1/*
2 * tkClipboard.c --
3 *
4 * 	This file manages the clipboard for the Tk toolkit,
5 * 	maintaining a collection of data buffers that will be
6 * 	supplied on demand to requesting applications.
7 *
8 * Copyright (c) 1994 The Regents of the University of California.
9 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
10 *
11 * See the file "license.terms" for information on usage and redistribution
12 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
13 *
14 * RCS: @(#) $Id: tkClipboard.c,v 1.12.2.1 2004/05/03 22:23:08 hobbs Exp $
15 */
16
17#include "tkInt.h"
18#include "tkPort.h"
19#include "tkSelect.h"
20
21/*
22 * Prototypes for procedures used only in this file:
23 */
24
25static int		ClipboardAppHandler _ANSI_ARGS_((ClientData clientData,
26			    int offset, char *buffer, int maxBytes));
27static int		ClipboardHandler _ANSI_ARGS_((ClientData clientData,
28			    int offset, char *buffer, int maxBytes));
29static int		ClipboardWindowHandler _ANSI_ARGS_((
30			    ClientData clientData, int offset, char *buffer,
31			    int maxBytes));
32static void		ClipboardLostSel _ANSI_ARGS_((ClientData clientData));
33static int		ClipboardGetProc _ANSI_ARGS_((ClientData clientData,
34			    Tcl_Interp *interp, char *portion));
35
36/*
37 *----------------------------------------------------------------------
38 *
39 * ClipboardHandler --
40 *
41 *	This procedure acts as selection handler for the
42 *	clipboard manager.  It extracts the required chunk of
43 *	data from the buffer chain for a given selection target.
44 *
45 * Results:
46 *	The return value is a count of the number of bytes
47 *	actually stored at buffer.
48 *
49 * Side effects:
50 *	None.
51 *
52 *----------------------------------------------------------------------
53 */
54
55static int
56ClipboardHandler(clientData, offset, buffer, maxBytes)
57    ClientData clientData;	/* Information about data to fetch. */
58    int offset;			/* Return selection bytes starting at this
59				 * offset. */
60    char *buffer;		/* Place to store converted selection. */
61    int maxBytes;		/* Maximum # of bytes to store at buffer. */
62{
63    TkClipboardTarget *targetPtr = (TkClipboardTarget*) clientData;
64    TkClipboardBuffer *cbPtr;
65    char *srcPtr, *destPtr;
66    int count = 0;
67    int scanned = 0;
68    size_t length, freeCount;
69
70    /*
71     * Skip to buffer containing offset byte
72     */
73
74    for (cbPtr = targetPtr->firstBufferPtr; ; cbPtr = cbPtr->nextPtr) {
75	if (cbPtr == NULL) {
76	    return 0;
77	}
78	if (scanned + cbPtr->length > offset) {
79	    break;
80	}
81	scanned += cbPtr->length;
82    }
83
84    /*
85     * Copy up to maxBytes or end of list, switching buffers as needed.
86     */
87
88    freeCount = maxBytes;
89    srcPtr = cbPtr->buffer + (offset - scanned);
90    destPtr = buffer;
91    length = cbPtr->length - (offset - scanned);
92    while (1) {
93	if (length > freeCount) {
94	    strncpy(destPtr, srcPtr, freeCount);
95	    return maxBytes;
96	} else {
97	    strncpy(destPtr, srcPtr, length);
98	    destPtr += length;
99	    count += length;
100	    freeCount -= length;
101	}
102	cbPtr = cbPtr->nextPtr;
103	if (cbPtr == NULL) {
104	    break;
105	}
106	srcPtr = cbPtr->buffer;
107	length = cbPtr->length;
108    }
109    return count;
110}
111
112/*
113 *----------------------------------------------------------------------
114 *
115 * ClipboardAppHandler --
116 *
117 *	This procedure acts as selection handler for retrievals of type
118 *	TK_APPLICATION.  It returns the name of the application that
119 *	owns the clipboard.  Note:  we can't use the default Tk
120 *	selection handler for this selection type, because the clipboard
121 *	window isn't a "real" window and doesn't have the necessary
122 *	information.
123 *
124 * Results:
125 *	The return value is a count of the number of bytes
126 *	actually stored at buffer.
127 *
128 * Side effects:
129 *	None.
130 *
131 *----------------------------------------------------------------------
132 */
133
134static int
135ClipboardAppHandler(clientData, offset, buffer, maxBytes)
136    ClientData clientData;	/* Pointer to TkDisplay structure. */
137    int offset;			/* Return selection bytes starting at this
138				 * offset. */
139    char *buffer;		/* Place to store converted selection. */
140    int maxBytes;		/* Maximum # of bytes to store at buffer. */
141{
142    TkDisplay *dispPtr = (TkDisplay *) clientData;
143    size_t length;
144    CONST char *p;
145
146    p = dispPtr->clipboardAppPtr->winPtr->nameUid;
147    length = strlen(p);
148    length -= offset;
149    if (length <= 0) {
150	return 0;
151    }
152    if (length > (size_t) maxBytes) {
153	length = maxBytes;
154    }
155    strncpy(buffer, p, length);
156    return length;
157}
158
159/*
160 *----------------------------------------------------------------------
161 *
162 * ClipboardWindowHandler --
163 *
164 *	This procedure acts as selection handler for retrievals of
165 *	type TK_WINDOW.  Since the clipboard doesn't correspond to
166 *	any particular window, we just return ".".  We can't use Tk's
167 *	default handler for this selection type, because the clipboard
168 *	window isn't a valid window.
169 *
170 * Results:
171 *	The return value is 1, the number of non-null bytes stored
172 *	at buffer.
173 *
174 * Side effects:
175 *	None.
176 *
177 *----------------------------------------------------------------------
178 */
179
180static int
181ClipboardWindowHandler(clientData, offset, buffer, maxBytes)
182    ClientData clientData;	/* Not used. */
183    int offset;			/* Return selection bytes starting at this
184				 * offset. */
185    char *buffer;		/* Place to store converted selection. */
186    int maxBytes;		/* Maximum # of bytes to store at buffer. */
187{
188    buffer[0] = '.';
189    buffer[1] = 0;
190    return 1;
191}
192
193/*
194 *----------------------------------------------------------------------
195 *
196 * ClipboardLostSel --
197 *
198 *	This procedure is invoked whenever clipboard ownership is
199 *	claimed by another window.  It just sets a flag so that we
200 *	know the clipboard was taken away.
201 *
202 * Results:
203 *	None.
204 *
205 * Side effects:
206 *	The clipboard is marked as inactive.
207 *
208 *----------------------------------------------------------------------
209 */
210
211static void
212ClipboardLostSel(clientData)
213    ClientData clientData;		/* Pointer to TkDisplay structure. */
214{
215    TkDisplay *dispPtr = (TkDisplay*) clientData;
216
217    dispPtr->clipboardActive = 0;
218}
219
220/*
221 *----------------------------------------------------------------------
222 *
223 * Tk_ClipboardClear --
224 *
225 *	Take control of the clipboard and clear out the previous
226 *	contents.  This procedure must be invoked before any
227 *	calls to Tk_ClipboardAppend.
228 *
229 * Results:
230 *	A standard Tcl result.  If an error occurs, an error message is
231 *	left in the interp's result.
232 *
233 * Side effects:
234 *	From now on, requests for the CLIPBOARD selection will be
235 *	directed to the clipboard manager routines associated with
236 *	clipWindow for the display of tkwin.  In order to guarantee
237 *	atomicity, no event handling should occur between
238 *	Tk_ClipboardClear and the following Tk_ClipboardAppend
239 *	calls.  This procedure may cause a user-defined LostSel command
240 * 	to be invoked when the CLIPBOARD is claimed, so any calling
241 *	function should be reentrant at the point Tk_ClipboardClear is
242 *	invoked.
243 *
244 *----------------------------------------------------------------------
245 */
246
247int
248Tk_ClipboardClear(interp, tkwin)
249    Tcl_Interp *interp;		/* Interpreter to use for error reporting. */
250    Tk_Window tkwin;		/* Window in application that is clearing
251				 * clipboard;  identifies application and
252				 * display. */
253{
254    TkWindow *winPtr = (TkWindow *) tkwin;
255    TkDisplay *dispPtr = winPtr->dispPtr;
256    TkClipboardTarget *targetPtr, *nextTargetPtr;
257    TkClipboardBuffer *cbPtr, *nextCbPtr;
258
259    if (dispPtr->clipWindow == NULL) {
260	int result;
261
262	result = TkClipInit(interp, dispPtr);
263	if (result != TCL_OK) {
264	    return result;
265	}
266    }
267
268    /*
269     * Discard any existing clipboard data and delete the selection
270     * handler(s) associated with that data.
271     */
272
273    for (targetPtr = dispPtr->clipTargetPtr; targetPtr != NULL;
274	    targetPtr = nextTargetPtr) {
275	for (cbPtr = targetPtr->firstBufferPtr; cbPtr != NULL;
276		cbPtr = nextCbPtr) {
277	    ckfree(cbPtr->buffer);
278	    nextCbPtr = cbPtr->nextPtr;
279	    ckfree((char *) cbPtr);
280	}
281	nextTargetPtr = targetPtr->nextPtr;
282	Tk_DeleteSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,
283		targetPtr->type);
284	ckfree((char *) targetPtr);
285    }
286    dispPtr->clipTargetPtr = NULL;
287
288    /*
289     * Reclaim the clipboard selection if we lost it.
290     */
291
292    if (!dispPtr->clipboardActive) {
293	Tk_OwnSelection(dispPtr->clipWindow, dispPtr->clipboardAtom,
294		ClipboardLostSel, (ClientData) dispPtr);
295	dispPtr->clipboardActive = 1;
296    }
297    dispPtr->clipboardAppPtr = winPtr->mainPtr;
298    return TCL_OK;
299}
300
301/*
302 *----------------------------------------------------------------------
303 *
304 * Tk_ClipboardAppend --
305 *
306 * 	Append a buffer of data to the clipboard.  The first buffer of
307 *	a given type determines the format for that type.  Any successive
308 *	appends to that type must have the same format or an error will
309 *	be returned.  Tk_ClipboardClear must be called before a sequence
310 *	of Tk_ClipboardAppend calls can be issued.  In order to guarantee
311 *	atomicity, no event handling should occur between Tk_ClipboardClear
312 *	and the following Tk_ClipboardAppend calls.
313 *
314 * Results:
315 *	A standard Tcl result.  If an error is returned, an error message
316 *	is left in the interp's result.
317 *
318 * Side effects:
319 * 	The specified buffer will be copied onto the end of the clipboard.
320 *	The clipboard maintains a list of buffers which will be used to
321 *	supply the data for a selection get request.  The first time a given
322 *	type is appended, Tk_ClipboardAppend will register a selection
323 * 	handler of the appropriate type.
324 *
325 *----------------------------------------------------------------------
326 */
327
328int
329Tk_ClipboardAppend(interp, tkwin, type, format, buffer)
330    Tcl_Interp *interp;		/* Used for error reporting. */
331    Tk_Window tkwin;		/* Window that selects a display. */
332    Atom type;			/* The desired conversion type for this
333				 * clipboard item, e.g. STRING or LENGTH. */
334    Atom format;		/* Format in which the selection
335				 * information should be returned to
336				 * the requestor. */
337    char* buffer;		/* NULL terminated string containing the data
338				 * to be added to the clipboard. */
339{
340    TkWindow *winPtr = (TkWindow *) tkwin;
341    TkDisplay *dispPtr = winPtr->dispPtr;
342    TkClipboardTarget *targetPtr;
343    TkClipboardBuffer *cbPtr;
344
345    /*
346     * If this application doesn't already own the clipboard, clear
347     * the clipboard.  If we don't own the clipboard selection, claim it.
348     */
349
350    if (dispPtr->clipboardAppPtr != winPtr->mainPtr) {
351	Tk_ClipboardClear(interp, tkwin);
352    } else if (!dispPtr->clipboardActive) {
353	Tk_OwnSelection(dispPtr->clipWindow, dispPtr->clipboardAtom,
354		ClipboardLostSel, (ClientData) dispPtr);
355	dispPtr->clipboardActive = 1;
356    }
357
358    /*
359     * Check to see if the specified target is already present on the
360     * clipboard.  If it isn't, we need to create a new target; otherwise,
361     * we just append the new buffer to the clipboard list.
362     */
363
364    for (targetPtr = dispPtr->clipTargetPtr; targetPtr != NULL;
365	    targetPtr = targetPtr->nextPtr) {
366	if (targetPtr->type == type)
367	    break;
368    }
369    if (targetPtr == NULL) {
370	targetPtr = (TkClipboardTarget*) ckalloc(sizeof(TkClipboardTarget));
371	targetPtr->type = type;
372	targetPtr->format = format;
373	targetPtr->firstBufferPtr = targetPtr->lastBufferPtr = NULL;
374	targetPtr->nextPtr = dispPtr->clipTargetPtr;
375	dispPtr->clipTargetPtr = targetPtr;
376	Tk_CreateSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,
377		type, ClipboardHandler, (ClientData) targetPtr, format);
378    } else if (targetPtr->format != format) {
379	Tcl_AppendResult(interp, "format \"", Tk_GetAtomName(tkwin, format),
380		"\" does not match current format \"",
381		Tk_GetAtomName(tkwin, targetPtr->format),"\" for ",
382		Tk_GetAtomName(tkwin, type), (char *) NULL);
383	return TCL_ERROR;
384    }
385
386    /*
387     * Append a new buffer to the buffer chain.
388     */
389
390    cbPtr = (TkClipboardBuffer*) ckalloc(sizeof(TkClipboardBuffer));
391    cbPtr->nextPtr = NULL;
392    if (targetPtr->lastBufferPtr != NULL) {
393	targetPtr->lastBufferPtr->nextPtr = cbPtr;
394    } else {
395	targetPtr->firstBufferPtr = cbPtr;
396    }
397    targetPtr->lastBufferPtr = cbPtr;
398
399    cbPtr->length = strlen(buffer);
400    cbPtr->buffer = (char *) ckalloc((unsigned) (cbPtr->length + 1));
401    strcpy(cbPtr->buffer, buffer);
402
403    TkSelUpdateClipboard((TkWindow*)(dispPtr->clipWindow), targetPtr);
404
405    return TCL_OK;
406}
407
408/*
409 *----------------------------------------------------------------------
410 *
411 * Tk_ClipboardObjCmd --
412 *
413 *	This procedure is invoked to process the "clipboard" Tcl
414 *	command.  See the user documentation for details on what
415 *	it does.
416 *
417 * Results:
418 *	A standard Tcl result.
419 *
420 * Side effects:
421 *	See the user documentation.
422 *
423 *----------------------------------------------------------------------
424 */
425
426int
427Tk_ClipboardObjCmd(clientData, interp, objc, objv)
428    ClientData clientData;	/* Main window associated with
429				 * interpreter. */
430    Tcl_Interp *interp;		/* Current interpreter. */
431    int objc;			/* Number of arguments. */
432    Tcl_Obj *CONST objv[];	/* Argument strings. */
433{
434    Tk_Window tkwin = (Tk_Window) clientData;
435    char *path = NULL;
436    Atom selection;
437    static CONST char *optionStrings[] = { "append", "clear", "get", NULL };
438    enum options { CLIPBOARD_APPEND, CLIPBOARD_CLEAR, CLIPBOARD_GET };
439    int index, i;
440
441    if (objc < 2) {
442	Tcl_WrongNumArgs(interp, 1, objv, "option ?arg arg ...?");
443	return TCL_ERROR;
444    }
445
446    if (Tcl_GetIndexFromObj(interp, objv[1], optionStrings, "option", 0,
447	    &index) != TCL_OK) {
448	return TCL_ERROR;
449    }
450
451    switch ((enum options) index) {
452	case CLIPBOARD_APPEND: {
453	    Atom target, format;
454	    char *targetName = NULL;
455	    char *formatName = NULL;
456	    char *string;
457	    static CONST char *appendOptionStrings[] = {
458		"-displayof", "-format", "-type", NULL
459	    };
460	    enum appendOptions { APPEND_DISPLAYOF, APPEND_FORMAT,
461				     APPEND_TYPE };
462	    int subIndex, length;
463
464	    for (i = 2; i < objc - 1; i++) {
465		string = Tcl_GetStringFromObj(objv[i], &length);
466		if (string[0] != '-') {
467		    break;
468		}
469
470		/*
471		 * If the argument is "--", it signifies the end of arguments.
472		 */
473		if (string[1] == '-' && length == 2) {
474		    i++;
475		    break;
476		}
477		if (Tcl_GetIndexFromObj(interp, objv[i], appendOptionStrings,
478			"option", 0, &subIndex) != TCL_OK) {
479		    return TCL_ERROR;
480		}
481
482		/*
483		 * Increment i so that it points to the value for the flag
484		 * instead of the flag itself.
485		 */
486
487		i++;
488		if (i >= objc) {
489		    Tcl_AppendResult(interp, "value for \"", string,
490			    "\" missing", (char *) NULL);
491		    return TCL_ERROR;
492		}
493		switch ((enum appendOptions) subIndex) {
494		    case APPEND_DISPLAYOF:
495			path = Tcl_GetString(objv[i]);
496			break;
497		    case APPEND_FORMAT:
498			formatName = Tcl_GetString(objv[i]);
499			break;
500		    case APPEND_TYPE:
501			targetName = Tcl_GetString(objv[i]);
502			break;
503		}
504	    }
505	    if (objc - i != 1) {
506		Tcl_WrongNumArgs(interp, 2, objv, "?options? data");
507		return TCL_ERROR;
508	    }
509	    if (path != NULL) {
510		tkwin = Tk_NameToWindow(interp, path, tkwin);
511	    }
512	    if (tkwin == NULL) {
513		return TCL_ERROR;
514	    }
515	    if (targetName != NULL) {
516		target = Tk_InternAtom(tkwin, targetName);
517	    } else {
518		target = XA_STRING;
519	    }
520	    if (formatName != NULL) {
521		format = Tk_InternAtom(tkwin, formatName);
522	    } else {
523		format = XA_STRING;
524	    }
525	    return Tk_ClipboardAppend(interp, tkwin, target, format,
526		    Tcl_GetString(objv[i]));
527	}
528	case CLIPBOARD_CLEAR: {
529	    static CONST char *clearOptionStrings[] = { "-displayof", NULL };
530	    enum clearOptions { CLEAR_DISPLAYOF };
531	    int subIndex;
532	    if (objc != 2 && objc != 4) {
533		Tcl_WrongNumArgs(interp, 2, objv, "?-displayof window?");
534		return TCL_ERROR;
535	    }
536
537	    if (objc == 4) {
538		if (Tcl_GetIndexFromObj(interp, objv[2], clearOptionStrings,
539			"option", 0, &subIndex) != TCL_OK) {
540		    return TCL_ERROR;
541		}
542		if ((enum clearOptions) subIndex == CLEAR_DISPLAYOF) {
543		    path = Tcl_GetString(objv[3]);
544		}
545	    }
546	    if (path != NULL) {
547		tkwin = Tk_NameToWindow(interp, path, tkwin);
548	    }
549	    if (tkwin == NULL) {
550		return TCL_ERROR;
551	    }
552	    return Tk_ClipboardClear(interp, tkwin);
553	}
554	case CLIPBOARD_GET: {
555	    Atom target;
556	    char *targetName = NULL;
557	    Tcl_DString selBytes;
558	    int result;
559	    char *string;
560	    static CONST char *getOptionStrings[] = {
561		"-displayof", "-type", NULL
562	    };
563	    enum getOptions { APPEND_DISPLAYOF, APPEND_TYPE };
564	    int subIndex;
565
566	    for (i = 2; i < objc; i++) {
567		string = Tcl_GetString(objv[i]);
568		if (string[0] != '-') {
569		    break;
570		}
571		if (Tcl_GetIndexFromObj(interp, objv[i], getOptionStrings,
572			"option", 0, &subIndex) != TCL_OK) {
573		    return TCL_ERROR;
574		}
575		i++;
576		if (i >= objc) {
577		    Tcl_AppendResult(interp, "value for \"", string,
578			    "\" missing", (char *) NULL);
579		    return TCL_ERROR;
580		}
581		switch ((enum getOptions) subIndex) {
582		    case APPEND_DISPLAYOF:
583			path = Tcl_GetString(objv[i]);
584			break;
585		    case APPEND_TYPE:
586			targetName = Tcl_GetString(objv[i]);
587			break;
588		}
589	    }
590	    if (path != NULL) {
591		tkwin = Tk_NameToWindow(interp, path, tkwin);
592	    }
593	    if (tkwin == NULL) {
594		return TCL_ERROR;
595	    }
596	    selection = Tk_InternAtom(tkwin, "CLIPBOARD");
597
598	    if (objc - i > 1) {
599		Tcl_WrongNumArgs(interp, 2, objv, "?options?");
600		return TCL_ERROR;
601	    } else if (objc - i == 1) {
602		target = Tk_InternAtom(tkwin, Tcl_GetString(objv[i]));
603	    } else if (targetName != NULL) {
604		target = Tk_InternAtom(tkwin, targetName);
605	    } else {
606		target = XA_STRING;
607	    }
608
609	    Tcl_DStringInit(&selBytes);
610	    result = Tk_GetSelection(interp, tkwin, selection, target,
611		    ClipboardGetProc, (ClientData) &selBytes);
612	    if (result == TCL_OK) {
613		Tcl_DStringResult(interp, &selBytes);
614	    } else {
615		Tcl_DStringFree(&selBytes);
616	    }
617	    return result;
618	}
619    }
620    return TCL_OK;
621}
622
623/*
624 *----------------------------------------------------------------------
625 *
626 * TkClipInit --
627 *
628 *	This procedure is called to initialize the window for claiming
629 *	clipboard ownership and for receiving selection get results.  This
630 *	function is called from tkSelect.c as well as tkClipboard.c.
631 *
632 * Results:
633 *	The result is a standard Tcl return value, which is normally TCL_OK.
634 *	If an error occurs then an error message is left in the interp's
635 *	result and TCL_ERROR is returned.
636 *
637 * Side effects:
638 *	Sets up the clipWindow and related data structures.
639 *
640 *----------------------------------------------------------------------
641 */
642
643int
644TkClipInit(interp, dispPtr)
645    Tcl_Interp *interp;		/* Interpreter to use for error
646				 * reporting. */
647    register TkDisplay *dispPtr;/* Display to initialize. */
648{
649    XSetWindowAttributes atts;
650
651    dispPtr->clipTargetPtr = NULL;
652    dispPtr->clipboardActive = 0;
653    dispPtr->clipboardAppPtr = NULL;
654
655    /*
656     * Create the window used for clipboard ownership and selection retrieval,
657     * and set up an event handler for it.
658     */
659
660    dispPtr->clipWindow = Tk_CreateWindow(interp, (Tk_Window) NULL,
661	    "_clip", DisplayString(dispPtr->display));
662    if (dispPtr->clipWindow == NULL) {
663	return TCL_ERROR;
664    }
665    Tcl_Preserve((ClientData) dispPtr->clipWindow);
666    atts.override_redirect = True;
667    Tk_ChangeWindowAttributes(dispPtr->clipWindow, CWOverrideRedirect, &atts);
668    Tk_MakeWindowExist(dispPtr->clipWindow);
669
670    if (dispPtr->multipleAtom == None) {
671	/*
672	 * Need to invoke selection initialization to make sure that
673	 * atoms we depend on below are defined.
674	 */
675
676	TkSelInit(dispPtr->clipWindow);
677    }
678
679    /*
680     * Create selection handlers for types TK_APPLICATION and TK_WINDOW
681     * on this window.  Can't use the default handlers for these types
682     * because this isn't a full-fledged window.
683     */
684
685    Tk_CreateSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,
686	    dispPtr->applicationAtom, ClipboardAppHandler,
687	    (ClientData) dispPtr, XA_STRING);
688    Tk_CreateSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,
689	    dispPtr->windowAtom, ClipboardWindowHandler,
690	    (ClientData) dispPtr, XA_STRING);
691    return TCL_OK;
692}
693
694/*
695 *--------------------------------------------------------------
696 *
697 * ClipboardGetProc --
698 *
699 *	This procedure is invoked to process pieces of the selection
700 *	as they arrive during "clipboard get" commands.
701 *
702 * Results:
703 *	Always returns TCL_OK.
704 *
705 * Side effects:
706 *	Bytes get appended to the dynamic string pointed to by the
707 *	clientData argument.
708 *
709 *--------------------------------------------------------------
710 */
711
712	/* ARGSUSED */
713static int
714ClipboardGetProc(clientData, interp, portion)
715    ClientData clientData;	/* Dynamic string holding partially
716				 * assembled selection. */
717    Tcl_Interp *interp;		/* Interpreter used for error
718				 * reporting (not used). */
719    char *portion;		/* New information to be appended. */
720{
721    Tcl_DStringAppend((Tcl_DString *) clientData, portion, -1);
722    return TCL_OK;
723}
724
725