1613488 - URL bar navigations in Fenix are slowed down by browser resizing

Status: RESOLVED MOVED

(GeckoView :: General, defect)

Description

[Markus Stange [:mstange]]

This profile of me pressing enter on "google.com" in the Fenix URL bar shows two IPCOut messages in the parent process marker chart that are causing extra work in the content process: "PBrowser::Msg_UpdateDimensions — sent to Web Content (Thread ID: 644)" and "PBrowser::Msg_UpdateEffects — sent to Web Content (Thread ID: 644)". These messages indicate that some resizing is going on.
In the content process, the resizes create additional work from extra restyles, reflows and paints. Depending on the complexity of the page that is currently loaded, this extra work can slow down navigations by a long time.

The browser is not visible while the URL bar is focused. Is it resized because the keyboard appears? Is this a Fenix bug?

Comment 1

[James Willcox (:snorp) ([e-mail]) (he/him)]

I think this is the same as bug 1583575.

Comment 2

[Markus Stange [:mstange]]

I'm seeing this when I navigate to a new URL in an existing tab. Do we use the initial size in that case, too?

Comment 3

[James Willcox (:snorp) ([e-mail]) (he/him)]

(In reply to Markus Stange [:mstange] from comment #2)

I'm seeing this when I navigate to a new URL in an existing tab. Do we use the initial size in that case, too?

Oh. No, there shouldn't be. Unduping!

Comment 4

[James Willcox (:snorp) ([e-mail]) (he/him)]

(Though obviously we still want to fix bug 1583575)

Comment 5

[Markus Stange [:mstange]]

(In reply to Markus Stange [:mstange] from comment #0)

The browser is not visible while the URL bar is focused. Is it resized because the keyboard appears? Is this a Fenix bug?

So yeah, based on the sizes of the screenshots captured by the profiler, it really looks like we're resizing GeckoView to make space for the keyboard.

Comment 6

[James Willcox (:snorp) ([e-mail]) (he/him)]

(In reply to Markus Stange [:mstange] from comment #5)

(In reply to Markus Stange [:mstange] from comment #0)

The browser is not visible while the URL bar is focused. Is it resized because the keyboard appears? Is this a Fenix bug?

So yeah, based on the sizes of the screenshots captured by the profiler, it really looks like we're resizing GeckoView to make space for the keyboard.

Ah, in that case there isn't much we can do. The app can choose a different mode where the keyboard is shown on top, but that introduces other issues (like not being able to see fields, etc).

Comment 7

[Markus Stange [:mstange]]

Attachment: screen when URL bar is focused

Resizing when the web page is visible is the right thing to do, sure! But when the URL bar is focused, the web page is not visible.

Comment 8

[James Willcox (:snorp) ([e-mail]) (he/him)]

Apparently the GeckoView instance is still in the hierarchy when the resize occurs. Fenix might be able to avoid this with some careful trickery.

Comment 9

[James Willcox (:snorp) ([e-mail]) (he/him)]

GeckoView can't really do anything about the resizing issue. This needs to be followed up in Fenix (or A-C).

Comment 10

[Emily Toop (:fluffyemily)]

Raised against Fenix as https://github.com/mozilla-mobile/fenix/issues/8399