'\"'\" 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.'\" '\" SCCS: @(#) selection.n 1.18 96/08/27 13:21:51'\" .so man.macros.TH selection n 4.0 Tk "Tk Built-In Commands".BS'\" Note:  do not modify the .SH NAME line immediately below!.SH NAMEselection \- Manipulate the X selection.SH SYNOPSIS\fBselection \fIoption\fR ?\fIarg arg ...\fR?.BE.SH DESCRIPTION.PPThis command provides a Tcl interface to the X selection mechanism andimplements the full selection functionality described in theX Inter-Client Communication Conventions Manual (ICCCM)..PPThe first argument to \fBselection\fR determines the format of therest of the arguments and the behavior of the command.  The followingforms are currently supported:.PP.TP\fBselection clear\fR ?\fB\-displayof\fR \fIwindow\fR? ?\fB\-selection\fR \fIselection\fR?If \fIselection\fR exists anywhere on \fIwindow\fR's display, clear itso that no window owns the selection anymore.  \fISelection\fRspecifies the X selection that should be cleared, and should be anatom name such as PRIMARY or CLIPBOARD; see the Inter-ClientCommunication Conventions Manual for complete details.\fISelection\fR defaults to PRIMARY and \fIwindow\fR defaults to ``.''.Returns an empty string. .TP\fBselection get\fR ?\fB\-displayof\fR \fIwindow\fR? ?\fB\-selection\fR \fIselection\fR? ?\fB\-type\fR \fItype\fR?Retrieves the value of \fIselection\fR from \fIwindow\fR's display andreturns it as a result.  \fISelection\fR defaults to PRIMARY and\fIwindow\fR defaults to ``.''. \fIType\fR specifies the form in which the selection is to be returned(the desired ``target'' for conversion, in ICCCM terminology), andshould be an atom name such as STRING or FILE_NAME; see theInter-Client Communication Conventions Manual for complete details.\fIType\fR defaults to STRING.  The selection owner may choose toreturn the selection in any of several different representationformats, such as STRING, ATOM, INTEGER, etc. (this format is differentthan the selection type; see the ICCCM for all the confusing details).If the selection is returned in a non-string format, such as INTEGERor ATOM, the \fBselection\fR command converts it to string format as acollection of fields separated by spaces: atoms are converted to theirtextual names, and anything else is converted to hexadecimal integers..TP\fBselection handle\fR ?\fB\-selection\fR \fIselection\fR? ?\fB\-type\fR \fItype\fR? ?\fB\-format\fR \fIformat\fR? \fIwindow command\fRCreates a handler for selection requests, such that \fIcommand\fR willbe executed whenever \fIselection\fR is owned by \fIwindow\fR andsomeone attempts to retrieve it in the form given by \fItype\fR(e.g. \fItype\fR is specified in the \fBselection get\fR command).\fISelection\fR defaults to PRIMARY, \fItype\fR defaults to STRING, and\fIformat\fR defaults to STRING.  If \fIcommand\fR is an empty stringthen any existing handler for \fIwindow\fR, \fItype\fR, and\fIselection\fR is removed..RS.PPWhen \fIselection\fR is requested, \fIwindow\fR is the selection owner,and \fItype\fR is the requested type, \fIcommand\fR will be executedas a Tcl command with two additional numbers appended to it(with space separators).  The two additional numbersare \fIoffset\fR and \fImaxBytes\fR:  \fIoffset\fR specifies a startingcharacter position in the selection and \fImaxBytes\fR gives the maximumnumber of bytes to retrieve.  The command should return a value consistingof at most \fImaxBytes\fR of the selection, starting at position\fIoffset\fR.  For very large selections (larger than \fImaxBytes\fR)the selection will be retrieved using several invocations of \fIcommand\fRwith increasing \fIoffset\fR values.  If \fIcommand\fR returns a stringwhose length is less than \fImaxBytes\fR, the return value is assumed toinclude all of the remainder of the selection;  if the length of\fIcommand\fR's result is equal to \fImaxBytes\fR then\fIcommand\fR will be invoked again, until it eventuallyreturns a result shorter than \fImaxBytes\fR.  The value of \fImaxBytes\fRwill always be relatively large (thousands of bytes)..PPIf \fIcommand\fR returns an error then the selection retrieval is rejectedjust as if the selection didn't exist at all..PPThe \fIformat\fR argument specifies the representation that should beused to transmit the selection to the requester (the second column ofTable 2 of the ICCCM), and defaults to STRING.  If \fIformat\fR isSTRING, the selection is transmitted as 8-bit ASCII characters (i.e.just in the form returned by \fIcommand\fR).  If \fIformat\fR isATOM, then the return value from \fIcommand\fR is divided into fieldsseparated by white space;  each field is converted to its atom value,and the 32-bit atom value is transmitted instead of the atom name.For any other \fIformat\fR, the return value from \fIcommand\fR isdivided into fields separated by white space and each field isconverted to a 32-bit integer;  an array of integers is transmittedto the selection requester..PPThe \fIformat\fR argument is needed only for compatibility withselection requesters that don't use Tk.  If Tk is beingused to retrieve the selection then the value is converted back toa string at the requesting end, so \fIformat\fR isirrelevant..RE.TP\fBselection own\fR ?\fB\-displayof\fR \fIwindow\fR? ?\fB\-selection\fR \fIselection\fR?.TP\fBselection own\fR ?\fB\-command\fR \fIcommand\fR? ?\fB\-selection\fR \fIselection\fR? \fIwindow\fRThe first form of \fBselection own\fR returns the path name of thewindow in this application that owns \fIselection\fR on the displaycontaining \fIwindow\fR, or an empty string if no window in thisapplication owns the selection.  \fISelection\fR defaults to PRIMARY and\fIwindow\fR defaults to ``.''..PPThe second form of \fBselection own\fR causes \fIwindow\fR to becomethe new owner of \fIselection\fR on \fIwindow\fR's display, returningan empty string as result. The existing owner, if any, is notifiedthat it has lost the selection.If \fIcommand\fR is specified, it is a Tcl script to execute whensome other window claims ownership of the selection away from\fIwindow\fR.  \fISelection\fR defaults to PRIMARY..SH KEYWORDSclear, format, handler, ICCCM, own, selection, target, type