1font(n) Tk Built-In Commands font(n)
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8 font - Create and inspect fonts.
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11 font option ?arg arg ...?
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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? ?--? ?char?
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-dependent limitations, such as the availability of
25 font families and point sizes. 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. If the
31 char argument is supplied, it must be a single character. The
32 font attributes returned will be those of the specific font used
33 to render that character, which will be different from the base
34 font if the base font does not contain the given character. If
35 char may be a hyphen, it should be preceded by -- to distinguish
36 it from a misspelled option.
37 font configure fontname ?option? ?value option value ...?
39 Query or modify the desired attributes for the named font called
40 fontname. If no option is specified, returns a list describing
41 all the options and their values for fontname. If a single
42 option is specified with no value, then returns the current
43 value of that attribute. If one or more option-value pairs are
44 specified, then the command modifies the given named font to
45 have the given values; in this case, all widgets using that font
46 will redisplay themselves using the new attributes for the font.
47 See FONT OPTIONS below for a list of the possible attributes.
48 Note that on Aqua/Mac OS X, the system fonts (see PLATFORM SPE‐
50 CIFIC FONTS below) may not be actually altered because they are
51 implemented by the system theme. To achieve the effect of modi‐
52 fication, use font actual to get their configuration and font
53 create to synthesize a copy of the font which can be modified.
54 font create ?fontname? ?option value ...?
56 Creates a new named font and returns its name. fontname speci‐
57 fies the name for the font; if it is omitted, then Tk generates
58 a new name of the form fontx, where x is an integer. There may
59 be any number of option-value pairs, which provide the desired
60 attributes for the new named font. See FONT OPTIONS below for a
61 list of the possible attributes.
62 font delete fontname ?fontname ...?
64 Delete the specified named fonts. If there are widgets using
65 the named font, the named font will not actually be deleted
66 until all the instances are released. Those widgets will con‐
67 tinue to display using the last known values for the named font.
68 If a deleted named font is subsequently recreated with another
69 call to font create, the widgets will use the new named font and
70 redisplay themselves using the new attributes of that font.
71 font families ?-displayof window?
73 The return value is a list of the case-insensitive names of all
74 font families that exist on window's display. If the window
75 argument is omitted, it defaults to the main window.
76 font measure font ?-displayof window? text
78 Measures the amount of space the string text would use in the
79 given font when displayed in window. font is a font descrip‐
80 tion; see FONT DESCRIPTIONS below. If the window argument is
81 omitted, it defaults to the main window. The return value is
82 the total width in pixels of text, not including the extra pix‐
83 els used by highly exaggerated characters such as cursive “f”.
84 If the string contains newlines or tabs, those characters are
85 not expanded or treated specially when measuring the string.
86 font metrics font ?-displayof window? ?option?
88 Returns information about the metrics (the font-specific data),
89 for font when it is used on window's display. font is a font
90 description; see FONT DESCRIPTIONS below. If the window argu‐
91 ment is omitted, it defaults to the main window. If option is
92 specified, returns the value of that metric; if it is omitted,
93 the return value is a list of all the metrics and their values.
94 See FONT METRICS below for a list of the possible metrics.
95 font names
97 The return value is a list of all the named fonts that are cur‐
98 rently defined.
99
101 The following formats are accepted as a font description anywhere font
102 is specified as an argument above; these same forms are also permitted
103 when specifying the -font option for widgets.
104 [1] fontname
106 The name of a named font, created using the font create command.
107 When a widget uses a named font, it is guaranteed that this will
108 never cause an error, as long as the named font exists, no mat‐
109 ter what potentially invalid or meaningless set of attributes
110 the named font has. If the named font cannot be displayed with
111 exactly the specified attributes, some other close font will be
112 substituted automatically.
113 [2] systemfont
115 The platform-specific name of a font, interpreted by the graph‐
116 ics server. This also includes, under X, an XLFD (see [4]) for
117 which a single “*” character was used to elide more than one
118 field in the middle of the name. See PLATFORM SPECIFIC FONTS
119 for a list of the system fonts.
120 [3] family ?size? ?style? ?style ...?
122 A properly formed list whose first element is the desired font
123 family and whose optional second element is the desired size.
124 The interpretation of the size attribute follows the same rules
125 described for -size in FONT OPTIONS below. Any additional
126 optional arguments following the size are font styles. Possible
127 values for the style arguments are as follows:
128 normal bold roman italic
130 underline overstrike
131 [4] X-font names (XLFD)
134 A Unix-centric font name of the form -foundry-fam‐
135 ily-weight-slant-setwidth-addstyle-pixel-point-resx-resy-spac‐
136 ing-width-charset-encoding. The “*” character may be used to
137 skip individual fields that the user does not care about. There
138 must be exactly one “*” for each field skipped, except that a
139 “*” at the end of the XLFD skips any remaining fields; the
140 shortest valid XLFD is simply “*”, signifying all fields as
141 defaults. Any fields that were skipped are given default val‐
142 ues. For compatibility, an XLFD always chooses a font of the
143 specified pixel size (not point size); although this interpreta‐
144 tion is not strictly correct, all existing applications using
145 XLFDs assumed that one “point” was in fact one pixel and would
146 display incorrectly (generally larger) if the correct size font
147 were actually used.
148 [5] option value ?option value ...?
150 A properly formed list of option-value pairs that specify the
151 desired attributes of the font, in the same format used when
152 defining a named font; see FONT OPTIONS below.
153 When font description font is used, the system attempts to parse the
155 description according to each of the above five rules, in the order
156 specified. Cases [1] and [2] must match the name of an existing named
157 font or of a system font. Cases [3], [4], and [5] are accepted on all
158 platforms and the closest available font will be used. In some situa‐
159 tions it may not be possible to find any close font (e.g., the font
160 family was a garbage value); in that case, some system-dependent
161 default font is chosen. If the font description does not match any of
162 the above patterns, an error is generated.
163
165 The following options are used by the font metrics command to query
166 font-specific data determined when the font was created. These proper‐
167 ties are for the whole font itself and not for individual characters
168 drawn in that font. In the following definitions, the “baseline” of a
169 font is the horizontal line where the bottom of most letters line up;
170 certain letters, such as lower-case “g” stick below the baseline.
171 -ascent
173 The amount in pixels that the tallest letter sticks up above the
174 baseline of the font, plus any extra blank space added by the
175 designer of the font.
176 -descent
178 The largest amount in pixels that any letter sticks down below
179 the baseline of the font, plus any extra blank space added by
180 the designer of the font.
181 -linespace
183 Returns how far apart vertically in pixels two lines of text
184 using the same font should be placed so that none of the charac‐
185 ters in one line overlap any of the characters in the other
186 line. This is generally the sum of the ascent above the base‐
187 line line plus the descent below the baseline.
188 -fixed
190 Returns a boolean flag that is “1” if this is a fixed-width
191 font, where each normal character is the same width as all the
192 other characters, or is “0” if this is a proportionally-spaced
193 font, where individual characters have different widths. The
194 widths of control characters, tab characters, and other non-
195 printing characters are not included when calculating this
196 value.
197
199 The following options are supported on all platforms, and are used when
200 constructing a named font or when specifying a font using style [5] as
201 above:
202 -family name
204 The case-insensitive font family name. Tk guarantees to support
205 the font families named Courier (a monospaced “typewriter”
206 font), Times (a serifed “newspaper” font), and Helvetica (a
207 sans-serif “European” font). The most closely matching native
208 font family will automatically be substituted when one of the
209 above font families is used. The name may also be the name of a
210 native, platform-specific font family; in that case it will work
211 as desired on one platform but may not display correctly on
212 other platforms. If the family is unspecified or unrecognized,
213 a platform-specific default font will be chosen.
214 -size size
216 The desired size of the font. If the size argument is a posi‐
217 tive number, it is interpreted as a size in points. If size is
218 a negative number, its absolute value is interpreted as a size
219 in pixels. If a font cannot be displayed at the specified size,
220 a nearby size will be chosen. If size is unspecified or zero, a
221 platform-dependent default size will be chosen.
222 Sizes should normally be specified in points so the application
224 will remain the same ruler size on the screen, even when chang‐
225 ing screen resolutions or moving scripts across platforms. How‐
226 ever, specifying pixels is useful in certain circumstances such
227 as when a piece of text must line up with respect to a fixed-
228 size bitmap. The mapping between points and pixels is set when
229 the application starts, based on properties of the installed
230 monitor, but it can be overridden by calling the tk scaling com‐
231 mand.
232 -weight weight
234 The nominal thickness of the characters in the font. The value
235 normal specifies a normal weight font, while bold specifies a
236 bold font. The closest available weight to the one specified
237 will be chosen. The default weight is normal.
238 -slant slant
240 The amount the characters in the font are slanted away from the
241 vertical. Valid values for slant are roman and italic. A roman
242 font is the normal, upright appearance of a font, while an
243 italic font is one that is tilted some number of degrees from
244 upright. The closest available slant to the one specified will
245 be chosen. The default slant is roman.
246 -underline boolean
248 The value is a boolean flag that specifies whether characters in
249 this font should be underlined. The default value for underline
250 is false.
251 -overstrike boolean
253 The value is a boolean flag that specifies whether a horizontal
254 line should be drawn through the middle of characters in this
255 font. The default value for overstrike is false.
256
258 The following named fonts are supported on all systems, and default to
259 values that match appropriate system defaults.
260 TkDefaultFont
262 This font is the default for all GUI items not otherwise speci‐
263 fied.
264 TkTextFont
266 This font should be used for user text in entry widgets, list‐
267 boxes etc.
268 TkFixedFont
270 This font is the standard fixed-width font.
271 TkMenuFont
273 This font is used for menu items.
274 TkHeadingFont
276 This font should be used for column headings in lists and
277 tables.
278 TkCaptionFont
280 This font should be used for window and dialog caption bars.
281 TkSmallCaptionFont
283 This font should be used for captions on contained windows or
284 tool dialogs.
285 TkIconFont
287 This font should be used for icon captions.
288 TkTooltipFont
290 This font should be used for tooltip windows (transient informa‐
291 tion windows).
292 It is not advised to change these fonts, as they may be modified by Tk
294 itself in response to system changes. Instead, make a copy of the font
295 and modify that.
296
298 The following system fonts are supported:
299 X Windows
301 All valid X font names, including those listed by xlsfonts(1),
302 are available.
303 MS Windows
305 The following fonts are supported, and are mapped to the user's
306 style defaults.
307 system ansi device
309 systemfixed ansifixed oemfixed
310 Mac OS X
313 The following fonts are supported, and are mapped to the user's
314 style defaults.
315 system application menu
317 Additionally, the following named fonts provide access to the
320 Aqua theme fonts:
321 systemSystemFont systemEmphasizedSystemFont
323 systemSmallSystemFontsystemSmallEmphasizedSystemFont
324 systemApplicationFontsystemLabelFont
325 systemViewsFont systemMenuTitleFont
326 systemMenuItemFont systemMenuItemMarkFont
327 systemMenuItemCmdKeyFontsystemWindowTitleFont
328 systemPushButtonFontsystemUtilityWindowTitleFont
329 systemAlertHeaderFontsystemToolbarFont
330 systemMiniSystemFontsystemDetailSystemFont
331 systemDetailEmphasizedSystemFont
332
335 Fill a text widget with lots of font demonstrators, one for every font
336 family installed on your system:
337 pack [text .t -wrap none] -fill both -expand 1
338 set count 0
339 set tabwidth 0
340 foreach family [lsort -dictionary [font families]] {
341 .t tag configure f[incr count] -font [list $family 10]
342 .t insert end ${family}:\t {} \
343 "This is a simple sampler\n" f$count
344 set w [font measure [.t cget -font] ${family}:]
345 if {$w+5 > $tabwidth} {
346 set tabwidth [expr {$w+5}]
347 .t configure -tabs $tabwidth
348 }
349 }
350
352 options(n)
353
355 font
356Tk 8.0 font(n)