4.3BSD - /usr/src/ucb/window/wwscroll.c

   1: #ifndef lint
   2: static char sccsid[] = "@(#)wwscroll.c	3.13 4/24/85";
   3: #endif
   4: 
   5: /*
   6:  * Copyright (c) 1983 Regents of the University of California,
   7:  * All rights reserved.  Redistribution permitted subject to
   8:  * the terms of the Berkeley Software License Agreement.
   9:  */
  10: 
  11: #include "ww.h"
  12: #include "tt.h"
  13: 
  14: wwscroll(w, n)
  15: register struct ww *w;
  16: int n;
  17: {
  18:     register dir;
  19:     register top;
  20: 
  21:     if (n == 0)
  22:         return;
  23:     dir = n < 0 ? -1 : 1;
  24:     top = w->ww_b.t - n;
  25:     if (top > w->ww_w.t)
  26:         top = w->ww_w.t;
  27:     else if (top + w->ww_b.nr < w->ww_w.b)
  28:         top = w->ww_w.b - w->ww_b.nr;
  29:     n = abs(top - w->ww_b.t);
  30:     if (n < w->ww_i.nr) {
  31:         while (--n >= 0) {
  32:             (void) wwscroll1(w, w->ww_i.t, w->ww_i.b, dir, 0);
  33:             w->ww_buf += dir;
  34:             w->ww_b.t -= dir;
  35:             w->ww_b.b -= dir;
  36:         }
  37:     } else {
  38:         w->ww_buf -= top - w->ww_b.t;
  39:         w->ww_b.t = top;
  40:         w->ww_b.b = top + w->ww_b.nr;
  41:         wwredrawwin(w);
  42:     }
  43: }
  44: 
  45: /*
  46:  * Scroll one line, between 'row1' and 'row2', in direction 'dir'.
  47:  * Don't adjust ww_scroll.
  48:  * And don't redraw 'leaveit' lines.
  49:  */
  50: wwscroll1(w, row1, row2, dir, leaveit)
  51: register struct ww *w;
  52: int row1, row2, dir;
  53: int leaveit;
  54: {
  55:     register i;
  56:     int row1x, row2x;
  57:     int nvis;
  58:     int nvismax;
  59:     int deleted = 0;
  60: 
  61:     /*
  62: 	 * See how many lines on the screen are affected.
  63: 	 * And calculate row1x, row2x, and left at the same time.
  64: 	 */
  65:     for (i = row1; i < row2 && w->ww_nvis[i] == 0; i++)
  66:         ;
  67:     if (i >= row2)          /* can't do any fancy stuff */
  68:         goto out;
  69:     row1x = i;
  70:     for (i = row2 - 1; i >= row1 && w->ww_nvis[i] == 0; i--)
  71:         ;
  72:     if (i <= row1x)
  73:         goto out;       /* just one line is easy */
  74:     row2x = i + 1;
  75: 
  76:     /*
  77: 	 * See how much of this window is visible.
  78: 	 */
  79:     nvismax = wwncol * (row2x - row1x);
  80:     nvis = 0;
  81:     for (i = row1x; i < row2x; i++)
  82:         nvis += w->ww_nvis[i];
  83: 
  84:     /*
  85: 	 * If it's a good idea to use delete and insert line
  86: 	 * and the terminal can, then do it.
  87: 	 */
  88:     if (nvis > nvismax / 2 && tt.tt_delline && tt.tt_insline) {
  89:         register union ww_char *tmp;
  90:         register union ww_char **cpp, **cqq;
  91: 
  92:         /*
  93: 		 * Don't worry about retain when scrolling down.
  94: 		 * But do worry when scrolling up.  For hp2621.
  95: 		 */
  96:         if (dir > 0) {
  97:             (*tt.tt_move)(row1x, 0);
  98:             (*tt.tt_delline)();
  99:             if (row2x < wwnrow) {
 100:                 (*tt.tt_move)(row2x - 1, 0);
 101:                 (*tt.tt_insline)();
 102:             }
 103:             /*
 104: 			 * Fix up the old screen.
 105: 			 */
 106:             cpp = &wwos[row1x];
 107:             cqq = cpp + 1;
 108:             tmp = *cpp;
 109:             for (i = row2x - row1x; --i > 0;)
 110:                 *cpp++ = *cqq++;
 111:             *cpp = tmp;
 112:         } else {
 113:             if (tt.tt_retain || row2x != wwnrow) {
 114:                 (*tt.tt_move)(row2x - 1, 0);
 115:                 (*tt.tt_delline)();
 116:             }
 117:             (*tt.tt_move)(row1x, 0);
 118:             (*tt.tt_insline)();
 119:             /*
 120: 			 * Fix up the old screen.
 121: 			 */
 122:             cpp = &wwos[row2x];
 123:             cqq = cpp - 1;
 124:             tmp = *cqq;
 125:             for (i = row2x - row1x; --i > 0;)
 126:                 *--cpp = *--cqq;
 127:             *cqq = tmp;
 128:         }
 129:         for (i = wwncol; --i >= 0;)
 130:             tmp++->c_w = ' ';
 131:         deleted++;
 132:     }
 133: 
 134:     /*
 135: 	 * Fix the new screen.
 136: 	 */
 137:     if (nvis == nvismax) {
 138:         /*
 139: 		 * Can shift whole lines.
 140: 		 */
 141:         if (dir > 0) {
 142:             {
 143:                 register union ww_char *tmp;
 144:                 register union ww_char **cpp, **cqq;
 145: 
 146:                 cpp = &wwns[row1x];
 147:                 cqq = cpp + 1;
 148:                 tmp = *cpp;
 149:                 for (i = row2x - row1x; --i > 0;)
 150:                     *cpp++ = *cqq++;
 151:                 *cpp = tmp;
 152:             }
 153:             if (deleted) {
 154:                 register char *p, *q;
 155: 
 156:                 p = &wwtouched[row1x];
 157:                 q = p + 1;
 158:                 for (i = row2x - row1x; --i > 0;)
 159:                     *p++ = *q++;
 160:                 *p |= WWU_TOUCHED;
 161:             } else {
 162:                 register char *p;
 163: 
 164:                 p = &wwtouched[row1x];
 165:                 for (i = row2x - row1x; --i >= 0;)
 166:                     *p++ |= WWU_MAJOR|WWU_TOUCHED;
 167:             }
 168:             wwredrawwin1(w, row1, row1x, dir);
 169:             wwredrawwin1(w, row2x - 1, row2 - leaveit, dir);
 170:         } else {
 171:             {
 172:                 register union ww_char *tmp;
 173:                 register union ww_char **cpp, **cqq;
 174: 
 175:                 cpp = &wwns[row2x];
 176:                 cqq = cpp - 1;
 177:                 tmp = *cqq;
 178:                 for (i = row2x - row1x; --i > 0;)
 179:                     *--cpp = *--cqq;
 180:                 *cqq = tmp;
 181:             }
 182:             if (deleted) {
 183:                 register char *p, *q;
 184: 
 185:                 p = &wwtouched[row2x];
 186:                 q = p - 1;
 187:                 for (i = row2x - row1x; --i > 0;)
 188:                     *--p = *--q;
 189:                 *q |= WWU_MAJOR|WWU_TOUCHED;
 190:             } else {
 191:                 register char *p;
 192: 
 193:                 p = &wwtouched[row1x];
 194:                 for (i = row2x - row1x; --i >= 0;)
 195:                     *p++ |= WWU_TOUCHED;
 196:             }
 197:             wwredrawwin1(w, row1 + leaveit, row1x + 1, dir);
 198:             wwredrawwin1(w, row2x, row2, dir);
 199:         }
 200:     } else {
 201: out:
 202:         if (dir > 0)
 203:             wwredrawwin1(w, row1, row2 - leaveit, dir);
 204:         else
 205:             wwredrawwin1(w, row1 + leaveit, row2, dir);
 206:     }
 207:     return deleted;
 208: }

Defined functions

Defined variables