1font(n) Tk Built-In Commands font(n)
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6
8 font - Create and inspect fonts.
9
11 font option ?arg arg ...?
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13
15 The font command provides several facilities for dealing with fonts,
16 such as defining named fonts and inspecting the actual attributes of a
17 font. The command has several different forms, determined by the first
18 argument. The following forms are currently supported:
19 font actual font ?-displayof window? ?option?
21 Returns information about the actual attributes that are
22 obtained when font is used on window's display; the actual
23 attributes obtained may differ from the attributes requested due
24 to platform-dependant limitations, such as the availability of
25 font families and pointsizes. font is a font description; see
26 FONT DESCRIPTIONS below. If the window argument is omitted, it
27 defaults to the main window. If option is specified, returns
28 the value of that attribute; if it is omitted, the return value
29 is a list of all the attributes and their values. See FONT
30 OPTIONS below for a list of the possible attributes.
31 font configure fontname ?option? ?value option value ...?
33 Query or modify the desired attributes for the named font called
34 fontname. If no option is specified, returns a list describing
35 all the options and their values for fontname. If a single
36 option is specified with no value, then returns the current
37 value of that attribute. If one or more option-value pairs are
38 specified, then the command modifies the given named font to
39 have the given values; in this case, all widgets using that font
40 will redisplay themselves using the new attributes for the font.
41 See FONT OPTIONS below for a list of the possible attributes.
42 font create ?fontname? ?option value ...?
44 Creates a new named font and returns its name. fontname speci‐
45 fies the name for the font; if it is omitted, then Tk generates
46 a new name of the form fontx, where x is an integer. There may
47 be any number of option-value pairs, which provide the desired
48 attributes for the new named font. See FONT OPTIONS below for a
49 list of the possible attributes.
50 font delete fontname ?fontname ...?
52 Delete the specified named fonts. If there are widgets using
53 the named font, the named font won't actually be deleted until
54 all the instances are released. Those widgets will continue to
55 display using the last known values for the named font. If a
56 deleted named font is subsequently recreated with another call
57 to font create, the widgets will use the new named font and
58 redisplay themselves using the new attributes of that font.
59 font families ?-displayof window?
61 The return value is a list of the case-insensitive names of all
62 font families that exist on window's display. If the window
63 argument is omitted, it defaults to the main window.
64 font measure font ?-displayof window? text
66 Measures the amount of space the string text would use in the
67 given font when displayed in window. font is a font descrip‐
68 tion; see FONT DESCRIPTIONS below. If the window argument is
69 omitted, it defaults to the main window. The return value is
70 the total width in pixels of text, not including the extra pix‐
71 els used by highly exaggerated characters such as cursive ``f''.
72 If the string contains newlines or tabs, those characters are
73 not expanded or treated specially when measuring the string.
74 font metrics font ?-displayof window? ?option?
76 Returns information about the metrics (the font-specific data),
77 for font when it is used on window's display. font is a font
78 description; see FONT DESCRIPTIONS below. If the window argu‐
79 ment is omitted, it defaults to the main window. If option is
80 specified, returns the value of that metric; if it is omitted,
81 the return value is a list of all the metrics and their values.
82 See FONT METRICS below for a list of the possible metrics.
83 font names
85 The return value is a list of all the named fonts that are cur‐
86 rently defined.
87
89 The following formats are accepted as a font description anywhere font
90 is specified as an argument above; these same forms are also permitted
91 when specifying the -font option for widgets.
92 [1] fontname
94 The name of a named font, created using the font create command.
95 When a widget uses a named font, it is guaranteed that this will
96 never cause an error, as long as the named font exists, no mat‐
97 ter what potentially invalid or meaningless set of attributes
98 the named font has. If the named font cannot be displayed with
99 exactly the specified attributes, some other close font will be
100 substituted automatically.
101 [2] systemfont
103 The platform-specific name of a font, interpreted by the graph‐
104 ics server. This also includes, under X, an XLFD (see [4]) for
105 which a single ``*'' character was used to elide more than one
106 field in the middle of the name. See PLATFORM-SPECIFIC issues
107 for a list of the system fonts.
108 [3] family ?size? ?style? ?style ...? │
110 A properly formed list whose first element is the desired font │
111 family and whose optional second element is the desired size. │
112 The interpretation of the size attribute follows the same rules │
113 described for -size in FONT OPTIONS below. Any additional │
114 optional arguments following the size are font styles. Possible │
115 values for the style arguments are as follows: │
116 normal bold roman italic underline overstrike │
117 [4] X-font names (XLFD) │
119 A Unix-centric font name of the form -foundry-family-weight- │
120 slant-setwidth-addstyle-pixel-point-resx-resy-spacing-width- │
121 charset-encoding. The ``*'' character may be used to skip indi‐ │
122 vidual fields that the user does not care about. There must be │
123 exactly one ``*'' for each field skipped, except that a ``*'' at │
124 the end of the XLFD skips any remaining fields; the shortest │
125 valid XLFD is simply ``*'', signifying all fields as defaults. │
126 Any fields that were skipped are given default values. For com‐ │
127 patibility, an XLFD always chooses a font of the specified pixel │
128 size (not point size); although this interpretation is not │
129 strictly correct, all existing applications using XLFDs assumed │
130 that one ``point'' was in fact one pixel and would display │
131 incorrectly (generally larger) if the correct size font were │
132 actually used.
133 [5] option value ?option value ...?
135 A properly formed list of option-value pairs that specify the
136 desired attributes of the font, in the same format used when
137 defining a named font; see FONT OPTIONS below.
138 When font description font is used, the system attempts to parse the
140 description according to each of the above five rules, in the order
141 specified. Cases [1] and [2] must match the name of an existing named
142 font or of a system font. Cases [3], [4], and [5] are accepted on all
143 platforms and the closest available font will be used. In some situa‐
144 tions it may not be possible to find any close font (e.g., the font
145 family was a garbage value); in that case, some system-dependant
146 default font is chosen. If the font description does not match any of
147 the above patterns, an error is generated.
148
150 The following options are used by the font metrics command to query
151 font-specific data determined when the font was created. These proper‐
152 ties are for the whole font itself and not for individual characters
153 drawn in that font. In the following definitions, the ``baseline'' of
154 a font is the horizontal line where the bottom of most letters line up;
155 certain letters, such as lower-case ``g'' stick below the baseline.
156 -ascent
158 The amount in pixels that the tallest letter sticks up above the
159 baseline of the font, plus any extra blank space added by the
160 designer of the font.
161 -descent
163 The largest amount in pixels that any letter sticks down below
164 the baseline of the font, plus any extra blank space added by
165 the designer of the font.
166 -linespace
168 Returns how far apart vertically in pixels two lines of text
169 using the same font should be placed so that none of the charac‐
170 ters in one line overlap any of the characters in the other
171 line. This is generally the sum of the ascent above the base‐
172 line line plus the descent below the baseline.
173 -fixed
175 Returns a boolean flag that is ``1'' if this is a fixed-width
176 font, where each normal character is the same width as all the
177 other characters, or is ``0'' if this is a proportionally-spaced
178 font, where individual characters have different widths. The
179 widths of control characters, tab characters, and other non-
180 printing characters are not included when calculating this
181 value.
182
184 The following options are supported on all platforms, and are used when
185 constructing a named font or when specifying a font using style [5] as
186 above:
187 -family name
189 The case-insensitive font family name. Tk guarantees to support
190 the font families named Courier (a monospaced ``typewriter''
191 font), Times (a serifed ``newspaper'' font), and Helvetica (a
192 sans-serif ``European'' font). The most closely matching native
193 font family will automatically be substituted when one of the
194 above font families is used. The name may also be the name of a
195 native, platform-specific font family; in that case it will work
196 as desired on one platform but may not display correctly on
197 other platforms. If the family is unspecified or unrecognized,
198 a platform-specific default font will be chosen. │
199 -size size │
201 The desired size of the font. If the size argument is a posi‐ │
202 tive number, it is interpreted as a size in points. If size is │
203 a negative number, its absolute value is interpreted as a size │
204 in pixels. If a font cannot be displayed at the specified size, │
205 a nearby size will be chosen. If size is unspecified or zero, a │
206 platform-dependent default size will be chosen. │
207 Sizes should normally be specified in points so the application │
209 will remain the same ruler size on the screen, even when chang‐ │
210 ing screen resolutions or moving scripts across platforms. How‐ │
211 ever, specifying pixels is useful in certain circumstances such │
212 as when a piece of text must line up with respect to a fixed- │
213 size bitmap. The mapping between points and pixels is set when │
214 the application starts, based on properties of the installed │
215 monitor, but it can be overridden by calling the tk scaling com‐ │
216 mand. │
217 -weight weight
219 The nominal thickness of the characters in the font. The value
220 normal specifies a normal weight font, while bold specifies a
221 bold font. The closest available weight to the one specified
222 will be chosen. The default weight is normal.
223 -slant slant
225 The amount the characters in the font are slanted away from the
226 vertical. Valid values for slant are roman and italic. A roman
227 font is the normal, upright appearance of a font, while an
228 italic font is one that is tilted some number of degrees from
229 upright. The closest available slant to the one specified will
230 be chosen. The default slant is roman.
231 -underline boolean
233 The value is a boolean flag that specifies whether characters in
234 this font should be underlined. The default value for underline
235 is false.
236 -overstrike boolean
238 The value is a boolean flag that specifies whether a horizontal
239 line should be drawn through the middle of characters in this
240 font. The default value for overstrike is false.
241
243 The following named system fonts are supported:
244 X Windows:
246 All valid X font names, including those listed by xls‐
247 fonts(1), are available.
248 MS Windows:
250 system ansi device systemfixed ansi‐
251 fixed oemfixed
252 Macintosh:
254 system application
255
257 Fill a text widget with lots of font demonstrators, one for every font
258 family installed on your system:
259 pack [text .t -wrap none] -fill both -expand 1
260 set count 0
261 set tabwidth 0
262 foreach family [lsort -dictionary [font families]] {
263 .t tag configure f[incr count] -font [list $family 10]
264 .t insert end ${family}:\t {} \
265 "This is a simple sampler\n" f$count
266 set w [font measure [.t cget -font] ${family}:]
267 if {$w+5 > $tabwidth} {
268 set tabwidth [expr {$w+5}]
269 .t configure -tabs $tabwidth
270 }
271 }
272
275 options(n)
276
279 font
280Tk 8.0 font(n)