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Tk_GetPixels (3)

translate between strings and screen units

SYNOPSIS

    #include <tk.h>
    int
    Tk_GetPixels(interp, tkwin, string, intPtr)
    int
    Tk_GetScreenMM(interp, tkwin, string, doublePtr)
    

ARGUMENTS

    "Tcl_Interp" *joinPtr Tcl_Interp *interp in Interpreter to use for error reporting. Tk_Window tkwin in Window whose screen geometry determines the conversion between absolute units and pixels. char *string in String that specifies a distance on the screen. int *intPtr out Pointer to location in which to store converted distance in pixels. double *doublePtr out Pointer to location in which to store converted distance in millimeters.

DESCRIPTION

    These two procedures take as argument a specification of distance on the screen (string) and compute the corresponding distance either in integer pixels or floating-point millimeters. In either case, string specifies a screen distance as a floating-point number followed by one of the following characters that indicates units:

    <none>

      The number specifies a distance in pixels.

    c

      The number specifies a distance in centimeters on the screen.

    i

      The number specifies a distance in inches on the screen.

    m

      The number specifies a distance in millimeters on the screen.

    p

      The number specifies a distance in printer's points (1/72 inch) on the screen.

    Tk_GetPixels converts string to the nearest even number of pixels and stores that value at *intPtr. Tk_GetScreenMM converts string to millimeters and stores the double-precision floating-point result at *doublePtr.

    Both procedures return TCL_OK under normal circumstances. If an error occurs (e.g. string contains a number followed by a character that isn't one of the ones above) then TCL_ERROR is returned and an error message is left in interp->result.

KEYWORDS

    centimeters, convert, inches, millimeters, pixels, points, screen units '\" '\" Copyright (c) 1994 The Regents of the University of California. '\" Copyright (c) 1994-1996 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: GetScroll.3,v 1.2 1998/09/14 18:22:51 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