idea

[rocal...@gmail.com]

I wonder how much our scrollbar implementation costs us. Each
scrollbar instantiates an XBL binding which creates five anonymous
elements, each of which gets a frame and has other overhead. Every
<select> has one scrollbar, every <textarea> has two, every <iframe>
and top-level document has two, and every overflow:auto element has
two. It would be an interesting experiment to remove the XBL binding
and see what difference that makes to Tp. I'll do it next time I need
to play with Talos. If it's a significant improvement, we could build
a specialized XUL element + frame combination that renders a native
scrollbar.

Rob

[smaug]

See also https://bugzilla.mozilla.org/show_bug.cgi?id=384612

[Boris Zbarsky]

rob...@ocallahan.org wrote:
> If it's a significant improvement, we could build
> a specialized XUL element + frame combination that renders a native
> scrollbar.

Didn't we use to do native scrollbars on the Mac and stop doing it because of
z-indexing issues, etc?

Also, how would this play with theming scrollbars?

-Boris

P.S. I think scrollbars do cost us, for what it's worth.

[Jonas Sicking]

Boris Zbarsky wrote:
> rob...@ocallahan.org wrote:
>> If it's a significant improvement, we could build
>> a specialized XUL element + frame combination that renders a native
>> scrollbar.
>
> Didn't we use to do native scrollbars on the Mac and stop doing it
> because of z-indexing issues, etc?
>
> Also, how would this play with theming scrollbars?

If we make the native-theme stuff hook in directly on the <scrollbar>
element, rather than on the individual parts, it would still be possible
to theme, by doing what themes do today. I.e. for the default theme we'd
have the following CSS:

scrollbar {
-moz-appearance: scrollbar;
}

but a theme would have

scrollbar {
-moz-binding: myscrollbar.xml#scrollbar;
}

/ Jonas

[rocal...@gmail.com]

On Sep 25, 1:21 am, Boris Zbarsky <bzbar...@mit.edu> wrote:
> rob...@ocallahan.org wrote:
> > If it's a significant improvement, we could build
> > a specialized XUL element + frame combination that renders a native
> > scrollbar.
>
> Didn't we use to do native scrollbars on the Mac and stop doing it because of
> z-indexing issues, etc?

Yeah. I didn't mean to use an actual native scrollbar. Just a single
frame with -moz-appearance:scrollbar and all scrollbar behaviour coded
directly into it.

Plus what Jonas said.

Rob

[Mike Schroepfer]

Um Awesome. Are there other areas that could use this treatment?

[Damon Sicore]

Is there a bug for this?

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[sayrer]

On Sep 24, 2:25 am, "rob...@ocallahan.org" <rocalla...@gmail.com>
wrote:

> I wonder how much our scrollbar implementation costs us.

I keep seeing scrollbar.xml::initScrollbars in DTrace profiles, so
maybe it costs a lot.

I filed bug 398941 to find out.

- Rob