RE: Tests which are dependent on local fonts and how 'line-height: normal' is computed

On Friday, April 20, 2012 5:40 PM Gérard Talbot wrote:
> Le Mer 18 avril 2012 20:31, "Gérard Talbot" a écrit :
> > Arron,
> > There are more and more tests which I am having difficulties doing
> reftests because
> > 1- they are dependent on how tall the line-height of the pass/fail
> conditions sentence <p> is: this varies from one font to another.
> E.g.:
> > http://test.csswg.org/suites/css2.1/nightly-unstable/html4/background-
> > attachment-applies-to-001.htm
> The amount of blue that we can see depends on the local font used. If I
> > use "DejaVu Serif", then line-height of <p> will be 19px. Therefore
> the
> > amount of blue will be:
> >     16px : body's margin-top collapsing with p's margin-top
> >   +
> >     19px : line-height of p
> >   +
> >     16px : margin-bottom of p
> >   ========
> >     51px
> > which will be substracted from the blue's height (96px) == 45px but if
> > I use "FreeSerif" font, then p's line-height: normal is going
> to
> > be computed as 20px ... which will affect the calculation of the
> height
> > of the blue rectangle that is going to be rendered.
> > Depending on the font used, the height of the blue rectangle can vary
> from 43px (rare and unlikely but possible), 44px (eg FreeSerif), 45px (DejaVu
> Serif).
> > 2- Another issue is that the number of line boxes of the pass/fail
> conditions <p> can become 2 if viewport width is set to minimum 640px;
> again, this would make an ordinary reftest wrong.
> > -----------
> > The solution I see + propose is to break the pass/fail condition into
> 2
> > line boxes when the pass/fail conditions sentence is long and then set
> p {line-height: 1.25em;}
> > The only way to create a reliable reftest is to control the height of
> line boxes.
> 
> 
> Arron,
> 
> I have modified 12 of those background-attachment-applies-to-*
> accordingly so that line-height of <p> sentence would be reliable, accurate
> and so that the associated reftest would be reliable when viewed in a 640px
> wide viewport.
> 
> changeset 3132:e566594c207c

Sounds good. I have a plan to start "again" on updating cases and finally begin reviewing the changes you have made. I should start hat in the next month or so. You will soon see some progress from my side on many of the issues you have logged. :)

--
Thanks,
Arron Eicholz

Received on Monday, 23 April 2012 15:41:56 UTC