469412 - remove native widgets from xul decks

Status: RESOLVED FIXED

(Core :: XUL, defect)

Description

[Brad Lassey [:blassey] (use needinfo?)]

Attachment: "turn off" native widgets in deck implimentation

Deck elements have been a significant performance problem for mobile, presumably because they create native widgets.

Comment 1

[Brad Lassey [:blassey] (use needinfo?)]

Attachment: test

Comment 2

[Brad Lassey [:blassey] (use needinfo?)]

Attachment: test results

Comment 3

[Boris Zbarsky [:bzbarsky]]

I assume you tested things like iframes in decks?  And trees in decks?  Trees in decks are why that code is there in the first place (see bug 43206).

I'm not quite sure what the test attached here is testing, fwiw.

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Some people use decks to work around bug 130078. Changing this would break them.

Comment 5

[Robert O'Callahan (:roc) (email my personal email if necessary)]

For that reason I think I'd prefer it if we turned off widgets based on checking some attribute of the <deck>, say <deck lightweight="true">.

Comment 6

[Brad Lassey [:blassey] (use needinfo?)]

(In reply to comment #5)
> For that reason I think I'd prefer it if we turned off widgets based on
> checking some attribute of the <deck>, say <deck lightweight="true">.

One thing that concerns me is an extension introducing a major performance problem by inadvertently.  If there was a flag, it might be better for it to be <deck forcenative="true"/>

Do you have an example of where someone is using this work around?

Comment 7

[Neil Deakin]

(In reply to comment #6)
> One thing that concerns me is an extension introducing a major performance
> problem by inadvertently.  If there was a flag, it might be better for it to be
> <deck forcenative="true"/>

That wouldn't be backwards compatible. If mobile wants all decks to not use widgets then maybe a preference or build-time option would be better. Essentially we don't want to have to have developers think about this kind of low-level thing, especially when we want to remove these widgets anyway.

Comment 8

[Robert O'Callahan (:roc) (email my personal email if necessary)]

(In reply to comment #6)
> (In reply to comment #5)
> > For that reason I think I'd prefer it if we turned off widgets based on
> > checking some attribute of the <deck>, say <deck lightweight="true">.
> 
> One thing that concerns me is an extension introducing a major performance
> problem by inadvertently.  If there was a flag, it might be better for it to be
> <deck forcenative="true"/>
> 
> Do you have an example of where someone is using this work around?

I don't have an example at hand, but I know that this work-around has been recommended to people in the past.

The safe thing to do here is to be backwards compatible. If we want to use a pref to switch this behaviour for mobile, that's OK with me. I could even accept an #ifdef, since I expect to be getting rid of these widgets anyway.

Comment 9

[Brad Lassey [:blassey] (use needinfo?)]

Attachment: ifdef's based on MOZ_GFX_OPTIMIZE_MOBILE

Comment 10

[:Gavin Sharp [email: [e-mail]]]

Perhaps MOZ_GFX_OPTIMIZE_MOBILE should be renamed to MOZ_OPTIMIZE_MOBILE if it's going to be used outside of gfx.

Comment 11

[Brad Lassey [:blassey] (use needinfo?)]

changeset:   23178:aed3c0bdeb72
tag:         qparent
user:        Brad Lassey <[e-mail]>
date:        Mon Dec 29 12:00:12 2008 -0500
summary:     bug 469412 -  remove native widgets from xul decks, mobile only r+sr=roc

Comment 12

[Brad Lassey [:blassey] (use needinfo?)]

pushed http://hg.mozilla.org/releases/mozilla-1.9.1/rev/45db3a2e209f