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NAME

       font - Create and inspect fonts.

SYNOPSIS

       font option ?arg arg ...?
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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? ?--? ?char?
              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-dependent limitations, such as the availability  of  font
              families and point sizes.  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.  If the char argument is supplied, it must be a
              single character. The font attributes returned will be those of the  specific  font
              used  to  render  that character, which will be different from the base font if the
              base font does not contain the given character.  If char may be a hyphen, it should
              be preceded by -- to distinguish it from a misspelled option.

       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.

              Note  that  on  Aqua/Mac OS X, the system fonts (see PLATFORM SPECIFIC FONTS below)
              may not be actually altered because they are implemented by the  system  theme.  To
              achieve  the effect of modification, use font actual to get their configuration and
              font create to synthesize a copy of the font which can be modified.

       font create ?fontname? ?option value ...?
              Creates a new named font and returns its name.  fontname specifies 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  will  not  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 description; 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 pixels 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  argument 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 currently defined.

FONT DESCRIPTIONS

       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 matter 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  graphics  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
              FONTS 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 individual 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 compatibility, 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 situations  it  may
       not  be  possible  to  find any close font (e.g., the font family was a garbage value); in
       that case, some system-dependent 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 properties 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 characters in one  line  overlap  any  of  the
              characters  in  the  other line.  This is generally the sum of the ascent above the
              baseline 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  positive  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 changing screen resolutions or moving
              scripts  across  platforms.   However,  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 command.

       -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.

STANDARD FONTS

       The  following  named fonts are supported on all systems, and default to values that match
       appropriate system defaults.

       TkDefaultFont
              This font is the default for all GUI items not otherwise specified.

       TkTextFont
              This font should be used for user text in entry widgets, listboxes etc.

       TkFixedFont
              This font is the standard fixed-width font.

       TkMenuFont
              This font is used for menu items.

       TkHeadingFont
              This font should be used for column headings in lists and tables.

       TkCaptionFont
              This font should be used for window and dialog caption bars.

       TkSmallCaptionFont
              This font should be used for captions on contained windows or tool dialogs.

       TkIconFont
              This font should be used for icon captions.

       TkTooltipFont
              This font should be used for tooltip windows (transient information windows).

       It is not advised to change these fonts, as they may be modified by Tk itself in  response
       to system changes. Instead, make a copy of the font and modify that.

PLATFORM SPECIFIC FONTS

       The following system fonts are supported:

       X Windows
              All valid X font names, including those listed by xlsfonts(1), are available.

       MS Windows
              The following fonts are supported, and are mapped to the user's style defaults.

                     system      ansi        device
                     systemfixed ansifixed   oemfixed

       Mac OS X
              The following fonts are supported, and are mapped to the user's style defaults.

                     system      application menu

              Additionally, the following named fonts provide access to the Aqua theme fonts:

                     systemSystemFont    systemEmphasizedSystemFont
                     systemSmallSystemFontsystemSmallEmphasizedSystemFont
                     systemApplicationFontsystemLabelFont
                     systemViewsFont     systemMenuTitleFont
                     systemMenuItemFont  systemMenuItemMarkFont
                     systemMenuItemCmdKeyFontsystemWindowTitleFont
                     systemPushButtonFontsystemUtilityWindowTitleFont
                     systemAlertHeaderFontsystemToolbarFont
                     systemMiniSystemFontsystemDetailSystemFont
                     systemDetailEmphasizedSystemFont

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(3tk)

KEYWORDS

       font