Re: [css-display]? Compositing, expensive things, and laziness

On Fri, May 31, 2013 at 9:34 PM, Robert O'Callahan <robert@ocallahan.org>wrote:

> If the transition duration is not much longer than the time required to
> paint the expensive content, that sounds bad no matter what you do, since
> delaying the start of the transition that much will make the UI appear
> unresponsive. Right?
>

No, not if the web author is in full control and able to choose to do other
things in the meanwhile. That is, while the expensive content is being
painted, other things can still happen in the UI (e.g. to go back to an
example from earlier in the thread, a spinner could start up) to make it
feel responsive.


> Is it important to notify the Web page when "the content is ready"? I
> thought we were going to do this entirely in the engine?
>

Without getting such a notification, the page won't know when it's safe to
remove placeholder content, or to make other changes that depend on the
expensive content being visible (e.g. the page might want to stop a spinner
from spinning once the expensive content is visible).

-Ali