src/common/history.c

   1 /* X-Chat
   2  * Copyright (C) 1998 Peter Zelezny.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  17  */
  18
  19 #include <string.h>
  20 #include <stdlib.h>
  21 #include "history.h"
  22
  23 void
  24 history_add (struct history *his, char *text)
  25 {
  26         if (his->lines[his->realpos])
  27                 free (his->lines[his->realpos]);
  28         his->lines[his->realpos] = strdup (text);
  29         his->realpos++;
  30         if (his->realpos == HISTORY_SIZE)
  31                 his->realpos = 0;
  32         his->pos = his->realpos;
  33 }
  34
  35 void
  36 history_free (struct history *his)
  37 {
  38         int i;
  39         for (i = 0; i < HISTORY_SIZE; i++)
  40         {
  41                 if (his->lines[i])
  42                 {
  43                         free (his->lines[i]);
  44                         his->lines[i] = 0;
  45                 }
  46         }
  47 }
  48
  49 char *
  50 history_down (struct history *his)
  51 {
  52         int next;
  53
  54         if (his->pos == his->realpos)   /* allow down only after up */
  55                 return 0;
  56         if (his->realpos == 0)
  57         {
  58                 if (his->pos == HISTORY_SIZE - 1)
  59                 {
  60                         his->pos = 0;
  61                         return "";
  62                 }
  63         } else
  64         {
  65                 if (his->pos == his->realpos - 1)
  66                 {
  67                         his->pos++;
  68                         return "";
  69                 }
  70         }
  71
  72         next = 0;
  73         if (his->pos < HISTORY_SIZE - 1)
  74                 next = his->pos + 1;
  75
  76         if (his->lines[next])
  77         {
  78                 his->pos = next;
  79                 return his->lines[his->pos];
  80         }
  81
  82         return 0;
  83 }
  84
  85 char *
  86 history_up (struct history *his, char *current_text)
  87 {
  88         int next;
  89
  90         if (his->realpos == HISTORY_SIZE - 1)
  91         {
  92                 if (his->pos == 0)
  93                         return 0;
  94         } else
  95         {
  96                 if (his->pos == his->realpos + 1)
  97                         return 0;
  98         }
  99
 100         next = HISTORY_SIZE - 1;
 101         if (his->pos != 0)
 102                 next = his->pos - 1;
 103
 104         if (his->lines[next])
 105         {
 106                 if
 107                 (
 108                         current_text[0] && strcmp(current_text, his->lines[next]) &&
 109                         (!his->lines[his->pos] || strcmp(current_text, his->lines[his->pos])) &&
 110                         (!his->lines[his->realpos] || strcmp(current_text, his->lines[his->pos]))
 111                 )
 112                 {
 113                         history_add (his, current_text);
 114                 }
 115
 116                 his->pos = next;
 117                 return his->lines[his->pos];
 118         }
 119
 120         return 0;
 121 }