font

font(3tk)                    Tk Built-In Commands                    font(3tk)



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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



Tk                                    8.0                            font(3tk)