960325 - Move Background into Homescreen App

Status: RESOLVED WORKSFORME

(Firefox OS Graveyard :: Gaia::Homescreen, defect, P1)

Description

[Mason Chang [Inactive] [:mchang]]

Move the background image into the homescreen app and out of the system app. This is so we see the background due to some platform optimizations.

Comment 1

[Mason Chang [Inactive] [:mchang]]

Attachment: Moves background to homescreen app. Credit to benwa.

Comment 2

[Mason Chang [Inactive] [:mchang]]

Attachment: https://www.dropbox.com/s/ji79ad1jeg9fa81/blackScreen.mov

Video of bug w/ this patch and bug 917416 to gecko. We see a black screen where the keyboard was for a split second.

Comment 3

[Mason Chang [Inactive] [:mchang]]

Might be related to bug 942750

Comment 4

[Mason Chang [Inactive] [:mchang]]

Still occurs w/o APZ

Comment 5

[Mason Chang [Inactive] [:mchang]]

Attachment: Layer Tree w/ Background in Homescreen App

Large amount of overpainting if we move the background into the homescreen app.

Comment 6

[Mason Chang [Inactive] [:mchang]]

Attachment: Original Layer Tree of Homescreen App

Comment 7

[Mason Chang [Inactive] [:mchang]]

Attachment: Layer Tree w/ 1 Homescreen

Interestingly, we don't explode the layer tree until after we pan to another homescreen.

Comment 8

[Mason Chang [Inactive] [:mchang]]

Attachment: Analysis of Layer Tree

We should be able to save 2 layers if we clean up dead thebes layers.

Comment 9

[Mason Chang [Inactive] [:mchang]]

Attachment: Layer Tree w/ CSS Tweaks

I was able to modify the css and reduce the homescreen overpainting. We still have 1 extra layer that is 1 pixel somewhere. But the changes + the optimizing the parent layer in bug 917416 puts us back to where we started with the original layer tree.

Comment 10

[Mason Chang [Inactive] [:mchang]]

Attachment: https://github.com/mozilla-b2g/gaia/pull/15919

Hello! We need to move the homescreen background into the homescreen app so we can optimize Gecko in bug 917416. If you could please review, I'd appreciate it. Thanks!

Comment 11

[(inactive after 6/18) Alive Kuo [:alive]]

What's the purpose? Does this mean we couldn't have transparent background anymore?

Comment 12

[Mason Chang [Inactive] [:mchang]]

We need to move the homescreen background into the homescreen app because we were always drawing the background even when other apps were painted over it. I don't think we can have a transparent background, but we couldn't before either. If it is in the system app, and the background is transparent, we would see what was behind it, which was just black. The effect would be the same whether the background was in the system app or homescreen app. Does that answer your question? Thanks!

Comment 13

[(inactive after 6/18) Alive Kuo [:alive]]

Thanks, I know what's the concern here.

Comment 14

[(inactive after 6/18) Alive Kuo [:alive]]

Comment on attachment 8369579 [details] [review]
https://github.com/mozilla-b2g/gaia/pull/15919

I could r+ for this concept but need Christian's feedback on homescreen app part.

Comment 15

[Cristian Rodriguez (:crdlc)]

Comment on attachment 8369579 [details] [review]
https://github.com/mozilla-b2g/gaia/pull/15919

Hi,

    I have some important comments from my point of view in Github. When they are addressed/answered please ask me again for a review

Thanks a lot

Comment 16

[Mason Chang [Inactive] [:mchang]]

Attachment: https://github.com/mozilla-b2g/gaia/pull/16098

Thanks for the feedback. I implemented your comments, please take another look. Thanks.

Comment 17

[Cristian Rodriguez (:crdlc)]

Comment on attachment 8372822 [details] [diff] [review]
https://github.com/mozilla-b2g/gaia/pull/16098

Hi, good job, looks good to me although there are still some details. Basically quick changes :) After addressing them, please ask me again for a review in order to put a R+

Thanks a lot

Comment 18

[Mason Chang [Inactive] [:mchang]]

Comment on attachment 8372822 [details] [diff] [review]
https://github.com/mozilla-b2g/gaia/pull/16098

Thanks for the feedback. Hopefully the last review!

Comment 19

[Cristian Rodriguez (:crdlc)]

Comment on attachment 8372822 [details] [diff] [review]
https://github.com/mozilla-b2g/gaia/pull/16098

Perfect!! Good job, thanks a lot, r+

Comment 20

[Mason Chang [Inactive] [:mchang]]

Attachment: https://github.com/mozilla-b2g/gaia/pull/16128

Thanks for the review! Carrying r+ over.

Comment 21

[(inactive after 6/18) Alive Kuo [:alive]]

I think we still needs to paint background in system app "only" when the homescreen is not loaded yet.
Otherwise if homescreen app is killed by OOM killer and the user returns to homescreen, he will see the 'black' or 'white' background which is very bad.

I am going to file a followup bug inside window management to fix this.

Comment 22

[Mason Chang [Inactive] [:mchang]]

Landed gaia master: 7540b00be89b65b180817564dfb4b8a0701179ca

Comment 23

[Mason Chang [Inactive] [:mchang]]

Backed out on gaia master - 588cfa86532ce38af02182926e4129400232c2e1.
See bug 917416.