Provided by: tk8.5-doc_8.5.15-2ubuntu3_all bug

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? ?--? ?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 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.  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.

       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 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 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
              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 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