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 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 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 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 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 exagerrated 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.
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 pointsize ?stylelist?
A properly formed list whose first element is the desired font family, whose second element is the desired pointsize, and whose last optional element stylelist is itself a list of font attributes. This format allows the user to easily specify a minimal set of attributes and get reasonable behavior. Possible values for the elements of stylelist are as follows:
normal bold roman italic underline overstrike
[4] X-font names (XLFD)
A fully specified XLFD is of the form -foundry-family-weight-slantsetwidth-addstyle-pixel-point-resx-resy-spacing-width-charsetencoding. A ``*'' character may be used to skip individual fields that the user does not care about. There must be exactly one ``*'' for each field elided, except that the last six (or fewer) fields may be elided by a single ``*''.
[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-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 fontspecific 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 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 pointsize
The desired size of the font, in points. If a font cannot be displayed at the specified pointsize, a nearby pointsize will be chosen. If the pointsize is unspecified, a platform-dependant default pointsize will be chosen.
-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.
The following named system fonts are supported:
X Windows:
All valid X font names, including those listed by xlsfonts(1), are available.
MS Windows:
system ansi device
KEYWORDS
font