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

RE: [XSL-FO] em

Expand Messages
  • Christopher R. Maden
    ... 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,
    Message 1 of 11 , May 14, 2001
    • 0 Attachment
      At 08:28 10-05-2001, Bryan Rasmussen wrote:
      >hmm maybe I'm mistaken, my understanding was that em should be used with the
      >@media print declaration in css as it didn't make any sense outside of a
      >printed medium. Of course I just might have accepted some pedant's prejudice
      >as being true, without thouroughly investigating the matter, although I've
      >noticed that anytime I use em outside of print it totally screws everything.

      <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
    • 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 2 of 11 , May 14, 2001
      • 0 Attachment
        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 3 of 11 , May 14, 2001
        • 0 Attachment
          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 4 of 11 , May 14, 2001
          • 0 Attachment
            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 5 of 11 , May 14, 2001
            • 0 Attachment
              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 6 of 11 , May 14, 2001
              • 0 Attachment
                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.