Itk - the [incr Tk] extension

         *  Add a binding onto the new component, so that when its
         *  window is destroyed, it will automatically remove itself
         *  from its parent's component list.  Avoid doing these things
         *  for the "hull" component, since it is a special case and
         *  these things are not really necessary.
         */
        Tcl_DStringSetLength(&buffer, 0);
        Tcl_DStringAppend(&buffer, "::bindtags ", -1);
        Tcl_DStringAppend(&buffer, path, -1);
        if (Tcl_Eval(interp, Tcl_DStringValue(&buffer)) != TCL_OK) {
            goto compFail;
        }

	/*
	 * NOTE: We need the [::itcl::code] because the itk_component
	 * method is protected.
	 */

        Tcl_DStringSetLength(&buffer, 0);
        Tcl_DStringAppend(&buffer, "::bind itk-destroy-", -1);
        Tcl_DStringAppend(&buffer, path, -1);
        Tcl_DStringAppend(&buffer, " <Destroy> [::itcl::code ", -1);

        Tcl_DStringAppend(&buffer,
            Tcl_GetStringFromObj(objNamePtr,(int*)NULL), -1);

        Tcl_DStringAppend(&buffer, " itk_component delete ", -1);
        Tcl_DStringAppend(&buffer, name, -1);
        Tcl_DStringAppend(&buffer, "]\n", -1);
        Tcl_DStringAppend(&buffer, "::bindtags ", -1);
        Tcl_DStringAppend(&buffer, path, -1);
        Tcl_DStringAppend(&buffer, " {itk-destroy-", -1);
        Tcl_DStringAppend(&buffer, path, -1);
        Tcl_DStringAppend(&buffer, " ", -1);
        Tcl_DStringAppend(&buffer, Tcl_GetStringResult(interp), -1);
        Tcl_DStringAppend(&buffer, "}", -1);

        if (Tcl_Eval(interp, Tcl_DStringValue(&buffer)) != TCL_OK) {
            goto compFail;
        }
    }

    /*
     *  Query the list of configuration options for this widget,

    if (objc != 4) {
        objPtr = Tcl_NewStringObj("usual", -1);
        Tcl_IncrRefCount(objPtr);
    } else {
        objPtr = objv[3];
    }


    Tcl_Eval(interp, "::namespace path [::lreplace [::namespace path] end+1 end ::itk::option-parser]");

    result = Tcl_EvalObj(interp, objPtr);
    Tcl_Eval(interp, "::namespace path [::lrange [::namespace path] 0 end-1]");


    if (objc != 4) {
        Tcl_DecrRefCount(objPtr);
    }
    if (result != TCL_OK) {
        goto compFail;
    }

       /*
        *  Clean up the binding tag that causes the widget to
        *  call this method automatically when destroyed.
        *  Ignore errors if anything goes wrong.
        */
        Tcl_DStringInit(&buffer);
        Tcl_DStringAppend(&buffer, "::itk::remove_destroy_hook ", -1);
        Tcl_DStringAppend(&buffer, archComp->pathName, -1);
        (void) Tcl_Eval(interp, Tcl_DStringValue(&buffer));
        Tcl_ResetResult(interp);
        Tcl_DStringFree(&buffer);

        Tcl_UnsetVar2(interp, "itk_component", token, 0);
        Tcl_DeleteHashEntry(entry);

     */

    if (result == TCL_OK) {
	/*
	 * Casting away CONST of newval only to satisfy Tcl 8.3 and
	 * earlier headers.
	 */

#if 1
	val = ItclSetInstanceVar(interp, Tcl_GetString(ivPtr->fullNamePtr),
		NULL, newval, contextObj, ivPtr->iclsPtr);
#else
        val = Tcl_SetVar2(interp, Tcl_GetString(ivPtr->fullNamePtr), (char *) NULL,
            (char *) newval, TCL_LEAVE_ERR_MSG);
#endif

        if (!val) {
            result = TCL_ERROR;
        }
    }

    if (result != TCL_OK) {

     *  If this variable has some "config" code, invoke it now.
     *
     *  NOTE:  Invoke the "config" code in the class scope
     *    containing the data member.
     */
    mcode = ivPtr->codePtr;
    if (mcode && mcode->bodyPtr) {
	Tcl_CallFrame frame;

	Itcl_PushCallFrame(interp, &frame, ivPtr->iclsPtr->nsPtr, 1);
	Itcl_SetContext(interp, contextObj);

        result = Tcl_EvalObjEx(interp, mcode->bodyPtr, 0);

	Itcl_UnsetContext(interp);
	Itcl_PopCallFrame(interp);

        if (result == TCL_OK) {
            Tcl_ResetResult(interp);
        } else {
            char msg[256];
            sprintf(msg, "\n    (error in configuration of public variable \"%.100s\")", Tcl_GetString(ivPtr->fullNamePtr));
            Tcl_AddErrorInfo(interp, msg);

    CONST char *v; 
    char *lastval;
    Tcl_HashEntry *entry;
    ArchOption *archOpt;
    Itcl_ListElem *part;
    ArchOptionPart *optPart;
    Itcl_InterpState istate;
    ItclClass *iclsPtr;
    ItclObject *ioPtr;

    /*
     *  Query the "itk_option" array to get the current setting.
     */
    entry = Tcl_FindHashEntry(&info->options, name);
    if (!entry) {
        /* Bug 227876
	 * Ensure that the interp result is unshared.
	 */

        Tcl_ResetResult (interp);
        Tcl_AppendStringsToObj(Tcl_GetObjResult(interp),
            "unknown option \"", name, "\"",
            (char*)NULL);
        return TCL_ERROR;
    }
    archOpt = (ArchOption*)Tcl_GetHashValue(entry);

#if 0
    v = Tcl_GetVar2(interp, "itk_option", archOpt->switchName, 0);
#else
    Itcl_GetContext(interp, &iclsPtr, &ioPtr);

    v = ItclGetInstanceVar(interp, "itk_option", archOpt->switchName,
	    ioPtr, iclsPtr);
#endif

    if (v) {
        lastval = (char*)ckalloc((unsigned)(strlen(v)+1));
        strcpy(lastval, v);
    } else {
        lastval = NULL;
    }

    /*
     *  Update the "itk_option" array with the new setting.
     */
#if 0
    if (!Tcl_SetVar2(interp, "itk_option", archOpt->switchName, value, 0)) {
#else
    if (!ItclSetInstanceVar(interp, "itk_option", archOpt->switchName, value,
	    ioPtr, iclsPtr)) {
#endif
        Itk_ArchOptAccessError(interp, info, archOpt);
        result = TCL_ERROR;
        goto configDone;
    }

    /*
     *  Scan through all option parts to handle the new setting.

     *  If the option configuration failed, then set the option
     *  back to its previous settings.  Scan back through all of
     *  the option parts and sync them up with the old value.
     */
    if (result == TCL_ERROR) {
        istate = Itcl_SaveInterpState(interp, result);

#if 0
        Tcl_SetVar2(interp, "itk_option", archOpt->switchName, lastval, 0);
#else
	ItclSetInstanceVar(interp, "itk_option", archOpt->switchName, lastval,
	    ioPtr, iclsPtr);
#endif

        part = Itcl_FirstListElem(&archOpt->parts);
        while (part) {
            optPart = (ArchOptionPart*)Itcl_GetListValue(part);
            (*optPart->configProc)(interp, info->itclObj,
                optPart->clientData, lastval);

    if (!parserNs) {
        Itk_DelMergeInfo((char*)mergeInfo);
        Tcl_AddErrorInfo(interp, "\n    (while initializing itk)");
        return TCL_ERROR;
    }
    Itcl_PreserveData((ClientData)mergeInfo);
    Itcl_EventuallyFree((ClientData)mergeInfo, Itk_DelMergeInfo);


    Tcl_CreateObjCommand(interp, "::itk::option-parser::keep",
        Itk_ArchOptKeepCmd,
        (ClientData)mergeInfo, (Tcl_CmdDeleteProc*)NULL);

    Tcl_CreateObjCommand(interp, "::itk::option-parser::ignore",
        Itk_ArchOptIgnoreCmd,

	}
    }
    ItclShowArgs(1, "Itk_ArchConfigureCmd2", objc, objv);
    if (objc == 1) {
        Tcl_DStringInit(&buffer);

        for (i=0; i < info->order.len; i++) {

            archOpt = (ArchOption*)Tcl_GetHashValue(info->order.list[i]);


	    val = ItclGetInstanceVar(interp, "itk_option", archOpt->switchName,

		    contextObj, contextClass);
            if (!val) {
                Itk_ArchOptAccessError(interp, info, archOpt);
                Tcl_DStringFree(&buffer);
                return TCL_ERROR;
            }

            Tcl_DStringStartSublist(&buffer);

        /*
         *  If there is just one argument, then query the information
         *  for that one argument and return:
         *    {name resName resClass init value}
         */
        if (objc == 2) {

            token = Tcl_GetString(objv[1]);
            entry = Tcl_FindHashEntry(&info->options, token);
            if (!entry) {
                Tcl_AppendStringsToObj(Tcl_GetObjResult(interp),
                    "unknown option \"", token, "\"",
                    (char*)NULL);
                return TCL_ERROR;
            }

            archOpt = (ArchOption*)Tcl_GetHashValue(entry);

	    val = ItclGetInstanceVar(interp, "itk_option", archOpt->switchName,
		    contextObj, contextClass);
            if (!val) {
                Itk_ArchOptAccessError(interp, info, archOpt);
                return TCL_ERROR;
            }

            Tcl_AppendElement(interp, archOpt->switchName);
            Tcl_AppendElement(interp,

    /*
     *  Otherwise, it must be a series of "-option value" assignments.
     *  Look up each option and assign the new value.
     */
    for (objc--,objv++; objc > 0; objc-=2, objv+=2) {
	char *value;
	int code;
//	Tcl_Namespace *save = Tcl_GetCurrentNamespace(interp);
        token = Tcl_GetString(objv[0]);
        if (objc < 2) {
            Tcl_AppendStringsToObj(Tcl_GetObjResult(interp),
                "value for \"", token, "\" missing",
                (char*)NULL);
            return TCL_ERROR;
        }
        value = Tcl_GetString(objv[1]);

//	Itcl_SetCallFrameNamespace(interp, contextObj->iclsPtr->nsPtr);
        code = Itk_ArchConfigOption(interp, info, token, value);
//	Itcl_SetCallFrameNamespace(interp, save);
        if (code != TCL_OK) {
            return TCL_ERROR;
        }
    }

    Tcl_ResetResult(interp);
    return TCL_OK;

    ItclObject *contextObj,    /* object being configured */
    ClientData cdata,          /* class option */
    CONST char *newval)        /* new value for this option */
{
    ItkClassOption *opt = (ItkClassOption*)cdata;
    int result = TCL_OK;
    ItclMemberCode *mcode;
    Tcl_CallFrame frame;

    /*
     *  If the option has any config code, execute it now.
     *  Make sure that the namespace context is set up correctly.
     */
    mcode = opt->codePtr;
    if (mcode && mcode->bodyPtr) {


	Itcl_PushCallFrame(interp, &frame, opt->iclsPtr->nsPtr, 1);
	Itcl_SetContext(interp, contextObj);


        result = Tcl_EvalObjEx(interp, mcode->bodyPtr, 0);

	Itcl_UnsetContext(interp);
	Itcl_PopCallFrame(interp);

	/* 
	 * Here we engage in some ugly hackery workaround until
	 * someone has time to come back and implement this
	 * properly.
	 *
	 * In Itcl/Itk 3, the same machinery was used to implement