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ActiveTcl User Guide
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- NAME
- font - Create and inspect fonts.
- SYNOPSIS
- font option ?arg arg ...?
- DESCRIPTION
- font actual
font ?-displayof window?
?option?
- font configure
fontname ?option? ?value option value
...?
- font create
?fontname? ?option value ...?
- font delete
fontname ?fontname ...?
- font families
?-displayof window?
- font measure
font ?-displayof window? text
- font metrics
font ?-displayof window?
?option?
- font names
- FONT DESCRIPTION
- [1] fontname
- [2]
systemfont
- [3] family
?size? ?style? ?style ...?
- [4] X-font names
(XLFD)
- [5] option value
?option value ...?
- FONT METRICS
- -ascent
- -descent
- -linespace
- -fixed
- FONT OPTIONS
- -family
name
- -size
size
- -weight
weight
- -slant
slant
- -underline
boolean
- -overstrike
boolean
- PLATFORM-SPECIFIC ISSUES
- X Windows:
- MS Windows:
- Macintosh:
- EXAMPLE
- SEE ALSO
- KEYWORDS
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:
- font actual font ?-displayof
window? ?option?
- 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-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
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.
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 ?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-dependant 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.
- -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.
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.
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
systemfixed ansifixed oemfixed
- Macintosh:
-
system application
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
font
Copyright © 1996 Sun Microsystems, Inc.
Copyright © 1995-1997 Roger E. Critchlow Jr.