C/C++ Users Group Library 1996 July/C-C++ Users Group Library July 1996.iso/vol_400/424_01/ed_157/change_case.c

C/C++ Source or Header | 1993-09-10 | 4.4 KB | 155 lines

/*
 * Copyright (C) 1992 by Rush Record ([e-mail])
 *
 * This file is part of ED.
 *
 * ED is free software; you can redistribute it and/or modify it under the terms
 * of the GNU General Public License as published by the Free Software Foundation.
 *
 * ED is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE.  See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with ED
 * (see the file COPYING).  If not, write to the Free Software Foundation, 675
 * Mass Ave, Cambridge, MA 02139, USA.
 */
#include "opsys.h"

#include <stdio.h>
#include <stdlib.h>

#include "rec.h"
#include "window.h"
#include "ed_dec.h"
#include "handy.h"
#include "buffer.h"

/******************************************************************************\
|Routine: change_case
|Callby: edit
|Purpose: Changes the case of all bytes (inclusive) between the current
|         position and another position at a given offset from the current
|         position. Optionally moves to the other end of the region.
|Arguments:
|    offset is the offset from the current position to the other end of the
|            region that is to be affected.
|    otherend is a flag that indicates that the cursor should be left at the
|            other end of the changed region.
|    table is the case-changing table, or NULL if they want capitalization.
\******************************************************************************/
Int change_case(offset,otherend,table)
register Int offset,otherend;
Uchar *table;
{
    register rec_ptr otherrec,rec;
    register Int otherbyt,otherrow,i,nrecs;

    if(offset < 0)    /* we are working backwards from current position */
    {
        if(CURREC == BASE->next && !CURBYT)    /* ignore backward at top of file */
            return(0);
/* find the other end of the buffer, backwards */
        otherrec = CURREC;
        otherbyt = CURBYT;
        otherrow = CURROW;
        nrecs = 1;
        while(offset++ < 0)
        {
            if(!otherbyt)
            {
                if(otherrec->prev == BASE)
                    return(0);
                otherrec = otherrec->prev;
                otherbyt = otherrec->length;
                otherrow--;
                nrecs++;
            }
            else
                otherbyt--;
        }
/* alter the record data structures and redisplay */
        if(nrecs == 1)
        {
            rec_chgcas(CURREC,otherbyt,CURBYT,table);    /* was entirely in current record */
            paint(CURROW,CURROW,FIRSTCOL);    /* repaint current record */
        }
        else
        {
/* deal with the database */
            rec = otherrec;
            if(otherbyt != otherrec->length)
                rec_chgcas(rec,otherbyt,otherrec->length,table);      /* trim the tail off the first record if necessary */
            rec = rec->next;
            for(i = 1;i < nrecs - 1;i++)    /* remove intervening records, if any */
            {
                rec_chgcas(rec,0,rec->length,table);
                rec = rec->next;
            }
            if(CURBYT != 0)
                rec_chgcas(rec,0,CURBYT,table);    /* trim the front off the last record if necessary */
/* fix the display */
            paint(max(TOPROW,otherrow),CURROW,FIRSTCOL);
        }
    }
/* we are deleting forwards from the current position */
    else
    {
        if(CURREC == BASE)    /* ignore forward at end of file */
            return(0);
/* find the other end of the buffer, forwards */
        otherrec = CURREC;
        otherbyt = CURBYT;
        otherrow = CURROW;
        nrecs = 1;
        while(offset-- > 0)
        {
            if(otherrec == BASE)
                return(0);
            if(otherbyt == otherrec->length)
            {
                otherrec = otherrec->next;
                otherbyt = 0;
                otherrow++;
                nrecs++;
            }
            else
                otherbyt++;
        }
/* alter the record data structures and redisplay */
        if(nrecs == 1)
        {
            rec_chgcas(CURREC,CURBYT,otherbyt,table);    /* kill was entirely in current record */
            paint(CURROW,CURROW,FIRSTCOL);    /* repaint current record */
        }
        else
        {
/* deal with the database */
            rec = CURREC;
            if(CURBYT != rec->length)
                rec_chgcas(CURREC,CURBYT,CURREC->length,table);       /* trim the tail off the first record if necessary */
            rec = rec->next;
            for(i = 1;i < nrecs - 1;i++)    /* remove intervening records, if any */
            {
                rec_chgcas(rec,0,rec->length,table);
                rec = rec->next;
            }
            if(otherbyt != 0)
                rec_chgcas(rec,0,otherbyt,table);    /* do the front on the last record if necessary */
/* fix the display */
            paint(CURROW,min(BOTROW,otherrow),FIRSTCOL);
        }
/* establish new location and column context */
    }
    if(otherend)
    {
        CURROW = otherrow;
        CURREC = otherrec;
        CURBYT = otherbyt;
        fix_scroll();
        WANTCOL = CURCOL;
    }
    return(1);
}