commands/elvis/move4.c

   1 /* move4.c */
   2
   3 /* Author:
   4  *      Steve Kirkendall
   5  *      14407 SW Teal Blvd. #C
   6  *      Beaverton, OR 97005
   7  *      kirkenda@cs.pdx.edu
   8  */
   9
  10
  11 /* This file contains movement functions which are screen-relative */
  12
  13 #include "config.h"
  14 #include "vi.h"
  15
  16 /* This moves the cursor to a particular row on the screen */
  17 /*ARGSUSED*/
  18 MARK m_row(m, cnt, key)
  19         MARK    m;      /* the cursor position */
  20         long    cnt;    /* the row we'll move to */
  21         int     key;    /* the keystroke of this move - H/L/M */
  22 {
  23         DEFAULT(1);
  24
  25         /* calculate destination line based on key */
  26         cnt--;
  27         switch (key)
  28         {
  29           case 'H':
  30                 cnt = topline + cnt;
  31                 break;
  32
  33           case 'M':
  34                 cnt = topline + (LINES - 1) / 2;
  35                 break;
  36
  37           case 'L':
  38                 cnt = botline - cnt;
  39                 break;
  40         }
  41
  42         /* return the mark of the destination line */
  43         return MARK_AT_LINE(cnt);
  44 }
  45
  46
  47 /* This function repositions the current line to show on a given row */
  48 MARK m_z(m, cnt, key)
  49         MARK    m;      /* the cursor */
  50         long    cnt;    /* the line number we're repositioning */
  51         int     key;    /* key struck after the z */
  52 {
  53         long    newtop;
  54         int     i;
  55
  56         /* Which line are we talking about? */
  57         if (cnt < 0 || cnt > nlines)
  58         {
  59                 return MARK_UNSET;
  60         }
  61         if (cnt)
  62         {
  63                 m = MARK_AT_LINE(cnt);
  64                 newtop = cnt;
  65         }
  66         else
  67         {
  68                 newtop = markline(m);
  69         }
  70
  71         /* allow a "window size" number to be entered */
  72         for (i = 0; key >= '0' && key <= '9'; key = getkey(0))
  73         {
  74                 i = i * 10 + key - '0';
  75         }
  76 #ifndef CRUNCH
  77         if (i > 0 && i <= LINES - 1)
  78         {
  79                 *o_window = i;
  80                 wset = TRUE;
  81         }
  82 #else
  83         /* the number is ignored if -DCRUNCH */
  84 #endif
  85
  86         /* figure out which line will have to be at the top of the screen */
  87         switch (key)
  88         {
  89           case '\n':
  90 #if OSK
  91           case '\l':
  92 #else
  93           case '\r':
  94 #endif
  95           case '+':
  96                 break;
  97
  98           case '.':
  99           case 'z':
 100                 newtop -= LINES / 2;
 101                 break;
 102
 103           case '-':
 104                 newtop -= LINES - 1;
 105                 break;
 106
 107           default:
 108                 return MARK_UNSET;
 109         }
 110
 111         /* make the new topline take effect */
 112         redraw(MARK_UNSET, FALSE);
 113         if (newtop >= 1)
 114         {
 115                 topline = newtop;
 116         }
 117         else
 118         {
 119                 topline = 1L;
 120         }
 121         redrawrange(0L, INFINITY, INFINITY);
 122
 123         /* The cursor doesn't move */
 124         return m;
 125 }
 126
 127
 128 /* This function scrolls the screen.  It does this by calling redraw() with
 129  * an off-screen line as the argument.  It will move the cursor if necessary
 130  * so that the cursor is on the new screen.
 131  */
 132 /*ARGSUSED*/
 133 MARK m_scroll(m, cnt, key)
 134         MARK    m;      /* the cursor position */
 135         long    cnt;    /* for some keys: the number of lines to scroll */
 136         int     key;    /* keystroke that causes this movement */
 137 {
 138         MARK    tmp;    /* a temporary mark, used as arg to redraw() */
 139
 140         /* adjust cnt, and maybe *o_scroll, depending of key */
 141         switch (key)
 142         {
 143           case ctrl('F'):
 144           case ctrl('B'):
 145                 DEFAULT(1);
 146                 redrawrange(0L, INFINITY, INFINITY); /* force complete redraw */
 147                 cnt = cnt * (LINES - 1) - 2; /* keeps two old lines on screen */
 148                 break;
 149
 150           case ctrl('E'):
 151           case ctrl('Y'):
 152                 DEFAULT(1);
 153                 break;
 154
 155           case ctrl('U'):
 156           case ctrl('D'):
 157                 if (cnt == 0) /* default */
 158                 {
 159                         cnt = *o_scroll;
 160                 }
 161                 else
 162                 {
 163                         if (cnt > LINES - 1)
 164                         {
 165                                 cnt = LINES - 1;
 166                         }
 167                         *o_scroll = cnt;
 168                 }
 169                 break;
 170         }
 171
 172         /* scroll up or down, depending on key */
 173         switch (key)
 174         {
 175           case ctrl('B'):
 176           case ctrl('Y'):
 177           case ctrl('U'):
 178                 cnt = topline - cnt;
 179                 if (cnt < 1L)
 180                 {
 181                         cnt = 1L;
 182                         m = MARK_FIRST;
 183                 }
 184                 tmp = MARK_AT_LINE(cnt) + markidx(m);
 185                 redraw(tmp, FALSE);
 186                 if (markline(m) > botline)
 187                 {
 188                         m = MARK_AT_LINE(botline);
 189                 }
 190                 break;
 191
 192           case ctrl('F'):
 193           case ctrl('E'):
 194           case ctrl('D'):
 195                 cnt = botline + cnt;
 196                 if (cnt > nlines)
 197                 {
 198                         cnt = nlines;
 199                         m = MARK_LAST;
 200                 }
 201                 tmp = MARK_AT_LINE(cnt) + markidx(m);
 202                 redraw(tmp, FALSE);
 203                 if (markline(m) < topline)
 204                 {
 205                         m = MARK_AT_LINE(topline);
 206                 }
 207                 break;
 208         }
 209
 210         return m;
 211 }