90579 - Add option to convert pixel font sizes to point

Status: RESOLVED WONTFIX

(Core :: CSS Parsing and Computation, enhancement)

Description

[Michael Dayah]

It would be very nice if there were an option to convert all pixel font-sizes 
set with CSS to point sizes. Using 12px or so to specify a default size for a 
document is becoming commonplace (bestbuy.com, netscape.com, go.com, 
hotmail.com, zdnet.com).

At anything above ~120dpi, small px font sizes are nearly invisible. It would 
be nice for those of us with high dpi displays, which will likely be dominant 
by the time Mozilla is released, to be able to read text without scaling every 
font on every page, most of which are just fine thanks to relative sizes.

The URL for this bug is just a long-winded argument for such a feature. Not 
necessary to read.

Comment 1

[sairuh (rarely reading bugmail)]

->gerv?

Comment 2

[Gervase Markham [:gerv]]

No :-) This would need backend support which I am not qualified to provide. rbs 
is in the area at the moment. rbs?

Gerv

Comment 3

[rbs]

Dup of bug 30910? If so, my font changes in bug 74186 has a fix for this.

Comment 4

[Michael Dayah]

I'm not sure I'd call it a duplicate. Maybe an alternate solution to the same 
problem. One issue is that authors may use different sizes to illustrate 
various level headings. 14px for top level, then 12 and 10. I'd select 14px for 
minimum size and lose all hierarchical information. Whereas 8pt is probably 
acceptable and above my minimum pixel size (at high dpi).

Comment 5

[rbs]

OK I see what you mean.

All the computations are done internally in a common base unit of reference 
called "twips". So 'pt', 'px', 'mm', etc, are converted internally to "twips".
And there are functions for PixelsToTwips and TwipsToPixels conversions, using a 
factor derived by the system from the dpi setting. So what you are asking is a 
configurable factor for the 'px' case to override the factor would otherwise be 
computed from the dpi setting. Nice to have, but not something that I can look 
at as I have other things in my plate.

Adding 'helpwanted' if that could make someone pick up the torch from the 
details I gave above.

Comment 6

[Gervase Markham [:gerv]]

This isn't one of mine :-)

Gerv

Comment 7

[Boris Zbarsky [:bzbarsky]]

Note that CSS "px" are not the same as screen "px".  This should be fixed by a
proper implementation of the CSS "px" unit.

Comment 8

[Gábor Stefanik]

Is this still an issue now that bug 177805 is gone?

Comment 9

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

While there are things we could do to improve users' ability to deal with poorly designed Web sites, I don't think the proposal in this bug is where we should focus our energy.  I think there are other approaches that are likely to help users more by being less destructive to the appearance and behavior of the Web sites they're trying to use.  So I don't think this approach is the way forward; I think if we want to do work here it should probably begin by studying problems that users have.