*	a given type determines the format for that type.  Any successive *	appends to that type must have the same format or an error will *	be returned.  Tk_ClipboardClear must be called before a sequence *	of Tk_ClipboardAppend calls can be issued.  In order to guarantee *	atomicity, no event handling should occur between Tk_ClipboardClear *	and the following Tk_AppendToClipboard calls. * * Results: *	A standard Tcl result.  If an error is returned, an error message *	is left in interp->result. * * Side effects: * 	The specified buffer will be copied onto the end of the clipboard. *	The clipboard maintains a list of buffers which will be used to *	supply the data for a selection get request.  The first time a given *	type is appended, Tk_ClipboardAppend will register a selection * 	handler of the appropriate type. * *---------------------------------------------------------------------- */intTk_ClipboardAppend(interp, tkwin, type, format, buffer)    Tcl_Interp *interp;		/* Used for error reporting. */    Tk_Window tkwin;		/* Window that selects a display. */    Atom type;			/* The desired conversion type for this				 * clipboard item, e.g. STRING or LENGTH. */    Atom format;		/* Format in which the selection				 * information should be returned to				 * the requestor. */    char* buffer;		/* NULL terminated string containing the data				 * to be added to the clipboard. */{    TkWindow *winPtr = (TkWindow *) tkwin;    TkDisplay *dispPtr = winPtr->dispPtr;    TkClipboardTarget *targetPtr;    TkClipboardBuffer *cbPtr;    /*     * If this application doesn't already own the clipboard, clear     * the clipboard.  If we don't own the clipboard selection, claim it.     */    if (dispPtr->clipboardAppPtr != winPtr->mainPtr) {	Tk_ClipboardClear(interp, tkwin);    } else if (!dispPtr->clipboardActive) {	Tk_OwnSelection(dispPtr->clipWindow, dispPtr->clipboardAtom,		ClipboardLostSel, (ClientData) dispPtr);	dispPtr->clipboardActive = 1;    }    /*     * Check to see if the specified target is already present on the     * clipboard.  If it isn't, we need to create a new target; otherwise,     * we just append the new buffer to the clipboard list.     */    for (targetPtr = dispPtr->clipTargetPtr; targetPtr != NULL;	    targetPtr = targetPtr->nextPtr) {	if (targetPtr->type == type)	    break;    }    if (targetPtr == NULL) {	targetPtr = (TkClipboardTarget*) ckalloc(sizeof(TkClipboardTarget));	targetPtr->type = type;	targetPtr->format = format;	targetPtr->firstBufferPtr = targetPtr->lastBufferPtr = NULL;	targetPtr->nextPtr = dispPtr->clipTargetPtr;	dispPtr->clipTargetPtr = targetPtr;	Tk_CreateSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,		type, ClipboardHandler, (ClientData) targetPtr, format);    } else if (targetPtr->format != format) {	Tcl_AppendResult(interp, "format \"", Tk_GetAtomName(tkwin, format),		"\" does not match current format \"",		Tk_GetAtomName(tkwin, targetPtr->format),"\" for ",		Tk_GetAtomName(tkwin, type), (char *) NULL);	return TCL_ERROR;    }    /*     * Append a new buffer to the buffer chain.     */    cbPtr = (TkClipboardBuffer*) ckalloc(sizeof(TkClipboardBuffer));    cbPtr->nextPtr = NULL;    if (targetPtr->lastBufferPtr != NULL) {	targetPtr->lastBufferPtr->nextPtr = cbPtr;    } else {	targetPtr->firstBufferPtr = cbPtr;    }    targetPtr->lastBufferPtr = cbPtr;    cbPtr->length = strlen(buffer);    cbPtr->buffer = (char *) ckalloc((unsigned) (cbPtr->length + 1));    strcpy(cbPtr->buffer, buffer);    TkSelUpdateClipboard((TkWindow*)(dispPtr->clipWindow), targetPtr);    return TCL_OK;}/* *---------------------------------------------------------------------- * * Tk_ClipboardCmd -- * *	This procedure is invoked to process the "clipboard" Tcl *	command.  See the user documentation for details on what *	it does. * * Results: *	A standard Tcl result. * * Side effects: *	See the user documentation. * *---------------------------------------------------------------------- */intTk_ClipboardCmd(clientData, interp, argc, argv)    ClientData clientData;	/* Main window associated with				 * interpreter. */    Tcl_Interp *interp;		/* Current interpreter. */    int argc;			/* Number of arguments. */    char **argv;		/* Argument strings. */{    Tk_Window tkwin = (Tk_Window) clientData;    char *path = NULL;    size_t length;    int count;    char c;    char **args;    if (argc < 2) {	Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],		" option ?arg arg ...?\"", (char *) NULL);	return TCL_ERROR;    }    c = argv[1][0];    length = strlen(argv[1]);    if ((c == 'a') && (strncmp(argv[1], "append", length) == 0)) {	Atom target, format;	char *targetName = NULL;	char *formatName = NULL;	for (count = argc-2, args = argv+2; count > 1; count -= 2, args += 2) {	    if (args[0][0] != '-') {		break;	    }	    c = args[0][1];	    length = strlen(args[0]);	    if ((c == '-') && (length == 2)) {		args++;		count--;		break;	    }	    if ((c == 'd') && (strncmp(args[0], "-displayof", length) == 0)) {		path = args[1];	    } else if ((c == 'f')		    && (strncmp(args[0], "-format", length) == 0)) {		formatName = args[1];	    } else if ((c == 't')		    && (strncmp(args[0], "-type", length) == 0)) {		targetName = args[1];	    } else {		Tcl_AppendResult(interp, "unknown option \"", args[0],			"\"", (char *) NULL);		return TCL_ERROR;	    }	}	if (count != 1) {	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],		    " append ?options? data\"", (char *) NULL);	    return TCL_ERROR;	}	if (path != NULL) {	    tkwin = Tk_NameToWindow(interp, path, tkwin);	}	if (tkwin == NULL) {	    return TCL_ERROR;	}	if (targetName != NULL) {	    target = Tk_InternAtom(tkwin, targetName);	} else {	    target = XA_STRING;	}	if (formatName != NULL) {	    format = Tk_InternAtom(tkwin, formatName);	} else {	    format = XA_STRING;	}	return Tk_ClipboardAppend(interp, tkwin, target, format, args[0]);    } else if ((c == 'c') && (strncmp(argv[1], "clear", length) == 0)) {	for (count = argc-2, args = argv+2; count > 0; count -= 2, args += 2) {	    if (args[0][0] != '-') {		break;	    }	    if (count < 2) {		Tcl_AppendResult(interp, "value for \"", *args,			"\" missing", (char *) NULL);		return TCL_ERROR;	    }	    c = args[0][1];	    length = strlen(args[0]);	    if ((c == 'd') && (strncmp(args[0], "-displayof", length) == 0)) {		path = args[1];	    } else {		Tcl_AppendResult(interp, "unknown option \"", args[0],			"\"", (char *) NULL);		return TCL_ERROR;	    }	}	if (count > 0) {	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],		    " clear ?options?\"", (char *) NULL);	    return TCL_ERROR;	}	if (path != NULL) {	    tkwin = Tk_NameToWindow(interp, path, tkwin);	}	if (tkwin == NULL) {	    return TCL_ERROR;	}	return Tk_ClipboardClear(interp, tkwin);    } else {	sprintf(interp->result,		"bad option \"%.50s\": must be clear or append",		argv[1]);	return TCL_ERROR;    }}/* *---------------------------------------------------------------------- * * TkClipInit -- * *	This procedure is called to initialize the window for claiming *	clipboard ownership and for receiving selection get results.  This *	function is called from tkSelect.c as well as tkClipboard.c. * * Results: *	The result is a standard Tcl return value, which is normally TCL_OK. *	If an error occurs then an error message is left in interp->result *	and TCL_ERROR is returned. * * Side effects: *	Sets up the clipWindow and related data structures. * *---------------------------------------------------------------------- */intTkClipInit(interp, dispPtr)    Tcl_Interp *interp;		/* Interpreter to use for error				 * reporting. */    register TkDisplay *dispPtr;/* Display to initialize. */{    XSetWindowAttributes atts;    dispPtr->clipTargetPtr = NULL;    dispPtr->clipboardActive = 0;    dispPtr->clipboardAppPtr = NULL;        /*     * Create the window used for clipboard ownership and selection retrieval,     * and set up an event handler for it.     */    dispPtr->clipWindow = Tk_CreateWindow(interp, (Tk_Window) NULL,	    "_clip", DisplayString(dispPtr->display));    if (dispPtr->clipWindow == NULL) {	return TCL_ERROR;    }    atts.override_redirect = True;    Tk_ChangeWindowAttributes(dispPtr->clipWindow, CWOverrideRedirect, &atts);    Tk_MakeWindowExist(dispPtr->clipWindow);    if (dispPtr->multipleAtom == None) {	/*	 * Need to invoke selection initialization to make sure that	 * atoms we depend on below are defined.	 */	TkSelInit(dispPtr->clipWindow);    }    /*     * Create selection handlers for types TK_APPLICATION and TK_WINDOW     * on this window.  Can't use the default handlers for these types     * because this isn't a full-fledged window.     */    Tk_CreateSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,	    dispPtr->applicationAtom, ClipboardAppHandler,	    (ClientData) dispPtr, XA_STRING);    Tk_CreateSelHandler(dispPtr->clipWindow, dispPtr->clipboardAtom,	    dispPtr->windowAtom, ClipboardWindowHandler,	    (ClientData) dispPtr, XA_STRING);    return TCL_OK;}