NAME
       font - Create and inspect fonts.

SYNOPSIS
       font option ?arg arg ...?

DESCRIPTION
       The  font  command  provides several facilities for dealing with fonts,
       such as defining named fonts and inspecting the actual attributes of  a
       font.  The command has several different forms, determined by the first
       argument.  The following forms are currently supported:

       font actual font ?-displayof window? ?option?
              Returns  information  about  the  actual  attributes  that   are
              obtained  when  font  is  used  on  window's display; the actual
              attributes obtained may differ from the attributes requested due
              to  platform-dependant  limitations, such as the availability of
              font families and pointsizes.  font is a font  description;  see
              FONT  DESCRIPTIONS below.  If the window argument is omitted, it
              defaults to the main window.  If option  is  specified,  returns
              the  value of that attribute; if it is omitted, the return value
              is a list of all the attributes  and  their  values.   See  FONT
              OPTIONS below for a list of the possible attributes.

       font configure fontname ?option? ?value option value ...?
              Query or modify the desired attributes for the named font called
              fontname.  If no option is specified, returns a list  describing
              all  the  options  and  their  values for fontname.  If a single
              option is specified with no  value,  then  returns  the  current
              value  of that attribute.  If one or more option-value pairs are
              specified, then the command modifies the  given  named  font  to
              have the given values; in this case, all widgets using that font
              will redisplay themselves using the new attributes for the font.
              See FONT OPTIONS below for a list of the possible attributes.

       font create ?fontname? ?option value ...?
              Creates  a new named font and returns its name.  fontname speci-
              fies the name for the font; if it is omitted, then Tk  generates
              a  new name of the form fontx, where x is an integer.  There may
              be any number of option-value pairs, which provide  the  desired
              attributes for the new named font.  See FONT OPTIONS below for a
              list of the possible attributes.

       font delete fontname ?fontname ...?
              Delete the specified named fonts.  If there  are  widgets  using
              the  named  font, the named font won't actually be deleted until
              all the instances are released.  Those widgets will continue  to
              display  using  the  last known values for the named font.  If a
              deleted named font is subsequently recreated with  another  call
              to  font  create,  the  widgets  will use the new named font and
              redisplay themselves using the new attributes of that font.

       font families ?-displayof window?
              The return value is a list of the case-insensitive names of  all
              font  families  that  exist  on window's display.  If the window
              argument is omitted, it defaults to the main window.

       font measure font ?-displayof window? text
              Measures the amount of space the string text would  use  in  the
              given  font  when  displayed in window.  font is a font descrip-
              tion; see FONT DESCRIPTIONS below.  If the  window  argument  is
              omitted,  it  defaults  to the main window.  The return value is
              the total width in pixels of text, not including the extra  pix-
              els used by highly exaggerated characters such as cursive ``f''.
              If the string contains newlines or tabs,  those  characters  are
              not expanded or treated specially when measuring the string.

       font metrics font ?-displayof window? ?option?
              Returns  information about the metrics (the font-specific data),
              for font when it is used on window's display.  font  is  a  font
              description;  see  FONT DESCRIPTIONS below.  If the window argu-
              ment is omitted, it defaults to the main window.  If  option  is
              specified,  returns  the value of that metric; if it is omitted,
              the return value is a list of all the metrics and their  values.
              See FONT METRICS below for a list of the possible metrics.

       font names
              The  return value is a list of all the named fonts that are cur-
              rently defined.

FONT DESCRIPTION
       The following formats are accepted as a font description anywhere  font
       is  specified as an argument above; these same forms are also permitted
       when specifying the -font option for widgets.

       [1] fontname
              The name of a named font, created using the font create command.
              When a widget uses a named font, it is guaranteed that this will
              never cause an error, as long as the named font exists, no  mat-
              ter  what  potentially  invalid or meaningless set of attributes
              the named font has.  If the named font cannot be displayed  with
              exactly  the specified attributes, some other close font will be
              substituted automatically.

       [2] systemfont
              The platform-specific name of a font, interpreted by the  graph-
              ics  server.  This also includes, under X, an XLFD (see [4]) for
              which a single ``*'' character was used to elide more  than  one
              field  in  the middle of the name.  See PLATFORM-SPECIFIC issues
              for a list of the system fonts.

       [3] family ?size? ?style? ?style ...?
              A properly formed list whose first element is the  desired  font
              family  and  whose  optional second element is the desired size.
              The interpretation of the size attribute follows the same  rules
              described  for  -size  in  FONT  OPTIONS  below.  Any additional
              optional arguments following the size are font styles.  Possible
              values for the style arguments are as follows:

                     normal      bold        roman      italic
                     underline   overstrike


       [4] X-font names (XLFD)
              A  Unix-centric  font  name  of the form -foundry-family-weight-
              slant-setwidth-addstyle-pixel-point-resx-resy-spacing-width-
              charset-encoding.  The ``*'' character may be used to skip indi-
              vidual fields that the user does not care about.  There must  be
              exactly one ``*'' for each field skipped, except that a ``*'' at
              the end of the XLFD skips any  remaining  fields;  the  shortest
              valid  XLFD  is simply ``*'', signifying all fields as defaults.
              Any fields that were skipped are given default values.  For com-
              patibility, an XLFD always chooses a font of the specified pixel
              size (not point  size);  although  this  interpretation  is  not
              strictly  correct, all existing applications using XLFDs assumed
              that one ``point'' was in  fact  one  pixel  and  would  display
              incorrectly  (generally  larger)  if  the correct size font were
              actually used.

       [5] option value ?option value ...?
              A properly formed list of option-value pairs  that  specify  the
              desired  attributes  of  the  font, in the same format used when
              defining a named font; see FONT OPTIONS below.

       When font description font is used, the system attempts  to  parse  the
       description  according  to  each  of the above five rules, in the order
       specified.  Cases [1] and [2] must match the name of an existing  named
       font  or of a system font.  Cases [3], [4], and [5] are accepted on all
       platforms and the closest available font will be used.  In some  situa-
       tions  it  may  not  be possible to find any close font (e.g., the font
       family was a  garbage  value);  in  that  case,  some  system-dependant
       default  font is chosen.  If the font description does not match any of
       the above patterns, an error is generated.

FONT METRICS
       The following options are used by the font  metrics  command  to  query
       font-specific data determined when the font was created.  These proper-
       ties are for the whole font itself and not  for  individual  characters
       drawn  in that font.  In the following definitions, the ``baseline'' of
       a font is the horizontal line where the bottom of most letters line up;
       certain letters, such as lower-case ``g'' stick below the baseline.

       -ascent
              The amount in pixels that the tallest letter sticks up above the
              baseline of the font, plus any extra blank space  added  by  the
              designer of the font.

       -descent
              The  largest  amount in pixels that any letter sticks down below
              the baseline of the font, plus any extra blank  space  added  by
              the designer of the font.

       -linespace
              Returns  how  far  apart  vertically in pixels two lines of text
              using the same font should be placed so that none of the charac-
              ters  in  one  line  overlap  any of the characters in the other
              line.  This is generally the sum of the ascent above  the  base-
              line line plus the descent below the baseline.

       -fixed
              Returns  a  boolean  flag that is ``1'' if this is a fixed-width
              font, where each normal character is the same width as  all  the
              other characters, or is ``0'' if this is a proportionally-spaced
              font, where individual characters have  different  widths.   The
              widths  of  control  characters,  tab characters, and other non-
              printing characters  are  not  included  when  calculating  this
              value.

FONT OPTIONS
       The following options are supported on all platforms, and are used when
       constructing a named font or when specifying a font using style [5]  as
       above:

       -family name
              The case-insensitive font family name.  Tk guarantees to support
              the font families named  Courier  (a  monospaced  ``typewriter''
              font),  Times  (a  serifed ``newspaper'' font), and Helvetica (a
              sans-serif ``European'' font).  The most closely matching native
              font  family  will  automatically be substituted when one of the
              above font families is used.  The name may also be the name of a
              native, platform-specific font family; in that case it will work
              as desired on one platform but  may  not  display  correctly  on
              other  platforms.  If the family is unspecified or unrecognized,
              a platform-specific default font will be chosen.

       -size size
              The desired size of the font.  If the size argument is  a  posi-
              tive  number, it is interpreted as a size in points.  If size is
              a negative number, its absolute value is interpreted as  a  size
              in pixels.  If a font cannot be displayed at the specified size,
              a nearby size will be chosen.  If size is unspecified or zero, a
              platform-dependent default size will be chosen.

              Sizes  should normally be specified in points so the application
              will remain the same ruler size on the screen, even when  chang-
              ing screen resolutions or moving scripts across platforms.  How-
              ever, specifying pixels is useful in certain circumstances  such
              as  when  a  piece of text must line up with respect to a fixed-
              size bitmap.  The mapping between points and pixels is set  when
              the  application  starts,  based  on properties of the installed
              monitor, but it can be overridden by calling the tk scaling com-
              mand.

       -weight weight
              The  nominal thickness of the characters in the font.  The value
              normal specifies a normal weight font, while  bold  specifies  a
              bold  font.   The  closest available weight to the one specified
              will be chosen.  The default weight is normal.

       -slant slant
              The amount the characters in the font are slanted away from  the
              vertical.  Valid values for slant are roman and italic.  A roman
              font is the normal, upright  appearance  of  a  font,  while  an
              italic  font  is  one that is tilted some number of degrees from
              upright.  The closest available slant to the one specified  will
              be chosen.  The default slant is roman.

       -underline boolean
              The value is a boolean flag that specifies whether characters in
              this font should be underlined.  The default value for underline
              is false.

       -overstrike boolean
              The  value is a boolean flag that specifies whether a horizontal
              line should be drawn through the middle of  characters  in  this
              font.  The default value for overstrike is false.

PLATFORM-SPECIFIC ISSUES
       The following named system fonts are supported:

              X Windows:
                     All  valid  X  font names, including those listed by xls-
                     fonts(1), are available.

              MS Windows:

                     system      ansi        device
                     systemfixed ansifixed   oemfixed


              Macintosh:

                     system      application


EXAMPLE
       Fill a text widget with lots of font demonstrators, one for every  font
       family installed on your system:
              pack [text .t -wrap none] -fill both -expand 1
              set count 0
              set tabwidth 0
              foreach family [lsort -dictionary [font families]] {
                  .t tag configure f[incr count] -font [list $family 10]
                  .t insert end ${family}:\t {} \
                          "This is a simple sampler\n" f$count
                  set w [font measure [.t cget -font] ${family}:]
                  if {$w+5 > $tabwidth} {
                      set tabwidth [expr {$w+5}]
                      .t configure -tabs $tabwidth
                  }
              }


SEE ALSO
       options(n)


KEYWORDS
