476063 - [FIX]should construct <legend>s by display when they're not in a fieldset

Status: RESOLVED FIXED

(Core :: Layout: Form Controls, defect)

Description

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

When <legend> elements are not in a fieldset, we should handle their frame construction based on the value of the 'display' CSS property rather than constructing an nsLegendFrame based on the tag name.  (I think HTML5 is using legend for other things, so this is reasonably important.)

Comment 1

[Boris Zbarsky [:bzbarsky]]

Attachment: Like so?

Comment 2

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 359693 [details] [diff] [review]
Like so?

Actually, this might not handle dynamic insertion of legends in a fieldset correctly.  I should double-check that (and write some tests to make sure).

Comment 3

[Boris Zbarsky [:bzbarsky]]

Attachment: Much better (dynamic insertion worked with the old patch, but _parsing_ works with this one!)

Comment 4

[Boris Zbarsky [:bzbarsky]]

The other option is to check our parent frame's content, I guess.

Comment 5

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Comment on attachment 359695 [details] [diff] [review]
Much better (dynamic insertion worked with the old patch, but _parsing_ works with this one!)

Might be good to have a comment explaining this check:
>+       (aParentFrame->GetType() != nsGkAtoms::fieldSetFrame &&
>+        aParentFrame->GetStyleContext()->GetPseudoType() !=
>+          nsCSSAnonBoxes::fieldsetContent))) {


I think checking the frame type is better; we'd want this check if we, in the future, supported changing what fieldsets look like using 'display'.  Then again, that doesn't match html.css...

r+sr=dbaron

Comment 6

[Boris Zbarsky [:bzbarsky]]

Pushed http://hg.mozilla.org/mozilla-central/rev/e99cc373f724

Comment 7

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

It occurs to me... we should probably also have, in forms.css:
  legend { display: block }
so that we're still mostly compatible with what we used to do (and, according to Hixie, what HTML5 intends for legend).

Comment 8

[Anne (:annevk)]

Note that bug 430416 still hinders the HTML5 case.

Comment 9

[Boris Zbarsky [:bzbarsky]]

Sure.  That's a pretty separate issue, though.  At least this fix allows constructing a fieldset-less DOM in which <legend> behaves sanely layout-wise via explicit DOM manipulation.

Agreed on the display thing; checked in http://hg.mozilla.org/mozilla-central/rev/65e8380bf4f9 with that change.

Comment 10

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

And I added a test for the display issue:
http://hg.mozilla.org/mozilla-central/rev/3381c874e76c