Initial revision

1 files changed, 1376 insertions, 0 deletions

diff --git a/generic/tkTextTag.c b/generic/tkTextTag.c
new file mode 100644
index 0000000..b5b04be
--- /dev/null
+++ b/generic/tkTextTag.c
@@ -0,0 +1,1376 @@
+/* 
+ * tkTextTag.c --
+ *
+ *	This module implements the "tag" subcommand of the widget command
+ *	for text widgets, plus most of the other high-level functions
+ *	related to tags.
+ *
+ * Copyright (c) 1992-1994 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: @(#) tkTextTag.c 1.39 97/02/07 13:51:52
+ */
+
+#include "default.h"
+#include "tkPort.h"
+#include "tk.h"
+#include "tkText.h"
+
+/*
+ * Information used for parsing tag configuration information:
+ */
+
+static Tk_ConfigSpec tagConfigSpecs[] = {
+    {TK_CONFIG_BORDER, "-background", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, border), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_BITMAP, "-bgstipple", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, bgStipple), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-borderwidth", (char *) NULL, (char *) NULL,
+	"0", Tk_Offset(TkTextTag, bdString),
+		TK_CONFIG_DONT_SET_DEFAULT|TK_CONFIG_NULL_OK},
+    {TK_CONFIG_BITMAP, "-fgstipple", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, fgStipple), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_FONT, "-font", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, tkfont), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_COLOR, "-foreground", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, fgColor), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-justify", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, justifyString), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-lmargin1", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, lMargin1String), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-lmargin2", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, lMargin2String), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-offset", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, offsetString), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-overstrike", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, overstrikeString),
+	TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-relief", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, reliefString), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-rmargin", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, rMarginString), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-spacing1", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, spacing1String), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-spacing2", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, spacing2String), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-spacing3", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, spacing3String), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-tabs", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, tabString), TK_CONFIG_NULL_OK},
+    {TK_CONFIG_STRING, "-underline", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, underlineString),
+	TK_CONFIG_NULL_OK},
+    {TK_CONFIG_UID, "-wrap", (char *) NULL, (char *) NULL,
+	(char *) NULL, Tk_Offset(TkTextTag, wrapMode),
+	TK_CONFIG_NULL_OK},
+    {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
+	(char *) NULL, 0, 0}
+};
+
+/*
+ * Forward declarations for procedures defined later in this file:
+ */
+
+static void		ChangeTagPriority _ANSI_ARGS_((TkText *textPtr,
+			    TkTextTag *tagPtr, int prio));
+static TkTextTag *	FindTag _ANSI_ARGS_((Tcl_Interp *interp,
+			    TkText *textPtr, char *tagName));
+static void		SortTags _ANSI_ARGS_((int numTags,
+			    TkTextTag **tagArrayPtr));
+static int		TagSortProc _ANSI_ARGS_((CONST VOID *first,
+			    CONST VOID *second));
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkTextTagCmd --
+ *
+ *	This procedure is invoked to process the "tag" options of
+ *	the widget command for text widgets. See the user documentation
+ *	for details on what it does.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	See the user documentation.
+ *
+ *--------------------------------------------------------------
+ */
+
+int
+TkTextTagCmd(textPtr, interp, argc, argv)
+    register TkText *textPtr;	/* Information about text widget. */
+    Tcl_Interp *interp;		/* Current interpreter. */
+    int argc;			/* Number of arguments. */
+    char **argv;		/* Argument strings.  Someone else has already
+				 * parsed this command enough to know that
+				 * argv[1] is "tag". */
+{
+    int c, i, addTag;
+    size_t length;
+    char *fullOption;
+    register TkTextTag *tagPtr;
+    TkTextIndex first, last, index1, index2;
+
+    if (argc < 3) {
+	Tcl_AppendResult(interp, "wrong # args: should be \"",
+		argv[0], " tag option ?arg arg ...?\"", (char *) NULL);
+	return TCL_ERROR;
+    }
+    c = argv[2][0];
+    length = strlen(argv[2]);
+    if ((c == 'a') && (strncmp(argv[2], "add", length) == 0)) {
+	fullOption = "add";
+	addTag = 1;
+
+	addAndRemove:
+	if (argc < 5) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag ", fullOption,
+		    " tagName index1 ?index2 index1 index2 ...?\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	tagPtr = TkTextCreateTag(textPtr, argv[3]);
+	for (i = 4; i < argc; i += 2) {
+	    if (TkTextGetIndex(interp, textPtr, argv[i], &index1) != TCL_OK) {
+		return TCL_ERROR;
+	    }
+	    if (argc > (i+1)) {
+		if (TkTextGetIndex(interp, textPtr, argv[i+1], &index2)
+			!= TCL_OK) {
+		    return TCL_ERROR;
+		}
+		if (TkTextIndexCmp(&index1, &index2) >= 0) {
+		    return TCL_OK;
+		}
+	    } else {
+		index2 = index1;
+		TkTextIndexForwChars(&index2, 1, &index2);
+	    }
+    
+	    if (tagPtr->affectsDisplay) {
+		TkTextRedrawTag(textPtr, &index1, &index2, tagPtr, !addTag);
+	    } else {
+		/*
+		 * Still need to trigger enter/leave events on tags that
+		 * have changed.
+		 */
+    
+		TkTextEventuallyRepick(textPtr);
+	    }
+	    TkBTreeTag(&index1, &index2, tagPtr, addTag);
+    
+	    /*
+	     * If the tag is "sel" then grab the selection if we're supposed
+	     * to export it and don't already have it.  Also, invalidate
+	     * partially-completed selection retrievals.
+	     */
+    
+	    if (tagPtr == textPtr->selTagPtr) {
+		if (addTag && textPtr->exportSelection
+			&& !(textPtr->flags & GOT_SELECTION)) {
+		    Tk_OwnSelection(textPtr->tkwin, XA_PRIMARY,
+			    TkTextLostSelection, (ClientData) textPtr);
+		    textPtr->flags |= GOT_SELECTION;
+		}
+		textPtr->abortSelections = 1;
+	    }
+	}
+    } else if ((c == 'b') && (strncmp(argv[2], "bind", length) == 0)) {
+	if ((argc < 4) || (argc > 6)) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag bind tagName ?sequence? ?command?\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	tagPtr = TkTextCreateTag(textPtr, argv[3]);
+
+	/*
+	 * Make a binding table if the widget doesn't already have
+	 * one.
+	 */
+
+	if (textPtr->bindingTable == NULL) {
+	    textPtr->bindingTable = Tk_CreateBindingTable(interp);
+	}
+
+	if (argc == 6) {
+	    int append = 0;
+	    unsigned long mask;
+
+	    if (argv[5][0] == 0) {
+		return Tk_DeleteBinding(interp, textPtr->bindingTable,
+			(ClientData) tagPtr, argv[4]);
+	    }
+	    if (argv[5][0] == '+') {
+		argv[5]++;
+		append = 1;
+	    }
+	    mask = Tk_CreateBinding(interp, textPtr->bindingTable,
+		    (ClientData) tagPtr, argv[4], argv[5], append);
+	    if (mask == 0) {
+		return TCL_ERROR;
+	    }
+	    if (mask & (unsigned) ~(ButtonMotionMask|Button1MotionMask
+		    |Button2MotionMask|Button3MotionMask|Button4MotionMask
+		    |Button5MotionMask|ButtonPressMask|ButtonReleaseMask
+		    |EnterWindowMask|LeaveWindowMask|KeyPressMask
+		    |KeyReleaseMask|PointerMotionMask|VirtualEventMask)) {
+		Tk_DeleteBinding(interp, textPtr->bindingTable,
+			(ClientData) tagPtr, argv[4]);
+		Tcl_ResetResult(interp);
+		Tcl_AppendResult(interp, "requested illegal events; ",
+			"only key, button, motion, enter, leave, and virtual ",
+			"events may be used", (char *) NULL);
+		return TCL_ERROR;
+	    }
+	} else if (argc == 5) {
+	    char *command;
+    
+	    command = Tk_GetBinding(interp, textPtr->bindingTable,
+		    (ClientData) tagPtr, argv[4]);
+	    if (command == NULL) {
+		return TCL_ERROR;
+	    }
+	    interp->result = command;
+	} else {
+	    Tk_GetAllBindings(interp, textPtr->bindingTable,
+		    (ClientData) tagPtr);
+	}
+    } else if ((c == 'c') && (strncmp(argv[2], "cget", length) == 0)
+	    && (length >= 2)) {
+	if (argc != 5) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag cget tagName option\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	tagPtr = FindTag(interp, textPtr, argv[3]);
+	if (tagPtr == NULL) {
+	    return TCL_ERROR;
+	}
+	return Tk_ConfigureValue(interp, textPtr->tkwin, tagConfigSpecs,
+		(char *) tagPtr, argv[4], 0);
+    } else if ((c == 'c') && (strncmp(argv[2], "configure", length) == 0)
+	    && (length >= 2)) {
+	if (argc < 4) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag configure tagName ?option? ?value? ",
+		    "?option value ...?\"", (char *) NULL);
+	    return TCL_ERROR;
+	}
+	tagPtr = TkTextCreateTag(textPtr, argv[3]);
+	if (argc == 4) {
+	    return Tk_ConfigureInfo(interp, textPtr->tkwin, tagConfigSpecs,
+		    (char *) tagPtr, (char *) NULL, 0);
+	} else if (argc == 5) {
+	    return Tk_ConfigureInfo(interp, textPtr->tkwin, tagConfigSpecs,
+		    (char *) tagPtr, argv[4], 0);
+	} else {
+	    int result;
+
+	    result = Tk_ConfigureWidget(interp, textPtr->tkwin, tagConfigSpecs,
+		    argc-4, argv+4, (char *) tagPtr, 0);
+	    /*
+	     * Some of the configuration options, like -underline
+	     * and -justify, require additional translation (this is
+	     * needed because we need to distinguish a particular value
+	     * of an option from "unspecified").
+	     */
+
+	    if (tagPtr->bdString != NULL) {
+		if (Tk_GetPixels(interp, textPtr->tkwin, tagPtr->bdString,
+			&tagPtr->borderWidth) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+		if (tagPtr->borderWidth < 0) {
+		    tagPtr->borderWidth = 0;
+		}
+	    }
+	    if (tagPtr->reliefString != NULL) {
+		if (Tk_GetRelief(interp, tagPtr->reliefString,
+			&tagPtr->relief) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+	    }
+	    if (tagPtr->justifyString != NULL) {
+		if (Tk_GetJustify(interp, tagPtr->justifyString,
+			&tagPtr->justify) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+	    }
+	    if (tagPtr->lMargin1String != NULL) {
+		if (Tk_GetPixels(interp, textPtr->tkwin,
+			tagPtr->lMargin1String, &tagPtr->lMargin1) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+	    }
+	    if (tagPtr->lMargin2String != NULL) {
+		if (Tk_GetPixels(interp, textPtr->tkwin,
+			tagPtr->lMargin2String, &tagPtr->lMargin2) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+	    }
+	    if (tagPtr->offsetString != NULL) {
+		if (Tk_GetPixels(interp, textPtr->tkwin, tagPtr->offsetString,
+			&tagPtr->offset) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+	    }
+	    if (tagPtr->overstrikeString != NULL) {
+		if (Tcl_GetBoolean(interp, tagPtr->overstrikeString,
+			&tagPtr->overstrike) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+	    }
+	    if (tagPtr->rMarginString != NULL) {
+		if (Tk_GetPixels(interp, textPtr->tkwin,
+			tagPtr->rMarginString, &tagPtr->rMargin) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+	    }
+	    if (tagPtr->spacing1String != NULL) {
+		if (Tk_GetPixels(interp, textPtr->tkwin,
+			tagPtr->spacing1String, &tagPtr->spacing1) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+		if (tagPtr->spacing1 < 0) {
+		    tagPtr->spacing1 = 0;
+		}
+	    }
+	    if (tagPtr->spacing2String != NULL) {
+		if (Tk_GetPixels(interp, textPtr->tkwin,
+			tagPtr->spacing2String, &tagPtr->spacing2) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+		if (tagPtr->spacing2 < 0) {
+		    tagPtr->spacing2 = 0;
+		}
+	    }
+	    if (tagPtr->spacing3String != NULL) {
+		if (Tk_GetPixels(interp, textPtr->tkwin,
+			tagPtr->spacing3String, &tagPtr->spacing3) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+		if (tagPtr->spacing3 < 0) {
+		    tagPtr->spacing3 = 0;
+		}
+	    }
+	    if (tagPtr->tabArrayPtr != NULL) {
+		ckfree((char *) tagPtr->tabArrayPtr);
+		tagPtr->tabArrayPtr = NULL;
+	    }
+	    if (tagPtr->tabString != NULL) {
+		tagPtr->tabArrayPtr = TkTextGetTabs(interp, textPtr->tkwin,
+			tagPtr->tabString);
+		if (tagPtr->tabArrayPtr == NULL) {
+		    return TCL_ERROR;
+		}
+	    }
+	    if (tagPtr->underlineString != NULL) {
+		if (Tcl_GetBoolean(interp, tagPtr->underlineString,
+			&tagPtr->underline) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+	    }
+	    if ((tagPtr->wrapMode != NULL)
+		    && (tagPtr->wrapMode != tkTextCharUid)
+		    && (tagPtr->wrapMode != tkTextNoneUid)
+		    && (tagPtr->wrapMode != tkTextWordUid)) {
+		Tcl_AppendResult(interp, "bad wrap mode \"", tagPtr->wrapMode,
+			"\": must be char, none, or word", (char *) NULL);
+		tagPtr->wrapMode = NULL;
+		return TCL_ERROR;
+	    }
+
+	    /*
+	     * If the "sel" tag was changed, be sure to mirror information
+	     * from the tag back into the text widget record.   NOTE: we
+	     * don't have to free up information in the widget record
+	     * before overwriting it, because it was mirrored in the tag
+	     * and hence freed when the tag field was overwritten.
+	     */
+
+	    if (tagPtr == textPtr->selTagPtr) {
+		textPtr->selBorder = tagPtr->border;
+		textPtr->selBdString = tagPtr->bdString;
+		textPtr->selFgColorPtr = tagPtr->fgColor;
+	    }
+	    tagPtr->affectsDisplay = 0;
+	    if ((tagPtr->border != NULL)
+		    || (tagPtr->bdString != NULL)
+		    || (tagPtr->reliefString != NULL)
+		    || (tagPtr->bgStipple != None)
+		    || (tagPtr->fgColor != NULL) || (tagPtr->tkfont != None)
+		    || (tagPtr->fgStipple != None)
+		    || (tagPtr->justifyString != NULL)
+		    || (tagPtr->lMargin1String != NULL)
+		    || (tagPtr->lMargin2String != NULL)
+		    || (tagPtr->offsetString != NULL)
+		    || (tagPtr->overstrikeString != NULL)
+		    || (tagPtr->rMarginString != NULL)
+		    || (tagPtr->spacing1String != NULL)
+		    || (tagPtr->spacing2String != NULL)
+		    || (tagPtr->spacing3String != NULL)
+		    || (tagPtr->tabString != NULL)
+		    || (tagPtr->underlineString != NULL)
+		    || (tagPtr->wrapMode != NULL)) {
+		tagPtr->affectsDisplay = 1;
+	    }
+	    TkTextRedrawTag(textPtr, (TkTextIndex *) NULL,
+		    (TkTextIndex *) NULL, tagPtr, 1);
+	    return result;
+	}
+    } else if ((c == 'd') && (strncmp(argv[2], "delete", length) == 0)) {
+	Tcl_HashEntry *hPtr;
+
+	if (argc < 4) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag delete tagName tagName ...\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	for (i = 3; i < argc; i++) {
+	    hPtr = Tcl_FindHashEntry(&textPtr->tagTable, argv[i]);
+	    if (hPtr == NULL) {
+		continue;
+	    }
+	    tagPtr = (TkTextTag *) Tcl_GetHashValue(hPtr);
+	    if (tagPtr == textPtr->selTagPtr) {
+		continue;
+	    }
+	    if (tagPtr->affectsDisplay) {
+		TkTextRedrawTag(textPtr, (TkTextIndex *) NULL,
+			(TkTextIndex *) NULL, tagPtr, 1);
+	    }
+	    TkBTreeTag(TkTextMakeIndex(textPtr->tree, 0, 0, &first),
+		    TkTextMakeIndex(textPtr->tree,
+			    TkBTreeNumLines(textPtr->tree), 0, &last),
+		    tagPtr, 0);
+	    Tcl_DeleteHashEntry(hPtr);
+	    if (textPtr->bindingTable != NULL) {
+		Tk_DeleteAllBindings(textPtr->bindingTable,
+			(ClientData) tagPtr);
+	    }
+	
+	    /*
+	     * Update the tag priorities to reflect the deletion of this tag.
+	     */
+
+	    ChangeTagPriority(textPtr, tagPtr, textPtr->numTags-1);
+	    textPtr->numTags -= 1;
+	    TkTextFreeTag(textPtr, tagPtr);
+	}
+    } else if ((c == 'l') && (strncmp(argv[2], "lower", length) == 0)) {
+	TkTextTag *tagPtr2;
+	int prio;
+
+	if ((argc != 4) && (argc != 5)) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag lower tagName ?belowThis?\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	tagPtr = FindTag(interp, textPtr, argv[3]);
+	if (tagPtr == NULL) {
+	    return TCL_ERROR;
+	}
+	if (argc == 5) {
+	    tagPtr2 = FindTag(interp, textPtr, argv[4]);
+	    if (tagPtr2 == NULL) {
+		return TCL_ERROR;
+	    }
+	    if (tagPtr->priority < tagPtr2->priority) {
+		prio = tagPtr2->priority - 1;
+	    } else {
+		prio = tagPtr2->priority;
+	    }
+	} else {
+	    prio = 0;
+	}
+	ChangeTagPriority(textPtr, tagPtr, prio);
+	TkTextRedrawTag(textPtr, (TkTextIndex *) NULL, (TkTextIndex *) NULL,
+		tagPtr, 1);
+    } else if ((c == 'n') && (strncmp(argv[2], "names", length) == 0)
+	    && (length >= 2)) {
+	TkTextTag **arrayPtr;
+	int arraySize;
+
+	if ((argc != 3) && (argc != 4)) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag names ?index?\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	if (argc == 3) {
+	    Tcl_HashSearch search;
+	    Tcl_HashEntry *hPtr;
+
+	    arrayPtr = (TkTextTag **) ckalloc((unsigned)
+		    (textPtr->numTags * sizeof(TkTextTag *)));
+	    for (i = 0, hPtr = Tcl_FirstHashEntry(&textPtr->tagTable, &search);
+		    hPtr != NULL; i++, hPtr = Tcl_NextHashEntry(&search)) {
+		arrayPtr[i] = (TkTextTag *) Tcl_GetHashValue(hPtr);
+	    }
+	    arraySize = textPtr->numTags;
+	} else {
+	    if (TkTextGetIndex(interp, textPtr, argv[3], &index1)
+		    != TCL_OK) {
+		return TCL_ERROR;
+	    }
+	    arrayPtr = TkBTreeGetTags(&index1, &arraySize);
+	    if (arrayPtr == NULL) {
+		return TCL_OK;
+	    }
+	}
+	SortTags(arraySize, arrayPtr);
+	for (i = 0; i < arraySize; i++) {
+	    tagPtr = arrayPtr[i];
+	    Tcl_AppendElement(interp, tagPtr->name);
+	}
+	ckfree((char *) arrayPtr);
+    } else if ((c == 'n') && (strncmp(argv[2], "nextrange", length) == 0)
+	    && (length >= 2)) {
+	TkTextSearch tSearch;
+	char position[TK_POS_CHARS];
+
+	if ((argc != 5) && (argc != 6)) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag nextrange tagName index1 ?index2?\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	tagPtr = FindTag((Tcl_Interp *) NULL, textPtr, argv[3]);
+	if (tagPtr == NULL) {
+	    return TCL_OK;
+	}
+	if (TkTextGetIndex(interp, textPtr, argv[4], &index1) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	TkTextMakeIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree),
+		0, &last);
+	if (argc == 5) {
+	    index2 = last;
+	} else if (TkTextGetIndex(interp, textPtr, argv[5], &index2)
+		!= TCL_OK) {
+	    return TCL_ERROR;
+	}
+
+	/*
+	 * The search below is a bit tricky.  Rather than use the B-tree
+	 * facilities to stop the search at index2, let it search up
+	 * until the end of the file but check for a position past index2
+	 * ourselves.  The reason for doing it this way is that we only
+	 * care whether the *start* of the range is before index2;  once
+	 * we find the start, we don't want TkBTreeNextTag to abort the
+	 * search because the end of the range is after index2.
+	 */
+
+	TkBTreeStartSearch(&index1, &last, tagPtr, &tSearch);
+	if (TkBTreeCharTagged(&index1, tagPtr)) {
+	    TkTextSegment *segPtr;
+	    int offset;
+
+	    /*
+	     * The first character is tagged.  See if there is an
+	     * on-toggle just before the character.  If not, then
+	     * skip to the end of this tagged range.
+	     */
+
+	    for (segPtr = index1.linePtr->segPtr, offset = index1.charIndex; 
+		    offset >= 0;
+		    offset -= segPtr->size, segPtr = segPtr->nextPtr) {
+		if ((offset == 0) && (segPtr->typePtr == &tkTextToggleOnType)
+			&& (segPtr->body.toggle.tagPtr == tagPtr)) {
+		    goto gotStart;
+		}
+	    }
+	    if (!TkBTreeNextTag(&tSearch)) {
+		 return TCL_OK;
+	    }
+	}
+
+	/*
+	 * Find the start of the tagged range.
+	 */
+
+	if (!TkBTreeNextTag(&tSearch)) {
+	    return TCL_OK;
+	}
+	gotStart:
+	if (TkTextIndexCmp(&tSearch.curIndex, &index2) >= 0) {
+	    return TCL_OK;
+	}
+	TkTextPrintIndex(&tSearch.curIndex, position);
+	Tcl_AppendElement(interp, position);
+	TkBTreeNextTag(&tSearch);
+	TkTextPrintIndex(&tSearch.curIndex, position);
+	Tcl_AppendElement(interp, position);
+    } else if ((c == 'p') && (strncmp(argv[2], "prevrange", length) == 0)
+	    && (length >= 2)) {
+	TkTextSearch tSearch;
+	char position1[TK_POS_CHARS];
+	char position2[TK_POS_CHARS];
+
+	if ((argc != 5) && (argc != 6)) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag prevrange tagName index1 ?index2?\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	tagPtr = FindTag((Tcl_Interp *) NULL, textPtr, argv[3]);
+	if (tagPtr == NULL) {
+	    return TCL_OK;
+	}
+	if (TkTextGetIndex(interp, textPtr, argv[4], &index1) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	if (argc == 5) {
+	    TkTextMakeIndex(textPtr->tree, 0, 0, &index2);
+	} else if (TkTextGetIndex(interp, textPtr, argv[5], &index2)
+		!= TCL_OK) {
+	    return TCL_ERROR;
+	}
+
+	/*
+	 * The search below is a bit weird.  The previous toggle can be
+	 * either an on or off toggle. If it is an on toggle, then we
+	 * need to turn around and search forward for the end toggle.
+	 * Otherwise we keep searching backwards.
+	 */
+
+	TkBTreeStartSearchBack(&index1, &index2, tagPtr, &tSearch);
+
+	if (!TkBTreePrevTag(&tSearch)) {
+	    return TCL_OK;
+	}
+	if (tSearch.segPtr->typePtr == &tkTextToggleOnType) {
+	    TkTextPrintIndex(&tSearch.curIndex, position1);
+	    TkTextMakeIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree),
+		    0, &last);
+	    TkBTreeStartSearch(&tSearch.curIndex, &last, tagPtr, &tSearch);
+	    TkBTreeNextTag(&tSearch);
+	    TkTextPrintIndex(&tSearch.curIndex, position2);
+	} else {
+	    TkTextPrintIndex(&tSearch.curIndex, position2);
+	    TkBTreePrevTag(&tSearch);
+	    if (TkTextIndexCmp(&tSearch.curIndex, &index2) < 0) {
+		return TCL_OK;
+	    }
+	    TkTextPrintIndex(&tSearch.curIndex, position1);
+	}
+	Tcl_AppendElement(interp, position1);
+	Tcl_AppendElement(interp, position2);
+    } else if ((c == 'r') && (strncmp(argv[2], "raise", length) == 0)
+	    && (length >= 3)) {
+	TkTextTag *tagPtr2;
+	int prio;
+
+	if ((argc != 4) && (argc != 5)) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag raise tagName ?aboveThis?\"",
+		    (char *) NULL);
+	    return TCL_ERROR;
+	}
+	tagPtr = FindTag(interp, textPtr, argv[3]);
+	if (tagPtr == NULL) {
+	    return TCL_ERROR;
+	}
+	if (argc == 5) {
+	    tagPtr2 = FindTag(interp, textPtr, argv[4]);
+	    if (tagPtr2 == NULL) {
+		return TCL_ERROR;
+	    }
+	    if (tagPtr->priority <= tagPtr2->priority) {
+		prio = tagPtr2->priority;
+	    } else {
+		prio = tagPtr2->priority + 1;
+	    }
+	} else {
+	    prio = textPtr->numTags-1;
+	}
+	ChangeTagPriority(textPtr, tagPtr, prio);
+	TkTextRedrawTag(textPtr, (TkTextIndex *) NULL, (TkTextIndex *) NULL,
+		tagPtr, 1);
+    } else if ((c == 'r') && (strncmp(argv[2], "ranges", length) == 0)
+	    && (length >= 3)) {
+	TkTextSearch tSearch;
+	char position[TK_POS_CHARS];
+
+	if (argc != 4) {
+	    Tcl_AppendResult(interp, "wrong # args: should be \"",
+		    argv[0], " tag ranges tagName\"", (char *) NULL);
+	    return TCL_ERROR;
+	}
+	tagPtr = FindTag((Tcl_Interp *) NULL, textPtr, argv[3]);
+	if (tagPtr == NULL) {
+	    return TCL_OK;
+	}
+	TkTextMakeIndex(textPtr->tree, 0, 0, &first);
+	TkTextMakeIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree),
+		0, &last);
+	TkBTreeStartSearch(&first, &last, tagPtr, &tSearch);
+	if (TkBTreeCharTagged(&first, tagPtr)) {
+	    TkTextPrintIndex(&first, position);
+	    Tcl_AppendElement(interp, position);
+	}
+	while (TkBTreeNextTag(&tSearch)) {
+	    TkTextPrintIndex(&tSearch.curIndex, position);
+	    Tcl_AppendElement(interp, position);
+	}
+    } else if ((c == 'r') && (strncmp(argv[2], "remove", length) == 0)
+	    && (length >= 2)) {
+	fullOption = "remove";
+	addTag = 0;
+	goto addAndRemove;
+    } else {
+	Tcl_AppendResult(interp, "bad tag option \"", argv[2],
+		"\": must be add, bind, cget, configure, delete, lower, ",
+		"names, nextrange, raise, ranges, or remove",
+		(char *) NULL);
+	return TCL_ERROR;
+    }
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkTextCreateTag --
+ *
+ *	Find the record describing a tag within a given text widget,
+ *	creating a new record if one doesn't already exist.
+ *
+ * Results:
+ *	The return value is a pointer to the TkTextTag record for tagName.
+ *
+ * Side effects:
+ *	A new tag record is created if there isn't one already defined
+ *	for tagName.
+ *
+ *----------------------------------------------------------------------
+ */
+
+TkTextTag *
+TkTextCreateTag(textPtr, tagName)
+    TkText *textPtr;		/* Widget in which tag is being used. */
+    char *tagName;		/* Name of desired tag. */
+{
+    register TkTextTag *tagPtr;
+    Tcl_HashEntry *hPtr;
+    int new;
+
+    hPtr = Tcl_CreateHashEntry(&textPtr->tagTable, tagName, &new);
+    if (!new) {
+	return (TkTextTag *) Tcl_GetHashValue(hPtr);
+    }
+
+    /*
+     * No existing entry.  Create a new one, initialize it, and add a
+     * pointer to it to the hash table entry.
+     */
+
+    tagPtr = (TkTextTag *) ckalloc(sizeof(TkTextTag));
+    tagPtr->name = Tcl_GetHashKey(&textPtr->tagTable, hPtr);
+    tagPtr->toggleCount = 0;
+    tagPtr->tagRootPtr = NULL;
+    tagPtr->priority = textPtr->numTags;
+    tagPtr->border = NULL;
+    tagPtr->bdString = NULL;
+    tagPtr->borderWidth = 0;
+    tagPtr->reliefString = NULL;
+    tagPtr->relief = TK_RELIEF_FLAT;
+    tagPtr->bgStipple = None;
+    tagPtr->fgColor = NULL;
+    tagPtr->tkfont = NULL;
+    tagPtr->fgStipple = None;
+    tagPtr->justifyString = NULL;
+    tagPtr->justify = TK_JUSTIFY_LEFT;
+    tagPtr->lMargin1String = NULL;
+    tagPtr->lMargin1 = 0;
+    tagPtr->lMargin2String = NULL;
+    tagPtr->lMargin2 = 0;
+    tagPtr->offsetString = NULL;
+    tagPtr->offset = 0;
+    tagPtr->overstrikeString = NULL;
+    tagPtr->overstrike = 0;
+    tagPtr->rMarginString = NULL;
+    tagPtr->rMargin = 0;
+    tagPtr->spacing1String = NULL;
+    tagPtr->spacing1 = 0;
+    tagPtr->spacing2String = NULL;
+    tagPtr->spacing2 = 0;
+    tagPtr->spacing3String = NULL;
+    tagPtr->spacing3 = 0;
+    tagPtr->tabString = NULL;
+    tagPtr->tabArrayPtr = NULL;
+    tagPtr->underlineString = NULL;
+    tagPtr->underline = 0;
+    tagPtr->wrapMode = NULL;
+    tagPtr->affectsDisplay = 0;
+    textPtr->numTags++;
+    Tcl_SetHashValue(hPtr, tagPtr);
+    return tagPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * FindTag --
+ *
+ *	See if tag is defined for a given widget.
+ *
+ * Results:
+ *	If tagName is defined in textPtr, a pointer to its TkTextTag
+ *	structure is returned.  Otherwise NULL is returned and an
+ *	error message is recorded in interp->result unless interp
+ *	is NULL.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static TkTextTag *
+FindTag(interp, textPtr, tagName)
+    Tcl_Interp *interp;		/* Interpreter to use for error message;
+				 * if NULL, then don't record an error
+				 * message. */
+    TkText *textPtr;		/* Widget in which tag is being used. */
+    char *tagName;		/* Name of desired tag. */
+{
+    Tcl_HashEntry *hPtr;
+
+    hPtr = Tcl_FindHashEntry(&textPtr->tagTable, tagName);
+    if (hPtr != NULL) {
+	return (TkTextTag *) Tcl_GetHashValue(hPtr);
+    }
+    if (interp != NULL) {
+	Tcl_AppendResult(interp, "tag \"", tagName,
+		"\" isn't defined in text widget", (char *) NULL);
+    }
+    return NULL;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkTextFreeTag --
+ *
+ *	This procedure is called when a tag is deleted to free up the
+ *	memory and other resources associated with the tag.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Memory and other resources are freed.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TkTextFreeTag(textPtr, tagPtr)
+    TkText *textPtr;			/* Info about overall widget. */
+    register TkTextTag *tagPtr;		/* Tag being deleted. */
+{
+    if (tagPtr->border != None) {
+	Tk_Free3DBorder(tagPtr->border);
+    }
+    if (tagPtr->bdString != NULL) {
+	ckfree(tagPtr->bdString);
+    }
+    if (tagPtr->reliefString != NULL) {
+	ckfree(tagPtr->reliefString);
+    }
+    if (tagPtr->bgStipple != None) {
+	Tk_FreeBitmap(textPtr->display, tagPtr->bgStipple);
+    }
+    if (tagPtr->fgColor != None) {
+	Tk_FreeColor(tagPtr->fgColor);
+    }
+    Tk_FreeFont(tagPtr->tkfont);
+    if (tagPtr->fgStipple != None) {
+	Tk_FreeBitmap(textPtr->display, tagPtr->fgStipple);
+    }
+    if (tagPtr->justifyString != NULL) {
+	ckfree(tagPtr->justifyString);
+    }
+    if (tagPtr->lMargin1String != NULL) {
+	ckfree(tagPtr->lMargin1String);
+    }
+    if (tagPtr->lMargin2String != NULL) {
+	ckfree(tagPtr->lMargin2String);
+    }
+    if (tagPtr->offsetString != NULL) {
+	ckfree(tagPtr->offsetString);
+    }
+    if (tagPtr->overstrikeString != NULL) {
+	ckfree(tagPtr->overstrikeString);
+    }
+    if (tagPtr->rMarginString != NULL) {
+	ckfree(tagPtr->rMarginString);
+    }
+    if (tagPtr->spacing1String != NULL) {
+	ckfree(tagPtr->spacing1String);
+    }
+    if (tagPtr->spacing2String != NULL) {
+	ckfree(tagPtr->spacing2String);
+    }
+    if (tagPtr->spacing3String != NULL) {
+	ckfree(tagPtr->spacing3String);
+    }
+    if (tagPtr->tabString != NULL) {
+	ckfree(tagPtr->tabString);
+    }
+    if (tagPtr->tabArrayPtr != NULL) {
+	ckfree((char *) tagPtr->tabArrayPtr);
+    }
+    if (tagPtr->underlineString != NULL) {
+	ckfree(tagPtr->underlineString);
+    }
+    ckfree((char *) tagPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * SortTags --
+ *
+ *	This procedure sorts an array of tag pointers in increasing
+ *	order of priority, optimizing for the common case where the
+ *	array is small.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+SortTags(numTags, tagArrayPtr)
+    int numTags;		/* Number of tag pointers at *tagArrayPtr. */
+    TkTextTag **tagArrayPtr;	/* Pointer to array of pointers. */
+{
+    int i, j, prio;
+    register TkTextTag **tagPtrPtr;
+    TkTextTag **maxPtrPtr, *tmp;
+
+    if (numTags < 2) {
+	return;
+    }
+    if (numTags < 20) {
+	for (i = numTags-1; i > 0; i--, tagArrayPtr++) {
+	    maxPtrPtr = tagPtrPtr = tagArrayPtr;
+	    prio = tagPtrPtr[0]->priority;
+	    for (j = i, tagPtrPtr++; j > 0; j--, tagPtrPtr++) {
+		if (tagPtrPtr[0]->priority < prio) {
+		    prio = tagPtrPtr[0]->priority;
+		    maxPtrPtr = tagPtrPtr;
+		}
+	    }
+	    tmp = *maxPtrPtr;
+	    *maxPtrPtr = *tagArrayPtr;
+	    *tagArrayPtr = tmp;
+	}
+    } else {
+	qsort((VOID *) tagArrayPtr, (unsigned) numTags, sizeof (TkTextTag *),
+		    TagSortProc);
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TagSortProc --
+ *
+ *	This procedure is called by qsort when sorting an array of
+ *	tags in priority order.
+ *
+ * Results:
+ *	The return value is -1 if the first argument should be before
+ *	the second element (i.e. it has lower priority), 0 if it's
+ *	equivalent (this should never happen!), and 1 if it should be
+ *	after the second element.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+TagSortProc(first, second)
+    CONST VOID *first, *second;		/* Elements to be compared. */
+{
+    TkTextTag *tagPtr1, *tagPtr2;
+
+    tagPtr1 = * (TkTextTag **) first;
+    tagPtr2 = * (TkTextTag **) second;
+    return tagPtr1->priority - tagPtr2->priority;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ChangeTagPriority --
+ *
+ *	This procedure changes the priority of a tag by modifying
+ *	its priority and the priorities of other tags that are affected
+ *	by the change.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Priorities may be changed for some or all of the tags in
+ *	textPtr.  The tags will be arranged so that there is exactly
+ *	one tag at each priority level between 0 and textPtr->numTags-1,
+ *	with tagPtr at priority "prio".
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+ChangeTagPriority(textPtr, tagPtr, prio)
+    TkText *textPtr;			/* Information about text widget. */
+    TkTextTag *tagPtr;			/* Tag whose priority is to be
+					 * changed. */
+    int prio;				/* New priority for tag. */
+{
+    int low, high, delta;
+    register TkTextTag *tagPtr2;
+    Tcl_HashEntry *hPtr;
+    Tcl_HashSearch search;
+
+    if (prio < 0) {
+	prio = 0;
+    }
+    if (prio >= textPtr->numTags) {
+	prio = textPtr->numTags-1;
+    }
+    if (prio == tagPtr->priority) {
+	return;
+    } else if (prio < tagPtr->priority) {
+	low = prio;
+	high = tagPtr->priority-1;
+	delta = 1;
+    } else {
+	low = tagPtr->priority+1;
+	high = prio;
+	delta = -1;
+    }
+    for (hPtr = Tcl_FirstHashEntry(&textPtr->tagTable, &search);
+	    hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
+	tagPtr2 = (TkTextTag *) Tcl_GetHashValue(hPtr);
+	if ((tagPtr2->priority >= low) && (tagPtr2->priority <= high)) {
+	    tagPtr2->priority += delta;
+	}
+    }
+    tagPtr->priority = prio;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkTextBindProc --
+ *
+ *	This procedure is invoked by the Tk dispatcher to handle
+ *	events associated with bindings on items.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Depends on the command invoked as part of the binding
+ *	(if there was any).
+ *
+ *--------------------------------------------------------------
+ */
+
+void
+TkTextBindProc(clientData, eventPtr)
+    ClientData clientData;		/* Pointer to canvas structure. */
+    XEvent *eventPtr;			/* Pointer to X event that just
+					 * happened. */
+{
+    TkText *textPtr = (TkText *) clientData;
+    int repick  = 0;
+
+# define AnyButtonMask (Button1Mask|Button2Mask|Button3Mask\
+	|Button4Mask|Button5Mask)
+
+    Tcl_Preserve((ClientData) textPtr);
+
+    /*
+     * This code simulates grabs for mouse buttons by keeping track
+     * of whether a button is pressed and refusing to pick a new current
+     * character while a button is pressed.
+     */
+
+    if (eventPtr->type == ButtonPress) {
+	textPtr->flags |= BUTTON_DOWN;
+    } else if (eventPtr->type == ButtonRelease) {
+	int mask;
+
+	switch (eventPtr->xbutton.button) {
+	    case Button1:
+		mask = Button1Mask;
+		break;
+	    case Button2:
+		mask = Button2Mask;
+		break;
+	    case Button3:
+		mask = Button3Mask;
+		break;
+	    case Button4:
+		mask = Button4Mask;
+		break;
+	    case Button5:
+		mask = Button5Mask;
+		break;
+	    default:
+		mask = 0;
+		break;
+	}
+	if ((eventPtr->xbutton.state & AnyButtonMask) == (unsigned) mask) {
+	    textPtr->flags &= ~BUTTON_DOWN;
+	    repick = 1;
+	}
+    } else if ((eventPtr->type == EnterNotify)
+	    || (eventPtr->type == LeaveNotify)) {
+	if (eventPtr->xcrossing.state & AnyButtonMask)  {
+	    textPtr->flags |= BUTTON_DOWN;
+	} else {
+	    textPtr->flags &= ~BUTTON_DOWN;
+	}
+	TkTextPickCurrent(textPtr, eventPtr);
+	goto done;
+    } else if (eventPtr->type == MotionNotify) {
+	if (eventPtr->xmotion.state & AnyButtonMask)  {
+	    textPtr->flags |= BUTTON_DOWN;
+	} else {
+	    textPtr->flags &= ~BUTTON_DOWN;
+	}
+	TkTextPickCurrent(textPtr, eventPtr);
+    }
+    if ((textPtr->numCurTags > 0) && (textPtr->bindingTable != NULL)
+	    && (textPtr->tkwin != NULL)) {
+	Tk_BindEvent(textPtr->bindingTable, eventPtr, textPtr->tkwin,
+		textPtr->numCurTags, (ClientData *) textPtr->curTagArrayPtr);
+    }
+    if (repick) {
+	unsigned int oldState;
+
+	oldState = eventPtr->xbutton.state;
+	eventPtr->xbutton.state &= ~(Button1Mask|Button2Mask
+		|Button3Mask|Button4Mask|Button5Mask);
+	TkTextPickCurrent(textPtr, eventPtr);
+	eventPtr->xbutton.state = oldState;
+    }
+
+    done:
+    Tcl_Release((ClientData) textPtr);
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkTextPickCurrent --
+ *
+ *	Find the character containing the coordinates in an event
+ *	and place the "current" mark on that character.  If the
+ *	"current" mark has moved then generate a fake leave event
+ *	on the old current character and a fake enter event on the new
+ *	current character.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The current mark for textPtr may change.  If it does,
+ *	then the commands associated with character entry and leave
+ *	could do just about anything.  For example, the text widget
+ *	might be deleted.  It is up to the caller to protect itself
+ *	with calls to Tcl_Preserve and Tcl_Release.
+ *
+ *--------------------------------------------------------------
+ */
+
+void
+TkTextPickCurrent(textPtr, eventPtr)
+    register TkText *textPtr;		/* Text widget in which to select
+					 * current character. */
+    XEvent *eventPtr;			/* Event describing location of
+					 * mouse cursor.  Must be EnterWindow,
+					 * LeaveWindow, ButtonRelease, or
+					 * MotionNotify. */
+{
+    TkTextIndex index;
+    TkTextTag **oldArrayPtr, **newArrayPtr;
+    TkTextTag **copyArrayPtr = NULL;	/* Initialization needed to prevent
+					 * compiler warning. */
+
+    int numOldTags, numNewTags, i, j, size;
+    XEvent event;
+
+    /*
+     * If a button is down, then don't do anything at all;  we'll be
+     * called again when all buttons are up, and we can repick then.
+     * This implements a form of mouse grabbing.
+     */
+
+    if (textPtr->flags & BUTTON_DOWN) {
+	if (((eventPtr->type == EnterNotify) || (eventPtr->type == LeaveNotify))
+		&& ((eventPtr->xcrossing.mode == NotifyGrab)
+		|| (eventPtr->xcrossing.mode == NotifyUngrab))) {
+	    /*
+	     * Special case:  the window is being entered or left because
+	     * of a grab or ungrab.  In this case, repick after all.
+	     * Furthermore, clear BUTTON_DOWN to release the simulated
+	     * grab.
+	     */
+
+	    textPtr->flags &= ~BUTTON_DOWN;
+	} else {
+	    return;
+	}
+    }
+
+    /*
+     * Save information about this event in the widget in case we have
+     * to synthesize more enter and leave events later (e.g. because a
+     * character was deleted, causing a new character to be underneath
+     * the mouse cursor).  Also translate MotionNotify events into
+     * EnterNotify events, since that's what gets reported to event
+     * handlers when the current character changes.
+     */
+
+    if (eventPtr != &textPtr->pickEvent) {
+	if ((eventPtr->type == MotionNotify)
+		|| (eventPtr->type == ButtonRelease)) {
+	    textPtr->pickEvent.xcrossing.type = EnterNotify;
+	    textPtr->pickEvent.xcrossing.serial = eventPtr->xmotion.serial;
+	    textPtr->pickEvent.xcrossing.send_event
+		    = eventPtr->xmotion.send_event;
+	    textPtr->pickEvent.xcrossing.display = eventPtr->xmotion.display;
+	    textPtr->pickEvent.xcrossing.window = eventPtr->xmotion.window;
+	    textPtr->pickEvent.xcrossing.root = eventPtr->xmotion.root;
+	    textPtr->pickEvent.xcrossing.subwindow = None;
+	    textPtr->pickEvent.xcrossing.time = eventPtr->xmotion.time;
+	    textPtr->pickEvent.xcrossing.x = eventPtr->xmotion.x;
+	    textPtr->pickEvent.xcrossing.y = eventPtr->xmotion.y;
+	    textPtr->pickEvent.xcrossing.x_root = eventPtr->xmotion.x_root;
+	    textPtr->pickEvent.xcrossing.y_root = eventPtr->xmotion.y_root;
+	    textPtr->pickEvent.xcrossing.mode = NotifyNormal;
+	    textPtr->pickEvent.xcrossing.detail = NotifyNonlinear;
+	    textPtr->pickEvent.xcrossing.same_screen
+		    = eventPtr->xmotion.same_screen;
+	    textPtr->pickEvent.xcrossing.focus = False;
+	    textPtr->pickEvent.xcrossing.state = eventPtr->xmotion.state;
+	} else  {
+	    textPtr->pickEvent = *eventPtr;
+	}
+    }
+
+    /*
+     * Find the new current character, then find and sort all of the
+     * tags associated with it.
+     */
+
+    if (textPtr->pickEvent.type != LeaveNotify) {
+	TkTextPixelIndex(textPtr, textPtr->pickEvent.xcrossing.x,
+		textPtr->pickEvent.xcrossing.y, &index);
+	newArrayPtr = TkBTreeGetTags(&index, &numNewTags);
+	SortTags(numNewTags, newArrayPtr);
+    } else {
+	newArrayPtr = NULL;
+	numNewTags = 0;
+    }
+
+    /*
+     * Resort the tags associated with the previous marked character
+     * (the priorities might have changed), then make a copy of the
+     * new tags, and compare the old tags to the copy, nullifying
+     * any tags that are present in both groups (i.e. the tags that
+     * haven't changed).
+     */
+
+    SortTags(textPtr->numCurTags, textPtr->curTagArrayPtr);
+    if (numNewTags > 0) {
+	size = numNewTags * sizeof(TkTextTag *);
+	copyArrayPtr = (TkTextTag **) ckalloc((unsigned) size);
+	memcpy((VOID *) copyArrayPtr, (VOID *) newArrayPtr, (size_t) size);
+	for (i = 0; i < textPtr->numCurTags; i++) {
+	    for (j = 0; j < numNewTags; j++) {
+		if (textPtr->curTagArrayPtr[i] == copyArrayPtr[j]) {
+		    textPtr->curTagArrayPtr[i] = NULL;
+		    copyArrayPtr[j] = NULL;
+		    break;
+		}
+	    }
+	}
+    }
+
+    /*
+     * Invoke the binding system with a LeaveNotify event for all of
+     * the tags that have gone away.  We have to be careful here,
+     * because it's possible that the binding could do something
+     * (like calling tkwait) that eventually modifies
+     * textPtr->curTagArrayPtr.  To avoid problems in situations like
+     * this, update curTagArrayPtr to its new value before invoking
+     * any bindings, and don't use it any more here.
+     */
+
+    numOldTags = textPtr->numCurTags;
+    textPtr->numCurTags = numNewTags;
+    oldArrayPtr = textPtr->curTagArrayPtr;
+    textPtr->curTagArrayPtr = newArrayPtr;
+    if (numOldTags != 0) {
+	if ((textPtr->bindingTable != NULL) && (textPtr->tkwin != NULL)) {
+	    event = textPtr->pickEvent;
+	    event.type = LeaveNotify;
+
+	    /*
+	     * Always use a detail of NotifyAncestor.  Besides being
+	     * consistent, this avoids problems where the binding code
+	     * will discard NotifyInferior events.
+	     */
+
+	    event.xcrossing.detail = NotifyAncestor;
+	    Tk_BindEvent(textPtr->bindingTable, &event, textPtr->tkwin,
+		    numOldTags, (ClientData *) oldArrayPtr);
+	}
+	ckfree((char *) oldArrayPtr);
+    }
+
+    /*
+     * Reset the "current" mark (be careful to recompute its location,
+     * since it might have changed during an event binding).  Then
+     * invoke the binding system with an EnterNotify event for all of
+     * the tags that have just appeared.
+     */
+
+    TkTextPixelIndex(textPtr, textPtr->pickEvent.xcrossing.x,
+	    textPtr->pickEvent.xcrossing.y, &index);
+    TkTextSetMark(textPtr, "current", &index);
+    if (numNewTags != 0) {
+	if ((textPtr->bindingTable != NULL) && (textPtr->tkwin != NULL)) {
+	    event = textPtr->pickEvent;
+	    event.type = EnterNotify;
+	    event.xcrossing.detail = NotifyAncestor;
+	    Tk_BindEvent(textPtr->bindingTable, &event, textPtr->tkwin,
+		    numNewTags, (ClientData *) copyArrayPtr);
+	}
+	ckfree((char *) copyArrayPtr);
+    }
+}