Initial revision

1 files changed, 1341 insertions, 0 deletions

diff --git a/generic/tkSelect.c b/generic/tkSelect.c
new file mode 100644
index 0000000..7263e30
--- /dev/null
+++ b/generic/tkSelect.c
@@ -0,0 +1,1341 @@
+/* 
+ * tkSelect.c --
+ *
+ *	This file manages the selection for the Tk toolkit,
+ *	translating between the standard X ICCCM conventions
+ *	and Tcl commands.
+ *
+ * Copyright (c) 1990-1993 The Regents of the University of California.
+ * Copyright (c) 1994-1995 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: @(#) tkSelect.c 1.57 96/05/03 10:52:40
+ */
+
+#include "tkInt.h"
+#include "tkSelect.h"
+
+/*
+ * When a selection handler is set up by invoking "selection handle",
+ * one of the following data structures is set up to hold information
+ * about the command to invoke and its interpreter.
+ */
+
+typedef struct {
+    Tcl_Interp *interp;		/* Interpreter in which to invoke command. */
+    int cmdLength;		/* # of non-NULL bytes in command. */
+    char command[4];		/* Command to invoke.  Actual space is
+				 * allocated as large as necessary.  This
+				 * must be the last entry in the structure. */
+} CommandInfo;
+
+/*
+ * When selection ownership is claimed with the "selection own" Tcl command,
+ * one of the following structures is created to record the Tcl command
+ * to be executed when the selection is lost again.
+ */
+
+typedef struct LostCommand {
+    Tcl_Interp *interp;		/* Interpreter in which to invoke command. */
+    char command[4];		/* Command to invoke.  Actual space is
+				 * allocated as large as necessary.  This
+				 * must be the last entry in the structure. */
+} LostCommand;
+
+/*
+ * Shared variables:
+ */
+
+TkSelInProgress *pendingPtr = NULL;
+				/* Topmost search in progress, or
+				 * NULL if none. */
+
+/*
+ * Forward declarations for procedures defined in this file:
+ */
+
+static int		HandleTclCommand _ANSI_ARGS_((ClientData clientData,
+			    int offset, char *buffer, int maxBytes));
+static void		LostSelection _ANSI_ARGS_((ClientData clientData));
+static int		SelGetProc _ANSI_ARGS_((ClientData clientData,
+			    Tcl_Interp *interp, char *portion));
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_CreateSelHandler --
+ *
+ *	This procedure is called to register a procedure
+ *	as the handler for selection requests of a particular
+ *	target type on a particular window for a particular
+ *	selection.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	In the future, whenever the selection is in tkwin's
+ *	window and someone requests the selection in the
+ *	form given by target, proc will be invoked to provide
+ *	part or all of the selection in the given form.  If
+ *	there was already a handler declared for the given
+ *	window, target and selection type, then it is replaced.
+ *	Proc should have the following form:
+ *
+ *	int
+ *	proc(clientData, offset, buffer, maxBytes)
+ *	    ClientData clientData;
+ *	    int offset;
+ *	    char *buffer;
+ *	    int maxBytes;
+ *	{
+ *	}
+ *
+ *	The clientData argument to proc will be the same as
+ *	the clientData argument to this procedure.  The offset
+ *	argument indicates which portion of the selection to
+ *	return:  skip the first offset bytes.  Buffer is a
+ *	pointer to an area in which to place the converted
+ *	selection, and maxBytes gives the number of bytes
+ *	available at buffer.  Proc should place the selection
+ *	in buffer as a string, and return a count of the number
+ *	of bytes of selection actually placed in buffer (not
+ *	including the terminating NULL character).  If the
+ *	return value equals maxBytes, this is a sign that there
+ *	is probably still more selection information available.
+ *
+ *--------------------------------------------------------------
+ */
+
+void
+Tk_CreateSelHandler(tkwin, selection, target, proc, clientData, format)
+    Tk_Window tkwin;		/* Token for window. */
+    Atom selection;		/* Selection to be handled. */
+    Atom target;		/* The kind of selection conversions
+				 * that can be handled by proc,
+				 * e.g. TARGETS or STRING. */
+    Tk_SelectionProc *proc;	/* Procedure to invoke to convert
+				 * selection to type "target". */
+    ClientData clientData;	/* Value to pass to proc. */
+    Atom format;		/* Format in which the selection
+				 * information should be returned to
+				 * the requestor. XA_STRING is best by
+				 * far, but anything listed in the ICCCM
+				 * will be tolerated (blech). */
+{
+    register TkSelHandler *selPtr;
+    TkWindow *winPtr = (TkWindow *) tkwin;
+
+    if (winPtr->dispPtr->multipleAtom == None) {
+	TkSelInit(tkwin);
+    }
+
+    /*
+     * See if there's already a handler for this target and selection on
+     * this window.  If so, re-use it.  If not, create a new one.
+     */
+
+    for (selPtr = winPtr->selHandlerList; ; selPtr = selPtr->nextPtr) {
+	if (selPtr == NULL) {
+	    selPtr = (TkSelHandler *) ckalloc(sizeof(TkSelHandler));
+	    selPtr->nextPtr = winPtr->selHandlerList;
+	    winPtr->selHandlerList = selPtr;
+	    break;
+	}
+	if ((selPtr->selection == selection) && (selPtr->target == target)) {
+
+	    /*
+	     * Special case:  when replacing handler created by
+	     * "selection handle", free up memory.  Should there be a
+	     * callback to allow other clients to do this too?
+	     */
+
+	    if (selPtr->proc == HandleTclCommand) {
+		ckfree((char *) selPtr->clientData);
+	    }
+	    break;
+	}
+    }
+    selPtr->selection = selection;
+    selPtr->target = target;
+    selPtr->format = format;
+    selPtr->proc = proc;
+    selPtr->clientData = clientData;
+    if (format == XA_STRING) {
+	selPtr->size = 8;
+    } else {
+	selPtr->size = 32;
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tk_DeleteSelHandler --
+ *
+ *	Remove the selection handler for a given window, target, and
+ *	selection, if it exists.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The selection handler for tkwin and target is removed.  If there
+ *	is no such handler then nothing happens.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tk_DeleteSelHandler(tkwin, selection, target)
+    Tk_Window tkwin;			/* Token for window. */
+    Atom selection;			/* The selection whose handler
+					 * is to be removed. */
+    Atom target;			/* The target whose selection
+					 * handler is to be removed. */
+{
+    TkWindow *winPtr = (TkWindow *) tkwin;
+    register TkSelHandler *selPtr, *prevPtr;
+    register TkSelInProgress *ipPtr;
+
+    /*
+     * Find the selection handler to be deleted, or return if it doesn't
+     * exist.
+     */ 
+
+    for (selPtr = winPtr->selHandlerList, prevPtr = NULL; ;
+	    prevPtr = selPtr, selPtr = selPtr->nextPtr) {
+	if (selPtr == NULL) {
+	    return;
+	}
+	if ((selPtr->selection == selection) && (selPtr->target == target)) {
+	    break;
+	}
+    }
+
+    /*
+     * If ConvertSelection is processing this handler, tell it that the
+     * handler is dead.
+     */
+
+    for (ipPtr = pendingPtr; ipPtr != NULL; ipPtr = ipPtr->nextPtr) {
+	if (ipPtr->selPtr == selPtr) {
+	    ipPtr->selPtr = NULL;
+	}
+    }
+
+    /*
+     * Free resources associated with the handler.
+     */
+
+    if (prevPtr == NULL) {
+	winPtr->selHandlerList = selPtr->nextPtr;
+    } else {
+	prevPtr->nextPtr = selPtr->nextPtr;
+    }
+    if (selPtr->proc == HandleTclCommand) {
+	ckfree((char *) selPtr->clientData);
+    }
+    ckfree((char *) selPtr);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_OwnSelection --
+ *
+ *	Arrange for tkwin to become the owner of a selection.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	From now on, requests for the selection will be directed
+ *	to procedures associated with tkwin (they must have been
+ *	declared with calls to Tk_CreateSelHandler).  When the
+ *	selection is lost by this window, proc will be invoked
+ *	(see the manual entry for details).  This procedure may
+ *	invoke callbacks, including Tcl scripts, so any calling
+ *	function should be reentrant at the point where
+ *	Tk_OwnSelection is invoked.
+ *
+ *--------------------------------------------------------------
+ */
+
+void
+Tk_OwnSelection(tkwin, selection, proc, clientData)
+    Tk_Window tkwin;		/* Window to become new selection
+				 * owner. */
+    Atom selection;		/* Selection that window should own. */
+    Tk_LostSelProc *proc;	/* Procedure to call when selection
+				 * is taken away from tkwin. */
+    ClientData clientData;	/* Arbitrary one-word argument to
+				 * pass to proc. */
+{
+    register TkWindow *winPtr = (TkWindow *) tkwin;
+    TkDisplay *dispPtr = winPtr->dispPtr;
+    TkSelectionInfo *infoPtr;
+    Tk_LostSelProc *clearProc = NULL;
+    ClientData clearData = NULL;	/* Initialization needed only to
+					 * prevent compiler warning. */
+    
+    
+    if (dispPtr->multipleAtom == None) {
+	TkSelInit(tkwin);
+    }
+    Tk_MakeWindowExist(tkwin);
+
+    /*
+     * This code is somewhat tricky.  First, we find the specified selection
+     * on the selection list.  If the previous owner is in this process, and
+     * is a different window, then we need to invoke the clearProc.  However,
+     * it's dangerous to call the clearProc right now, because it could
+     * invoke a Tcl script that wrecks the current state (e.g. it could
+     * delete the window).  To be safe, defer the call until the end of the
+     * procedure when we no longer care about the state.
+     */
+
+    for (infoPtr = dispPtr->selectionInfoPtr; infoPtr != NULL;
+	    infoPtr = infoPtr->nextPtr) {
+	if (infoPtr->selection == selection) {
+	    break;
+	}
+    }
+    if (infoPtr == NULL) {
+	infoPtr = (TkSelectionInfo*) ckalloc(sizeof(TkSelectionInfo));
+	infoPtr->selection = selection;
+	infoPtr->nextPtr = dispPtr->selectionInfoPtr;
+	dispPtr->selectionInfoPtr = infoPtr;
+    } else if (infoPtr->clearProc != NULL) {
+	if (infoPtr->owner != tkwin) {
+	    clearProc = infoPtr->clearProc;
+	    clearData = infoPtr->clearData;
+	} else if (infoPtr->clearProc == LostSelection) {
+	    /*
+	     * If the selection handler is one created by "selection own",
+	     * be sure to free the record for it;  otherwise there will be
+	     * a memory leak.
+	     */
+
+	    ckfree((char *) infoPtr->clearData);
+	}
+    }
+
+    infoPtr->owner = tkwin;
+    infoPtr->serial = NextRequest(winPtr->display);
+    infoPtr->clearProc = proc;
+    infoPtr->clearData = clientData;
+
+    /*
+     * Note that we are using CurrentTime, even though ICCCM recommends against
+     * this practice (the problem is that we don't necessarily have a valid
+     * time to use).  We will not be able to retrieve a useful timestamp for
+     * the TIMESTAMP target later.
+     */
+
+    infoPtr->time = CurrentTime;
+
+    /*
+     * Note that we are not checking to see if the selection claim succeeded.
+     * If the ownership does not change, then the clearProc may never be
+     * invoked, and we will return incorrect information when queried for the
+     * current selection owner.
+     */
+
+    XSetSelectionOwner(winPtr->display, infoPtr->selection, winPtr->window,
+	    infoPtr->time);
+
+    /*
+     * Now that we are done, we can invoke clearProc without running into
+     * reentrancy problems.
+     */
+
+    if (clearProc != NULL) {
+	(*clearProc)(clearData);
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tk_ClearSelection --
+ *
+ *	Eliminate the specified selection on tkwin's display, if there is one.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The specified selection is cleared, so that future requests to retrieve
+ *	it will fail until some application owns it again.  This procedure
+ *	invokes callbacks, possibly including Tcl scripts, so any calling
+ *	function should be reentrant at the point Tk_ClearSelection is invoked.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tk_ClearSelection(tkwin, selection)
+    Tk_Window tkwin;		/* Window that selects a display. */
+    Atom selection;		/* Selection to be cancelled. */
+{
+    register TkWindow *winPtr = (TkWindow *) tkwin;
+    TkDisplay *dispPtr = winPtr->dispPtr;
+    TkSelectionInfo *infoPtr;
+    TkSelectionInfo *prevPtr;
+    TkSelectionInfo *nextPtr;
+    Tk_LostSelProc *clearProc = NULL;
+    ClientData clearData = NULL;	/* Initialization needed only to
+					 * prevent compiler warning. */
+
+    if (dispPtr->multipleAtom == None) {
+	TkSelInit(tkwin);
+    }
+
+    for (infoPtr = dispPtr->selectionInfoPtr, prevPtr = NULL;
+	     infoPtr != NULL; infoPtr = nextPtr) {
+	nextPtr = infoPtr->nextPtr;
+	if (infoPtr->selection == selection) {
+	    if (prevPtr == NULL) {
+		dispPtr->selectionInfoPtr = nextPtr;
+	    } else {
+		prevPtr->nextPtr = nextPtr;
+	    }
+	    break;
+	}
+	prevPtr = infoPtr;
+    }
+    
+    if (infoPtr != NULL) {
+	clearProc = infoPtr->clearProc;
+	clearData = infoPtr->clearData;
+	ckfree((char *) infoPtr);
+    }
+    XSetSelectionOwner(winPtr->display, selection, None, CurrentTime);
+
+    if (clearProc != NULL) {
+	(*clearProc)(clearData);
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_GetSelection --
+ *
+ *	Retrieve the value of a selection and pass it off (in
+ *	pieces, possibly) to a given procedure.
+ *
+ * Results:
+ *	The return value is a standard Tcl return value.
+ *	If an error occurs (such as no selection exists)
+ *	then an error message is left in interp->result.
+ *
+ * Side effects:
+ *	The standard X11 protocols are used to retrieve the
+ *	selection.  When it arrives, it is passed to proc.  If
+ *	the selection is very large, it will be passed to proc
+ *	in several pieces.  Proc should have the following
+ *	structure:
+ *
+ *	int
+ *	proc(clientData, interp, portion)
+ *	    ClientData clientData;
+ *	    Tcl_Interp *interp;
+ *	    char *portion;
+ *	{
+ *	}
+ *
+ *	The interp and clientData arguments to proc will be the
+ *	same as the corresponding arguments to Tk_GetSelection.
+ *	The portion argument points to a character string
+ *	containing part of the selection, and numBytes indicates
+ *	the length of the portion, not including the terminating
+ *	NULL character.  If the selection arrives in several pieces,
+ *	the "portion" arguments in separate calls will contain
+ *	successive parts of the selection.  Proc should normally
+ *	return TCL_OK.  If it detects an error then it should return
+ *	TCL_ERROR and leave an error message in interp->result; the
+ *	remainder of the selection retrieval will be aborted.
+ *
+ *--------------------------------------------------------------
+ */
+
+int
+Tk_GetSelection(interp, tkwin, selection, target, proc, clientData)
+    Tcl_Interp *interp;		/* Interpreter to use for reporting
+				 * errors. */
+    Tk_Window tkwin;		/* Window on whose behalf to retrieve
+				 * the selection (determines display
+				 * from which to retrieve). */
+    Atom selection;		/* Selection to retrieve. */
+    Atom target;		/* Desired form in which selection
+				 * is to be returned. */
+    Tk_GetSelProc *proc;	/* Procedure to call to process the
+				 * selection, once it has been retrieved. */
+    ClientData clientData;	/* Arbitrary value to pass to proc. */
+{
+    TkWindow *winPtr = (TkWindow *) tkwin;
+    TkDisplay *dispPtr = winPtr->dispPtr;
+    TkSelectionInfo *infoPtr;
+
+    if (dispPtr->multipleAtom == None) {
+	TkSelInit(tkwin);
+    }
+
+    /*
+     * If the selection is owned by a window managed by this
+     * process, then call the retrieval procedure directly,
+     * rather than going through the X server (it's dangerous
+     * to go through the X server in this case because it could
+     * result in deadlock if an INCR-style selection results).
+     */
+
+    for (infoPtr = dispPtr->selectionInfoPtr; infoPtr != NULL;
+	    infoPtr = infoPtr->nextPtr) {
+	if (infoPtr->selection == selection)
+	    break;
+    }
+    if (infoPtr != NULL) {
+	register TkSelHandler *selPtr;
+	int offset, result, count;
+	char buffer[TK_SEL_BYTES_AT_ONCE+1];
+	TkSelInProgress ip;
+
+	for (selPtr = ((TkWindow *) infoPtr->owner)->selHandlerList;
+		selPtr != NULL; selPtr = selPtr->nextPtr) {
+	    if ((selPtr->target == target)
+		    && (selPtr->selection == selection)) {
+		break;
+	    }
+	}
+	if (selPtr == NULL) {
+	    Atom type;
+
+	    count = TkSelDefaultSelection(infoPtr, target, buffer,
+		    TK_SEL_BYTES_AT_ONCE, &type);
+	    if (count > TK_SEL_BYTES_AT_ONCE) {
+		panic("selection handler returned too many bytes");
+	    }
+	    if (count < 0) {
+		goto cantget;
+	    }
+	    buffer[count] = 0;
+	    result = (*proc)(clientData, interp, buffer);
+	} else {
+	    offset = 0;
+	    result = TCL_OK;
+	    ip.selPtr = selPtr;
+	    ip.nextPtr = pendingPtr;
+	    pendingPtr = &ip;
+	    while (1) {
+		count = (selPtr->proc)(selPtr->clientData, offset, buffer,
+			TK_SEL_BYTES_AT_ONCE);
+		if ((count < 0) || (ip.selPtr == NULL)) {
+		    pendingPtr = ip.nextPtr;
+		    goto cantget;
+		}
+		if (count > TK_SEL_BYTES_AT_ONCE) {
+		    panic("selection handler returned too many bytes");
+		}
+		buffer[count] = '\0';
+		result = (*proc)(clientData, interp, buffer);
+		if ((result != TCL_OK) || (count < TK_SEL_BYTES_AT_ONCE)
+			|| (ip.selPtr == NULL)) {
+		    break;
+		}
+		offset += count;
+	    }
+	    pendingPtr = ip.nextPtr;
+	}
+	return result;
+    }
+
+    /*
+     * The selection is owned by some other process.
+     */
+
+    return TkSelGetSelection(interp, tkwin, selection, target, proc,
+	    clientData);
+
+    cantget:
+    Tcl_AppendResult(interp, Tk_GetAtomName(tkwin, selection),
+	" selection doesn't exist or form \"", Tk_GetAtomName(tkwin, target),
+	"\" not defined", (char *) NULL);
+    return TCL_ERROR;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Tk_SelectionCmd --
+ *
+ *	This procedure is invoked to process the "selection" Tcl
+ *	command.  See the user documentation for details on what
+ *	it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	See the user documentation.
+ *
+ *--------------------------------------------------------------
+ */
+
+int
+Tk_SelectionCmd(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;
+    Atom selection;
+    char *selName = NULL;
+    int c, count;
+    size_t length;
+    char **args;
+
+    if (argc < 2) {
+	sprintf(interp->result,
+		"wrong # args: should be \"%.50s option ?arg arg ...?\"",
+		argv[0]);
+	return TCL_ERROR;
+    }
+    c = argv[1][0];
+    length = strlen(argv[1]);
+    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 if ((c == 's')
+		    && (strncmp(args[0], "-selection", length) == 0)) {
+		selName = args[1];
+	    } else {
+		Tcl_AppendResult(interp, "unknown option \"", args[0],
+			"\"", (char *) NULL);
+		return TCL_ERROR;
+	    }
+	}
+	if (count == 1) {
+	    path = args[0];
+	} else if (count > 1) {
+	    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;
+	}
+	if (selName != NULL) {
+	    selection = Tk_InternAtom(tkwin, selName);
+	} else {
+	    selection = XA_PRIMARY;
+	}
+	    
+	Tk_ClearSelection(tkwin, selection);
+	return TCL_OK;
+    } else if ((c == 'g') && (strncmp(argv[1], "get", length) == 0)) {
+	Atom target;
+	char *targetName = NULL;
+	Tcl_DString selBytes;
+	int result;
+	
+	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 if ((c == 's')
+		    && (strncmp(args[0], "-selection", length) == 0)) {
+		selName = 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 (path != NULL) {
+	    tkwin = Tk_NameToWindow(interp, path, tkwin);
+	}
+	if (tkwin == NULL) {
+	    return TCL_ERROR;
+	}
+	if (selName != NULL) {
+	    selection = Tk_InternAtom(tkwin, selName);
+	} else {
+	    selection = XA_PRIMARY;
+	}
+	if (count > 1) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+		    " get ?options?\"", (char *) NULL);
+	    return TCL_ERROR;
+	} else if (count == 1) {
+	    target = Tk_InternAtom(tkwin, args[0]);
+	} else if (targetName != NULL) {
+	    target = Tk_InternAtom(tkwin, targetName);
+	} else {
+	    target = XA_STRING;
+	}
+
+	Tcl_DStringInit(&selBytes);
+	result = Tk_GetSelection(interp, tkwin, selection, target, SelGetProc,
+		(ClientData) &selBytes);
+	if (result == TCL_OK) {
+	    Tcl_DStringResult(interp, &selBytes);
+	} else {
+	    Tcl_DStringFree(&selBytes);
+	}
+	return result;
+    } else if ((c == 'h') && (strncmp(argv[1], "handle", length) == 0)) {
+	Atom target, format;
+	char *targetName = NULL;
+	char *formatName = NULL;
+	register CommandInfo *cmdInfoPtr;
+	int cmdLength;
+	
+	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 == 'f') && (strncmp(args[0], "-format", length) == 0)) {
+		formatName = args[1];
+	    } else if ((c == 's')
+		    && (strncmp(args[0], "-selection", length) == 0)) {
+		selName = 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 < 2) || (count > 4)) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+		    " handle ?options? window command\"", (char *) NULL);
+	    return TCL_ERROR;
+	}
+	tkwin = Tk_NameToWindow(interp, args[0], tkwin);
+	if (tkwin == NULL) {
+	    return TCL_ERROR;
+	}
+	if (selName != NULL) {
+	    selection = Tk_InternAtom(tkwin, selName);
+	} else {
+	    selection = XA_PRIMARY;
+	}
+	    
+	if (count > 2) {
+	    target = Tk_InternAtom(tkwin, args[2]);
+	} else if (targetName != NULL) {
+	    target = Tk_InternAtom(tkwin, targetName);
+	} else {
+	    target = XA_STRING;
+	}
+	if (count > 3) {
+	    format = Tk_InternAtom(tkwin, args[3]);
+	} else if (formatName != NULL) {
+	    format = Tk_InternAtom(tkwin, formatName);
+	} else {
+	    format = XA_STRING;
+	}
+	cmdLength = strlen(args[1]);
+	if (cmdLength == 0) {
+	    Tk_DeleteSelHandler(tkwin, selection, target);
+	} else {
+	    cmdInfoPtr = (CommandInfo *) ckalloc((unsigned) (
+		    sizeof(CommandInfo) - 3 + cmdLength));
+	    cmdInfoPtr->interp = interp;
+	    cmdInfoPtr->cmdLength = cmdLength;
+	    strcpy(cmdInfoPtr->command, args[1]);
+	    Tk_CreateSelHandler(tkwin, selection, target, HandleTclCommand,
+		    (ClientData) cmdInfoPtr, format);
+	}
+	return TCL_OK;
+    } else if ((c == 'o') && (strncmp(argv[1], "own", length) == 0)) {
+	register LostCommand *lostPtr;
+	char *script = NULL;
+	int cmdLength;
+
+	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 == 'c') && (strncmp(args[0], "-command", length) == 0)) {
+		script = args[1];
+	    } else if ((c == 'd')
+		    && (strncmp(args[0], "-displayof", length) == 0)) {
+		path = args[1];
+	    } else if ((c == 's')
+		    && (strncmp(args[0], "-selection", length) == 0)) {
+		selName = args[1];
+	    } else {
+		Tcl_AppendResult(interp, "unknown option \"", args[0],
+			"\"", (char *) NULL);
+		return TCL_ERROR;
+	    }
+	}
+
+	if (count > 2) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+		    " own ?options? ?window?\"", (char *) NULL);
+	    return TCL_ERROR;
+	}
+	if (selName != NULL) {
+	    selection = Tk_InternAtom(tkwin, selName);
+	} else {
+	    selection = XA_PRIMARY;
+	}
+	if (count == 0) {
+	    TkSelectionInfo *infoPtr;
+	    TkWindow *winPtr;
+	    if (path != NULL) {
+		tkwin = Tk_NameToWindow(interp, path, tkwin);
+	    }
+	    if (tkwin == NULL) {
+		return TCL_ERROR;
+	    }
+	    winPtr = (TkWindow *)tkwin;
+	    for (infoPtr = winPtr->dispPtr->selectionInfoPtr; infoPtr != NULL;
+		    infoPtr = infoPtr->nextPtr) {
+		if (infoPtr->selection == selection)
+		    break;
+	    }
+
+	    /*
+	     * Ignore the internal clipboard window.
+	     */
+
+	    if ((infoPtr != NULL)
+		    && (infoPtr->owner != winPtr->dispPtr->clipWindow)) {
+		interp->result = Tk_PathName(infoPtr->owner);
+	    }
+	    return TCL_OK;
+	}
+	tkwin = Tk_NameToWindow(interp, args[0], tkwin);
+	if (tkwin == NULL) {
+	    return TCL_ERROR;
+	}
+	if (count == 2) {
+	    script = args[1];
+	}
+	if (script == NULL) {
+	    Tk_OwnSelection(tkwin, selection, (Tk_LostSelProc *) NULL,
+		    (ClientData) NULL);
+	    return TCL_OK;
+	}
+	cmdLength = strlen(script);
+	lostPtr = (LostCommand *) ckalloc((unsigned) (sizeof(LostCommand)
+		-3 + cmdLength));
+	lostPtr->interp = interp;
+	strcpy(lostPtr->command, script);
+	Tk_OwnSelection(tkwin, selection, LostSelection, (ClientData) lostPtr);
+	return TCL_OK;
+    } else {
+	sprintf(interp->result,
+		"bad option \"%.50s\": must be clear, get, handle, or own",
+		argv[1]);
+	return TCL_ERROR;
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkSelDeadWindow --
+ *
+ *	This procedure is invoked just before a TkWindow is deleted.
+ *	It performs selection-related cleanup.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Frees up memory associated with the selection.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkSelDeadWindow(winPtr)
+    register TkWindow *winPtr;	/* Window that's being deleted. */
+{
+    register TkSelHandler *selPtr;
+    register TkSelInProgress *ipPtr;
+    TkSelectionInfo *infoPtr, *prevPtr, *nextPtr;
+
+    /*
+     * While deleting all the handlers, be careful to check whether
+     * ConvertSelection or TkSelPropProc are about to process one of the
+     * deleted handlers.
+     */
+
+    while (winPtr->selHandlerList != NULL) {
+	selPtr = winPtr->selHandlerList;
+	winPtr->selHandlerList = selPtr->nextPtr;
+	for (ipPtr = pendingPtr; ipPtr != NULL; ipPtr = ipPtr->nextPtr) {
+	    if (ipPtr->selPtr == selPtr) {
+		ipPtr->selPtr = NULL;
+	    }
+	}
+	if (selPtr->proc == HandleTclCommand) {
+	    ckfree((char *) selPtr->clientData);
+	}
+	ckfree((char *) selPtr);
+    }
+
+    /*
+     * Remove selections owned by window being deleted.
+     */
+
+    for (infoPtr = winPtr->dispPtr->selectionInfoPtr, prevPtr = NULL;
+	     infoPtr != NULL; infoPtr = nextPtr) {
+	nextPtr = infoPtr->nextPtr;
+	if (infoPtr->owner == (Tk_Window) winPtr) {
+	    if (infoPtr->clearProc == LostSelection) {
+		ckfree((char *) infoPtr->clearData);
+	    }
+	    ckfree((char *) infoPtr);
+	    infoPtr = prevPtr;
+	    if (prevPtr == NULL) {
+		winPtr->dispPtr->selectionInfoPtr = nextPtr;
+	    } else {
+		prevPtr->nextPtr = nextPtr;
+	    }
+	}
+	prevPtr = infoPtr;
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkSelInit --
+ *
+ *	Initialize selection-related information for a display.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Selection-related information is initialized.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkSelInit(tkwin)
+    Tk_Window tkwin;		/* Window token (used to find
+				 * display to initialize). */
+{
+    register TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr;
+
+    /*
+     * Fetch commonly-used atoms.
+     */
+
+    dispPtr->multipleAtom = Tk_InternAtom(tkwin, "MULTIPLE");
+    dispPtr->incrAtom = Tk_InternAtom(tkwin, "INCR");
+    dispPtr->targetsAtom = Tk_InternAtom(tkwin, "TARGETS");
+    dispPtr->timestampAtom = Tk_InternAtom(tkwin, "TIMESTAMP");
+    dispPtr->textAtom = Tk_InternAtom(tkwin, "TEXT");
+    dispPtr->compoundTextAtom = Tk_InternAtom(tkwin, "COMPOUND_TEXT");
+    dispPtr->applicationAtom = Tk_InternAtom(tkwin, "TK_APPLICATION");
+    dispPtr->windowAtom = Tk_InternAtom(tkwin, "TK_WINDOW");
+    dispPtr->clipboardAtom = Tk_InternAtom(tkwin, "CLIPBOARD");
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkSelClearSelection --
+ *
+ *	This procedure is invoked to process a SelectionClear event.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Invokes the clear procedure for the window which lost the
+ *	selection.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkSelClearSelection(tkwin, eventPtr)
+    Tk_Window tkwin;		/* Window for which event was targeted. */
+    register XEvent *eventPtr;	/* X SelectionClear event. */
+{
+    register TkWindow *winPtr = (TkWindow *) tkwin;
+    TkDisplay *dispPtr = winPtr->dispPtr;
+    TkSelectionInfo *infoPtr;
+    TkSelectionInfo *prevPtr;
+
+    /*
+     * Invoke clear procedure for window that just lost the selection.  This
+     * code is a bit tricky, because any callbacks due to selection changes
+     * between windows managed by the process have already been made.  Thus,
+     * ignore the event unless it refers to the window that's currently the
+     * selection owner and the event was generated after the server saw the
+     * SetSelectionOwner request.
+     */
+
+    for (infoPtr = dispPtr->selectionInfoPtr, prevPtr = NULL;
+	 infoPtr != NULL; infoPtr = infoPtr->nextPtr) {
+	if (infoPtr->selection == eventPtr->xselectionclear.selection) {
+	    break;
+	}
+	prevPtr = infoPtr;
+    }
+
+    if (infoPtr != NULL && (infoPtr->owner == tkwin)
+	    && (eventPtr->xselectionclear.serial >= (unsigned) infoPtr->serial)) {
+	if (prevPtr == NULL) {
+	    dispPtr->selectionInfoPtr = infoPtr->nextPtr;
+	} else {
+	    prevPtr->nextPtr = infoPtr->nextPtr;
+	}
+
+	/*
+	 * Because of reentrancy problems, calling clearProc must be done
+	 * after the infoPtr has been removed from the selectionInfoPtr
+	 * list (clearProc could modify the list, e.g. by creating
+	 * a new selection).
+	 */
+
+	if (infoPtr->clearProc != NULL) {
+	    (*infoPtr->clearProc)(infoPtr->clearData);
+	}
+	ckfree((char *) infoPtr);
+    }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * SelGetProc --
+ *
+ *	This procedure is invoked to process pieces of the selection
+ *	as they arrive during "selection get" commands.
+ *
+ * Results:
+ *	Always returns TCL_OK.
+ *
+ * Side effects:
+ *	Bytes get appended to the dynamic string pointed to by the
+ *	clientData argument.
+ *
+ *--------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+static int
+SelGetProc(clientData, interp, portion)
+    ClientData clientData;	/* Dynamic string holding partially
+				 * assembled selection. */
+    Tcl_Interp *interp;		/* Interpreter used for error
+				 * reporting (not used). */
+    char *portion;		/* New information to be appended. */
+{
+    Tcl_DStringAppend((Tcl_DString *) clientData, portion, -1);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * HandleTclCommand --
+ *
+ *	This procedure acts as selection handler for handlers created
+ *	by the "selection handle" command.  It invokes a Tcl command to
+ *	retrieve the selection.
+ *
+ * Results:
+ *	The return value is a count of the number of bytes actually
+ *	stored at buffer, or -1 if an error occurs while executing
+ *	the Tcl command to retrieve the selection.
+ *
+ * Side effects:
+ *	None except for things done by the Tcl command.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+HandleTclCommand(clientData, offset, buffer, maxBytes)
+    ClientData clientData;	/* Information about command to execute. */
+    int offset;			/* Return selection bytes starting at this
+				 * offset. */
+    char *buffer;		/* Place to store converted selection. */
+    int maxBytes;		/* Maximum # of bytes to store at buffer. */
+{
+    CommandInfo *cmdInfoPtr = (CommandInfo *) clientData;
+    int spaceNeeded, length;
+#define MAX_STATIC_SIZE 100
+    char staticSpace[MAX_STATIC_SIZE];
+    char *command;
+    Tcl_Interp *interp;
+    Tcl_DString oldResult;
+
+    /*
+     * We must copy the interpreter pointer from CommandInfo because the
+     * command could delete the handler, freeing the CommandInfo data before we
+     * are done using it. We must also protect the interpreter from being
+     * deleted too soo.
+     */
+
+    interp = cmdInfoPtr->interp;
+    Tcl_Preserve((ClientData) interp);
+
+    /*
+     * First, generate a command by taking the command string
+     * and appending the offset and maximum # of bytes.
+     */
+
+    spaceNeeded = cmdInfoPtr->cmdLength + 30;
+    if (spaceNeeded < MAX_STATIC_SIZE) {
+	command = staticSpace;
+    } else {
+	command = (char *) ckalloc((unsigned) spaceNeeded);
+    }
+    sprintf(command, "%s %d %d", cmdInfoPtr->command, offset, maxBytes);
+
+    /*
+     * Execute the command.  Be sure to restore the state of the
+     * interpreter after executing the command.
+     */
+
+    Tcl_DStringInit(&oldResult);
+    Tcl_DStringGetResult(interp, &oldResult);
+    if (TkCopyAndGlobalEval(interp, command) == TCL_OK) {
+	length = strlen(interp->result);
+	if (length > maxBytes) {
+	    length = maxBytes;
+	}
+	memcpy((VOID *) buffer, (VOID *) interp->result, (size_t) length);
+	buffer[length] = '\0';
+    } else {
+	length = -1;
+    }
+    Tcl_DStringResult(interp, &oldResult);
+
+    if (command != staticSpace) {
+	ckfree(command);
+    }
+
+    Tcl_Release((ClientData) interp);
+    return length;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkSelDefaultSelection --
+ *
+ *	This procedure is called to generate selection information
+ *	for a few standard targets such as TIMESTAMP and TARGETS.
+ *	It is invoked only if no handler has been declared by the
+ *	application.
+ *
+ * Results:
+ *	If "target" is a standard target understood by this procedure,
+ *	the selection is converted to that form and stored as a
+ *	character string in buffer.  The type of the selection (e.g.
+ *	STRING or ATOM) is stored in *typePtr, and the return value is
+ *	a count of the # of non-NULL bytes at buffer.  If the target
+ *	wasn't understood, or if there isn't enough space at buffer
+ *	to hold the entire selection (no INCR-mode transfers for this
+ *	stuff!), then -1 is returned.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TkSelDefaultSelection(infoPtr, target, buffer, maxBytes, typePtr)
+    TkSelectionInfo *infoPtr;	/* Info about selection being retrieved. */
+    Atom target;		/* Desired form of selection. */
+    char *buffer;		/* Place to put selection characters. */
+    int maxBytes;		/* Maximum # of bytes to store at buffer. */
+    Atom *typePtr;		/* Store here the type of the selection,
+				 * for use in converting to proper X format. */
+{
+    register TkWindow *winPtr = (TkWindow *) infoPtr->owner;
+    TkDisplay *dispPtr = winPtr->dispPtr;
+
+    if (target == dispPtr->timestampAtom) {
+	if (maxBytes < 20) {
+	    return -1;
+	}
+	sprintf(buffer, "0x%x", (unsigned int) infoPtr->time);
+	*typePtr = XA_INTEGER;
+	return strlen(buffer);
+    }
+
+    if (target == dispPtr->targetsAtom) {
+	register TkSelHandler *selPtr;
+	char *atomString;
+	int length, atomLength;
+
+	if (maxBytes < 50) {
+	    return -1;
+	}
+	strcpy(buffer, "MULTIPLE TARGETS TIMESTAMP TK_APPLICATION TK_WINDOW");
+	length = strlen(buffer);
+	for (selPtr = winPtr->selHandlerList; selPtr != NULL;
+		selPtr = selPtr->nextPtr) {
+	    if ((selPtr->selection == infoPtr->selection)
+		    && (selPtr->target != dispPtr->applicationAtom)
+		    && (selPtr->target != dispPtr->windowAtom)) {
+		atomString = Tk_GetAtomName((Tk_Window) winPtr,
+			selPtr->target);
+		atomLength = strlen(atomString) + 1;
+		if ((length + atomLength) >= maxBytes) {
+		    return -1;
+		}
+		sprintf(buffer+length, " %s", atomString);
+		length += atomLength;
+	    }
+	}
+	*typePtr = XA_ATOM;
+	return length;
+    }
+
+    if (target == dispPtr->applicationAtom) {
+	int length;
+	char *name = winPtr->mainPtr->winPtr->nameUid;
+
+	length = strlen(name);
+	if (maxBytes <= length) {
+	    return -1;
+	}
+	strcpy(buffer, name);
+	*typePtr = XA_STRING;
+	return length;
+    }
+
+    if (target == dispPtr->windowAtom) {
+	int length;
+	char *name = winPtr->pathName;
+
+	length = strlen(name);
+	if (maxBytes <= length) {
+	    return -1;
+	}
+	strcpy(buffer, name);
+	*typePtr = XA_STRING;
+	return length;
+    }
+
+    return -1;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * LostSelection --
+ *
+ *	This procedure is invoked when a window has lost ownership of
+ *	the selection and the ownership was claimed with the command
+ *	"selection own".
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	A Tcl script is executed;  it can do almost anything.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+LostSelection(clientData)
+    ClientData clientData;		/* Pointer to CommandInfo structure. */
+{
+    LostCommand *lostPtr = (LostCommand *) clientData;
+    char *oldResultString;
+    Tcl_FreeProc *oldFreeProc;
+    Tcl_Interp *interp;
+
+    interp = lostPtr->interp;
+    Tcl_Preserve((ClientData) interp);
+    
+    /*
+     * Execute the command.  Save the interpreter's result, if any, and
+     * restore it after executing the command.
+     */
+
+    oldFreeProc = interp->freeProc;
+    if (oldFreeProc != TCL_STATIC) {
+	oldResultString = interp->result;
+    } else {
+	oldResultString = (char *) ckalloc((unsigned)
+		(strlen(interp->result) + 1));
+	strcpy(oldResultString, interp->result);
+	oldFreeProc = TCL_DYNAMIC;
+    }
+    interp->freeProc = TCL_STATIC;
+    if (TkCopyAndGlobalEval(interp, lostPtr->command) != TCL_OK) {
+	Tcl_BackgroundError(interp);
+    }
+    Tcl_FreeResult(interp);
+    interp->result = oldResultString;
+    interp->freeProc = oldFreeProc;
+
+    Tcl_Release((ClientData) interp);
+    
+    /*
+     * Free the storage for the command, since we're done with it now.
+     */
+
+    ckfree((char *) lostPtr);
+}