Manual Pages for UNIX Operating System command usage for man Tk_FontId

Tk Library Procedures                              Tk_FontId(3TK)



_________________________________________________________________

NAME
     Tk_FontId, Tk_GetFontMetrics, Tk_PostscriptFontName - acces-
     sor functions for fonts

SYNOPSIS
     #include 

     Font
     Tk_FontId(tkfont)

     void
     Tk_GetFontMetrics(tkfont, fmPtr)

     int
     Tk_PostscriptFontName(tkfont, dsPtr)


ARGUMENTS
     Tk_Font          tkfont   (in)      Opaque font token  being
                                         queried.  Must have been
                                         returned by  a  previous
                                         call to Tk_GetFont.

     Tk_FontMetrics   *fmPtr   (out)     Pointer to structure  in
                                         which  the  font metrics
                                         for   tkfont   will   be
                                         stored.

     Tcl_DString      *dsPtr   (out)     Pointer to  an  initial-
                                         ized    Tcl_DString   to
                                         which the  name  of  the
                                         Postscript   font   that
                                         corresponds  to   tkfont
                                         will be appended.
_________________________________________________________________


DESCRIPTION
     Given a tkfont, Tk_FontId returns the token that  should  be
     selected into an XGCValues structure in order to construct a
     graphics context that can be used to draw text in the speci-
     fied font.

     Tk_GetFontMetrics  computes   the   ascent,   descent,   and
     linespace of the tkfont in pixels and stores those values in
     the structure pointer to by fmPtr.  These values can be used
     in  computations such as to space multiple lines of text, to
     align the baselines of text in different fonts, and to vert-
     ically  align text in a given region.  See the documentation
     for the font command for definitions of  the  terms  ascent,



Tk                      Last change: 8.0                        1






Tk Library Procedures                              Tk_FontId(3TK)



     descent, and linespace, used in font metrics.

     Tk_PostscriptFontName maps a  tkfont  to  the  corresponding
     Postcript  font name that should be used when printing.  The
     return value is the size in points of  the  tkfont  and  the
     Postscript font name is appended to dsPtr.  DsPtr must refer
     to  an  initialized  Tcl_DString.   Given  a  ``reasonable''
     Postscript  printer,  the  following  screen  font  families
     should print correctly:

          Avant Garde,  Arial,  Bookman,  Courier,  Courier  New,
          Geneva,  Helvetica, Monaco, New Century Schoolbook, New
          York, Palatino, Symbol, Times, Times  New  Roman,  Zapf
          Chancery, and Zapf Dingbats.

     Any other font families may not print correctly because  the
     computed  Postscript font name may be incorrect or not exist
     on the printer.

DATA STRUCTURES                                                    |
     The   Tk_FontMetrics   data    structure    is    used    by  |
     Tk_GetFontMetrics  to return information about a font and is  |
     defined as follows:                                           |
          typedef struct Tk_FontMetrics {                          |
              int ascent;                                          |
              int descent;                                         |
              int linespace;                                       |
          } Tk_FontMetrics;                                        |
     The linespace field is the amount in pixels that the tallest  |
     letter  sticks  up  above the baseline, plus any extra blank  |
     space added by the designer of the font.                      |

     The descent is the largest amount in pixels that any  letter  |
     sticks  below the baseline, plus any extra blank space added  |
     by the designer of the font.                                  |

     The linespace is the sum of the ascent and descent.  How far  |
     apart two lines of text in the same font should be placed so  |
     that none of the characters in one line overlap any  of  the  |
     characters in the other line.

KEYWORDS
     font

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:








Tk                      Last change: 8.0                        2






Tk Library Procedures                              Tk_FontId(3TK)



     _______________________________________
    |   ATTRIBUTE TYPE   |  ATTRIBUTE VALUE|
    |____________________|__________________|_
    | Availability       |  runtime/tk-8   |
    |____________________|__________________|_
    | Interface Stability|  Uncommitted    |
    |____________________|_________________|

NOTES
     Source for Tk is available on http://opensolaris.org.













































Tk                      Last change: 8.0                        3