Re: [xsl] FO checkbox from 2 inline ZapfDingbat characters

["Kevin Brown" <kevin@xxxxxxxxxxx>]

Jacobus:

> how will something like this be supported on the
various FO processors

Can't help you there, we only tend to test with our own product :). That
said, it basically says lay down one character and then move an additional
-"X"pt's to place the next character. Negative values for letter spacing are
allowed according to the standard so it really isn't a trick. In fact, this
is how many composite characters are composed in several languages. It works
perfectly in RenderX.

> also in different output mediums.

PDF works fine with negative letter spacing and so does our Postscript and
PPML output. Our XPS output would also work but you would have to use
Truetype fonts and not Adobe fonts with XPS. SVG would work but not how you
may think -- RenderX SVG output maps text directly from our intermediate
format. Our SVG output would create two different <svg:text> elements at
absolute positions, one over the other. AFP would probably not be supported
as it doesn't support negative letter spacing, I did not test that. I also
don't think that our HTML output would work, it is created much like SVG.
The absolute <div>'s would overlap and the second character's <div> would
obscure the top one.

Note: I would recommend this solution for PDF above all others. Embedding a
font subset for one or a few characters is a waste. In fact, many think the
solution is to dig out their old copy of Arial Unicode MS just to extract a
few characters. That font is copyrighted and users should be aware of use
restrictions. It is also huge and would slow rendering time just to dig out
one character. Lastly, it includes a huge header that can add 200kb to the
size of a PDF for only one character. That is, for FO Renderers that do the
right thing according to copyright laws and include all the prologue for the
font when embedding as RenderX does.

When dealing with PDF and Postscript, there are advantages to try and stay
within the base 14 font set when possible.

Kevin Brown
RenderX


------------------------------

Date: Wed, 24 Mar 2010 09:34:23 +0200
To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
From: Jacobus Reyneke <jacobusreyneke@xxxxxxxxx>
Subject: Re: [xsl] FO checkbox from 2 inline ZapfDingbat characters
Message-ID: <226b4e0b1003240034k585d894dk8674e35c86f04d44@xxxxxxxxxxxxxx>

> You can also use a little known trick ....
>
> <fo:block font-size=3D"12pt">
> =C2=A0 =C2=A0 =C2=A0 =C2=A0<fo:inline font-family=3D"ZapfDingbats" letter=
-spacing=3D"-12pt">=E2=9D=8F</fo:inline>
> =C2=A0 =C2=A0 =C2=A0 =C2=A0<fo:inline font-family=3D"ZapfDingbats" baseli=
ne-shift=3D"2pt">=E2=9C=93</fo:inline>
> </fo:block>
>
> You set the letter-spacing to the negative value of the font-size. You ma=
y need to also adjust the baseline-shift for larger fonts (a little larger)=
.
>
> Kevin Brown
> RenderX

Clever Kevin ;-)

Out of interest, how will something like this be supported on the
various FO processors and also in different output mediums. I suppose
only PDF and SVG will deal with this correctly, or am I being stupid
again?