poshist.c

   1 /* $MirOS: contrib/code/jupp/poshist.c,v 1.2 2008/05/13 13:08:24 tg Exp $ */
   2 /*
   3  *      Position history
   4  *      Copyright
   5  *              (C) 1992 Joseph H. Allen
   6  *
   7  *      This file is part of JOE (Joe's Own Editor)
   8  */
   9 #include "config.h"
  10 #include "types.h"
  11
  12 #ifdef HAVE_STDLIB_H
  13 #include <stdlib.h>
  14 #endif
  15
  16 #include "b.h"
  17 #include "queue.h"
  18 #include "w.h"
  19
  20 typedef struct pos POS;
  21
  22 struct pos {
  23         LINK(POS) link;
  24         P *p;
  25         W *w;
  26 };
  27
  28 POS pos = { {&pos, &pos} };
  29 POS frpos = { {&frpos, &frpos} };
  30 POS *curpos = &pos;
  31 int npos = 0;
  32
  33 static void markpos(W *w, P *p)
  34 {
  35         POS *new = alitem(&frpos, sizeof(POS));
  36
  37         new->p = NULL;
  38         pdupown(p, &new->p);
  39         poffline(new->p);
  40         new->w = w;
  41         enqueb(POS, link, &pos, new);
  42         if (npos == 20) {
  43                 new = pos.link.next;
  44                 prm(new->p);
  45                 demote(POS, link, &frpos, new);
  46         } else {
  47                 ++npos;
  48         }
  49 }
  50
  51 void afterpos(void)
  52 {
  53         if (curpos != &pos) {
  54                 demote(POS, link, &pos, curpos);
  55                 curpos = &pos;
  56         }
  57 }
  58
  59 void aftermove(W *w, P *p)
  60 {
  61         if (pos.link.prev != &pos && pos.link.prev->w == w && pos.link.prev->p && labs(pos.link.prev->p->line - p->line) < 3) {
  62                 poffline(pset(pos.link.prev->p, p));
  63         } else {
  64                 markpos(w, p);
  65         }
  66 }
  67
  68 void windie(W *w)
  69 {
  70         POS *n;
  71
  72         for (n = pos.link.prev; n != &pos; n = n->link.prev) {
  73                 if (n->w == w) {
  74                         n->w = NULL;
  75                 }
  76         }
  77 }
  78
  79 int unextpos(BW *bw)
  80 {
  81         W *w = bw->parent;
  82
  83       lp:
  84         if (curpos->link.next != &pos && curpos != &pos) {
  85                 curpos = curpos->link.next;
  86                 if (!curpos->p || !curpos->w) {
  87                         goto lp;
  88                 }
  89                 if (w->t->curwin == curpos->w && curpos->p->byte == ((BW *) w->t->curwin->object)->cursor->byte) {
  90                         goto lp;
  91                 }
  92                 if (w->t->curwin != curpos->w) {
  93                         w->t->curwin = curpos->w;
  94                         if (w->t->curwin->y == -1) {
  95                                 wfit(w->t);
  96                         }
  97                 }
  98                 w = w->t->curwin;
  99                 bw = (BW *) w->object;
 100                 if (bw->cursor->byte != curpos->p->byte) {
 101                         pset(bw->cursor, curpos->p);
 102                 }
 103                 return 0;
 104         } else {
 105                 return -1;
 106         }
 107 }
 108
 109 int uprevpos(BW *bw)
 110 {
 111         W *w = bw->parent;
 112
 113       lp:
 114         if (curpos->link.prev != &pos) {
 115                 curpos = curpos->link.prev;
 116                 if (!curpos->p || !curpos->w) {
 117                         goto lp;
 118                 }
 119                 if (w->t->curwin == curpos->w && curpos->p->byte == ((BW *) w->t->curwin->object)->cursor->byte) {
 120                         goto lp;
 121                 }
 122                 if (w->t->curwin != curpos->w) {
 123                         w->t->curwin = curpos->w;
 124                         if (w->t->curwin->y == -1) {
 125                                 wfit(w->t);
 126                         }
 127                 }
 128                 w = w->t->curwin;
 129                 bw = (BW *) w->object;
 130                 if (bw->cursor->byte != curpos->p->byte) {
 131                         pset(bw->cursor, curpos->p);
 132                 }
 133                 return 0;
 134         } else {
 135                 return -1;
 136         }
 137 }