Tk_GetFontStruct (3)
maintain database of fonts
SYNOPSIS
#include <tk.h>
XFontStruct *
Tk_GetFontStruct(interp, tkwin, nameId)
char *
Tk_NameOfFontStruct(fontStructPtr)
Tk_FreeFontStruct(fontStructPtr)
ARGUMENTS
"XFontStruct" *fontStructPtr
Tcl_Interp *interp in
Interpreter to use for error reporting.
Tk_Window tkwin in
Token for window in which font will be used.
Tk_Uid nameId in
Name of desired font.
XFontStruct *fontStructPtr in
Font structure to return name for or delete.
DESCRIPTION
Tk_GetFont loads the font indicated
by nameId and returns a pointer to information about the
font. The pointer returned by Tk_GetFont
will remain valid until Tk_FreeFont
is called to release it.
NameId can be either a font name or pattern; any
value that could be passed to XLoadQueryFont may be
passed to Tk_GetFont. If Tk_GetFont is unsuccessful
(because, for example, there is no font corresponding to
nameId) then it returns NULL and stores an error
message in interp->result.
Tk_GetFont maintains a database of all fonts it has allocated.
If the same nameId is requested multiple times (e.g. by
different windows or for different purposes), then additional
calls for the same nameId will be handled very quickly, without
involving the X server. For this reason, it is generally better
to use Tk_GetFont in place of X library procedures like
XLoadQueryFont.
The procedure Tk_NameOfFontStruct is roughly the inverse of
Tk_GetFontStruct. If its fontStructPtr argument was created
by Tk_GetFontStruct, then the return value is the nameId
argument that was passed to Tk_GetFontStruct to create the
font. If fontStructPtr was not created by a call
to Tk_GetFontStruct, then the return value is a hexadecimal string
giving the X identifier for the associated font.
Note: the string returned by Tk_NameOfFontStruct is
only guaranteed to persist until the next call to Tk_NameOfFontStruct.
When a font returned by Tk_GetFont is no longer
needed, Tk_FreeFont should be called to release it.
There should be exactly one call to Tk_FreeFont for
each call to Tk_GetFont. When a font is no longer in
use anywhere (i.e. it has been freed as many times as it has been gotten)
Tk_FreeFont will release it to the X server and delete it from
the database.
KEYWORDS
font
'\"
'\" Copyright (c) 1995-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
'\" RCS: @(#) $Id: NameOfImg.3,v 1.2 1998/09/14 18:22:53 stanton Exp $
'\"
'\" The definitions below are for supplemental macros used in Tcl/Tk
'\" manual entries.
'\"
'\" .AP type name in/out ?indent?
'\" Start paragraph describing an argument to a library procedure.
'\" type is type of argument (int, etc.), in/out is either "in", "out",
'\" or "in/out" to describe whether procedure reads or modifies arg,
'\" and indent is equivalent to second arg of .IP (shouldn't ever be
'\" needed; use .AS below instead)
'\"
'\" .AS ?type? ?name?
'\" Give maximum sizes of arguments for setting tab stops. Type and
'\" name are examples of largest possible arguments that will be passed
'\" to .AP later. If args are omitted, default tab stops are used.
'\"
'\" .BS
'\" Start box enclosure. From here until next .BE, everything will be
'\" enclosed in one large box.
'\"
'\" .BE
'\" End of box enclosure.
'\"
'\" .CS
'\" Begin code excerpt.
'\"
'\" .CE
'\" End code excerpt.
'\"
'\" .VS ?version? ?br?
'\" Begin vertical sidebar, for use in marking newly-changed parts
'\" of man pages. The first argument is ignored and used for recording
'\" the version when the .VS was added, so that the sidebars can be
'\" found and removed when they reach a certain age. If another argument
'\" is present, then a line break is forced before starting the sidebar.
'\"
'\" .VE
'\" End of vertical sidebar.
'\"
'\" .DS
'\" Begin an indented unfilled display.
'\"
'\" .DE
'\" End of indented unfilled display.
'\"
'\" .SO
'\" Start of list of standard options for a Tk widget. The
'\" options follow on successive lines, in four columns separated
'\" by tabs.
'\"
'\" .SE
'\" End of list of standard options for a Tk widget.
'\"
'\" .OP cmdName dbName dbClass
'\" Start of description of a specific option. cmdName gives the
'\" option's name as specified in the class command, dbName gives
'\" the option's name in the option database, and dbClass gives
'\" the option's class in the option database.
'\"
'\" .UL arg1 arg2
'\" Print arg1 underlined, then print arg2 normally.
'\"
'\" RCS: @(#) $Id: man.macros,v 1.2 1998/09/14 18:39:54 stanton Exp $
'\"
'\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
t .wh -1.3i ^B
^l \n(.l
b
'\" # Start an argument description
AP
!"\\$4"" .TP \\$4
\{\
!"\\$2"" .TP \\n()Cu
.TP 15
|