DOKK / manpages / debian 11 / tk8.6-doc / font.3tk.en
font(3tk) Tk Built-In Commands font(3tk) 







font - Create and inspect fonts.








font option ?arg arg ...?










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:



  

  
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.

  

  
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.





  

  
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.

  

  
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.

  

  
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.

  

  
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.

  

  
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.

  

  
The return value is a list of all the named fonts that are currently
      defined.










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.








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.



  

  
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.

  

  
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.

  

  
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.

  

  
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.










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:



  

  
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.

  

  
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.





  

  
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.

  

  
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.

  

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

  

  
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.










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



  

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

  

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

  

  
This font is the standard fixed-width font.

  

  
This font is used for menu items.

  

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

  

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

  

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

  

  
This font should be used for icon captions.

  

  
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.








The following system fonts are supported:



  

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

  

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








system	ansi	device
systemfixed	ansifixed	oemfixed









  

  
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
systemSmallSystemFont	systemSmallEmphasizedSystemFont
systemApplicationFont	systemLabelFont
systemViewsFont	systemMenuTitleFont
systemMenuItemFont	systemMenuItemMarkFont
systemMenuItemCmdKeyFont	systemWindowTitleFont
systemPushButtonFont	systemUtilityWindowTitleFont
systemAlertHeaderFont	systemToolbarFont
systemMiniSystemFont	systemDetailSystemFont
systemDetailEmphasizedSystemFont














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


    }
}










options(3tk)








font







  

    8.0
    Tk