739457 - Images loaded into background tabs are decoded immediately

Status: RESOLVED FIXED

(Core :: Graphics: ImageLib, defect)

Description

[Justin Lebar (not reading bugmail)]

I thought setting decodeondraw = true was supposed to make us wait until a tab is focused before we decode its images, but either that's wrong, or it's broken.

Either way, this is particularly problematic now that we have a cap on the amount of decoded image data we'll keep around, because we can end up in the case where we load a background tab, decode all its images, and then immediately throw those images away, because we don't have space for them!

Comment 1

[Justin Lebar (not reading bugmail)]

Attachment: Patch v1

Comment 2

[Joe Drew (not getting mail)]

Comment on attachment 609548 [details] [diff] [review]
Patch v1

I'm not convinced that putting it into a single if statement is actually better for readability, but it's not a big deal.

Comment 3

[Justin Lebar (not reading bugmail)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/20d19312ccc1

Comment 4

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/20d19312ccc1

Comment 5

[Timothy Nikkel (:tnikkel)]

the presshell->IsVisible() check will work for hidden tabs, but it will also report that iframes that have an ancestor with CSS visibility: hidden as not visible. I'm not sure if that is desirable or not.

Also, you might want to also check IsActive on the presshell, I think that now returns false for foreground tabs in minimized windows (which is not covered by IsVisible). Or you might not want to.

Comment 6

[Justin Lebar (not reading bugmail)]

It sounds like IsVisible is at least sensible here.

Comment 7

[Timothy Nikkel (:tnikkel)]

Yeah, I just added those comments in case IsVisible wasn't doing what you expected. But it sounds like it is.