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/*

 * ------------------------------------------------------------------------

 *      PACKAGE:  [incr Tk]

 *  DESCRIPTION:  Building mega-widgets with [incr Tcl]

 *

 *  [incr Tk] provides a framework for building composite "mega-widgets"

 *  using [incr Tcl] classes.  It defines a set of base classes that are

 *  specialized to create all other widgets.

 *

 *  This part defines some utility procedures that are useful for

 *  [incr Tk].

 *

 * ========================================================================

 *  AUTHOR:  Michael J. McLennan

 *           Bell Labs Innovations for Lucent Technologies

 *           mmclennan@lucent.com

 *           http://www.tcltk.com/itcl

 *

 *     RCS:  $Id: itk_util.c,v 1.1.1.1 2002-01-16 10:24:47 markom Exp $

 * ========================================================================

 *           Copyright (c) 1993-1998  Lucent Technologies, Inc.

 * ------------------------------------------------------------------------

 * See the file "license.terms" for information on usage and redistribution

 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.

 */

#include "itk.h"

/*

 * ------------------------------------------------------------------------

 *  Itk_OptListInit()

 *

 *  Initializes an ordered option list, allocating a certain amount of

 *  memory for an initial option list.

 * ------------------------------------------------------------------------

 */

void

Itk_OptListInit(olist, options)

    ItkOptList *olist;       /* list to be initialized */

    Tcl_HashTable *options;  /* table containing the real option entries */

{

    olist->options = options;

    olist->len = 0;

    olist->max = 10;

    olist->list = (Tcl_HashEntry**)ckalloc(

        (unsigned)(olist->max*sizeof(Tcl_HashEntry*))

    );

}

/*

 * ------------------------------------------------------------------------

 *  Itk_OptListFree()

 *

 *  Frees an ordered option list created by Itk_OptListInit().

 *  This only frees the memory associated with the list, not the

 *  list itself.

 * ------------------------------------------------------------------------

 */

void

Itk_OptListFree(olist)

    ItkOptList *olist;     /* list to be freed */

{

    ckfree((char*)olist->list);

    olist->len = olist->max = 0;

}

/*

 * ------------------------------------------------------------------------

 *  Itk_OptListAdd()

 *

 *  Adds the hash table entry for an option like '-background' to an

 *  ordered list of options.  The list is kept in alphabetical order,

 *  so that it can be searched quickly and printed out in order.

 * ------------------------------------------------------------------------

 */

void

Itk_OptListAdd(olist, entry)

    ItkOptList *olist;     /* ordered list */

    Tcl_HashEntry *entry;  /* entry to be added to the list */

{

    int i, first, last, cmp, pos, size;

    Tcl_HashEntry** newOrder;

    char *swname, *optname;

    /*

     *  Make sure that the option list is big enough.  Resize

     *  if needed.

     */

    if (olist->len >= olist->max) {

        size = olist->max*sizeof(Tcl_HashEntry*);

        newOrder = (Tcl_HashEntry**)ckalloc((unsigned)2*size);

        memcpy((VOID*)newOrder, (VOID*)olist->list, (size_t)size);

        ckfree((char*)olist->list);

        olist->list = newOrder;

        olist->max *= 2;

    }

    /*

     *  Perform a binary search to find the option switch quickly.

     */

    first = 0;

    last  = olist->len-1;

    swname = Tcl_GetHashKey(olist->options, entry) + 1;

    while (last >= first) {

        pos = (first+last)/2;

        optname = Tcl_GetHashKey(olist->options, olist->list[pos]) + 1;

        if (*swname == *optname) {

            cmp = strcmp(swname, optname);

            if (cmp == 0) {

                break;    /* found it! */

            }

        }

        else if (*swname < *optname) {

            cmp = -1;

        }

        else {

            cmp = 1;

        }

        if (cmp > 0)

            first = pos+1;

        else

            last = pos-1;

    }

    /*

     *  If a matching entry was not found, then insert one.

     */

    if (last < first) {

        pos = first;

        for (i=olist->len; i > pos; i--) {

            olist->list[i] = olist->list[i-1];

        }

        olist->list[pos] = entry;

        olist->len++;

    }

}

/*

 * ------------------------------------------------------------------------

 *  Itk_OptListRemove()

 *

 *  Removes a hash table entry from an ordered list of options.

 *  This negates the action of Itk_OptionListAdd(), and is usually

 *  called when an option is completely removed from a mega-widget.

 *  This should be called before the entry is removed from the

 *  real option table.

 * ------------------------------------------------------------------------

 */

void

Itk_OptListRemove(olist, entry)

    ItkOptList *olist;     /* ordered list */

    Tcl_HashEntry *entry;  /* entry to be removed from the list */

{

    int pos = 0;

    int i, first, last, cmp;

    char *swname, *optname;

    first = 0;

    last  = olist->len-1;

    swname = Tcl_GetHashKey(olist->options, entry) + 1;

    while (last >= first) {

        pos = (first+last)/2;

        optname = Tcl_GetHashKey(olist->options, olist->list[pos]) + 1;

        if (*swname == *optname) {

            cmp = strcmp(swname, optname);

            if (cmp == 0) {

                break;    /* found it! */

            }

        }

        else if (*swname < *optname) {

            cmp = -1;

        }

        else {

            cmp = 1;

        }

        if (cmp > 0)

            first = pos+1;

        else

            last = pos-1;

    }

    /*

     *  If a matching entry was found, then remove it.

     */

    if (last >= first) {

        olist->len--;

        for (i=pos; i < olist->len; i++) {

            olist->list[i] = olist->list[i+1];

        }

    }

}