Tk_GetFontStruct

XFontStruct *
Tk_GetFontStruct(interp, tkwin, nameId)

char *
Tk_NameOfFontStruct(fontStructPtr)

Tk_FreeFontStruct(fontStructPtr)

ARGUMENTS

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.

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