926875 - Move the iframe.focus call out of the hot path to avoid an expensive reflow

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia::System, defect)

Description

[Vivien Nicolas (:vingtetun) (:21) - (NOT reading bugmails, needinfo? please)]

Attachment: move.focus.out.hot.path.patch

Comment 1

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

Comment on attachment 817110 [details] [diff] [review]
move.focus.out.hot.path.patch

Review of attachment 817110 [details] [diff] [review]:
-----------------------------------------------------------------

::: apps/system/js/window_manager.js
@@ +360,5 @@
>        waitForNextPaint(frame, function makeWindowActive() {
>          frame.classList.add('render');
> +
> +        // Giving focus to the frame can create an expensive reflow, so let's
> +        // delay it until the frame has rendered.

Add a simple check here to avoid race condition.
Maybe: frame.classList.contains('active') or something represents it's foreground.

Comment 2

[Vivien Nicolas (:vingtetun) (:21) - (NOT reading bugmails, needinfo? please)]

Attachment: move.focus.out.hot.path.patch

Comment 3

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

Comment on attachment 817114 [details] [diff] [review]
move.focus.out.hot.path.patch

Review of attachment 817114 [details] [diff] [review]:
-----------------------------------------------------------------

r+

Comment 4

[Vivien Nicolas (:vingtetun) (:21) - (NOT reading bugmails, needinfo? please)]

https://github.com/mozilla-b2g/gaia/commit/e7672f8c3e7c52d111f1eedcf406be24c697efa9