shared_source/c_tk_base_7_5_w_mods/tktext.c

/* $Header$ */

/* 
 * tkText.c --
 *
 *      This module provides a big chunk of the implementation of
 *      multi-line editable text widgets for Tk.  Among other things,
 *      it provides the Tcl command interfaces to text widgets and
 *      the display code.  The B-tree representation of text is
 *      implemented elsewhere.
 *
 * Copyright (c) 1992-1994 The Regents of the University of California.
 * Copyright (c) 1994-1996 Sun Microsystems, Inc.
 * Copyright (c) 1999 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tktext.c,v 1.1.1.1 2001/06/13 05:08:42 dtashley Exp $
 */

#include "default.h"
#include "tkPort.h"
#include "tkInt.h"

#ifdef MAC_TCL
#define Style TkStyle
#define DInfo TkDInfo
#endif

#include "tkText.h"

/*
 * Custom options for handling "-state"
 */

static Tk_CustomOption stateOption = {
    (Tk_OptionParseProc *) TkStateParseProc,
    TkStatePrintProc, (ClientData) NULL /* only "normal" and "disabled" */
};

/*
 * Information used to parse text configuration options:
 */

static Tk_ConfigSpec configSpecs[] = {
    {TK_CONFIG_BORDER, "-background", "background", "Background",
        DEF_TEXT_BG_COLOR, Tk_Offset(TkText, border), TK_CONFIG_COLOR_ONLY},
    {TK_CONFIG_BORDER, "-background", "background", "Background",
        DEF_TEXT_BG_MONO, Tk_Offset(TkText, border), TK_CONFIG_MONO_ONLY},
    {TK_CONFIG_SYNONYM, "-bd", "borderWidth", (char *) NULL,
        (char *) NULL, 0, 0},
    {TK_CONFIG_SYNONYM, "-bg", "background", (char *) NULL,
        (char *) NULL, 0, 0},
    {TK_CONFIG_PIXELS, "-borderwidth", "borderWidth", "BorderWidth",
        DEF_TEXT_BORDER_WIDTH, Tk_Offset(TkText, borderWidth), 0},
    {TK_CONFIG_ACTIVE_CURSOR, "-cursor", "cursor", "Cursor",
        DEF_TEXT_CURSOR, Tk_Offset(TkText, cursor), TK_CONFIG_NULL_OK},
    {TK_CONFIG_BOOLEAN, "-exportselection", "exportSelection",
        "ExportSelection", DEF_TEXT_EXPORT_SELECTION,
        Tk_Offset(TkText, exportSelection), 0},
    {TK_CONFIG_SYNONYM, "-fg", "foreground", (char *) NULL,
        (char *) NULL, 0, 0},
    {TK_CONFIG_FONT, "-font", "font", "Font",
        DEF_TEXT_FONT, Tk_Offset(TkText, tkfont), 0},
    {TK_CONFIG_COLOR, "-foreground", "foreground", "Foreground",
        DEF_TEXT_FG, Tk_Offset(TkText, fgColor), 0},
    {TK_CONFIG_PIXELS, "-height", "height", "Height",
        DEF_TEXT_HEIGHT, Tk_Offset(TkText, height), 0},
    {TK_CONFIG_COLOR, "-highlightbackground", "highlightBackground",
        "HighlightBackground", DEF_TEXT_HIGHLIGHT_BG,
        Tk_Offset(TkText, highlightBgColorPtr), 0},
    {TK_CONFIG_COLOR, "-highlightcolor", "highlightColor", "HighlightColor",
        DEF_TEXT_HIGHLIGHT, Tk_Offset(TkText, highlightColorPtr), 0},
    {TK_CONFIG_PIXELS, "-highlightthickness", "highlightThickness",
        "HighlightThickness",
        DEF_TEXT_HIGHLIGHT_WIDTH, Tk_Offset(TkText, highlightWidth), 0},
    {TK_CONFIG_BORDER, "-insertbackground", "insertBackground", "Foreground",
        DEF_TEXT_INSERT_BG, Tk_Offset(TkText, insertBorder), 0},
    {TK_CONFIG_PIXELS, "-insertborderwidth", "insertBorderWidth", "BorderWidth",
        DEF_TEXT_INSERT_BD_COLOR, Tk_Offset(TkText, insertBorderWidth),
        TK_CONFIG_COLOR_ONLY},
    {TK_CONFIG_PIXELS, "-insertborderwidth", "insertBorderWidth", "BorderWidth",
        DEF_TEXT_INSERT_BD_MONO, Tk_Offset(TkText, insertBorderWidth),
        TK_CONFIG_MONO_ONLY},
    {TK_CONFIG_INT, "-insertofftime", "insertOffTime", "OffTime",
        DEF_TEXT_INSERT_OFF_TIME, Tk_Offset(TkText, insertOffTime), 0},
    {TK_CONFIG_INT, "-insertontime", "insertOnTime", "OnTime",
        DEF_TEXT_INSERT_ON_TIME, Tk_Offset(TkText, insertOnTime), 0},
    {TK_CONFIG_PIXELS, "-insertwidth", "insertWidth", "InsertWidth",
        DEF_TEXT_INSERT_WIDTH, Tk_Offset(TkText, insertWidth), 0},
    {TK_CONFIG_PIXELS, "-padx", "padX", "Pad",
        DEF_TEXT_PADX, Tk_Offset(TkText, padX), 0},
    {TK_CONFIG_PIXELS, "-pady", "padY", "Pad",
        DEF_TEXT_PADY, Tk_Offset(TkText, padY), 0},
    {TK_CONFIG_RELIEF, "-relief", "relief", "Relief",
        DEF_TEXT_RELIEF, Tk_Offset(TkText, relief), 0},
    {TK_CONFIG_BORDER, "-selectbackground", "selectBackground", "Foreground",
        DEF_TEXT_SELECT_COLOR, Tk_Offset(TkText, selBorder),
        TK_CONFIG_COLOR_ONLY},
    {TK_CONFIG_BORDER, "-selectbackground", "selectBackground", "Foreground",
        DEF_TEXT_SELECT_MONO, Tk_Offset(TkText, selBorder),
        TK_CONFIG_MONO_ONLY},
    {TK_CONFIG_STRING, "-selectborderwidth", "selectBorderWidth", "BorderWidth",
        DEF_TEXT_SELECT_BD_COLOR, Tk_Offset(TkText, selBdString),
        TK_CONFIG_COLOR_ONLY|TK_CONFIG_NULL_OK},
    {TK_CONFIG_STRING, "-selectborderwidth", "selectBorderWidth", "BorderWidth",
        DEF_TEXT_SELECT_BD_MONO, Tk_Offset(TkText, selBdString),
        TK_CONFIG_MONO_ONLY|TK_CONFIG_NULL_OK},
    {TK_CONFIG_COLOR, "-selectforeground", "selectForeground", "Background",
        DEF_TEXT_SELECT_FG_COLOR, Tk_Offset(TkText, selFgColorPtr),
        TK_CONFIG_COLOR_ONLY},
    {TK_CONFIG_COLOR, "-selectforeground", "selectForeground", "Background",
        DEF_TEXT_SELECT_FG_MONO, Tk_Offset(TkText, selFgColorPtr),
        TK_CONFIG_MONO_ONLY},
    {TK_CONFIG_BOOLEAN, "-setgrid", "setGrid", "SetGrid",
        DEF_TEXT_SET_GRID, Tk_Offset(TkText, setGrid), 0},
    {TK_CONFIG_PIXELS, "-spacing1", "spacing1", "Spacing",
        DEF_TEXT_SPACING1, Tk_Offset(TkText, spacing1),
        TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_PIXELS, "-spacing2", "spacing2", "Spacing",
        DEF_TEXT_SPACING2, Tk_Offset(TkText, spacing2),
        TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_PIXELS, "-spacing3", "spacing3", "Spacing",
        DEF_TEXT_SPACING3, Tk_Offset(TkText, spacing3),
        TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_CUSTOM, "-state", "state", "State",
        DEF_TEXT_STATE, Tk_Offset(TkText, state), 0, &stateOption},
    {TK_CONFIG_STRING, "-tabs", "tabs", "Tabs",
        DEF_TEXT_TABS, Tk_Offset(TkText, tabOptionString), TK_CONFIG_NULL_OK},
    {TK_CONFIG_STRING, "-takefocus", "takeFocus", "TakeFocus",
        DEF_TEXT_TAKE_FOCUS, Tk_Offset(TkText, takeFocus),
        TK_CONFIG_NULL_OK},
    {TK_CONFIG_INT, "-width", "width", "Width",
        DEF_TEXT_WIDTH, Tk_Offset(TkText, width), 0},
    {TK_CONFIG_CUSTOM, 
    "-wrap", "wrap", "Wrap",
        DEF_TEXT_WRAP, 
   Tk_Offset(TkText, wrapMode), 
   0, 
   &textWrapModeOption},
    {TK_CONFIG_STRING, "-xscrollcommand", "xScrollCommand", "ScrollCommand",
        DEF_TEXT_XSCROLL_COMMAND, Tk_Offset(TkText, xScrollCmd),
        TK_CONFIG_NULL_OK},
    {TK_CONFIG_STRING, "-yscrollcommand", "yScrollCommand", "ScrollCommand",
        DEF_TEXT_YSCROLL_COMMAND, Tk_Offset(TkText, yScrollCmd),
        TK_CONFIG_NULL_OK},
    {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
        (char *) NULL, 0, 0}
};

/*
 * Boolean variable indicating whether or not special debugging code
 * should be executed.
 */

int tkTextDebug = 0;

/*
 * Custom options for handling "-wrap":
 */

static int              WrapModeParseProc _ANSI_ARGS_((ClientData clientData,
                            Tcl_Interp *interp, Tk_Window tkwin, char *value,
                            char *widgRec, int offset));
static char *           WrapModePrintProc _ANSI_ARGS_((ClientData clientData,
                            Tk_Window tkwin, char *widgRec, int offset,
                            Tcl_FreeProc **freeProcPtr));

Tk_CustomOption textWrapModeOption = {
    WrapModeParseProc,
    WrapModePrintProc,
    (ClientData) NULL
};

/*
 *--------------------------------------------------------------
 *
 * WrapModeParseProc --
 *
 *      This procedure is invoked during option processing to handle
 *      "-wrap" options for text widgets.
 *
 * Results:
 *      A standard Tcl return value.
 *
 * Side effects:
 *      The wrap mode for a given item gets replaced by the wrap mode
 *      indicated in the value argument.
 *
 *--------------------------------------------------------------
 */

static int
WrapModeParseProc(clientData, interp, tkwin, value, widgRec, offset)
    ClientData clientData;              /* some flags.*/
    Tcl_Interp *interp;                 /* Used for reporting errors. */
    Tk_Window tkwin;                    /* Window containing canvas widget. */
    char *value;                        /* Value of option (list of tag
                                         * names). */
    char *widgRec;                      /* Pointer to record for item. */
    int offset;                         /* Offset into item. */
{
    int c;
    size_t length;

    register TkWrapMode *wrapPtr = (TkWrapMode *) (widgRec + offset);

    if(value == NULL || *value == 0) {
        *wrapPtr = TEXT_WRAPMODE_NULL;
        return TCL_OK;
    }

    c = value[0];
    length = strlen(value);

    if ((c == 'c') && (strncmp(value, "char", length) == 0)) {
        *wrapPtr = TEXT_WRAPMODE_CHAR;
        return TCL_OK;
    }
    if ((c == 'n') && (strncmp(value, "none", length) == 0)) {
        *wrapPtr = TEXT_WRAPMODE_NONE;
        return TCL_OK;
    }
    if ((c == 'w') && (strncmp(value, "word", length) == 0)) {
        *wrapPtr = TEXT_WRAPMODE_WORD;
        return TCL_OK;
    }
    Tcl_AppendResult(interp, "bad wrap mode \"", value,
            "\": must be char, none, or word",
            (char *) NULL);
    *wrapPtr = TEXT_WRAPMODE_CHAR;
    return TCL_ERROR;
}

/*
 *--------------------------------------------------------------
 *
 * WrapModePrintProc --
 *
 *      This procedure is invoked by the Tk configuration code
 *      to produce a printable string for the "-wrap" configuration
 *      option for canvas items.
 *
 * Results:
 *      The return value is a string describing the state for
 *      the item referred to by "widgRec".  In addition, *freeProcPtr
 *      is filled in with the address of a procedure to call to free
 *      the result string when it's no longer needed (or NULL to
 *      indicate that the string doesn't need to be freed).
 *
 * Side effects:
 *      None.
 *
 *--------------------------------------------------------------
 */

static char *
WrapModePrintProc(clientData, tkwin, widgRec, offset, freeProcPtr)
    ClientData clientData;              /* Ignored. */
    Tk_Window tkwin;                    /* Window containing canvas widget. */
    char *widgRec;                      /* Pointer to record for item. */
    int offset;                         /* Ignored. */
    Tcl_FreeProc **freeProcPtr;         /* Pointer to variable to fill in with
                                         * information about how to reclaim
                                         * storage for return string. */
{
    register TkWrapMode *wrapPtr = (TkWrapMode *) (widgRec + offset);

    if (*wrapPtr==TEXT_WRAPMODE_CHAR) {
        return "char";
    } else if (*wrapPtr==TEXT_WRAPMODE_NONE) {
        return "none";
    } else if (*wrapPtr==TEXT_WRAPMODE_WORD) {
        return "word";
    } else {
        return "";
    }
}

/*
 * Forward declarations for procedures defined later in this file:
 */

static int              ConfigureText _ANSI_ARGS_((Tcl_Interp *interp,
                            TkText *textPtr, int argc, char **argv, int flags));
static int              DeleteChars _ANSI_ARGS_((TkText *textPtr,
                            char *index1String, char *index2String));
static void             DestroyText _ANSI_ARGS_((char *memPtr));
static void             InsertChars _ANSI_ARGS_((TkText *textPtr,
                            TkTextIndex *indexPtr, char *string));
static void             TextBlinkProc _ANSI_ARGS_((ClientData clientData));
static void             TextCmdDeletedProc _ANSI_ARGS_((
                            ClientData clientData));
static void             TextEventProc _ANSI_ARGS_((ClientData clientData,
                            XEvent *eventPtr));
static int              TextFetchSelection _ANSI_ARGS_((ClientData clientData,
                            int offset, char *buffer, int maxBytes));
static int              TextSearchCmd _ANSI_ARGS_((TkText *textPtr,
                            Tcl_Interp *interp, int argc, char **argv));
static int              TextWidgetCmd _ANSI_ARGS_((ClientData clientData,
                            Tcl_Interp *interp, int argc, char **argv));
static void             TextWorldChanged _ANSI_ARGS_((
                            ClientData instanceData));
static int              TextDumpCmd _ANSI_ARGS_((TkText *textPtr,
                            Tcl_Interp *interp, int argc, char **argv));
static void             DumpLine _ANSI_ARGS_((Tcl_Interp *interp, 
                            TkText *textPtr, int what, TkTextLine *linePtr,
                            int start, int end, int lineno, char *command));
static int              DumpSegment _ANSI_ARGS_((Tcl_Interp *interp, char *key,
                            char *value, char * command, TkTextIndex *index,
                            int what));

/*
 * The structure below defines text class behavior by means of procedures
 * that can be invoked from generic window code.
 */

static TkClassProcs textClass = {
    NULL,                       /* createProc. */
    TextWorldChanged,           /* geometryProc. */
    NULL                        /* modalProc. */
};


/*
 *--------------------------------------------------------------
 *
 * Tk_TextCmd --
 *
 *      This procedure is invoked to process the "text" 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_TextCmd(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;
    Tk_Window new;
    register TkText *textPtr;
    TkTextIndex startIndex;

    if (argc < 2) {
        Tcl_AppendResult(interp, "wrong # args: should be \"",
                argv[0], " pathName ?options?\"", (char *) NULL);
        return TCL_ERROR;
    }

    /*
     * Create the window.
     */

    new = Tk_CreateWindowFromPath(interp, tkwin, argv[1], (char *) NULL);
    if (new == NULL) {
        return TCL_ERROR;
    }

    textPtr = (TkText *) ckalloc(sizeof(TkText));
    textPtr->tkwin = new;
    textPtr->display = Tk_Display(new);
    textPtr->interp = interp;
    textPtr->widgetCmd = Tcl_CreateCommand(interp,
            Tk_PathName(textPtr->tkwin), TextWidgetCmd,
            (ClientData) textPtr, TextCmdDeletedProc);
    textPtr->tree = TkBTreeCreate(textPtr);
    Tcl_InitHashTable(&textPtr->tagTable, TCL_STRING_KEYS);
    textPtr->numTags = 0;
    Tcl_InitHashTable(&textPtr->markTable, TCL_STRING_KEYS);
    Tcl_InitHashTable(&textPtr->windowTable, TCL_STRING_KEYS);
    Tcl_InitHashTable(&textPtr->imageTable, TCL_STRING_KEYS);
    textPtr->state = TK_STATE_NORMAL;
    textPtr->border = NULL;
    textPtr->borderWidth = 0;
    textPtr->padX = 0;
    textPtr->padY = 0;
    textPtr->relief = TK_RELIEF_FLAT;
    textPtr->highlightWidth = 0;
    textPtr->highlightBgColorPtr = NULL;
    textPtr->highlightColorPtr = NULL;
    textPtr->cursor = None;
    textPtr->fgColor = NULL;
    textPtr->tkfont = NULL;
    textPtr->charWidth = 1;
    textPtr->spacing1 = 0;
    textPtr->spacing2 = 0;
    textPtr->spacing3 = 0;
    textPtr->tabOptionString = NULL;
    textPtr->tabArrayPtr = NULL;
    textPtr->wrapMode = TEXT_WRAPMODE_CHAR;
    textPtr->width = 0;
    textPtr->height = 0;
    textPtr->setGrid = 0;
    textPtr->prevWidth = Tk_Width(new);
    textPtr->prevHeight = Tk_Height(new);
    TkTextCreateDInfo(textPtr);
    TkTextMakeByteIndex(textPtr->tree, 0, 0, &startIndex);
    TkTextSetYView(textPtr, &startIndex, 0);
    textPtr->selTagPtr = NULL;
    textPtr->selBorder = NULL;
    textPtr->selBdString = NULL;
    textPtr->selFgColorPtr = NULL;
    textPtr->exportSelection = 1;
    textPtr->abortSelections = 0;
    textPtr->insertMarkPtr = NULL;
    textPtr->insertBorder = NULL;
    textPtr->insertWidth = 0;
    textPtr->insertBorderWidth = 0;
    textPtr->insertOnTime = 0;
    textPtr->insertOffTime = 0;
    textPtr->insertBlinkHandler = (Tcl_TimerToken) NULL;
    textPtr->bindingTable = NULL;
    textPtr->currentMarkPtr = NULL;
    textPtr->pickEvent.type = LeaveNotify;
    textPtr->pickEvent.xcrossing.x = 0;
    textPtr->pickEvent.xcrossing.y = 0;
    textPtr->numCurTags = 0;
    textPtr->curTagArrayPtr = NULL;
    textPtr->takeFocus = NULL;
    textPtr->xScrollCmd = NULL;
    textPtr->yScrollCmd = NULL;
    textPtr->flags = 0;

    /*
     * Create the "sel" tag and the "current" and "insert" marks.
     */

    textPtr->selTagPtr = TkTextCreateTag(textPtr, "sel");
    textPtr->selTagPtr->reliefString =
            (char *) ckalloc(sizeof(DEF_TEXT_SELECT_RELIEF));
    strcpy(textPtr->selTagPtr->reliefString, DEF_TEXT_SELECT_RELIEF);
    textPtr->selTagPtr->relief = TK_RELIEF_RAISED;
    textPtr->currentMarkPtr = TkTextSetMark(textPtr, "current", &startIndex);
    textPtr->insertMarkPtr = TkTextSetMark(textPtr, "insert", &startIndex);

    Tk_SetClass(textPtr->tkwin, "Text");
    TkSetClassProcs(textPtr->tkwin, &textClass, (ClientData) textPtr);
    Tk_CreateEventHandler(textPtr->tkwin,
            ExposureMask|StructureNotifyMask|FocusChangeMask,
            TextEventProc, (ClientData) textPtr);
    Tk_CreateEventHandler(textPtr->tkwin, KeyPressMask|KeyReleaseMask
            |ButtonPressMask|ButtonReleaseMask|EnterWindowMask
            |LeaveWindowMask|PointerMotionMask|VirtualEventMask,
            TkTextBindProc, (ClientData) textPtr);
    Tk_CreateSelHandler(textPtr->tkwin, XA_PRIMARY, XA_STRING,
            TextFetchSelection, (ClientData) textPtr, XA_STRING);
    if (ConfigureText(interp, textPtr, argc-2, argv+2, 0) != TCL_OK) {
        Tk_DestroyWindow(textPtr->tkwin);
        return TCL_ERROR;
    }
    Tcl_SetResult(interp, Tk_PathName(textPtr->tkwin), TCL_STATIC);

    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * TextWidgetCmd --
 *
 *      This procedure is invoked to process the Tcl command
 *      that corresponds to a text widget.  See the user
 *      documentation for details on what it does.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      See the user documentation.
 *
 *--------------------------------------------------------------
 */

static int
TextWidgetCmd(clientData, interp, argc, argv)
    ClientData clientData;      /* Information about text widget. */
    Tcl_Interp *interp;         /* Current interpreter. */
    int argc;                   /* Number of arguments. */
    char **argv;                /* Argument strings. */
{
    register TkText *textPtr = (TkText *) clientData;
    int result = TCL_OK;
    size_t length;
    int c;
    TkTextIndex index1, index2;

    if (argc < 2) {
        Tcl_AppendResult(interp, "wrong # args: should be \"",
                argv[0], " option ?arg arg ...?\"", (char *) NULL);
        return TCL_ERROR;
    }
    Tcl_Preserve((ClientData) textPtr);
    c = argv[1][0];
    length = strlen(argv[1]);
    if ((c == 'b') && (strncmp(argv[1], "bbox", length) == 0)) {
        int x, y, width, height;

        if (argc != 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " bbox index\"", (char *) NULL);
            result = TCL_ERROR;
            goto done;
        }
        if (TkTextGetIndex(interp, textPtr, argv[2], &index1) != TCL_OK) {
            result = TCL_ERROR;
            goto done;
        }
        if (TkTextCharBbox(textPtr, &index1, &x, &y, &width, &height) == 0) {
            char buf[TCL_INTEGER_SPACE * 4];
            
            sprintf(buf, "%d %d %d %d", x, y, width, height);
            Tcl_SetResult(interp, buf, TCL_VOLATILE);
        }
    } else if ((c == 'c') && (strncmp(argv[1], "cget", length) == 0)
            && (length >= 2)) {
        if (argc != 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " cget option\"",
                    (char *) NULL);
            result = TCL_ERROR;
            goto done;
        }
        result = Tk_ConfigureValue(interp, textPtr->tkwin, configSpecs,
                (char *) textPtr, argv[2], 0);
    } else if ((c == 'c') && (strncmp(argv[1], "compare", length) == 0)
            && (length >= 3)) {
        int relation, value;
        char *p;

        if (argc != 5) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " compare index1 op index2\"", (char *) NULL);
            result = TCL_ERROR;
            goto done;
        }
        if ((TkTextGetIndex(interp, textPtr, argv[2], &index1) != TCL_OK)
                || (TkTextGetIndex(interp, textPtr, argv[4], &index2)
                != TCL_OK)) {
            result = TCL_ERROR;
            goto done;
        }
        relation = TkTextIndexCmp(&index1, &index2);
        p = argv[3];
        if (p[0] == '<') {
                value = (relation < 0);
            if ((p[1] == '=') && (p[2] == 0)) {
                value = (relation <= 0);
            } else if (p[1] != 0) {
                compareError:
                Tcl_AppendResult(interp, "bad comparison operator \"",
                        argv[3], "\": must be <, <=, ==, >=, >, or !=",
                        (char *) NULL);
                result = TCL_ERROR;
                goto done;
            }
        } else if (p[0] == '>') {
                value = (relation > 0);
            if ((p[1] == '=') && (p[2] == 0)) {
                value = (relation >= 0);
            } else if (p[1] != 0) {
                goto compareError;
            }
        } else if ((p[0] == '=') && (p[1] == '=') && (p[2] == 0)) {
            value = (relation == 0);
        } else if ((p[0] == '!') && (p[1] == '=') && (p[2] == 0)) {
            value = (relation != 0);
        } else {
            goto compareError;
        }
        Tcl_SetResult(interp, ((value) ? "1" : "0"), TCL_STATIC);
    } else if ((c == 'c') && (strncmp(argv[1], "configure", length) == 0)
            && (length >= 3)) {
        if (argc == 2) {
            result = Tk_ConfigureInfo(interp, textPtr->tkwin, configSpecs,
                    (char *) textPtr, (char *) NULL, 0);
        } else if (argc == 3) {
            result = Tk_ConfigureInfo(interp, textPtr->tkwin, configSpecs,
                    (char *) textPtr, argv[2], 0);
        } else {
            result = ConfigureText(interp, textPtr, argc-2, argv+2,
                    TK_CONFIG_ARGV_ONLY);
        }
    } else if ((c == 'd') && (strncmp(argv[1], "debug", length) == 0)
            && (length >= 3)) {
        if (argc > 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " debug boolean\"", (char *) NULL);
            result = TCL_ERROR;
            goto done;
        }
        if (argc == 2) {
            Tcl_SetResult(interp, ((tkBTreeDebug) ? "1" : "0"), TCL_STATIC);
        } else {
            if (Tcl_GetBoolean(interp, argv[2], &tkBTreeDebug) != TCL_OK) {
                result = TCL_ERROR;
                goto done;
            }
            tkTextDebug = tkBTreeDebug;
        }
    } else if ((c == 'd') && (strncmp(argv[1], "delete", length) == 0)
            && (length >= 3)) {
        if ((argc != 3) && (argc != 4)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " delete index1 ?index2?\"", (char *) NULL);
            result = TCL_ERROR;
            goto done;
        }
        if (textPtr->state == TK_STATE_NORMAL) {
            result = DeleteChars(textPtr, argv[2],
                    (argc == 4) ? argv[3] : (char *) NULL);
        }
    } else if ((c == 'd') && (strncmp(argv[1], "dlineinfo", length) == 0)
            && (length >= 2)) {
        int x, y, width, height, base;

        if (argc != 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " dlineinfo index\"", (char *) NULL);
            result = TCL_ERROR;
            goto done;
        }
        if (TkTextGetIndex(interp, textPtr, argv[2], &index1) != TCL_OK) {
            result = TCL_ERROR;
            goto done;
        }
        if (TkTextDLineInfo(textPtr, &index1, &x, &y, &width, &height, &base)
                == 0) {
            char buf[TCL_INTEGER_SPACE * 5];
            
            sprintf(buf, "%d %d %d %d %d", x, y, width, height, base);
            Tcl_SetResult(interp, buf, TCL_VOLATILE);
        }
    } else if ((c == 'g') && (strncmp(argv[1], "get", length) == 0)) {
        if ((argc != 3) && (argc != 4)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " get index1 ?index2?\"", (char *) NULL);
            result = TCL_ERROR;
            goto done;
        }
        if (TkTextGetIndex(interp, textPtr, argv[2], &index1) != TCL_OK) {
            result = TCL_ERROR;
            goto done;
        }
        if (argc == 3) {
            index2 = index1;
            TkTextIndexForwChars(&index2, 1, &index2);
        } else if (TkTextGetIndex(interp, textPtr, argv[3], &index2)
                != TCL_OK) {
            result = TCL_ERROR;
            goto done;
        }
        if (TkTextIndexCmp(&index1, &index2) >= 0) {
            goto done;
        }
        while (1) {
            int offset, last, savedChar;
            TkTextSegment *segPtr;

            segPtr = TkTextIndexToSeg(&index1, &offset);
            last = segPtr->size;
            if (index1.linePtr == index2.linePtr) {
                int last2;

                if (index2.byteIndex == index1.byteIndex) {
                    break;
                }
                last2 = index2.byteIndex - index1.byteIndex + offset;
                if (last2 < last) {
                    last = last2;
                }
            }
            if (segPtr->typePtr == &tkTextCharType) {
                savedChar = segPtr->body.chars[last];
                segPtr->body.chars[last] = 0;
                Tcl_AppendResult(interp, segPtr->body.chars + offset,
                        (char *) NULL);
                segPtr->body.chars[last] = savedChar;
            }
            TkTextIndexForwBytes(&index1, last-offset, &index1);
        }
    } else if ((c == 'i') && (strncmp(argv[1], "index", length) == 0)
            && (length >= 3)) {
        char buf[200];

        if (argc != 3) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " index index\"",
                    (char *) NULL);
            result = TCL_ERROR;
            goto done;
        }
        if (TkTextGetIndex(interp, textPtr, argv[2], &index1) != TCL_OK) {
            result = TCL_ERROR;
            goto done;
        }
        TkTextPrintIndex(&index1, buf);
        Tcl_SetResult(interp, buf, TCL_VOLATILE);
    } else if ((c == 'i') && (strncmp(argv[1], "insert", length) == 0)
            && (length >= 3)) {
        int i, j, numTags;
        char **tagNames;
        TkTextTag **oldTagArrayPtr;

        if (argc < 4) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0],
                    " insert index chars ?tagList chars tagList ...?\"",
                    (char *) NULL);
            result = TCL_ERROR;
            goto done;
        }
        if (TkTextGetIndex(interp, textPtr, argv[2], &index1) != TCL_OK) {
            result = TCL_ERROR;
            goto done;
        }
        if (textPtr->state == TK_STATE_NORMAL) {
            for (j = 3;  j < argc; j += 2) {
                InsertChars(textPtr, &index1, argv[j]);
                if (argc > (j+1)) {
                    TkTextIndexForwBytes(&index1, (int) strlen(argv[j]),
                            &index2);
                    oldTagArrayPtr = TkBTreeGetTags(&index1, &numTags);
                    if (oldTagArrayPtr != NULL) {
                        for (i = 0; i < numTags; i++) {
                            TkBTreeTag(&index1, &index2, oldTagArrayPtr[i], 0);
                        }
                        ckfree((char *) oldTagArrayPtr);
                    }
                    if (Tcl_SplitList(interp, argv[j+1], &numTags, &tagNames)
                            != TCL_OK) {
                        result = TCL_ERROR;
                        goto done;
                    }
                    for (i = 0; i < numTags; i++) {
                        TkBTreeTag(&index1, &index2,
                                TkTextCreateTag(textPtr, tagNames[i]), 1);
                    }
                    ckfree((char *) tagNames);
                    index1 = index2;
                }
            }
        }
    } else if ((c == 'd') && (strncmp(argv[1], "dump", length) == 0)) {
        result = TextDumpCmd(textPtr, interp, argc, argv);
    } else if ((c == 'i') && (strncmp(argv[1], "image", length) == 0)) {
        result = TkTextImageCmd(textPtr, interp, argc, argv);
    } else if ((c == 'm') && (strncmp(argv[1], "mark", length) == 0)) {
        result = TkTextMarkCmd(textPtr, interp, argc, argv);
    } else if ((c == 's') && (strcmp(argv[1], "scan") == 0) && (length >= 2)) {
        result = TkTextScanCmd(textPtr, interp, argc, argv);
    } else if ((c == 's') && (strcmp(argv[1], "search") == 0)
            && (length >= 3)) {
        result = TextSearchCmd(textPtr, interp, argc, argv);
    } else if ((c == 's') && (strcmp(argv[1], "see") == 0) && (length >= 3)) {
        result = TkTextSeeCmd(textPtr, interp, argc, argv);
    } else if ((c == 't') && (strcmp(argv[1], "tag") == 0)) {
        result = TkTextTagCmd(textPtr, interp, argc, argv);
    } else if ((c == 'w') && (strncmp(argv[1], "window", length) == 0)) {
        result = TkTextWindowCmd(textPtr, interp, argc, argv);
    } else if ((c == 'x') && (strncmp(argv[1], "xview", length) == 0)) {
        result = TkTextXviewCmd(textPtr, interp, argc, argv);
    } else if ((c == 'y') && (strncmp(argv[1], "yview", length) == 0)
            && (length >= 2)) {
        result = TkTextYviewCmd(textPtr, interp, argc, argv);
    } else {
        Tcl_AppendResult(interp, "bad option \"", argv[1],
                "\": must be bbox, cget, compare, configure, debug, delete, ",
                "dlineinfo, dump, get, image, index, insert, mark, scan, ",
                "search, see, tag, window, xview, or yview",
                (char *) NULL);
        result = TCL_ERROR;
    }

    done:
    Tcl_Release((ClientData) textPtr);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * DestroyText --
 *
 *      This procedure is invoked by Tcl_EventuallyFree or Tcl_Release
 *      to clean up the internal structure of a text at a safe time
 *      (when no-one is using it anymore).
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Everything associated with the text is freed up.
 *
 *----------------------------------------------------------------------
 */

static void
DestroyText(memPtr)
    char *memPtr;               /* Info about text widget. */
{
    register TkText *textPtr = (TkText *) memPtr;
    Tcl_HashSearch search;
    Tcl_HashEntry *hPtr;
    TkTextTag *tagPtr;

    /*
     * Free up all the stuff that requires special handling, then
     * let Tk_FreeOptions handle all the standard option-related
     * stuff.  Special note:  free up display-related information
     * before deleting the B-tree, since display-related stuff
     * may refer to stuff in the B-tree.
     */

    TkTextFreeDInfo(textPtr);
    TkBTreeDestroy(textPtr->tree);
    for (hPtr = Tcl_FirstHashEntry(&textPtr->tagTable, &search);
            hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
        tagPtr = (TkTextTag *) Tcl_GetHashValue(hPtr);
        TkTextFreeTag(textPtr, tagPtr);
    }
    Tcl_DeleteHashTable(&textPtr->tagTable);
    for (hPtr = Tcl_FirstHashEntry(&textPtr->markTable, &search);
            hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
        ckfree((char *) Tcl_GetHashValue(hPtr));
    }
    Tcl_DeleteHashTable(&textPtr->markTable);
    if (textPtr->tabArrayPtr != NULL) {
        ckfree((char *) textPtr->tabArrayPtr);
    }
    if (textPtr->insertBlinkHandler != NULL) {
        Tcl_DeleteTimerHandler(textPtr->insertBlinkHandler);
    }
    if (textPtr->bindingTable != NULL) {
        Tk_DeleteBindingTable(textPtr->bindingTable);
    }

    /*
     * NOTE: do NOT free up selBorder, selBdString, or selFgColorPtr:
     * they are duplicates of information in the "sel" tag, which was
     * freed up as part of deleting the tags above.
     */

    textPtr->selBorder = NULL;
    textPtr->selBdString = NULL;
    textPtr->selFgColorPtr = NULL;
    Tk_FreeOptions(configSpecs, (char *) textPtr, textPtr->display, 0);
    ckfree((char *) textPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * ConfigureText --
 *
 *      This procedure is called to process an argv/argc list, plus
 *      the Tk option database, in order to configure (or
 *      reconfigure) a text widget.
 *
 * Results:
 *      The return value is a standard Tcl result.  If TCL_ERROR is
 *      returned, then the interp's result contains an error message.
 *
 * Side effects:
 *      Configuration information, such as text string, colors, font,
 *      etc. get set for textPtr;  old resources get freed, if there
 *      were any.
 *
 *----------------------------------------------------------------------
 */

static int
ConfigureText(interp, textPtr, argc, argv, flags)
    Tcl_Interp *interp;         /* Used for error reporting. */
    register TkText *textPtr;   /* Information about widget;  may or may
                                 * not already have values for some fields. */
    int argc;                   /* Number of valid entries in argv. */
    char **argv;                /* Arguments. */
    int flags;                  /* Flags to pass to Tk_ConfigureWidget. */
{
    int oldExport = textPtr->exportSelection;

    if (Tk_ConfigureWidget(interp, textPtr->tkwin, configSpecs,
            argc, argv, (char *) textPtr, flags) != TCL_OK) {
        return TCL_ERROR;
    }

    /*
     * A few other options also need special processing, such as parsing
     * the geometry and setting the background from a 3-D border.
     */

    Tk_SetBackgroundFromBorder(textPtr->tkwin, textPtr->border);

    /*
     * Don't allow negative spacings.
     */

    if (textPtr->spacing1 < 0) {
        textPtr->spacing1 = 0;
    }
    if (textPtr->spacing2 < 0) {
        textPtr->spacing2 = 0;
    }
    if (textPtr->spacing3 < 0) {
        textPtr->spacing3 = 0;
    }

    /*
     * Parse tab stops.
     */

    if (textPtr->tabArrayPtr != NULL) {
        ckfree((char *) textPtr->tabArrayPtr);
        textPtr->tabArrayPtr = NULL;
    }
    if (textPtr->tabOptionString != NULL) {
        textPtr->tabArrayPtr = TkTextGetTabs(interp, textPtr->tkwin,
                textPtr->tabOptionString);
        if (textPtr->tabArrayPtr == NULL) {
            Tcl_AddErrorInfo(interp,"\n    (while processing -tabs option)");
            return TCL_ERROR;
        }
    }

    /*
     * Make sure that configuration options are properly mirrored
     * between the widget record and the "sel" tags.  NOTE: we don't
     * have to free up information during the mirroring;  old
     * information was freed when it was replaced in the widget
     * record.
     */

    textPtr->selTagPtr->border = textPtr->selBorder;
    if (textPtr->selTagPtr->bdString != textPtr->selBdString) {
        textPtr->selTagPtr->bdString = textPtr->selBdString;
        if (textPtr->selBdString != NULL) {
            if (Tk_GetPixels(interp, textPtr->tkwin, textPtr->selBdString,
                    &textPtr->selTagPtr->borderWidth) != TCL_OK) {
                return TCL_ERROR;
            }
            if (textPtr->selTagPtr->borderWidth < 0) {
                textPtr->selTagPtr->borderWidth = 0;
            }
        }
    }
    textPtr->selTagPtr->fgColor = textPtr->selFgColorPtr;
    textPtr->selTagPtr->affectsDisplay = 0;
    if ((textPtr->selTagPtr->border != NULL)
            || (textPtr->selTagPtr->bdString != NULL)
            || (textPtr->selTagPtr->reliefString != NULL)
            || (textPtr->selTagPtr->bgStipple != None)
            || (textPtr->selTagPtr->fgColor != NULL)
            || (textPtr->selTagPtr->tkfont != None)
            || (textPtr->selTagPtr->fgStipple != None)
            || (textPtr->selTagPtr->justifyString != NULL)
            || (textPtr->selTagPtr->lMargin1String != NULL)
            || (textPtr->selTagPtr->lMargin2String != NULL)
            || (textPtr->selTagPtr->offsetString != NULL)
            || (textPtr->selTagPtr->overstrikeString != NULL)
            || (textPtr->selTagPtr->rMarginString != NULL)
            || (textPtr->selTagPtr->spacing1String != NULL)
            || (textPtr->selTagPtr->spacing2String != NULL)
            || (textPtr->selTagPtr->spacing3String != NULL)
            || (textPtr->selTagPtr->tabString != NULL)
            || (textPtr->selTagPtr->underlineString != NULL)
            || (textPtr->selTagPtr->elideString != NULL)
            || (textPtr->selTagPtr->wrapMode != TEXT_WRAPMODE_NULL)) {
        textPtr->selTagPtr->affectsDisplay = 1;
    }
    TkTextRedrawTag(textPtr, (TkTextIndex *) NULL, (TkTextIndex *) NULL,
            textPtr->selTagPtr, 1);

    /*
     * Claim the selection if we've suddenly started exporting it and there
     * are tagged characters.
     */

    if (textPtr->exportSelection && (!oldExport)) {
        TkTextSearch search;
        TkTextIndex first, last;

        TkTextMakeByteIndex(textPtr->tree, 0, 0, &first);
        TkTextMakeByteIndex(textPtr->tree,
                TkBTreeNumLines(textPtr->tree), 0, &last);
        TkBTreeStartSearch(&first, &last, textPtr->selTagPtr, &search);
        if (TkBTreeCharTagged(&first, textPtr->selTagPtr)
                || TkBTreeNextTag(&search)) {
            Tk_OwnSelection(textPtr->tkwin, XA_PRIMARY, TkTextLostSelection,
                    (ClientData) textPtr);
            textPtr->flags |= GOT_SELECTION;
        }
    }

    /*
     * Register the desired geometry for the window, and arrange for
     * the window to be redisplayed.
     */

    if (textPtr->width <= 0) {
        textPtr->width = 1;
    }
    if (textPtr->height <= 0) {
        textPtr->height = 1;
    }
    TextWorldChanged((ClientData) textPtr);
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * TextWorldChanged --
 *
 *      This procedure is called when the world has changed in some
 *      way and the widget needs to recompute all its graphics contexts
 *      and determine its new geometry.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Configures all tags in the Text with a empty argc/argv, for
 *      the side effect of causing all the items to recompute their
 *      geometry and to be redisplayed.
 *
 *---------------------------------------------------------------------------
 */
 
static void
TextWorldChanged(instanceData)
    ClientData instanceData;    /* Information about widget. */
{
    TkText *textPtr;
    Tk_FontMetrics fm;

    textPtr = (TkText *) instanceData;

    textPtr->charWidth = Tk_TextWidth(textPtr->tkfont, "0", 1);
    if (textPtr->charWidth <= 0) {
        textPtr->charWidth = 1;
    }
    Tk_GetFontMetrics(textPtr->tkfont, &fm);
    Tk_GeometryRequest(textPtr->tkwin,
            textPtr->width * textPtr->charWidth + 2*textPtr->borderWidth
                    + 2*textPtr->padX + 2*textPtr->highlightWidth,
            textPtr->height * (fm.linespace + textPtr->spacing1
                    + textPtr->spacing3) + 2*textPtr->borderWidth
                    + 2*textPtr->padY + 2*textPtr->highlightWidth);
    Tk_SetInternalBorder(textPtr->tkwin,
            textPtr->borderWidth + textPtr->highlightWidth);
    if (textPtr->setGrid) {
        Tk_SetGrid(textPtr->tkwin, textPtr->width, textPtr->height,
                textPtr->charWidth, fm.linespace);
    } else {
        Tk_UnsetGrid(textPtr->tkwin);
    }

    TkTextRelayoutWindow(textPtr);
}

/*
 *--------------------------------------------------------------
 *
 * TextEventProc --
 *
 *      This procedure is invoked by the Tk dispatcher on
 *      structure changes to a text.  For texts with 3D
 *      borders, this procedure is also invoked for exposures.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      When the window gets deleted, internal structures get
 *      cleaned up.  When it gets exposed, it is redisplayed.
 *
 *--------------------------------------------------------------
 */

static void
TextEventProc(clientData, eventPtr)
    ClientData clientData;      /* Information about window. */
    register XEvent *eventPtr;  /* Information about event. */
{
    register TkText *textPtr = (TkText *) clientData;
    TkTextIndex index, index2;

    if (eventPtr->type == Expose) {
        TkTextRedrawRegion(textPtr, eventPtr->xexpose.x,
                eventPtr->xexpose.y, eventPtr->xexpose.width,
                eventPtr->xexpose.height);
    } else if (eventPtr->type == ConfigureNotify) {
        if ((textPtr->prevWidth != Tk_Width(textPtr->tkwin))
                || (textPtr->prevHeight != Tk_Height(textPtr->tkwin))) {
            TkTextRelayoutWindow(textPtr);
            textPtr->prevWidth = Tk_Width(textPtr->tkwin);
            textPtr->prevHeight = Tk_Height(textPtr->tkwin);
        }
    } else if (eventPtr->type == DestroyNotify) {
        if (textPtr->tkwin != NULL) {
            if (textPtr->setGrid) {
                Tk_UnsetGrid(textPtr->tkwin);
            }
            textPtr->tkwin = NULL;
            Tcl_DeleteCommandFromToken(textPtr->interp,
                    textPtr->widgetCmd);
        }
        Tcl_EventuallyFree((ClientData) textPtr, DestroyText);
    } else if ((eventPtr->type == FocusIn) || (eventPtr->type == FocusOut)) {
        if (eventPtr->xfocus.detail != NotifyInferior) {
            Tcl_DeleteTimerHandler(textPtr->insertBlinkHandler);
            if (eventPtr->type == FocusIn) {
                textPtr->flags |= GOT_FOCUS | INSERT_ON;
                if (textPtr->insertOffTime != 0) {
                    textPtr->insertBlinkHandler = Tcl_CreateTimerHandler(
                            textPtr->insertOnTime, TextBlinkProc,
                            (ClientData) textPtr);
                }
            } else {
                textPtr->flags &= ~(GOT_FOCUS | INSERT_ON);
                textPtr->insertBlinkHandler = (Tcl_TimerToken) NULL;
            }
#ifndef ALWAYS_SHOW_SELECTION
            TkTextRedrawTag(textPtr, NULL, NULL, textPtr->selTagPtr, 1);
#endif
            TkTextMarkSegToIndex(textPtr, textPtr->insertMarkPtr, &index);
            TkTextIndexForwChars(&index, 1, &index2);
            TkTextChanged(textPtr, &index, &index2);
            if (textPtr->highlightWidth > 0) {
                TkTextRedrawRegion(textPtr, 0, 0, textPtr->highlightWidth,
                        textPtr->highlightWidth);
            }
        }
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TextCmdDeletedProc --
 *
 *      This procedure is invoked when a widget command is deleted.  If
 *      the widget isn't already in the process of being destroyed,
 *      this command destroys it.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The widget is destroyed.
 *
 *----------------------------------------------------------------------
 */

static void
TextCmdDeletedProc(clientData)
    ClientData clientData;      /* Pointer to widget record for widget. */
{
    TkText *textPtr = (TkText *) clientData;
    Tk_Window tkwin = textPtr->tkwin;

    /*
     * This procedure could be invoked either because the window was
     * destroyed and the command was then deleted (in which case tkwin
     * is NULL) or because the command was deleted, and then this procedure
     * destroys the widget.
     */

    if (tkwin != NULL) {
        if (textPtr->setGrid) {
            Tk_UnsetGrid(textPtr->tkwin);
        }
        textPtr->tkwin = NULL;
        Tk_DestroyWindow(tkwin);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * InsertChars --
 *
 *      This procedure implements most of the functionality of the
 *      "insert" widget command.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The characters in "string" get added to the text just before
 *      the character indicated by "indexPtr".
 *
 *----------------------------------------------------------------------
 */

static void
InsertChars(textPtr, indexPtr, string)
    TkText *textPtr;            /* Overall information about text widget. */
    TkTextIndex *indexPtr;      /* Where to insert new characters.  May be
                                 * modified and/or invalidated. */
    char *string;               /* Null-terminated string containing new
                                 * information to add to text. */
{
    int lineIndex, resetView, offset;
    TkTextIndex newTop;

    /*
     * Don't allow insertions on the last (dummy) line of the text.
     */

    lineIndex = TkBTreeLineIndex(indexPtr->linePtr);
    if (lineIndex == TkBTreeNumLines(textPtr->tree)) {
        lineIndex--;
        TkTextMakeByteIndex(textPtr->tree, lineIndex, 1000000, indexPtr);
    }

    /*
     * Notify the display module that lines are about to change, then do
     * the insertion.  If the insertion occurs on the top line of the
     * widget (textPtr->topIndex), then we have to recompute topIndex
     * after the insertion, since the insertion could invalidate it.
     */

    resetView = offset = 0;
    if (indexPtr->linePtr == textPtr->topIndex.linePtr) {
        resetView = 1;
        offset = textPtr->topIndex.byteIndex;
        if (offset > indexPtr->byteIndex) {
            offset += strlen(string);
        }
    }
    TkTextChanged(textPtr, indexPtr, indexPtr);
    TkBTreeInsertChars(indexPtr, string);
    if (resetView) {
        TkTextMakeByteIndex(textPtr->tree, lineIndex, 0, &newTop);
        TkTextIndexForwBytes(&newTop, offset, &newTop);
        TkTextSetYView(textPtr, &newTop, 0);
    }

    /*
     * Invalidate any selection retrievals in progress.
     */

    textPtr->abortSelections = 1;
}

/*
 *----------------------------------------------------------------------
 *
 * DeleteChars --
 *
 *      This procedure implements most of the functionality of the
 *      "delete" widget command.
 *
 * Results:
 *      Returns a standard Tcl result, and leaves an error message
 *      in textPtr->interp if there is an error.
 *
 * Side effects:
 *      Characters get deleted from the text.
 *
 *----------------------------------------------------------------------
 */

static int
DeleteChars(textPtr, index1String, index2String)
    TkText *textPtr;            /* Overall information about text widget. */
    char *index1String;         /* String describing location of first
                                 * character to delete. */
    char *index2String;         /* String describing location of last
                                 * character to delete.  NULL means just
                                 * delete the one character given by
                                 * index1String. */
{
    int line1, line2, line, byteIndex, resetView;
    TkTextIndex index1, index2;

    /*
     * Parse the starting and stopping indices.
     */

    if (TkTextGetIndex(textPtr->interp, textPtr, index1String, &index1)
            != TCL_OK) {
        return TCL_ERROR;
    }
    if (index2String != NULL) {
        if (TkTextGetIndex(textPtr->interp, textPtr, index2String, &index2)
                != TCL_OK) {
            return TCL_ERROR;
        }
    } else {
        index2 = index1;
        TkTextIndexForwChars(&index2, 1, &index2);
    }

    /*
     * Make sure there's really something to delete.
     */

    if (TkTextIndexCmp(&index1, &index2) >= 0) {
        return TCL_OK;
    }

    /*
     * The code below is ugly, but it's needed to make sure there
     * is always a dummy empty line at the end of the text.  If the
     * final newline of the file (just before the dummy line) is being
     * deleted, then back up index to just before the newline.  If
     * there is a newline just before the first character being deleted,
     * then back up the first index too, so that an even number of lines
     * gets deleted.  Furthermore, remove any tags that are present on
     * the newline that isn't going to be deleted after all (this simulates
     * deleting the newline and then adding a "clean" one back again).
     */

    line1 = TkBTreeLineIndex(index1.linePtr);
    line2 = TkBTreeLineIndex(index2.linePtr);
    if (line2 == TkBTreeNumLines(textPtr->tree)) {
        TkTextTag **arrayPtr;
        int arraySize, i;
        TkTextIndex oldIndex2;

        oldIndex2 = index2;
        TkTextIndexBackChars(&oldIndex2, 1, &index2);
        line2--;
        if ((index1.byteIndex == 0) && (line1 != 0)) {
            TkTextIndexBackChars(&index1, 1, &index1);
            line1--;
        }
        arrayPtr = TkBTreeGetTags(&index2, &arraySize);
        if (arrayPtr != NULL) {
            for (i = 0; i < arraySize; i++) {
                TkBTreeTag(&index2, &oldIndex2, arrayPtr[i], 0);
            }
            ckfree((char *) arrayPtr);
        }
    }

    /*
     * Tell the display what's about to happen so it can discard
     * obsolete display information, then do the deletion.  Also,
     * if the deletion involves the top line on the screen, then
     * we have to reset the view (the deletion will invalidate
     * textPtr->topIndex).  Compute what the new first character
     * will be, then do the deletion, then reset the view.
     */

    TkTextChanged(textPtr, &index1, &index2);
    resetView = 0;
    line = 0;
    byteIndex = 0;
    if (TkTextIndexCmp(&index2, &textPtr->topIndex) >= 0) {
        if (TkTextIndexCmp(&index1, &textPtr->topIndex) <= 0) {
            /*
             * Deletion range straddles topIndex: use the beginning
             * of the range as the new topIndex.
             */

            resetView = 1;
            line = line1;
            byteIndex = index1.byteIndex;
        } else if (index1.linePtr == textPtr->topIndex.linePtr) {
            /*
             * Deletion range starts on top line but after topIndex.
             * Use the current topIndex as the new one.
             */

            resetView = 1;
            line = line1;
            byteIndex = textPtr->topIndex.byteIndex;
        }
    } else if (index2.linePtr == textPtr->topIndex.linePtr) {
        /*
         * Deletion range ends on top line but before topIndex.
         * Figure out what will be the new character index for
         * the character currently pointed to by topIndex.
         */

        resetView = 1;
        line = line2;
        byteIndex = textPtr->topIndex.byteIndex;
        if (index1.linePtr != index2.linePtr) {
            byteIndex -= index2.byteIndex;
        } else {
            byteIndex -= (index2.byteIndex - index1.byteIndex);
        }
    }
    TkBTreeDeleteChars(&index1, &index2);
    if (resetView) {
        TkTextMakeByteIndex(textPtr->tree, line, byteIndex, &index1);
        TkTextSetYView(textPtr, &index1, 0);
    }

    /*
     * Invalidate any selection retrievals in progress.
     */

    textPtr->abortSelections = 1;

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TextFetchSelection --
 *
 *      This procedure is called back by Tk when the selection is
 *      requested by someone.  It returns part or all of the selection
 *      in a buffer provided by the caller.
 *
 * Results:
 *      The return value is the number of non-NULL bytes stored
 *      at buffer.  Buffer is filled (or partially filled) with a
 *      NULL-terminated string containing part or all of the selection,
 *      as given by offset and maxBytes.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
TextFetchSelection(clientData, offset, buffer, maxBytes)
    ClientData clientData;              /* Information about text widget. */
    int offset;                         /* Offset within selection of first
                                         * character to be returned. */
    char *buffer;                       /* Location in which to place
                                         * selection. */
    int maxBytes;                       /* Maximum number of bytes to place
                                         * at buffer, not including terminating
                                         * NULL character. */
{
    register TkText *textPtr = (TkText *) clientData;
    TkTextIndex eof;
    int count, chunkSize, offsetInSeg;
    TkTextSearch search;
    TkTextSegment *segPtr;

    if (!textPtr->exportSelection) {
        return -1;
    }

    /*
     * Find the beginning of the next range of selected text.  Note:  if
     * the selection is being retrieved in multiple pieces (offset != 0)
     * and some modification has been made to the text that affects the
     * selection then reject the selection request (make 'em start over
     * again).
     */

    if (offset == 0) {
        TkTextMakeByteIndex(textPtr->tree, 0, 0, &textPtr->selIndex);
        textPtr->abortSelections = 0;
    } else if (textPtr->abortSelections) {
        return 0;
    }
    TkTextMakeByteIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree), 0, &eof);
    TkBTreeStartSearch(&textPtr->selIndex, &eof, textPtr->selTagPtr, &search);
    if (!TkBTreeCharTagged(&textPtr->selIndex, textPtr->selTagPtr)) {
        if (!TkBTreeNextTag(&search)) {
            if (offset == 0) {
                return -1;
            } else {
                return 0;
            }
        }
        textPtr->selIndex = search.curIndex;
    }

    /*
     * Each iteration through the outer loop below scans one selected range.
     * Each iteration through the inner loop scans one segment in the
     * selected range.
     */

    count = 0;
    while (1) {
        /*
         * Find the end of the current range of selected text.
         */

        if (!TkBTreeNextTag(&search)) {
            panic("TextFetchSelection couldn't find end of range");
        }

        /*
         * Copy information from character segments into the buffer
         * until either we run out of space in the buffer or we get
         * to the end of this range of text.
         */

        while (1) {
            if (maxBytes == 0) {
                goto done;
            }
            segPtr = TkTextIndexToSeg(&textPtr->selIndex, &offsetInSeg);
            chunkSize = segPtr->size - offsetInSeg;
            if (chunkSize > maxBytes) {
                chunkSize = maxBytes;
            }
            if (textPtr->selIndex.linePtr == search.curIndex.linePtr) {
                int leftInRange;

                leftInRange = search.curIndex.byteIndex
                        - textPtr->selIndex.byteIndex;
                if (leftInRange < chunkSize) {
                    chunkSize = leftInRange;
                    if (chunkSize <= 0) {
                        break;
                    }
                }
            }
            if ((segPtr->typePtr == &tkTextCharType)
                    && !TkTextIsElided(textPtr, &textPtr->selIndex)) {
                memcpy((VOID *) buffer, (VOID *) (segPtr->body.chars
                        + offsetInSeg), (size_t) chunkSize);
                buffer += chunkSize;
                maxBytes -= chunkSize;
                count += chunkSize;
            }
            TkTextIndexForwBytes(&textPtr->selIndex, chunkSize,
                    &textPtr->selIndex);
        }

        /*
         * Find the beginning of the next range of selected text.
         */

        if (!TkBTreeNextTag(&search)) {
            break;
        }
        textPtr->selIndex = search.curIndex;
    }

    done:
    *buffer = 0;
    return count;
}

/*
 *----------------------------------------------------------------------
 *
 * TkTextLostSelection --
 *
 *      This procedure is called back by Tk when the selection is
 *      grabbed away from a text widget.  On Windows and Mac systems, we
 *      want to remember the selection for the next time the focus
 *      enters the window.  On Unix, just remove the "sel" tag from
 *      everything in the widget.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The "sel" tag is cleared from the window.
 *
 *----------------------------------------------------------------------
 */

void
TkTextLostSelection(clientData)
    ClientData clientData;              /* Information about text widget. */
{
    register TkText *textPtr = (TkText *) clientData;
#ifdef ALWAYS_SHOW_SELECTION
    TkTextIndex start, end;

    if (!textPtr->exportSelection) {
        return;
    }

    /*
     * On Windows and Mac systems, we want to remember the selection
     * for the next time the focus enters the window.  On Unix, 
     * just remove the "sel" tag from everything in the widget.
     */

    TkTextMakeByteIndex(textPtr->tree, 0, 0, &start);
    TkTextMakeByteIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree), 0, &end);
    TkTextRedrawTag(textPtr, &start, &end, textPtr->selTagPtr, 1);
    TkBTreeTag(&start, &end, textPtr->selTagPtr, 0);
#endif
    textPtr->flags &= ~GOT_SELECTION;
}

/*
 *----------------------------------------------------------------------
 *
 * TextBlinkProc --
 *
 *      This procedure is called as a timer handler to blink the
 *      insertion cursor off and on.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The cursor gets turned on or off, redisplay gets invoked,
 *      and this procedure reschedules itself.
 *
 *----------------------------------------------------------------------
 */

static void
TextBlinkProc(clientData)
    ClientData clientData;      /* Pointer to record describing text. */
{
    register TkText *textPtr = (TkText *) clientData;
    TkTextIndex index;
    int x, y, w, h;

    if ((textPtr->state == TK_STATE_DISABLED) ||
            !(textPtr->flags & GOT_FOCUS) || (textPtr->insertOffTime == 0)) {
        return;
    }
    if (textPtr->flags & INSERT_ON) {
        textPtr->flags &= ~INSERT_ON;
        textPtr->insertBlinkHandler = Tcl_CreateTimerHandler(
                textPtr->insertOffTime, TextBlinkProc, (ClientData) textPtr);
    } else {
        textPtr->flags |= INSERT_ON;
        textPtr->insertBlinkHandler = Tcl_CreateTimerHandler(
                textPtr->insertOnTime, TextBlinkProc, (ClientData) textPtr);
    }
    TkTextMarkSegToIndex(textPtr, textPtr->insertMarkPtr, &index);
    TkTextCharBbox(textPtr, &index, &x, &y, &w, &h);
    TkTextRedrawRegion(textPtr, x - textPtr->insertWidth / 2, y,
            textPtr->insertWidth, h);
}

/*
 *----------------------------------------------------------------------
 *
 * TextSearchCmd --
 *
 *      This procedure is invoked to process the "search" 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.
 *
 *----------------------------------------------------------------------
 */

static int
TextSearchCmd(textPtr, interp, argc, argv)
    TkText *textPtr;            /* Information about text widget. */
    Tcl_Interp *interp;         /* Current interpreter. */
    int argc;                   /* Number of arguments. */
    char **argv;                /* Argument strings. */
{
    int backwards, exact, searchElide, c, i, argsLeft, noCase, leftToScan;
    size_t length;
    int numLines, startingLine, startingByte, lineNum, firstByte, lastByte;
    int code, matchLength, matchByte, passes, stopLine, searchWholeText;
    int patLength;
    char *arg, *pattern, *varName, *p, *startOfLine;
    char buffer[20];
    TkTextIndex index, stopIndex;
    Tcl_DString line, patDString;
    TkTextSegment *segPtr;
    TkTextLine *linePtr;
    TkTextIndex curIndex;
    Tcl_RegExp regexp = NULL;           /* Initialization needed only to
                                         * prevent compiler warning. */

    /*
     * Parse switches and other arguments.
     */

    exact = 1;
    searchElide = 0;
    curIndex.tree = textPtr->tree;
    backwards = 0;
    noCase = 0;
    varName = NULL;
    for (i = 2; i < argc; i++) {
        arg = argv[i];
        if (arg[0] != '-') {
            break;
        }
        length = strlen(arg);
        if (length < 2) {
            badSwitch:
            Tcl_AppendResult(interp, "bad switch \"", arg,
                    "\": must be --, -backward, -count, -elide, -exact, ",
                    "-forward, -nocase, or -regexp", (char *) NULL);
            return TCL_ERROR;
        }
        c = arg[1];
        if ((c == 'b') && (strncmp(argv[i], "-backwards", length) == 0)) {
            backwards = 1;
        } else if ((c == 'c') && (strncmp(argv[i], "-count", length) == 0)) {
            if (i >= (argc-1)) {
                Tcl_SetResult(interp, "no value given for \"-count\" option",
                        TCL_STATIC);
                return TCL_ERROR;
            }
            i++;
            varName = argv[i];
        } else if ((c == 'e') && (length > 2)
                && (strncmp(argv[i], "-exact", length) == 0)) {
            exact = 1;
        } else if ((c == 'e') && (length > 2)
                && (strncmp(argv[i], "-elide", length) == 0)) {
            searchElide = 1;
        } else if ((c == 'h') && (strncmp(argv[i], "-hidden", length) == 0)) {
            /*
             * -hidden is kept around for backwards compatibility with
             * the dash patch, but -elide is the official option
             */
            searchElide = 1;
        } else if ((c == 'f') && (strncmp(argv[i], "-forwards", length) == 0)) {
            backwards = 0;
        } else if ((c == 'n') && (strncmp(argv[i], "-nocase", length) == 0)) {
            noCase = 1;
        } else if ((c == 'r') && (strncmp(argv[i], "-regexp", length) == 0)) {
            exact = 0;
        } else if ((c == '-') && (strncmp(argv[i], "--", length) == 0)) {
            i++;
            break;
        } else {
            goto badSwitch;
        }
    }
    argsLeft = argc - (i+2);
    if ((argsLeft != 0) && (argsLeft != 1)) {
        Tcl_AppendResult(interp, "wrong # args: should be \"",
                argv[0], " search ?switches? pattern index ?stopIndex?\"",
                (char *) NULL);
        return TCL_ERROR;
    }
    pattern = argv[i];

    /*
     * Convert the pattern to lower-case if we're supposed to ignore case.
     */

    if (noCase) {
        Tcl_DStringInit(&patDString);
        Tcl_DStringAppend(&patDString, pattern, -1);
        pattern = Tcl_DStringValue(&patDString);
        Tcl_UtfToLower(pattern);
    }

    Tcl_DStringInit(&line);
    if (TkTextGetIndex(interp, textPtr, argv[i+1], &index) != TCL_OK) {
        code = TCL_ERROR;
        goto done;
    }
    numLines = TkBTreeNumLines(textPtr->tree);
    startingLine = TkBTreeLineIndex(index.linePtr);
    startingByte = index.byteIndex;
    if (startingLine >= numLines) {
        if (backwards) {
            startingLine = TkBTreeNumLines(textPtr->tree) - 1;
            startingByte = TkBTreeBytesInLine(TkBTreeFindLine(textPtr->tree,
                    startingLine));
        } else {
            startingLine = 0;
            startingByte = 0;
        }
    }
    if (argsLeft == 1) {
        if (TkTextGetIndex(interp, textPtr, argv[i+2], &stopIndex) != TCL_OK) {
            code = TCL_ERROR;
            goto done;
        }
        stopLine = TkBTreeLineIndex(stopIndex.linePtr);
        if (!backwards && (stopLine == numLines)) {
            stopLine = numLines-1;
        }
        searchWholeText = 0;
    } else {
        stopLine = 0;
        searchWholeText = 1;
    }

    /*
     * Scan through all of the lines of the text circularly, starting
     * at the given index.
     */

    matchLength = patLength = 0;        /* Only needed to prevent compiler
                                         * warnings. */
    if (exact) {
        patLength = strlen(pattern);
    } else {
        regexp = Tcl_RegExpCompile(interp, pattern);
        if (regexp == NULL) {
            code = TCL_ERROR;
            goto done;
        }
    }
    lineNum = startingLine;
    code = TCL_OK;
    for (passes = 0; passes < 2; ) {
        if (lineNum >= numLines) {
            /*
             * Don't search the dummy last line of the text.
             */

            goto nextLine;
        }

        /*
         * Extract the text from the line.  If we're doing regular
         * expression matching, drop the newline from the line, so
         * that "$" can be used to match the end of the line.
         */

        linePtr = TkBTreeFindLine(textPtr->tree, lineNum);
        curIndex.linePtr = linePtr; curIndex.byteIndex = 0;
        for (segPtr = linePtr->segPtr; segPtr != NULL;
                curIndex.byteIndex += segPtr->size, segPtr = segPtr->nextPtr) {
            if ((segPtr->typePtr != &tkTextCharType)
                    || (!searchElide && TkTextIsElided(textPtr, &curIndex))) {
                continue;
            }
            Tcl_DStringAppend(&line, segPtr->body.chars, segPtr->size);
        }
        if (!exact) {
            Tcl_DStringSetLength(&line, Tcl_DStringLength(&line)-1);
        }
        startOfLine = Tcl_DStringValue(&line);

        /*
         * If we're ignoring case, convert the line to lower case.
         */

        if (noCase) {
            Tcl_DStringSetLength(&line,
                    Tcl_UtfToLower(Tcl_DStringValue(&line)));
        }

        /*
         * Check for matches within the current line.  If so, and if we're
         * searching backwards, repeat the search to find the last match
         * in the line.  (Note: The lastByte should include the NULL char
         * so we can handle searching for end of line easier.)
         */

        matchByte = -1;
        firstByte = 0;
        lastByte = Tcl_DStringLength(&line) + 1;
        if (lineNum == startingLine) {
            int indexInDString;

            /*
             * The starting line is tricky: the first time we see it
             * we check one part of the line, and the second pass through
             * we check the other part of the line.  We have to be very
             * careful here because there could be embedded windows or
             * other things that are not in the extracted line.  Rescan
             * the original line to compute the index in it of the first
             * character.
             */

            indexInDString = startingByte;
            for (segPtr = linePtr->segPtr, leftToScan = startingByte;
                    leftToScan > 0; segPtr = segPtr->nextPtr) {
                if (segPtr->typePtr != &tkTextCharType) {
                    indexInDString -= segPtr->size;
                }
                leftToScan -= segPtr->size;
            }

            passes++;
            if ((passes == 1) ^ backwards) {
                /*
                 * Only use the last part of the line.
                 */

                firstByte = indexInDString;
                if ((firstByte >= Tcl_DStringLength(&line))
                        && !((Tcl_DStringLength(&line) == 0) && !exact)) {
                    goto nextLine;
                }
            } else {
                /*
                 * Use only the first part of the line.
                 */

                lastByte = indexInDString;
            }
        }
        do {
            int thisLength;
            Tcl_UniChar ch;

            if (exact) {
                p = strstr(startOfLine + firstByte,     /* INTL: Native. */
                        pattern); 
                if (p == NULL) {
                    break;
                }
                i = p - startOfLine;
                thisLength = patLength;
            } else {
                char *start, *end;
                int match;

                match = Tcl_RegExpExec(interp, regexp,
                        startOfLine + firstByte, startOfLine);
                if (match < 0) {
                    code = TCL_ERROR;
                    goto done;
                }
                if (!match) {
                    break;
                }
                Tcl_RegExpRange(regexp, 0, &start, &end);
                i = start - startOfLine;
                thisLength = end - start;
            }
            if (i >= lastByte) {
                break;
            }
            matchByte = i;
            matchLength = thisLength;
            firstByte = i + Tcl_UtfToUniChar(startOfLine + matchByte, &ch);
        } while (backwards);

        /*
         * If we found a match then we're done.  Make sure that
         * the match occurred before the stopping index, if one was
         * specified.
         */

        if (matchByte >= 0) {
            int numChars;

            /*
             * Convert the byte length to a character count.
             */

            numChars = Tcl_NumUtfChars(startOfLine + matchByte,
                    matchLength);

            /*
             * The index information returned by the regular expression
             * parser only considers textual information:  it doesn't
             * account for embedded windows or any other non-textual info.
             * Scan through the line's segments again to adjust both
             * matchChar and matchCount.
             */

            for (segPtr = linePtr->segPtr, leftToScan = matchByte;
                    leftToScan >= 0; segPtr = segPtr->nextPtr) {
                if (segPtr->typePtr != &tkTextCharType) {
                    matchByte += segPtr->size;
                    continue;
                }
                leftToScan -= segPtr->size;
            }
            for (leftToScan += matchLength; leftToScan > 0;
                    segPtr = segPtr->nextPtr) {
                if (segPtr->typePtr != &tkTextCharType) {
                    numChars += segPtr->size;
                    continue;
                }
                leftToScan -= segPtr->size;
            }
            TkTextMakeByteIndex(textPtr->tree, lineNum, matchByte, &index);
            if (!searchWholeText) {
                if (!backwards && (TkTextIndexCmp(&index, &stopIndex) >= 0)) {
                    goto done;
                }
                if (backwards && (TkTextIndexCmp(&index, &stopIndex) < 0)) {
                    goto done;
                }
            }
            if (varName != NULL) {
                sprintf(buffer, "%d", numChars);
                if (Tcl_SetVar(interp, varName, buffer, TCL_LEAVE_ERR_MSG)
                        == NULL) {
                    code = TCL_ERROR;
                    goto done;
                }
            }
            TkTextPrintIndex(&index, buffer);
            Tcl_SetResult(interp, buffer, TCL_VOLATILE);
            goto done;
        }

        /*
         * Go to the next (or previous) line;
         */

        nextLine:
        if (backwards) {
            lineNum--;
            if (!searchWholeText) {
                if (lineNum < stopLine) {
                    break;
                }
            } else if (lineNum < 0) {
                lineNum = numLines-1;
            }
        } else {
            lineNum++;
            if (!searchWholeText) {
                if (lineNum > stopLine) {
                    break;
                }
            } else if (lineNum >= numLines) {
                lineNum = 0;
            }
        }
        Tcl_DStringSetLength(&line, 0);
    }
    done:
    Tcl_DStringFree(&line);
    if (noCase) {
        Tcl_DStringFree(&patDString);
    }
    return code;
}

/*
 *----------------------------------------------------------------------
 *
 * TkTextGetTabs --
 *
 *      Parses a string description of a set of tab stops.
 *
 * Results:
 *      The return value is a pointer to a malloc'ed structure holding
 *      parsed information about the tab stops.  If an error occurred
 *      then the return value is NULL and an error message is left in
 *      the interp's result.
 *
 * Side effects:
 *      Memory is allocated for the structure that is returned.  It is
 *      up to the caller to free this structure when it is no longer
 *      needed.
 *
 *----------------------------------------------------------------------
 */

TkTextTabArray *
TkTextGetTabs(interp, tkwin, string)
    Tcl_Interp *interp;                 /* Used for error reporting. */
    Tk_Window tkwin;                    /* Window in which the tabs will be
                                         * used. */
    char *string;                       /* Description of the tab stops.  See
                                         * the text manual entry for details. */
{
    int argc, i, count, c;
    char **argv;
    TkTextTabArray *tabArrayPtr;
    TkTextTab *tabPtr;
    Tcl_UniChar ch;

    if (Tcl_SplitList(interp, string, &argc, &argv) != TCL_OK) {
        return NULL;
    }

    /*
     * First find out how many entries we need to allocate in the
     * tab array.
     */

    count = 0;
    for (i = 0; i < argc; i++) {
        c = argv[i][0];
        if ((c != 'l') && (c != 'r') && (c != 'c') && (c != 'n')) {
            count++;
        }
    }

    /*
     * Parse the elements of the list one at a time to fill in the
     * array.
     */

    tabArrayPtr = (TkTextTabArray *) ckalloc((unsigned)
            (sizeof(TkTextTabArray) + (count-1)*sizeof(TkTextTab)));
    tabArrayPtr->numTabs = 0;
    for (i = 0, tabPtr = &tabArrayPtr->tabs[0]; i  < argc; i++, tabPtr++) {
        if (Tk_GetPixels(interp, tkwin, argv[i], &tabPtr->location)
                != TCL_OK) {
            goto error;
        }
        tabArrayPtr->numTabs++;

        /*
         * See if there is an explicit alignment in the next list
         * element.  Otherwise just use "left".
         */

        tabPtr->alignment = LEFT;
        if ((i+1) == argc) {
            continue;
        }
        Tcl_UtfToUniChar(argv[i+1], &ch);
        if (!Tcl_UniCharIsAlpha(ch)) {
            continue;
        }
        i += 1;
        c = argv[i][0];
        if ((c == 'l') && (strncmp(argv[i], "left",
                strlen(argv[i])) == 0)) {
            tabPtr->alignment = LEFT;
        } else if ((c == 'r') && (strncmp(argv[i], "right",
                strlen(argv[i])) == 0)) {
            tabPtr->alignment = RIGHT;
        } else if ((c == 'c') && (strncmp(argv[i], "center",
                strlen(argv[i])) == 0)) {
            tabPtr->alignment = CENTER;
        } else if ((c == 'n') && (strncmp(argv[i],
                "numeric", strlen(argv[i])) == 0)) {
            tabPtr->alignment = NUMERIC;
        } else {
            Tcl_AppendResult(interp, "bad tab alignment \"",
                    argv[i], "\": must be left, right, center, or numeric",
                    (char *) NULL);
            goto error;
        }
    }
    ckfree((char *) argv);
    return tabArrayPtr;

    error:
    ckfree((char *) tabArrayPtr);
    ckfree((char *) argv);
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * TextDumpCmd --
 *
 *      Return information about the text, tags, marks, and embedded windows
 *      and images in a text widget.  See the man page for the description
 *      of the text dump operation for all the details.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      Memory is allocated for the result, if needed (standard Tcl result
 *      side effects).
 *
 *----------------------------------------------------------------------
 */

static int
TextDumpCmd(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 "dump". */
{
    TkTextIndex index1, index2;
    int arg;
    int lineno;                 /* Current line number */
    int what = 0;               /* bitfield to select segment types */
    int atEnd;                  /* True if dumping up to logical end */
    TkTextLine *linePtr;
    char *command = NULL;       /* Script callback to apply to segments */
#define TK_DUMP_TEXT    0x1
#define TK_DUMP_MARK    0x2
#define TK_DUMP_TAG     0x4
#define TK_DUMP_WIN     0x8
#define TK_DUMP_IMG     0x10
#define TK_DUMP_ALL     (TK_DUMP_TEXT|TK_DUMP_MARK|TK_DUMP_TAG| \
        TK_DUMP_WIN|TK_DUMP_IMG)

    for (arg=2 ; argv[arg] != (char *) NULL ; arg++) {
        size_t len;
        if (argv[arg][0] != '-') {
            break;
        }
        len = strlen(argv[arg]);
        if (strncmp("-all", argv[arg], len) == 0) {
            what = TK_DUMP_ALL;
        } else if (strncmp("-text", argv[arg], len) == 0) {
            what |= TK_DUMP_TEXT;
        } else if (strncmp("-tag", argv[arg], len) == 0) {
            what |= TK_DUMP_TAG;
        } else if (strncmp("-mark", argv[arg], len) == 0) {
            what |= TK_DUMP_MARK;
        } else if (strncmp("-image", argv[arg], len) == 0) {
            what |= TK_DUMP_IMG;
        } else if (strncmp("-window", argv[arg], len) == 0) {
            what |= TK_DUMP_WIN;
        } else if (strncmp("-command", argv[arg], len) == 0) {
            arg++;
            if (arg >= argc) {
                Tcl_AppendResult(interp, "Usage: ", argv[0], " dump ?-all -image -text -mark -tag -window? ?-command script? index ?index2?", NULL);
                return TCL_ERROR;
            }
            command = argv[arg];
        } else {
            Tcl_AppendResult(interp, "Usage: ", argv[0], " dump ?-all -image -text -mark -tag -window? ?-command script? index ?index2?", NULL);
            return TCL_ERROR;
        }
    }
    if (arg >= argc) {
        Tcl_AppendResult(interp, "Usage: ", argv[0], " dump ?-all -image -text -mark -tag -window? ?-command script? index ?index2?", NULL);
        return TCL_ERROR;
    }
    if (what == 0) {
        what = TK_DUMP_ALL;
    }
    if (TkTextGetIndex(interp, textPtr, argv[arg], &index1) != TCL_OK) {
        return TCL_ERROR;
    }
    lineno = TkBTreeLineIndex(index1.linePtr);
    arg++;
    atEnd = 0;
    if (argc == arg) {
        TkTextIndexForwChars(&index1, 1, &index2);
    } else {
        if (TkTextGetIndex(interp, textPtr, argv[arg], &index2) != TCL_OK) {
            return TCL_ERROR;
        }
        if (strncmp(argv[arg], "end", strlen(argv[arg])) == 0) {
            atEnd = 1;
        }
    }
    if (TkTextIndexCmp(&index1, &index2) >= 0) {
        return TCL_OK;
    }
    if (index1.linePtr == index2.linePtr) {
        DumpLine(interp, textPtr, what, index1.linePtr,
            index1.byteIndex, index2.byteIndex, lineno, command);
    } else {
        DumpLine(interp, textPtr, what, index1.linePtr,
                index1.byteIndex, 32000000, lineno, command);
        linePtr = index1.linePtr;
        while ((linePtr = TkBTreeNextLine(linePtr)) != (TkTextLine *)NULL) {
            lineno++;
            if (linePtr == index2.linePtr) {
                break;
            }
            DumpLine(interp, textPtr, what, linePtr, 0, 32000000,
                    lineno, command);
        }
        DumpLine(interp, textPtr, what, index2.linePtr, 0,
                index2.byteIndex, lineno, command);
    }
    /*
     * Special case to get the leftovers hiding at the end mark.
     */
    if (atEnd) {
        DumpLine(interp, textPtr, what & ~TK_DUMP_TEXT, index2.linePtr,
                0, 1, lineno, command);                     

    }
    return TCL_OK;
}

/*
 * DumpLine
 *      Return information about a given text line from character
 *      position "start" up to, but not including, "end".
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      None, but see DumpSegment.
 */
static void
DumpLine(interp, textPtr, what, linePtr, startByte, endByte, lineno, command)
    Tcl_Interp *interp;
    TkText *textPtr;
    int what;                   /* bit flags to select segment types */
    TkTextLine *linePtr;        /* The current line */
    int startByte, endByte;     /* Byte range to dump */
    int lineno;                 /* Line number for indices dump */
    char *command;              /* Script to apply to the segment */
{
    int offset;
    TkTextSegment *segPtr;
    TkTextIndex index;
    /*
     * Must loop through line looking at its segments.
     * character
     * toggleOn, toggleOff
     * mark
     * image
     * window
     */

    for (offset = 0, segPtr = linePtr->segPtr ;
            (offset < endByte) && (segPtr != (TkTextSegment *)NULL) ;
            offset += segPtr->size, segPtr = segPtr->nextPtr) {
        if ((what & TK_DUMP_TEXT) && (segPtr->typePtr == &tkTextCharType) &&
                (offset + segPtr->size > startByte)) {
            char savedChar;                     /* Last char used in the seg */
            int last = segPtr->size;            /* Index of savedChar */
            int first = 0;                      /* Index of first char in seg */
            if (offset + segPtr->size > endByte) {
                last = endByte - offset;
            }
            if (startByte > offset) {
                first = startByte - offset;
            }
            savedChar = segPtr->body.chars[last];
            segPtr->body.chars[last] = '\0';
            
            TkTextMakeByteIndex(textPtr->tree, lineno, offset + first, &index);
            DumpSegment(interp, "text", segPtr->body.chars + first,
                    command, &index, what);
            segPtr->body.chars[last] = savedChar;
        } else if ((offset >= startByte)) {
            if ((what & TK_DUMP_MARK) && (segPtr->typePtr->name[0] == 'm')) {
                TkTextMark *markPtr = (TkTextMark *)&segPtr->body;
                char *name = Tcl_GetHashKey(&textPtr->markTable, markPtr->hPtr);

                TkTextMakeByteIndex(textPtr->tree, lineno, offset, &index);
                DumpSegment(interp, "mark", name, command, &index, what);
            } else if ((what & TK_DUMP_TAG) &&
                        (segPtr->typePtr == &tkTextToggleOnType)) {
                TkTextMakeByteIndex(textPtr->tree, lineno, offset, &index);
                DumpSegment(interp, "tagon",
                        segPtr->body.toggle.tagPtr->name,
                        command, &index, what);
            } else if ((what & TK_DUMP_TAG) && 
                        (segPtr->typePtr == &tkTextToggleOffType)) {
                TkTextMakeByteIndex(textPtr->tree, lineno, offset, &index);
                DumpSegment(interp, "tagoff",
                        segPtr->body.toggle.tagPtr->name,
                        command, &index, what);
            } else if ((what & TK_DUMP_IMG) && 
                        (segPtr->typePtr->name[0] == 'i')) {
                TkTextEmbImage *eiPtr = (TkTextEmbImage *)&segPtr->body;
                char *name = (eiPtr->name ==  NULL) ? "" : eiPtr->name;
                TkTextMakeByteIndex(textPtr->tree, lineno, offset, &index);
                DumpSegment(interp, "image", name,
                        command, &index, what);
            } else if ((what & TK_DUMP_WIN) && 
                        (segPtr->typePtr->name[0] == 'w')) {
                TkTextEmbWindow *ewPtr = (TkTextEmbWindow *)&segPtr->body;
                char *pathname;
                if (ewPtr->tkwin == (Tk_Window) NULL) {
                    pathname = "";
                } else {
                    pathname = Tk_PathName(ewPtr->tkwin);
                }
                TkTextMakeByteIndex(textPtr->tree, lineno, offset, &index);
                DumpSegment(interp, "window", pathname,
                        command, &index, what);
            }
        }
    }
}

/*
 * DumpSegment
 *      Either append information about the current segment to the result,
 *      or make a script callback with that information as arguments.
 *
 * Results:
 *      None
 *
 * Side effects:
 *      Either evals the callback or appends elements to the result string.
 */
static int
DumpSegment(interp, key, value, command, index, what)
    Tcl_Interp *interp;
    char *key;                  /* Segment type key */
    char *value;                /* Segment value */
    char *command;              /* Script callback */
    TkTextIndex *index;         /* index with line/byte position info */
    int what;                   /* Look for TK_DUMP_INDEX bit */
{
    char buffer[TCL_INTEGER_SPACE*2];
    TkTextPrintIndex(index, buffer);
    if (command == (char *) NULL) {
        Tcl_AppendElement(interp, key);
        Tcl_AppendElement(interp, value);
        Tcl_AppendElement(interp, buffer);
        return TCL_OK;
    } else {
        char *argv[4];
        char *list;
        int result;
        argv[0] = key;
        argv[1] = value;
        argv[2] = buffer;
        argv[3] = (char *) NULL;
        list = Tcl_Merge(3, argv);
        result = Tcl_VarEval(interp, command, " ", list, (char *) NULL);
        ckfree(list);
        return result;
    }
}

/* End of tktext.c */