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Prevent about:home from creating a full window component alpha layer

RESOLVED FIXED in Firefox 13

Status

()

Firefox
General
RESOLVED FIXED
5 years ago
3 years ago

People

(Reporter: bas, Assigned: fryn)

Tracking

13 Branch
Firefox 14
Points:
---
Dependency tree / graph

Firefox Tracking Flags

(firefox13 fixed)

Details

(Whiteboard: [qa-])

Attachments

(1 attachment)

(Reporter)

Description

5 years ago
The google interface at about:home in our nightlies appears to create a full window size component alpha layer. From the looks of the page that seems needlessly complicated. It's possible we're doing something suboptimal.
It's the fixed background:

html {
  background-color: hsl(0,0%,90%);
  background-image: url(chrome://browser/content/abouthome/noise.png),
                    -moz-linear-gradient(hsla(0,0%,100%,.7), hsla(0,0%,100%,.4));
}

I can't actually tell what the background images are doing ... the background looks like a solid color to me.
Component: Layout → General
Product: Core → Firefox
QA Contact: layout → general
Target Milestone: --- → Firefox 13
oh, there's a "background-attachment: fixed;" rule in aboutHome.css that I accidentally trimmed.

I'm pretty sure we don't need that rule, at least.
(Assignee)

Comment 3

5 years ago
(In reply to Robert O'Callahan (:roc) (Mozilla Corporation) from comment #1)
> I can't actually tell what the background images are doing ... the
> background looks like a solid color to me.

It's not a solid color. It's a noise texture, but yes it is subtle and intentionally so.
See the following sites for other examples of this type of noise texture in their backgrounds:
https://www.youtube.com/
http://cl.ly/2F3M1T0L3E3h2C3A3f2X

(In reply to Robert O'Callahan (:roc) (Mozilla Corporation) from comment #2)
> oh, there's a "background-attachment: fixed;" rule in aboutHome.css that I
> accidentally trimmed.
> 
> I'm pretty sure we don't need that rule, at least.

No, we don't. Does removing that rule fix this bug?
(Assignee)

Comment 4

5 years ago
Created attachment 610565 [details] [diff] [review]
patch

The background-attachment shouldn't be `fixed` anyway.
Assignee: nobody → fryn
Status: NEW → ASSIGNED
Attachment #610565 - Flags: review?(mak77)
Comment on attachment 610565 [details] [diff] [review]
patch

Review of attachment 610565 [details] [diff] [review]:
-----------------------------------------------------------------

I thought was part of the design specs, good to know it's not.

Btw, it's still unclear, if this is really a perf problem, of which size? This is becoming more common on the Web (the transparent texture) as pointed out, is there a problem at the platform level or just it's something we should evangelize against?
And finally, if just removing the fixed is enough to solve the perf problem.
Attachment #610565 - Flags: review?(mak77) → review+
The problem is not the texture, it's 'background-attachment:fixed'.

It's not a big problem. Probably no-one would have noticed if Bas hadn't been doing some testing. But making about:home a bit faster to render, with a bit less memory usage, is worth it.

We could fix this case with an optimization in the engine. The reason we use extra resources here is so that we create a separate layer for the fixed background so that scrolling is snappy if you scroll the page. about:home usually doesn't need a scrollbar so we can expect that scrolling won't happen. We could detect that and turn off the separate layer for that case. But we have no data to indicate whether that would be worth doing in general.
(Assignee)

Comment 7

5 years ago
(In reply to Robert O'Callahan (:roc) (Mozilla Corporation) from comment #6)
> The problem is not the texture, it's 'background-attachment:fixed'.

Great! I'm glad you and Bas caught this, since background-attachment should have been `scroll` design-wise anyway, but we didn't notice it, since as you noted "about:home usually doesn't need a scrollbar". :)

Thanks, mak, for the review. :)

https://hg.mozilla.org/integration/fx-team/rev/7cc16b3f172d

Should this get ported to aurora?
Summary: about:home on nightlies creates a full window component alpha layer → Prevent about:home from creating a full window component alpha layer
Whiteboard: [fixed-in-fx-team]
Might as well, it's minimal risk.
(Assignee)

Comment 9

5 years ago
Comment on attachment 610565 [details] [diff] [review]
patch

[Approval Request Comment]
User impact if declined: Slower rendering and more memory usage for about:home.
Risk to taking this patch: None.
String changes made by this patch: None.
Attachment #610565 - Flags: approval-mozilla-aurora?
OS: Windows 7 → All
Hardware: x86_64 → All
Target Milestone: Firefox 13 → Firefox 14
Version: unspecified → 13 Branch
https://hg.mozilla.org/mozilla-central/rev/7cc16b3f172d
Status: ASSIGNED → RESOLVED
Last Resolved: 5 years ago
Resolution: --- → FIXED
Whiteboard: [fixed-in-fx-team]
Comment on attachment 610565 [details] [diff] [review]
patch

[Triage Comment]
Very simple, low-risk change in support of about:home perf. Approved for Aurora 13.
Attachment #610565 - Flags: approval-mozilla-aurora? → approval-mozilla-aurora+
https://hg.mozilla.org/releases/mozilla-aurora/rev/01fbbc855886
status-firefox13: --- → fixed
(Assignee)

Updated

5 years ago
Blocks: 711157
(Assignee)

Updated

5 years ago
Depends on: 746466
Is there a test QA can use to verify this fix?
Whiteboard: [qa?]
(Assignee)

Comment 14

5 years ago
(In reply to Anthony Hughes, Mozilla QA (irc: ashughes) from comment #13)
> Is there a test QA can use to verify this fix?

I don't know, but it's not necessary, imho.
Whiteboard: [qa?] → [qa-]
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