There is no such guarantee for background tabs.  For example, browsers 
may show tab previews in various contexts (Panorama in Firefox 4, e.g.).

>     2)  There is some potential for abuse (e.g. putting up dialogs to make
>         yourself the active tab if you determine that you aren't, though
>         perhaps this is a quality of implementation issue).  I can
>         particularly see things like ads doing this so you don't just
>         switch to a different tab while they're running.

I'd really appreciate some comment on this.  I'm pretty worried about 
adding features that we then have to start working around people abusing 
almost immediately...

-Boris