'\"
'\" Copyright (c) 1990-1994 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.
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.TH Tk_GetSelection 3 4.0 Tk "Tk Library Procedures"
.so man.macros
.BS
.SH NAME
Tk_GetSelection \- retrieve the contents of a selection
.SH SYNOPSIS
.nf
\fB#include <tk.h>\fR
.sp
int
\fBTk_GetSelection\fR(\fIinterp, tkwin, selection, target, proc, clientData\fR)
.SH ARGUMENTS
.AS Tk_GetSelProc clientData
.AP Tcl_Interp *interp in
Interpreter to use for reporting errors.
.AP Tk_Window tkwin in
Window on whose behalf to retrieve the selection (determines
display from which to retrieve).
.AP Atom selection in
The name of the selection to be retrieved.
.AP Atom target in
Form in which to retrieve selection.
.AP Tk_GetSelProc *proc in
Procedure to invoke to process pieces of the selection as they
are retrieved.
.AP ClientData clientData in
Arbitrary one-word value to pass to \fIproc\fR.
.BE
.SH DESCRIPTION
.PP
\fBTk_GetSelection\fR retrieves the selection specified by the atom
\fIselection\fR in the format specified by \fItarget\fR.  The
selection may actually be retrieved in several pieces; as each piece
is retrieved, \fIproc\fR is called to process the piece.  \fIProc\fR
should have arguments and result that match the type
\fBTk_GetSelProc\fR:
.PP
.CS
typedef int \fBTk_GetSelProc\fR(
        ClientData \fIclientData\fR,
        Tcl_Interp *\fIinterp\fR,
        char *\fIportion\fR);
.CE
.PP
The \fIclientData\fR and \fIinterp\fR parameters to \fIproc\fR
will be copies of the corresponding arguments to
\fBTk_GetSelection\fR.  \fIPortion\fR will be a pointer to
a string containing part or all of the selection.  For large
selections, \fIproc\fR will be called several times with successive
portions of the selection.  The X Inter-Client Communication
Conventions Manual allows a selection to be returned in formats
other than strings, e.g. as an array of atoms or integers.  If
this happens, Tk converts the selection back into a string
before calling \fIproc\fR.  If a selection is returned as an
array of atoms, Tk converts it to a string containing the atom names
separated by white space.  For any other format besides string,
Tk converts a selection to a string containing hexadecimal
values separated by white space.
.PP
\fBTk_GetSelection\fR returns to its caller when the selection has
been completely retrieved and processed by \fIproc\fR, or when a
fatal error has occurred (e.g. the selection owner did not respond
promptly).  \fBTk_GetSelection\fR normally returns \fBTCL_OK\fR;  if
an error occurs, it returns \fBTCL_ERROR\fR and leaves an error message
in interpreter \fIinterp\fR's result.  \fIProc\fR should also return either
\fBTCL_OK\fR or \fBTCL_ERROR\fR.  If \fIproc\fR encounters an error in
dealing with the selection, it should leave an error message in the
interpreter result and return \fBTCL_ERROR\fR;  this will abort the
selection retrieval.
.SH KEYWORDS
format, get, selection retrieval