'\"
'\" 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.
'\" 
'\" SCCS: @(#) Clipboard.3 1.5 96/03/26 18:04:10
'\" 
.so man.macros
.TH Tk_ClipboardClear 3 4.0 Tk "Tk Library Procedures"
.BS
.SH NAME
Tk_ClipboardClear, Tk_ClipboardAppend \- Manage the clipboard
.SH SYNOPSIS
.nf
\fB#include <tk.h>\fR
.sp
int
\fBTk_ClipboardClear\fR(\fIinterp, tkwin\fR)
.sp
int
\fBTk_ClipboardAppend\fR(\fIinterp, tkwin, target, format, buffer\fR)
.SH ARGUMENTS
.AS Tk_ClipboardClear tkwin
.AP Tcl_Interp *interp in
Interpreter to use for reporting errors.
.AP Tk_Window tkwin in
Window that determines which display's clipboard to manipulate.
.AP Atom target in
Conversion type for this clipboard item;  has same meaning as
\fItarget\fR argument to \fBTk_CreateSelHandler\fR.
.AP Atom format in
Representation to use when data is retrieved;  has same meaning as
\fIformat\fR argument to \fBTk_CreateSelHandler\fR.
.AP char *buffer in
Null terminated string containing the data to be appended to the clipboard.
.BE

.SH DESCRIPTION
.PP
These two procedures manage the clipboard for Tk.
The clipboard is typically managed by calling \fBTk_ClipboardClear\fR
once, then calling \fBTk_ClipboardAppend\fR to add data for any
number of targets.
.PP
\fBTk_ClipboardClear\fR claims the CLIPBOARD selection and frees any
data items previously stored on the clipboard in this application.  
It normally returns TCL_OK, but if an error occurs it returns
TCL_ERROR and leaves an error message in \fIinterp->result\fR.
\fBTk_ClipboardClear\fR must be called before a sequence of
\fBTk_ClipboardAppend\fR calls can be issued.
.PP
\fBTk_ClipboardAppend\fR appends a buffer of data to the clipboard.
The first buffer for a given \fItarget\fR determines the \fIformat\fR
for that \fItarget\fR.
Any successive appends for that \fItarget\fR must have
the same format or an error will be returned.
\fBTk_ClipboardAppend\fR returns TCL_OK if the buffer is
successfully copied onto the clipboard.  If the clipboard is not
currently owned by the application, either
because \fBTk_ClipboardClear\fR has not been called or because
ownership of the clipboard has changed since the last call to
\fBTk_ClipboardClear\fR,
\fBTk_ClipboardAppend\fR returns TCL_ERROR and leaves an error message in
\fIinterp->result\fR.
.PP
In order to guarantee atomicity, no event handling should occur
between \fBTk_ClipboardClear\fR and the following
\fBTk_ClipboardAppend\fR calls (otherwise someone could retrieve
a partially completed clipboard or claim ownership away from
this application).
.PP
\fBTk_ClipboardClear\fR may invoke callbacks, including arbitrary
Tcl scripts, as a result of losing the CLIPBOARD selection, so
any calling function should take care to be reentrant at the point
\fBTk_ClipboardClear\fR is invoked.

.SH KEYWORDS
append, clipboard, clear, format, type
