Loading ...
Sorry, an error occurred while loading the content.
 

RE: [XSL-FO] em

Expand Messages
  • Joshua Kimmel
    If that s true about using the em, that it doesn t change based on the font sizes with in my fo document, then that s cool. I won t use it. But if that s
    Message 1 of 11 , May 14, 2001
      If that's true about using the em, that it doesn't change based on the font
      sizes with in my fo document, then that's cool. I won't use it. But if
      that's true, then I'm confused as to why the FOP designers provide any
      support for it at all, which they seem to do, just strange inconsistent
      support.
      I guess I was just hoping to see if anyone knew how to set the font in one
      place in the fo document, such that using em would recognize it as the
      parent font of the document and therefore whenever I change the font size or
      style, it would change the preferred sizes of the wherever I had used the em
      unit.

      My old method was to measure the width of the "M" in whatever font manually,
      then code it in as a variable, and then just multiply by it wherever I
      needed to maintain a size of say exactly 60 characters in the specified
      font.

      Additionally, I haven't found anything that says that the current use of the
      em unit is equal to the fonts current size. CSS books still claims its use
      as being equal to the M of the current font, and fop's support for the em
      unit doesn't hold up to that either.

      Josh

      _________________
      Josh Kimmel
      Content Developer
      iam technology


      ******************************************
      <confusion/>

      I'm not sure what CSS has to do with this; we're talking about XSL here.

      An "em" started as the size of the metal body of an M in a typeface, but
      has now come to mean a linear unit of measurement equal to the current font
      size. When working with a twelve-point font, 1 em == 12 pt. This should
      work equally well in print or on-line, and is in fact preferable to
      absolute measurement on-line, since all measurements will scale if the user
      changes his or her preferred font size.

      But this question was about FOP. FOP produces PDF, which is a static
      format designed for printing. Even when viewed on line, the text still
      can't be resized, and so therefore an em doesn't change.

      -Chris
      --
      Christopher R. Maden, XML Consultant
      DTDs/schemas - conversion - ebooks - publishing - Web - B2B - training
      <URL: http://crism.maden.org/consulting/ >
      PGP Fingerprint: BBA6 4085 DED0 E176 D6D4 5DFC AC52 F825 AFEC 58DA


      To unsubscribe from this group, send an email to:
      XSL-FO-unsubscribe@egroups.com



      Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    • Tony Graham
      ... From the XSL CR: 5.9.7.2. Relative Lengths A relative length is a unit-based value that is measured against the current value of the font-size property.
      Message 2 of 11 , May 14, 2001
        Joshua Kimmel wrote at 14 May 2001 09:38:47 -0400:
        > Additionally, I haven't found anything that says that the current use of the
        > em unit is equal to the fonts current size. CSS books still claims its use
        > as being equal to the M of the current font, and fop's support for the em
        > unit doesn't hold up to that either.

        From the XSL CR:

        5.9.7.2. Relative Lengths

        A relative length is a unit-based value that is measured against
        the current value of the font-size property.

        There is only one relative unit of measure, the "em". The
        definition of "1em" is equal to the current font size. For example,
        a value of "1.25em" is 1.25 times the current font size.

        When an em measurement is used in an expression, it is converted
        according to the font-size value of the current property's
        context. The result of the expression is an absolute length. See §
        7.7.4 font-size on page 193

        Regards,


        Tony Graham
        ------------------------------------------------------------------------
        Tony Graham mailto:tony.graham@...
        Sun Microsystems Ireland Ltd Phone: +353 1 8199708
        Hamilton House, East Point Business Park, Dublin 3 x(70)19708
      • Joshua Kimmel
        Hey, now that s some good information. Thank you for pointing it out to me. Josh ... From: Tony Graham [mailto:Tony.Graham@ireland.sun.com] Sent: Monday, May
        Message 3 of 11 , May 14, 2001
          Hey, now that's some good information. Thank you for pointing it out to me.

          Josh

          -----Original Message-----
          From: Tony Graham [mailto:Tony.Graham@...]
          Sent: Monday, May 14, 2001 9:51 AM
          To: XSL-FO@yahoogroups.com
          Subject: RE: [XSL-FO] em


          Joshua Kimmel wrote at 14 May 2001 09:38:47 -0400:
          > Additionally, I haven't found anything that says that the current use of
          the
          > em unit is equal to the fonts current size. CSS books still claims its
          use
          > as being equal to the M of the current font, and fop's support for the em
          > unit doesn't hold up to that either.

          >From the XSL CR:

          5.9.7.2. Relative Lengths

          A relative length is a unit-based value that is measured against
          the current value of the font-size property.

          There is only one relative unit of measure, the "em". The
          definition of "1em" is equal to the current font size. For example,
          a value of "1.25em" is 1.25 times the current font size.

          When an em measurement is used in an expression, it is converted
          according to the font-size value of the current property's
          context. The result of the expression is an absolute length. See §
          7.7.4 font-size on page 193

          Regards,


          Tony Graham
          ------------------------------------------------------------------------
          Tony Graham mailto:tony.graham@...
          Sun Microsystems Ireland Ltd Phone: +353 1 8199708
          Hamilton House, East Point Business Park, Dublin 3 x(70)19708

          To unsubscribe from this group, send an email to:
          XSL-FO-unsubscribe@egroups.com



          Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
        • Christopher R. Maden
          ... An em-spec d measurement can t change *while viewing* a PDF, because the font size can t change. When formatting a document
          Message 4 of 11 , May 14, 2001
            At 06:38 14-05-2001, Joshua Kimmel wrote:
            >If that's true about using the em, that it doesn't change based on the font
            >sizes with in my fo document, then that's cool.

            <confusion amount="more"/>

            An em-spec'd measurement can't change *while viewing* a PDF, because the
            font size can't change. When formatting a document using XSL, 1 em will
            always be the current font size. It won't *change* as such, over time, but
            1 em will mean different lengths in different FOs, depending on the font
            size in use for that FO.

            >My old method was to measure the width of the "M" in whatever font manually,
            >then code it in as a variable, and then just multiply by it wherever I
            >needed to maintain a size of say exactly 60 characters in the specified
            >font.

            Ah. An average character width, unless you're using a fixed-pitch
            typeface, is not going to be 1 em. It will vary based on the face itself;
            a good way to take the measure is to type out the lowercase alphabet in
            that face and measure it.

            >Additionally, I haven't found anything that says that the current use of the
            >em unit is equal to the fonts current size.

            I believe Tony's quote from the spec fulfilled that. Out of curiousity:
            where were you looking?

            >CSS books still claims its use
            >as being equal to the M of the current font, and fop's support for the em
            >unit doesn't hold up to that either.

            Section 4.3.2 of CSS 2 says "em: the 'font-size' of the relevant font";
            section 6.1 of CSS 1 says much the same. If books about CSS disagree with
            the spec, they're wrong. In any case, we're dealing with XSL, which
            addresses a slightly different domain from CSS, and expectations based on
            CSS may prove misleading.

            -Chris
            --
            Christopher R. Maden, XML Consultant
            DTDs/schemas - conversion - ebooks - publishing - Web - B2B - training
            <URL: http://crism.maden.org/consulting/ >
            PGP Fingerprint: BBA6 4085 DED0 E176 D6D4 5DFC AC52 F825 AFEC 58DA
          • Joshua Kimmel
            I appreciate the information I ve been given. I believe I have been schooled effectively. :) 1st lesson learned. Read spec more carefully. 2nd lesson.
            Message 5 of 11 , May 14, 2001
              I appreciate the information I've been given. I believe I have been
              "schooled" effectively. :)

              1st lesson learned. Read spec more carefully.
              2nd lesson. Don't trust all CSS information to be mostly true in FO.
              3rd lesson. read better books.

              Now that I feel I have a better understanding of the em in the FO realm, has
              anybody used it in FOP?

              I mean, if I'm using it to determine a column width, and I have multiple
              fonts and sizes within my document, how do I code so a specific font is
              within the scope of that column width?

              Josh


              At 06:38 14-05-2001, Joshua Kimmel wrote:
              >If that's true about using the em, that it doesn't change based on the font
              >sizes with in my fo document, then that's cool.

              <confusion amount="more"/>

              An em-spec'd measurement can't change *while viewing* a PDF, because the
              font size can't change. When formatting a document using XSL, 1 em will
              always be the current font size. It won't *change* as such, over time, but
              1 em will mean different lengths in different FOs, depending on the font
              size in use for that FO.

              >My old method was to measure the width of the "M" in whatever font
              manually,
              >then code it in as a variable, and then just multiply by it wherever I
              >needed to maintain a size of say exactly 60 characters in the specified
              >font.

              Ah. An average character width, unless you're using a fixed-pitch
              typeface, is not going to be 1 em. It will vary based on the face itself;
              a good way to take the measure is to type out the lowercase alphabet in
              that face and measure it.

              >Additionally, I haven't found anything that says that the current use of
              the
              >em unit is equal to the fonts current size.

              I believe Tony's quote from the spec fulfilled that. Out of curiousity:
              where were you looking?

              >CSS books still claims its use
              >as being equal to the M of the current font, and fop's support for the em
              >unit doesn't hold up to that either.

              Section 4.3.2 of CSS 2 says "em: the 'font-size' of the relevant font";
              section 6.1 of CSS 1 says much the same. If books about CSS disagree with
              the spec, they're wrong. In any case, we're dealing with XSL, which
              addresses a slightly different domain from CSS, and expectations based on
              CSS may prove misleading.

              -Chris
              --
              Christopher R. Maden, XML Consultant
              DTDs/schemas - conversion - ebooks - publishing - Web - B2B - training
              <URL: http://crism.maden.org/consulting/ >
              PGP Fingerprint: BBA6 4085 DED0 E176 D6D4 5DFC AC52 F825 AFEC 58DA


              To unsubscribe from this group, send an email to:
              XSL-FO-unsubscribe@egroups.com



              Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
            Your message has been successfully submitted and would be delivered to recipients shortly.