[whatwg] Deferring image load
svartman95 at gmail.com
Mon Feb 13 06:29:30 PST 2012
On Mon, 13 Feb 2012 14:17:28 -0000, Boris Zbarsky <bzbarsky at mit.edu> wrote:
> This is a difficult optimization to make. You can only do it for images
> that have a height and width specified in the markup, and worse yet it
> leads to pretty bad flicker as the user scrolls (because network
> roundtrip times are measured in hundreds of milliseconds to seconds). So
> doing this by default is not likely to happen. Having a page opt into
> it is a different story, though.
Well, UAs would fetch the images to be displayed first first, and then
prefetch images until they have more than a screenful of undisplayed
content loaded. But yes, fast scrolling would break this. Not even knowing
the rough size of images before fetching them makes them hard to lay out
until they have been downloaded.
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