package req Tk
# tk
grid [scale .s1]
.s1 configure -orient horizontal
.s1 set 10
destroy .s1
# tk oo
grid [Scale .s1]
.s1 configure -orient horizontal
.s1 set 10
destroy .s1
# additional features
grid [Scale .s1]
.s1 ?
oo::define ::Scale method add args {puts $args}
.s1 ?
.s1 add
.s1 destroy

/*
 * tkScale.c --
 *
 *        This module implements a scale widgets for the Tk toolkit. A scale
 *        displays a slider that can be adjusted to change a value; it also
 *        displays numeric labels and a textual label, if desired.
 *
 *        The modifications to use floating-point values are based on an
 *        implementation by Paul Mackerras. The -variable option is due to
 *        Henning Schulzrinne. All of these are used with permission.
 *
 * Copyright (c) 1990-1994 The Regents of the University of California.
 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
 * Copyright (c) 1998-2000 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "default.h"
#include "tkInt.h"
#include "tkScale.h"

#if defined(_WIN32)
#define snprintf _snprintf
#endif

/*
 * The following table defines the legal values for the -orient option. It is
 * used together with the "enum orient" declaration in tkScale.h.
 */

static const char *const orientStrings[] = {
    "horizontal", "vertical", NULL
};

/*
 * The following table defines the legal values for the -state option. It is
 * used together with the "enum state" declaration in tkScale.h.
 */

static const char *const stateStrings[] = {
    "active", "disabled", "normal", NULL
};

static const Tk_OptionSpec optionSpecs[] = {
    {TK_OPTION_BORDER, "-activebackground", "activeBackground", "Foreground",
        DEF_SCALE_ACTIVE_BG_COLOR, -1, Tk_Offset(TkScale, activeBorder),
        0, DEF_SCALE_ACTIVE_BG_MONO, 0},
    {TK_OPTION_BORDER, "-background", "background", "Background",
        DEF_SCALE_BG_COLOR, -1, Tk_Offset(TkScale, bgBorder),
        0, DEF_SCALE_BG_MONO, 0},
    {TK_OPTION_DOUBLE, "-bigincrement", "bigIncrement", "BigIncrement",
        DEF_SCALE_BIG_INCREMENT, -1, Tk_Offset(TkScale, bigIncrement),
        0, 0, 0},
    {TK_OPTION_SYNONYM, "-bd", NULL, NULL,
        NULL, 0, -1, 0, "-borderwidth", 0},
    {TK_OPTION_SYNONYM, "-bg", NULL, NULL,
        NULL, 0, -1, 0, "-background", 0},
    {TK_OPTION_PIXELS, "-borderwidth", "borderWidth", "BorderWidth",
        DEF_SCALE_BORDER_WIDTH, -1, Tk_Offset(TkScale, borderWidth),
        0, 0, 0},
    {TK_OPTION_STRING, "-command", "command", "Command",
        DEF_SCALE_COMMAND, -1, Tk_Offset(TkScale, command),
        TK_OPTION_NULL_OK, 0, 0},
    {TK_OPTION_CURSOR, "-cursor", "cursor", "Cursor",
        DEF_SCALE_CURSOR, -1, Tk_Offset(TkScale, cursor),
        TK_OPTION_NULL_OK, 0, 0},
    {TK_OPTION_INT, "-digits", "digits", "Digits",
        DEF_SCALE_DIGITS, -1, Tk_Offset(TkScale, digits),
        0, 0, 0},
    {TK_OPTION_SYNONYM, "-fg", "foreground", NULL,
        NULL, 0, -1, 0, "-foreground", 0},
    {TK_OPTION_FONT, "-font", "font", "Font",
        DEF_SCALE_FONT, -1, Tk_Offset(TkScale, tkfont), 0, 0, 0},
    {TK_OPTION_COLOR, "-foreground", "foreground", "Foreground",
        DEF_SCALE_FG_COLOR, -1, Tk_Offset(TkScale, textColorPtr), 0,
        (ClientData) DEF_SCALE_FG_MONO, 0},
    {TK_OPTION_DOUBLE, "-from", "from", "From", DEF_SCALE_FROM, -1,
        Tk_Offset(TkScale, fromValue), 0, 0, 0},
    {TK_OPTION_BORDER, "-highlightbackground", "highlightBackground",
        "HighlightBackground", DEF_SCALE_HIGHLIGHT_BG_COLOR,
        -1, Tk_Offset(TkScale, highlightBorder),
        0, DEF_SCALE_HIGHLIGHT_BG_MONO, 0},
    {TK_OPTION_COLOR, "-highlightcolor", "highlightColor", "HighlightColor",
        DEF_SCALE_HIGHLIGHT, -1, Tk_Offset(TkScale, highlightColorPtr),
        0, 0, 0},
    {TK_OPTION_PIXELS, "-highlightthickness", "highlightThickness",
        "HighlightThickness", DEF_SCALE_HIGHLIGHT_WIDTH, -1,
        Tk_Offset(TkScale, highlightWidth), 0, 0, 0},
    {TK_OPTION_STRING, "-label", "label", "Label",
        DEF_SCALE_LABEL, -1, Tk_Offset(TkScale, label),
        TK_OPTION_NULL_OK, 0, 0},
    {TK_OPTION_PIXELS, "-length", "length", "Length",
        DEF_SCALE_LENGTH, -1, Tk_Offset(TkScale, length), 0, 0, 0},
    {TK_OPTION_STRING_TABLE, "-orient", "orient", "Orient",
        DEF_SCALE_ORIENT, -1, Tk_Offset(TkScale, orient),
        0, orientStrings, 0},
    {TK_OPTION_RELIEF, "-relief", "relief", "Relief",
        DEF_SCALE_RELIEF, -1, Tk_Offset(TkScale, relief), 0, 0, 0},
    {TK_OPTION_INT, "-repeatdelay", "repeatDelay", "RepeatDelay",
        DEF_SCALE_REPEAT_DELAY, -1, Tk_Offset(TkScale, repeatDelay),
        0, 0, 0},
    {TK_OPTION_INT, "-repeatinterval", "repeatInterval", "RepeatInterval",
        DEF_SCALE_REPEAT_INTERVAL, -1, Tk_Offset(TkScale, repeatInterval),
        0, 0, 0},
    {TK_OPTION_DOUBLE, "-resolution", "resolution", "Resolution",
        DEF_SCALE_RESOLUTION, -1, Tk_Offset(TkScale, resolution),
        0, 0, 0},
    {TK_OPTION_BOOLEAN, "-showvalue", "showValue", "ShowValue",
        DEF_SCALE_SHOW_VALUE, -1, Tk_Offset(TkScale, showValue),
        0, 0, 0},
    {TK_OPTION_PIXELS, "-sliderlength", "sliderLength", "SliderLength",
        DEF_SCALE_SLIDER_LENGTH, -1, Tk_Offset(TkScale, sliderLength),
        0, 0, 0},
    {TK_OPTION_RELIEF, "-sliderrelief", "sliderRelief", "SliderRelief",
        DEF_SCALE_SLIDER_RELIEF, -1, Tk_Offset(TkScale, sliderRelief),
        0, 0, 0},
    {TK_OPTION_STRING_TABLE, "-state", "state", "State",
        DEF_SCALE_STATE, -1, Tk_Offset(TkScale, state),
        0, stateStrings, 0},
    {TK_OPTION_STRING, "-takefocus", "takeFocus", "TakeFocus",
        DEF_SCALE_TAKE_FOCUS, Tk_Offset(TkScale, takeFocusPtr), -1,
        TK_OPTION_NULL_OK, 0, 0},
    {TK_OPTION_DOUBLE, "-tickinterval", "tickInterval", "TickInterval",
        DEF_SCALE_TICK_INTERVAL, -1, Tk_Offset(TkScale, tickInterval),
        0, 0, 0},
    {TK_OPTION_DOUBLE, "-to", "to", "To",
        DEF_SCALE_TO, -1, Tk_Offset(TkScale, toValue), 0, 0, 0},
    {TK_OPTION_COLOR, "-troughcolor", "troughColor", "Background",
        DEF_SCALE_TROUGH_COLOR, -1, Tk_Offset(TkScale, troughColorPtr),
        0, DEF_SCALE_TROUGH_MONO, 0},
    {TK_OPTION_STRING, "-variable", "variable", "Variable",
        DEF_SCALE_VARIABLE, Tk_Offset(TkScale, varNamePtr), -1,
        TK_OPTION_NULL_OK, 0, 0},
    {TK_OPTION_PIXELS, "-width", "width", "Width",
        DEF_SCALE_WIDTH, -1, Tk_Offset(TkScale, width), 0, 0, 0},
    {TK_OPTION_END, NULL, NULL, NULL, NULL, 0, -1, 0, 0, 0}
};

/*
 * The following tables define the scale widget commands and map the indexes
 * into the string tables into a single enumerated type used to dispatch the
 * scale widget command.
 */

static const char *const commandNames[] = {
    "cget", "configure", "coords", "get", "identify", "set", NULL
};

enum command {
    COMMAND_CGET, COMMAND_CONFIGURE, COMMAND_COORDS, COMMAND_GET,
    COMMAND_IDENTIFY, COMMAND_SET
};

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

static void                ComputeFormat(TkScale *scalePtr);
static void                ComputeScaleGeometry(TkScale *scalePtr);
static int                ConfigureScale(Tcl_Interp *interp, TkScale *scalePtr,
                            int objc, Tcl_Obj *const objv[]);
static void                DestroyScale(char *memPtr);
static void                ScaleCmdDeletedProc(ClientData clientData);
static void                ScaleEventProc(ClientData clientData,
                            XEvent *eventPtr);
static char *                ScaleVarProc(ClientData clientData,
                            Tcl_Interp *interp, const char *name1,
                            const char *name2, int flags);
static int                ScaleWidgetObjCmd(ClientData clientData,
                            Tcl_Interp *interp, int objc,
                            Tcl_Obj *const objv[]);
static void                ScaleWorldChanged(ClientData instanceData);
static void                ScaleSetVariable(TkScale *scalePtr);

static TkScale        *ScaleCreate(ClientData instanceData,
                                Tcl_Interp *interp, int objc,
                                Tcl_Obj *const objv[]);
/*
 * The structure below defines scale class behavior by means of procedures
 * that can be invoked from generic window code.
 */

static const Tk_ClassProcs scaleClass = {
    sizeof(Tk_ClassProcs),        /* size */
    ScaleWorldChanged,                /* worldChangedProc */
    NULL,                                        /* createProc */
    NULL                                        /* modalProc */
};

/*
 *--------------------------------------------------------------
 *
 * Tk_ScaleObjCmd --
 *
 *        This procedure is invoked to process the "scale" 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_ScaleObjCmd(
        ClientData clientData,        /* NULL. */
        Tcl_Interp *interp,                /* Current interpreter. */
        int objc,                        /* Number of arguments. */
        Tcl_Obj *const objv[])        /* Argument values. */
{

        if (objc < 2) {
                Tcl_WrongNumArgs(interp, 1, objv, "pathName ?-option value ...?");
                return TCL_ERROR;
        }

        if (ScaleCreate(NULL, interp, objc, objv) == NULL) {
                return TCL_ERROR;
        }
        return TCL_OK;
}

static TkScale *ScaleCreate(
        ClientData clientData,        /* NULL. */
        Tcl_Interp *interp,                /* Current interpreter. */
        int objc,                        /* Number of arguments. */
        Tcl_Obj *const objv[])        /* Argument values. */
{
        register TkScale *scalePtr;
        Tk_OptionTable optionTable;
        Tk_Window tkwin;

        tkwin = Tk_CreateWindowFromPath(interp, Tk_MainWindow(interp),
            Tcl_GetString(objv[1]), NULL);
    if (tkwin == NULL) {
                return NULL;
    }

    /*
     * Create the option table for this widget class. If it has already been
     * created, the cached pointer will be returned.
     */

    optionTable = Tk_CreateOptionTable(interp, optionSpecs);

    Tk_SetClass(tkwin, "Scale");
    scalePtr = TkpCreateScale(tkwin);

    /*
     * Initialize fields that won't be initialized by ConfigureScale, or which
     * ConfigureScale expects to have reasonable values (e.g. resource
     * pointers).
     */

    scalePtr->tkwin                = tkwin;
    scalePtr->display                = Tk_Display(tkwin);
    scalePtr->interp                = interp;
        if (clientData == (ClientData)NULL) {
                scalePtr->widgetCmd = Tcl_CreateObjCommand(interp,
                        Tk_PathName(scalePtr->tkwin), ScaleWidgetObjCmd,
                        scalePtr, ScaleCmdDeletedProc);
        }
        else {
                scalePtr->widgetCmd = clientData;
        }
    scalePtr->optionTable        = optionTable;
    scalePtr->orient                = ORIENT_VERTICAL;
    scalePtr->width                = 0;
    scalePtr->length                = 0;
    scalePtr->value                = 0.0;
    scalePtr->varNamePtr        = NULL;
    scalePtr->fromValue                = 0.0;
    scalePtr->toValue                = 0.0;
    scalePtr->tickInterval        = 0.0;
    scalePtr->resolution        = 1.0;
    scalePtr->digits                = 0;
    scalePtr->bigIncrement        = 0.0;
    scalePtr->command                = NULL;
    scalePtr->repeatDelay        = 0;
    scalePtr->repeatInterval        = 0;
    scalePtr->label                = NULL;
    scalePtr->labelLength        = 0;
    scalePtr->state                = STATE_NORMAL;
    scalePtr->borderWidth        = 0;
    scalePtr->bgBorder                = NULL;
    scalePtr->activeBorder        = NULL;
    scalePtr->sliderRelief        = TK_RELIEF_RAISED;
    scalePtr->troughColorPtr        = NULL;
    scalePtr->troughGC                = None;
    scalePtr->copyGC                = None;
    scalePtr->tkfont                = NULL;
    scalePtr->textColorPtr        = NULL;
    scalePtr->textGC                = None;
    scalePtr->relief                = TK_RELIEF_FLAT;
    scalePtr->highlightWidth        = 0;
    scalePtr->highlightBorder        = NULL;
    scalePtr->highlightColorPtr        = NULL;
    scalePtr->inset                = 0;
    scalePtr->sliderLength        = 0;
    scalePtr->showValue                = 0;
    scalePtr->horizLabelY        = 0;
    scalePtr->horizValueY        = 0;
    scalePtr->horizTroughY        = 0;
    scalePtr->horizTickY        = 0;
    scalePtr->vertTickRightX        = 0;
    scalePtr->vertValueRightX        = 0;
    scalePtr->vertTroughX        = 0;
    scalePtr->vertLabelX        = 0;
    scalePtr->fontHeight        = 0;
    scalePtr->cursor                = None;
    scalePtr->takeFocusPtr        = NULL;
    scalePtr->flags                = NEVER_SET;

    Tk_SetClassProcs(scalePtr->tkwin, &scaleClass, scalePtr);
    Tk_CreateEventHandler(scalePtr->tkwin,
            ExposureMask|StructureNotifyMask|FocusChangeMask,
            ScaleEventProc, scalePtr);

    if ((Tk_InitOptions(interp, (char *) scalePtr, optionTable, tkwin)
            != TCL_OK) ||
            (ConfigureScale(interp, scalePtr, objc - 2, objv + 2) != TCL_OK)) {
        Tk_DestroyWindow(scalePtr->tkwin);
                return NULL;
    }

    /*
     * The widget was just created, no command callback must be invoked.
     */

    scalePtr->flags &= ~INVOKE_COMMAND;

    Tcl_SetObjResult(interp, TkNewWindowObj(scalePtr->tkwin));
    return scalePtr;
}

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

static int
ScaleWidgetObjCmd(
    ClientData clientData,        /* Information about scale widget. */
    Tcl_Interp *interp,                /* Current interpreter. */
    int objc,                        /* Number of arguments. */
    Tcl_Obj *const objv[])        /* Argument strings. */
{
    TkScale *scalePtr = clientData;
    Tcl_Obj *objPtr;
    int index, result;

    if (objc < 2) {
        Tcl_WrongNumArgs(interp, 1, objv, "option ?arg ...?");
        return TCL_ERROR;
    }
    result = Tcl_GetIndexFromObjStruct(interp, objv[1], commandNames,
            sizeof(char *), "option", 0, &index);
    if (result != TCL_OK) {
        return result;
    }
    Tcl_Preserve(scalePtr);

    switch (index) {
    case COMMAND_CGET:
        if (objc != 3) {
            Tcl_WrongNumArgs(interp, 1, objv, "cget option");
            goto error;
        }
        objPtr = Tk_GetOptionValue(interp, (char *) scalePtr,
                scalePtr->optionTable, objv[2], scalePtr->tkwin);
        if (objPtr == NULL) {
            goto error;
        }
        Tcl_SetObjResult(interp, objPtr);
        break;
    case COMMAND_CONFIGURE:
        if (objc <= 3) {
            objPtr = Tk_GetOptionInfo(interp, (char *) scalePtr,
                    scalePtr->optionTable,
                    (objc == 3) ? objv[2] : NULL, scalePtr->tkwin);
            if (objPtr == NULL) {
                goto error;
            }
            Tcl_SetObjResult(interp, objPtr);
        } else {
            result = ConfigureScale(interp, scalePtr, objc-2, objv+2);
        }
        break;
    case COMMAND_COORDS: {
        int x, y;
        double value;
        Tcl_Obj *coords[2];

        if ((objc != 2) && (objc != 3)) {
            Tcl_WrongNumArgs(interp, 1, objv, "coords ?value?");
            goto error;
        }
        if (objc == 3) {
            if (Tcl_GetDoubleFromObj(interp, objv[2], &value) != TCL_OK) {
                goto error;
            }
        } else {
            value = scalePtr->value;
        }
        if (scalePtr->orient == ORIENT_VERTICAL) {
            x = scalePtr->vertTroughX + scalePtr->width/2
                    + scalePtr->borderWidth;
            y = TkScaleValueToPixel(scalePtr, value);
        } else {
            x = TkScaleValueToPixel(scalePtr, value);
            y = scalePtr->horizTroughY + scalePtr->width/2
                    + scalePtr->borderWidth;
        }
        coords[0] = Tcl_NewIntObj(x);
        coords[1] = Tcl_NewIntObj(y);
        Tcl_SetObjResult(interp, Tcl_NewListObj(2, coords));
        break;
    }
    case COMMAND_GET: {
        double value;
        int x, y;

        if ((objc != 2) && (objc != 4)) {
            Tcl_WrongNumArgs(interp, 1, objv, "get ?x y?");
            goto error;
        }
        if (objc == 2) {
            value = scalePtr->value;
        } else {
            if ((Tcl_GetIntFromObj(interp, objv[2], &x) != TCL_OK) ||
                    (Tcl_GetIntFromObj(interp, objv[3], &y) != TCL_OK)) {
                goto error;
            }
            value = TkScalePixelToValue(scalePtr, x, y);
        }
        Tcl_SetObjResult(interp, Tcl_ObjPrintf(scalePtr->format, value));
        break;
    }
    case COMMAND_IDENTIFY: {
        int x, y;
        const char *zone = "";

        if (objc != 4) {
            Tcl_WrongNumArgs(interp, 1, objv, "identify x y");
            goto error;
        }
        if ((Tcl_GetIntFromObj(interp, objv[2], &x) != TCL_OK)
                || (Tcl_GetIntFromObj(interp, objv[3], &y) != TCL_OK)) {
            goto error;
        }
        switch (TkpScaleElement(scalePtr, x, y)) {
        case TROUGH1:        zone = "trough1"; break;
        case SLIDER:        zone = "slider";  break;
        case TROUGH2:        zone = "trough2"; break;
        }
        Tcl_SetObjResult(interp, Tcl_NewStringObj(zone, -1));
        break;
    }
    case COMMAND_SET: {
        double value;

        if (objc != 3) {
            Tcl_WrongNumArgs(interp, 1, objv, "set value");
            goto error;
        }
        if (Tcl_GetDoubleFromObj(interp, objv[2], &value) != TCL_OK) {
            goto error;
        }
        if (scalePtr->state != STATE_DISABLED) {
            TkScaleSetValue(scalePtr, value, 1, 1);
        }
        break;
    }
    }
    Tcl_Release(scalePtr);
    return result;

  error:
    Tcl_Release(scalePtr);
    return TCL_ERROR;
}

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

static void
DestroyScale(
    char *memPtr)        /* Info about scale widget. */
{
    register TkScale *scalePtr = (TkScale *) memPtr;

        scalePtr->flags |= SCALE_DELETED;

        if (scalePtr->widgetCmd) {
                Tcl_DeleteCommandFromToken(scalePtr->interp, scalePtr->widgetCmd);
        }
    if (scalePtr->flags & REDRAW_PENDING) {
        Tcl_CancelIdleCall(TkpDisplayScale, scalePtr);
    }

    /*
     * Free up all the stuff that requires special handling, then let
     * Tk_FreeOptions handle all the standard option-related stuff.
     */

    if (scalePtr->varNamePtr != NULL) {
        Tcl_UntraceVar2(scalePtr->interp, Tcl_GetString(scalePtr->varNamePtr),
                NULL, TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
                ScaleVarProc, scalePtr);
    }
    if (scalePtr->troughGC != None) {
        Tk_FreeGC(scalePtr->display, scalePtr->troughGC);
    }
    if (scalePtr->copyGC != None) {
        Tk_FreeGC(scalePtr->display, scalePtr->copyGC);
    }
    if (scalePtr->textGC != None) {
        Tk_FreeGC(scalePtr->display, scalePtr->textGC);
    }
    Tk_FreeConfigOptions((char *) scalePtr, scalePtr->optionTable,
            scalePtr->tkwin);
    scalePtr->tkwin = NULL;
    TkpDestroyScale(scalePtr);
}

/*
 *----------------------------------------------------------------------
 *
 * ConfigureScale --
 *
 *        This procedure is called to process an argv/argc list, plus the Tk
 *        option database, in order to configure (or reconfigure) a scale
 *        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 colors, border width, etc. get set
 *        for scalePtr; old resources get freed, if there were any.
 *
 *----------------------------------------------------------------------
 */

static int
ConfigureScale(
    Tcl_Interp *interp,                /* Used for error reporting. */
    register TkScale *scalePtr,        /* Information about widget; may or may not
                                 * already have values for some fields. */
    int objc,                        /* Number of valid entries in objv. */
    Tcl_Obj *const objv[])        /* Argument values. */
{
    Tk_SavedOptions savedOptions;
    Tcl_Obj *errorResult = NULL;
    int error;
    double varValue;

    /*
     * Eliminate any existing trace on a variable monitored by the scale.
     */

    if (scalePtr->varNamePtr != NULL) {
        Tcl_UntraceVar2(interp, Tcl_GetString(scalePtr->varNamePtr),
                NULL, TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
                ScaleVarProc, scalePtr);
    }

    for (error = 0; error <= 1; error++) {
        if (!error) {
            /*
             * First pass: set options to new values.
             */

            if (Tk_SetOptions(interp, (char *) scalePtr,
                    scalePtr->optionTable, objc, objv, scalePtr->tkwin,
                    &savedOptions, NULL) != TCL_OK) {
                continue;
            }
        } else {
            /*
             * Second pass: restore options to old values.
             */

            errorResult = Tcl_GetObjResult(interp);
            Tcl_IncrRefCount(errorResult);
            Tk_RestoreSavedOptions(&savedOptions);
        }

        /*
         * If the scale is tied to the value of a variable, then set the
         * scale's value from the value of the variable, if it exists and it
         * holds a valid double value.
         */

        if (scalePtr->varNamePtr != NULL) {
            double value;
            Tcl_Obj *valuePtr;

            valuePtr = Tcl_ObjGetVar2(interp, scalePtr->varNamePtr, NULL,
                    TCL_GLOBAL_ONLY);
            if ((valuePtr != NULL) &&
                    (Tcl_GetDoubleFromObj(NULL, valuePtr, &value) == TCL_OK)) {
                scalePtr->value = TkRoundToResolution(scalePtr, value);
            }
        }

        /*
         * Several options need special processing, such as parsing the
         * orientation and creating GCs.
         */

        scalePtr->fromValue = TkRoundToResolution(scalePtr,
                scalePtr->fromValue);
        scalePtr->toValue = TkRoundToResolution(scalePtr, scalePtr->toValue);
        scalePtr->tickInterval = TkRoundToResolution(scalePtr,
                scalePtr->tickInterval);

        /*
         * Make sure that the tick interval has the right sign so that
         * addition moves from fromValue to toValue.
         */

        if ((scalePtr->tickInterval < 0)
                ^ ((scalePtr->toValue - scalePtr->fromValue) < 0)) {
            scalePtr->tickInterval = -scalePtr->tickInterval;
        }

        ComputeFormat(scalePtr);

        scalePtr->labelLength = scalePtr->label ? (int)strlen(scalePtr->label) : 0;

        Tk_SetBackgroundFromBorder(scalePtr->tkwin, scalePtr->bgBorder);

        if (scalePtr->highlightWidth < 0) {
            scalePtr->highlightWidth = 0;
        }
        scalePtr->inset = scalePtr->highlightWidth + scalePtr->borderWidth;
        break;
    }
    if (!error) {
        Tk_FreeSavedOptions(&savedOptions);
    }

    /*
     * Set the scale value to itself; all this does is to make sure that the
     * scale's value is within the new acceptable range for the scale. We
     * don't set the var here because we need to make special checks for
     * possibly changed varNamePtr.
     */

    TkScaleSetValue(scalePtr, scalePtr->value, 0, 1);

    /*
     * Reestablish the variable trace, if it is needed.
     */

    if (scalePtr->varNamePtr != NULL) {
        Tcl_Obj *valuePtr;

        /*
         * Set the associated variable only when the new value differs from
         * the current value, or the variable doesn't yet exist.
         */

        valuePtr = Tcl_ObjGetVar2(interp, scalePtr->varNamePtr, NULL,
                TCL_GLOBAL_ONLY);
        if ((valuePtr == NULL) || (Tcl_GetDoubleFromObj(NULL,
                valuePtr, &varValue) != TCL_OK)) {
            ScaleSetVariable(scalePtr);
        } else {
            char varString[TCL_DOUBLE_SPACE], scaleString[TCL_DOUBLE_SPACE];

            Tcl_PrintDouble(NULL, varValue, varString);
            Tcl_PrintDouble(NULL, scalePtr->value, scaleString);
            if (strcmp(varString, scaleString)) {
                ScaleSetVariable(scalePtr);
            }
        }
        Tcl_TraceVar2(interp, Tcl_GetString(scalePtr->varNamePtr),
                NULL, TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
                ScaleVarProc, scalePtr);
    }

    ScaleWorldChanged(scalePtr);
    if (error) {
        Tcl_SetObjResult(interp, errorResult);
        Tcl_DecrRefCount(errorResult);
        return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * ScaleWorldChanged --
 *
 *        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:
 *        Scale will be relayed out and redisplayed.
 *
 *---------------------------------------------------------------------------
 */

static void
ScaleWorldChanged(
    ClientData instanceData)        /* Information about widget. */
{
    XGCValues gcValues;
    GC gc;
    TkScale *scalePtr = instanceData;

    gcValues.foreground = scalePtr->troughColorPtr->pixel;
    gc = Tk_GetGC(scalePtr->tkwin, GCForeground, &gcValues);
    if (scalePtr->troughGC != None) {
        Tk_FreeGC(scalePtr->display, scalePtr->troughGC);
    }
    scalePtr->troughGC = gc;

    gcValues.font = Tk_FontId(scalePtr->tkfont);
    gcValues.foreground = scalePtr->textColorPtr->pixel;
    gc = Tk_GetGC(scalePtr->tkwin, GCForeground | GCFont, &gcValues);
    if (scalePtr->textGC != None) {
        Tk_FreeGC(scalePtr->display, scalePtr->textGC);
    }
    scalePtr->textGC = gc;

    if (scalePtr->copyGC == None) {
        gcValues.graphics_exposures = False;
        scalePtr->copyGC = Tk_GetGC(scalePtr->tkwin, GCGraphicsExposures,
                &gcValues);
    }
    scalePtr->inset = scalePtr->highlightWidth + scalePtr->borderWidth;

    /*
     * Recompute display-related information, and let the geometry manager
     * know how much space is needed now.
     */

    ComputeScaleGeometry(scalePtr);

    TkEventuallyRedrawScale(scalePtr, REDRAW_ALL);
}

/*
 *----------------------------------------------------------------------
 *
 * ComputeFormat --
 *
 *        This procedure is invoked to recompute the "format" field of a scale's
 *        widget record, which determines how the value of the scale is
 *        converted to a string.
 *
 * Results:
 *        None.
 *
 * Side effects:
 *        The format field of scalePtr is modified.
 *
 *----------------------------------------------------------------------
 */

static void
ComputeFormat(
    TkScale *scalePtr)                /* Information about scale widget. */
{
    double maxValue, x;
    int mostSigDigit, numDigits, leastSigDigit, afterDecimal;
    int eDigits, fDigits;

    /*
     * Compute the displacement from the decimal of the most significant digit
     * required for any number in the scale's range.
     */

    maxValue = fabs(scalePtr->fromValue);
    x = fabs(scalePtr->toValue);
    if (x > maxValue) {
        maxValue = x;
    }
    if (maxValue == 0) {
        maxValue = 1;
    }
    mostSigDigit = (int) floor(log10(maxValue));

    /*
     * If the number of significant digits wasn't specified explicitly,
     * compute it. It's the difference between the most significant digit
     * needed to represent any number on the scale and the most significant
     * digit of the smallest difference between numbers on the scale. In other
     * words, display enough digits so that at least one digit will be
     * different between any two adjacent positions of the scale.
     */

    numDigits = scalePtr->digits;
    if (numDigits > TCL_MAX_PREC) {
        numDigits = 0;
    }
    if (numDigits <= 0) {
        if (scalePtr->resolution > 0) {
            /*
             * A resolution was specified for the scale, so just use it.
             */

            leastSigDigit = (int) floor(log10(scalePtr->resolution));
        } else {
            /*
             * No resolution was specified, so compute the difference in value
             * between adjacent pixels and use it for the least significant
             * digit.
             */

            x = fabs(scalePtr->fromValue - scalePtr->toValue);
            if (scalePtr->length > 0) {
                x /= scalePtr->length;
            }
            if (x > 0){
                leastSigDigit = (int) floor(log10(x));
            } else {
                leastSigDigit = 0;
            }
        }
        numDigits = mostSigDigit - leastSigDigit + 1;
        if (numDigits < 1) {
            numDigits = 1;
        }
    }

    /*
     * Compute the number of characters required using "e" format and "f"
     * format, and then choose whichever one takes fewer characters.
     */

    eDigits = numDigits + 4;
    if (numDigits > 1) {
        eDigits++;                        /* Decimal point. */
    }
    afterDecimal = numDigits - mostSigDigit - 1;
    if (afterDecimal < 0) {
        afterDecimal = 0;
    }
    fDigits = (mostSigDigit >= 0) ? mostSigDigit + afterDecimal : afterDecimal;
    if (afterDecimal > 0) {
        fDigits++;                        /* Decimal point. */
    }
    if (mostSigDigit < 0) {
        fDigits++;                        /* Zero to left of decimal point. */
    }
    if (fDigits <= eDigits) {
        sprintf(scalePtr->format, "%%.%df", afterDecimal);
    } else {
        sprintf(scalePtr->format, "%%.%de", numDigits-1);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * ComputeScaleGeometry --
 *
 *        This procedure is called to compute various geometrical information
 *        for a scale, such as where various things get displayed. It's called
 *        when the window is reconfigured.
 *
 * Results:
 *        None.
 *
 * Side effects:
 *        Display-related numbers get changed in *scalePtr. The geometry manager
 *        gets told about the window's preferred size.
 *
 *----------------------------------------------------------------------
 */

static void
ComputeScaleGeometry(
    register TkScale *scalePtr)        /* Information about widget. */
{
    char valueString[TCL_DOUBLE_SPACE];
    int tmp, valuePixels, x, y, extraSpace;
    Tk_FontMetrics fm;

    Tk_GetFontMetrics(scalePtr->tkfont, &fm);
    scalePtr->fontHeight = fm.linespace + SPACING;

    /*
     * Horizontal scales are simpler than vertical ones because all sizes are
     * the same (the height of a line of text); handle them first and then
     * quit.
     */

    if (scalePtr->orient == ORIENT_HORIZONTAL) {
        y = scalePtr->inset;
        extraSpace = 0;
        if (scalePtr->labelLength != 0) {
            scalePtr->horizLabelY = y + SPACING;
            y += scalePtr->fontHeight;
            extraSpace = SPACING;
        }
        if (scalePtr->showValue) {
            scalePtr->horizValueY = y + SPACING;
            y += scalePtr->fontHeight;
            extraSpace = SPACING;
        } else {
            scalePtr->horizValueY = y;
        }
        y += extraSpace;
        scalePtr->horizTroughY = y;
        y += scalePtr->width + 2*scalePtr->borderWidth;
        if (scalePtr->tickInterval != 0) {
            scalePtr->horizTickY = y + SPACING;
            y += scalePtr->fontHeight + SPACING;
        }
        Tk_GeometryRequest(scalePtr->tkwin,
                scalePtr->length + 2*scalePtr->inset, y + scalePtr->inset);
        Tk_SetInternalBorder(scalePtr->tkwin, scalePtr->inset);
        return;
    }

    /*
     * Vertical scale: compute the amount of space needed to display the
     * scales value by formatting strings for the two end points; use
     * whichever length is longer.
     */

    if (snprintf(valueString, TCL_DOUBLE_SPACE, scalePtr->format,
            scalePtr->fromValue) < 0) {
        valueString[TCL_DOUBLE_SPACE - 1] = '\0';
    }
    valuePixels = Tk_TextWidth(scalePtr->tkfont, valueString, -1);

    if (snprintf(valueString, TCL_DOUBLE_SPACE, scalePtr->format,
            scalePtr->toValue) < 0) {
        valueString[TCL_DOUBLE_SPACE - 1] = '\0';
    }
    tmp = Tk_TextWidth(scalePtr->tkfont, valueString, -1);
    if (valuePixels < tmp) {
        valuePixels = tmp;
    }

    /*
     * Assign x-locations to the elements of the scale, working from left to
     * right.
     */

    x = scalePtr->inset;
    if ((scalePtr->tickInterval != 0) && (scalePtr->showValue)) {
        scalePtr->vertTickRightX = x + SPACING + valuePixels;
        scalePtr->vertValueRightX = scalePtr->vertTickRightX + valuePixels
                + fm.ascent/2;
        x = scalePtr->vertValueRightX + SPACING;
    } else if (scalePtr->tickInterval != 0) {
        scalePtr->vertTickRightX = x + SPACING + valuePixels;
        scalePtr->vertValueRightX = scalePtr->vertTickRightX;
        x = scalePtr->vertTickRightX + SPACING;
    } else if (scalePtr->showValue) {
        scalePtr->vertTickRightX = x;
        scalePtr->vertValueRightX = x + SPACING + valuePixels;
        x = scalePtr->vertValueRightX + SPACING;
    } else {
        scalePtr->vertTickRightX = x;
        scalePtr->vertValueRightX = x;
    }
    scalePtr->vertTroughX = x;
    x += 2*scalePtr->borderWidth + scalePtr->width;
    if (scalePtr->labelLength == 0) {
        scalePtr->vertLabelX = 0;
    } else {
        scalePtr->vertLabelX = x + fm.ascent/2;
        x = scalePtr->vertLabelX + fm.ascent/2
            + Tk_TextWidth(scalePtr->tkfont, scalePtr->label,
                    scalePtr->labelLength);
    }
    Tk_GeometryRequest(scalePtr->tkwin, x + scalePtr->inset,
            scalePtr->length + 2*scalePtr->inset);
    Tk_SetInternalBorder(scalePtr->tkwin, scalePtr->inset);
}

/*
 *--------------------------------------------------------------
 *
 * ScaleEventProc --
 *
 *        This procedure is invoked by the Tk dispatcher for various events on
 *        scales.
 *
 * Results:
 *        None.
 *
 * Side effects:
 *        When the window gets deleted, internal structures get cleaned up.
 *        When it gets exposed, it is redisplayed.
 *
 *--------------------------------------------------------------
 */

static void
ScaleEventProc(
    ClientData clientData,        /* Information about window. */
    XEvent *eventPtr)                /* Information about event. */
{
    TkScale *scalePtr = clientData;

    if ((eventPtr->type == Expose) && (eventPtr->xexpose.count == 0)) {
        TkEventuallyRedrawScale(scalePtr, REDRAW_ALL);
    } else if (eventPtr->type == DestroyNotify) {
        DestroyScale(clientData);
    } else if (eventPtr->type == ConfigureNotify) {
        ComputeScaleGeometry(scalePtr);
        TkEventuallyRedrawScale(scalePtr, REDRAW_ALL);
    } else if (eventPtr->type == FocusIn) {
        if (eventPtr->xfocus.detail != NotifyInferior) {
            scalePtr->flags |= GOT_FOCUS;
            if (scalePtr->highlightWidth > 0) {
                TkEventuallyRedrawScale(scalePtr, REDRAW_ALL);
            }
        }
    } else if (eventPtr->type == FocusOut) {
        if (eventPtr->xfocus.detail != NotifyInferior) {
            scalePtr->flags &= ~GOT_FOCUS;
            if (scalePtr->highlightWidth > 0) {
                TkEventuallyRedrawScale(scalePtr, REDRAW_ALL);
            }
        }
    }
}

/*
 *----------------------------------------------------------------------
 *
 * ScaleCmdDeletedProc --
 *
 *        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
ScaleCmdDeletedProc(
    ClientData clientData)        /* Pointer to widget record for widget. */
{
    TkScale *scalePtr = clientData;
    Tk_Window tkwin = scalePtr->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 (!(scalePtr->flags & SCALE_DELETED)) {
        scalePtr->flags |= SCALE_DELETED;
        Tk_DestroyWindow(tkwin);
    }
}

/*
 *--------------------------------------------------------------
 *
 * TkEventuallyRedrawScale --
 *
 *        Arrange for part or all of a scale widget to redrawn at the next
 *        convenient time in the future.
 *
 * Results:
 *        None.
 *
 * Side effects:
 *        If "what" is REDRAW_SLIDER then just the slider and the value readout
 *        will be redrawn; if "what" is REDRAW_ALL then the entire widget will
 *        be redrawn.
 *
 *--------------------------------------------------------------
 */

void
TkEventuallyRedrawScale(
    register TkScale *scalePtr,        /* Information about widget. */
    int what)                        /* What to redraw: REDRAW_SLIDER or
                                 * REDRAW_ALL. */
{
    if ((what == 0) || (scalePtr->tkwin == NULL)
            || !Tk_IsMapped(scalePtr->tkwin)) {
        return;
    }
    if (!(scalePtr->flags & REDRAW_PENDING)) {
        scalePtr->flags |= REDRAW_PENDING;
        Tcl_DoWhenIdle(TkpDisplayScale, scalePtr);
    }
    scalePtr->flags |= what;
}

/*
 *--------------------------------------------------------------
 *
 * TkRoundToResolution --
 *
 *        Round a given floating-point value to the nearest multiple of the
 *        scale's resolution.
 *
 * Results:
 *        The return value is the rounded result.
 *
 * Side effects:
 *        None.
 *
 *--------------------------------------------------------------
 */

double
TkRoundToResolution(
    TkScale *scalePtr,                /* Information about scale widget. */
    double value)                /* Value to round. */
{
    double rem, rounded, tick;

    if (scalePtr->resolution <= 0) {
        return value;
    }
    tick = floor(value/scalePtr->resolution);
    rounded = scalePtr->resolution * tick;
    rem = value - rounded;
    if (rem < 0) {
        if (rem <= -scalePtr->resolution/2) {
            rounded = (tick - 1.0) * scalePtr->resolution;
        }
    } else {
        if (rem >= scalePtr->resolution/2) {
            rounded = (tick + 1.0) * scalePtr->resolution;
        }
    }
    return rounded;
}

/*
 *----------------------------------------------------------------------
 *
 * ScaleVarProc --
 *
 *        This procedure is invoked by Tcl whenever someone modifies a variable
 *        associated with a scale widget.
 *
 * Results:
 *        NULL is always returned.
 *
 * Side effects:
 *        The value displayed in the scale will change to match the variable's
 *        new value. If the variable has a bogus value then it is reset to the
 *        value of the scale.
 *
 *----------------------------------------------------------------------
 */

    /* ARGSUSED */
static char *
ScaleVarProc(
    ClientData clientData,        /* Information about button. */
    Tcl_Interp *interp,                /* Interpreter containing variable. */
    const char *name1,                /* Name of variable. */
    const char *name2,                /* Second part of variable name. */
    int flags)                        /* Information about what happened. */
{
    register TkScale *scalePtr = clientData;
    const char *resultStr;
    double value;
    Tcl_Obj *valuePtr;
    int result;

    /*
     * See ticket [5d991b82].
     */

    if (scalePtr->varNamePtr == NULL) {
        if (!(flags & TCL_INTERP_DESTROYED)) {
            Tcl_UntraceVar2(interp, name1, name2,
                    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
                    ScaleVarProc, clientData);
        }
        return NULL;
    }

    /*
     * If the variable is unset, then immediately recreate it unless the whole
     * interpreter is going away.
     */

    if (flags & TCL_TRACE_UNSETS) {
        if ((flags & TCL_TRACE_DESTROYED) && !(flags & TCL_INTERP_DESTROYED)) {
            Tcl_TraceVar2(interp, Tcl_GetString(scalePtr->varNamePtr),
                    NULL, TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
                    ScaleVarProc, clientData);
            scalePtr->flags |= NEVER_SET;
            TkScaleSetValue(scalePtr, scalePtr->value, 1, 0);
        }
        return NULL;
    }

    /*
     * If we came here because we updated the variable (in TkScaleSetValue),
     * then ignore the trace. Otherwise update the scale with the value of the
     * variable.
     */

    if (scalePtr->flags & SETTING_VAR) {
        return NULL;
    }
    resultStr = NULL;
    valuePtr = Tcl_ObjGetVar2(interp, scalePtr->varNamePtr, NULL,
            TCL_GLOBAL_ONLY);
    result = Tcl_GetDoubleFromObj(interp, valuePtr, &value);
    if (result != TCL_OK) {
        resultStr = "can't assign non-numeric value to scale variable";
        ScaleSetVariable(scalePtr);
    } else {
        scalePtr->value = TkRoundToResolution(scalePtr, value);

        /*
         * This code is a bit tricky because it sets the scale's value before
         * calling TkScaleSetValue. This way, TkScaleSetValue won't bother to
         * set the variable again or to invoke the -command. However, it also
         * won't redisplay the scale, so we have to ask for that explicitly.
         */

        TkScaleSetValue(scalePtr, scalePtr->value, 1, 0);
    }
    TkEventuallyRedrawScale(scalePtr, REDRAW_SLIDER);

    return (char *) resultStr;
}

/*
 *--------------------------------------------------------------
 *
 * TkScaleSetValue --
 *
 *        This procedure changes the value of a scale and invokes a Tcl command
 *        to reflect the current position of a scale
 *
 * Results:
 *        None.
 *
 * Side effects:
 *        A Tcl command is invoked, and an additional error-processing command
 *        may also be invoked. The scale's slider is redrawn.
 *
 *--------------------------------------------------------------
 */

void
TkScaleSetValue(
    register TkScale *scalePtr,        /* Info about widget. */
    double value,                /* New value for scale. Gets adjusted if it's
                                 * off the scale. */
    int setVar,                        /* Non-zero means reflect new value through to
                                 * associated variable, if any. */
    int invokeCommand)                /* Non-zero means invoked -command option to
                                 * notify of new value, 0 means don't. */
{
    value = TkRoundToResolution(scalePtr, value);
    if ((value < scalePtr->fromValue)
            ^ (scalePtr->toValue < scalePtr->fromValue)) {
        value = scalePtr->fromValue;
    }
    if ((value > scalePtr->toValue)
            ^ (scalePtr->toValue < scalePtr->fromValue)) {
        value = scalePtr->toValue;
    }
    if (scalePtr->flags & NEVER_SET) {
        scalePtr->flags &= ~NEVER_SET;
    } else if (scalePtr->value == value) {
        return;
    }
    scalePtr->value = value;

    /*
     * Schedule command callback invocation only if there is such a command
     * already registered, otherwise the callback would trigger later when
     * configuring the widget -command option even if the value did not change.
     */

    if ((invokeCommand) && (scalePtr->command != NULL)) {
        scalePtr->flags |= INVOKE_COMMAND;
    }
    TkEventuallyRedrawScale(scalePtr, REDRAW_SLIDER);

    if (setVar && scalePtr->varNamePtr) {
        ScaleSetVariable(scalePtr);
    }
}

/*
 *--------------------------------------------------------------
 *
 * ScaleSetVariable --
 *
 *        This procedure sets the variable associated with a scale, if any.
 *
 * Results:
 *        None.
 *
 * Side effects:
 *        Other write traces on the variable will trigger.
 *
 *--------------------------------------------------------------
 */

static void
ScaleSetVariable(
    register TkScale *scalePtr)        /* Info about widget. */
{
    if (scalePtr->varNamePtr != NULL) {
        char string[TCL_DOUBLE_SPACE];

        if (snprintf(string, TCL_DOUBLE_SPACE, scalePtr->format,
                scalePtr->value) < 0) {
            string[TCL_DOUBLE_SPACE - 1] = '\0';
        }
        scalePtr->flags |= SETTING_VAR;
        Tcl_ObjSetVar2(scalePtr->interp, scalePtr->varNamePtr, NULL,
                Tcl_NewStringObj(string, -1), TCL_GLOBAL_ONLY);
        scalePtr->flags &= ~SETTING_VAR;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TkScalePixelToValue --
 *
 *        Given a pixel within a scale window, return the scale reading
 *        corresponding to that pixel.
 *
 * Results:
 *        A double-precision scale reading. If the value is outside the legal
 *        range for the scale then it's rounded to the nearest end of the scale.
 *
 * Side effects:
 *        None.
 *
 *----------------------------------------------------------------------
 */

double
TkScalePixelToValue(
    register TkScale *scalePtr,        /* Information about widget. */
    int x, int y)                /* Coordinates of point within window. */
{
    double value, pixelRange;

    if (scalePtr->orient == ORIENT_VERTICAL) {
        pixelRange = Tk_Height(scalePtr->tkwin) - scalePtr->sliderLength
                - 2*scalePtr->inset - 2*scalePtr->borderWidth;
        value = y;
    } else {
        pixelRange = Tk_Width(scalePtr->tkwin) - scalePtr->sliderLength
                - 2*scalePtr->inset - 2*scalePtr->borderWidth;
        value = x;
    }

    if (pixelRange <= 0) {
        /*
         * Not enough room for the slider to actually slide: just return the
         * scale's current value.
         */

        return scalePtr->value;
    }
    value -= scalePtr->sliderLength/2 + scalePtr->inset
            + scalePtr->borderWidth;
    value /= pixelRange;
    if (value < 0) {
        value = 0;
    }
    if (value > 1) {
        value = 1;
    }
    value = scalePtr->fromValue +
                value * (scalePtr->toValue - scalePtr->fromValue);
    return TkRoundToResolution(scalePtr, value);
}

/*
 *----------------------------------------------------------------------
 *
 * TkScaleValueToPixel --
 *
 *        Given a reading of the scale, return the x-coordinate or y-coordinate
 *        corresponding to that reading, depending on whether the scale is
 *        vertical or horizontal, respectively.
 *
 * Results:
 *        An integer value giving the pixel location corresponding to reading.
 *        The value is restricted to lie within the defined range for the scale.
 *
 * Side effects:
 *        None.
 *
 *----------------------------------------------------------------------
 */

int
TkScaleValueToPixel(
    register TkScale *scalePtr,        /* Information about widget. */
    double value)                /* Reading of the widget. */
{
    int y, pixelRange;
    double valueRange;

    valueRange = scalePtr->toValue - scalePtr->fromValue;
    pixelRange = ((scalePtr->orient == ORIENT_VERTICAL)
            ? Tk_Height(scalePtr->tkwin) : Tk_Width(scalePtr->tkwin))
        - scalePtr->sliderLength - 2*scalePtr->inset - 2*scalePtr->borderWidth;
    if (valueRange == 0) {
        y = 0;
    } else {
        y = (int) ((value - scalePtr->fromValue) * pixelRange
                / valueRange + 0.5);
        if (y < 0) {
            y = 0;
        } else if (y > pixelRange) {
            y = pixelRange;
        }
    }
    y += scalePtr->sliderLength/2 + scalePtr->inset + scalePtr->borderWidth;
    return y;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */

#include "tclOO.h"
static int ScaleConstructor(
        ClientData clientData,
        Tcl_Interp *interp,
        Tcl_ObjectContext objectContext,
        int objc,
        Tcl_Obj *const objv[]);
static int ScaleMethod(
        ClientData clientData,
        Tcl_Interp *interp,
        Tcl_ObjectContext objectContext,
        int objc,
        Tcl_Obj *const objv[]);
static void ScaleMetaDelete(

        ClientData clientData);


static Tcl_MethodType scaleMethods[] = {
        { TCL_OO_METHOD_VERSION_CURRENT , NULL , ScaleConstructor    , NULL , NULL },
        { TCL_OO_METHOD_VERSION_CURRENT , "cget"      , ScaleMethod , NULL , NULL },
        { TCL_OO_METHOD_VERSION_CURRENT , "configure" , ScaleMethod , NULL , NULL },
        { TCL_OO_METHOD_VERSION_CURRENT , "coords"     ,ScaleMethod , NULL , NULL },
        { TCL_OO_METHOD_VERSION_CURRENT , "get"       , ScaleMethod , NULL , NULL },
        { TCL_OO_METHOD_VERSION_CURRENT , "identify"  , ScaleMethod , NULL , NULL },
        { TCL_OO_METHOD_VERSION_CURRENT , "set"       , ScaleMethod , NULL , NULL },
        { -1    , NULL          , NULL     , NULL , NULL }
};
static Tcl_ObjectMetadataType Scale_Meta = {

        TCL_OO_METADATA_VERSION_CURRENT,

        "Scale_Meta",

        ScaleMetaDelete,

        NULL

};



/*

* ScaleMetaDelete --

*/

static void

ScaleMetaDelete(

        ClientData clientData

) {

        register TkScale *scalePtr = clientData;

        /* Destroy window will calling DestroyScale() also. */
        if (scalePtr && (!(scalePtr->flags & SCALE_DELETED))) {
                Tk_DestroyWindow(scalePtr->tkwin);

        }

}


/* oo::widget::scale create .path ... */
static int ScaleConstructor(
        ClientData clientData,
        Tcl_Interp *interp,
        Tcl_ObjectContext objectContext,
        int objc,
        Tcl_Obj *const objv[])
{
        Tcl_Object object;
        TkScale *scalePtr;

        /* Get current object. Should not fail? */
        if ((object = Tcl_ObjectContextObject(objectContext)) == NULL) {
                return TCL_ERROR;
        }
        /* Check calling args */
        if (objc < 3 || strcmp("create", Tcl_GetString(objv[1])) != 0) {
                Tcl_WrongNumArgs(interp, 1, objv, "create pathName ?-option value? ...");
                return TCL_ERROR;
        }
        scalePtr = ScaleCreate((ClientData)Tcl_GetObjectCommand(object), interp, objc - 1, objv + 1);
        if (scalePtr == NULL) {
                return TCL_ERROR;
        }
        Tcl_ObjectSetMetadata(object, &Scale_Meta, (ClientData)scalePtr);
        return TCL_OK;
}

static int ScaleMethod(
        ClientData clientData,
        Tcl_Interp *interp,
        Tcl_ObjectContext objectContext,
        int objc,
        Tcl_Obj *const objv[])
{
        return ScaleWidgetObjCmd(Tcl_ObjectGetMetadata(Tcl_ObjectContextObject(objectContext), &Scale_Meta), interp, objc, objv);

}

int TkOOScaleInit(Tcl_Interp *interp) {
        Tcl_Class clazz;
        Tcl_Object object;
        Tcl_Obj *objPtr;
        int i;
        /* Create class like tk command and remove oo functions from widget commands */
        static const char *initScript =
                "::oo::class create ::Scale {"
                "  self method unknown {args} {uplevel #0 ::Scale create {*}$args; return [lindex $args 0]}\n"
                "  self unexport new destroy\n"
                "  unexport new create\n"
                "}";

        /* Needed oo extension */
        if (Tcl_OOInitStubs(interp) == NULL) { return TCL_ERROR; }
        if (Tcl_PkgRequire(interp, "TclOO", "1.0", 0) == NULL) { return TCL_ERROR; }


        /* Create widget class. */
        if (Tcl_Eval(interp, initScript) != TCL_OK) {
                return TCL_ERROR;
        }
        /* Get class object */
        objPtr = Tcl_NewStringObj("::Scale", -1);
        Tcl_IncrRefCount(objPtr);
        if ((object = Tcl_GetObjectFromObj(interp, objPtr)) == NULL) {
                Tcl_DecrRefCount(objPtr);
                return TCL_ERROR;
        }
        Tcl_DecrRefCount(objPtr);
        if ((clazz = Tcl_GetObjectAsClass(object)) == NULL) {
                return TCL_ERROR;
        }
        /* Add methods */
        Tcl_ClassSetConstructor(interp, clazz, Tcl_NewMethod(interp, clazz, NULL, 1, &scaleMethods[0], NULL));
        for (i = 1; scaleMethods[i].name != NULL; i++) {
                Tcl_NewMethod(interp, clazz, Tcl_NewStringObj(scaleMethods[i].name, -1), 1, &scaleMethods[i], NULL);
        }

        return TCL_OK;
}