- From: Glenn Maynard <glenn@zewt.org>
- Date: Thu, 20 Jan 2011 18:33:16 -0500
- To: Drew Wilson <atwilson@google.com>
- Cc: Alex Komoroske <komoroske@chromium.org>, Boris Zbarsky <bzbarsky@mit.edu>, public-webapps@w3.org
- Message-ID: <AANLkTi=8ZMGcjfNZfwz0VJjMthzY7ooOEUVcP38iGjr9@mail.gmail.com>
On Thu, Jan 20, 2011 at 4:24 PM, Drew Wilson <atwilson@google.com> wrote: > In the latter case, I actually don't think your current definition of > visible ("is the focused tab in some browser window somewhere, even if that > window is completely obscured by other windows") adequately addresses that > use case (either the page would just hook focus/blur(), or it would really > want to know if its actually visible to the user, rather than just being the > topmost tab in a completely obscured window. It permits treating obscured windows as visible, since detecting a fully obscured window in every possible case may be difficult, but browsers should be strongly encouraged to treat obscured windows as hidden whenever possible. There's a big difference between a window maximized on my secondary monitor but not focused, and a window in a background tab that's not visible at all. On Wed, Jan 19, 2011 at 9:22 PM, Alex Komoroske <komoroske@chromium.org> wrote: > Use cases Some other use cases: - A page that's rendering animations (whether cosmetically, or for a game) can suspend them, and any related timers, to save resources if it's not visible. - If a page is playing a video and filtering video pixel data through a worker (eg. to apply a gamma curve), it can suspend the possibly expensive filter while it's not visible. - If a page is playing a video with no audio, it can pause the video when it's not visible. (You probably don't want to do this with video containing audio, though that's also possible.) (In principle, a live video stream with audio and video could suspend the video part of the stream when not visible, to save a significant amount of bandwidth, but of course that would need protocol and API support that may never exist.) -- Glenn Maynard
Received on Thursday, 20 January 2011 23:33:49 UTC