window.c

   1 /*
   2  * Copyright 2004-2005 Timo Hirvonen
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * 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
  17  * 02111-1307, USA.
  18  */
  19
  20 #include "window.h"
  21 #include "xmalloc.h"
  22 #include "debug.h"
  23
  24 #include <stdlib.h>
  25
  26 static void sel_changed(struct window *win)
  27 {
  28         if (win->sel_changed)
  29                 win->sel_changed();
  30         win->changed = 1;
  31 }
  32
  33 struct window *window_new(int (*get_prev)(struct iter *), int (*get_next)(struct iter *))
  34 {
  35         struct window *win;
  36
  37         win = xnew(struct window, 1);
  38         win->get_next = get_next;
  39         win->get_prev = get_prev;
  40         win->sel_changed = NULL;
  41         win->nr_rows = 1;
  42         win->changed = 1;
  43         iter_init(&win->head);
  44         iter_init(&win->top);
  45         iter_init(&win->sel);
  46         return win;
  47 }
  48
  49 void window_free(struct window *win)
  50 {
  51         free(win);
  52 }
  53
  54 void window_set_empty(struct window *win)
  55 {
  56         iter_init(&win->head);
  57         iter_init(&win->top);
  58         iter_init(&win->sel);
  59         sel_changed(win);
  60 }
  61
  62 void window_set_contents(struct window *win, void *head)
  63 {
  64         struct iter first;
  65
  66         win->head.data0 = head;
  67         win->head.data1 = NULL;
  68         win->head.data2 = NULL;
  69         first = win->head;
  70         win->get_next(&first);
  71         win->top = first;
  72         win->sel = first;
  73         sel_changed(win);
  74 }
  75
  76 void window_set_nr_rows(struct window *win, int nr_rows)
  77 {
  78         struct iter old_sel;
  79
  80         if (nr_rows < 1)
  81                 return;
  82         win->nr_rows = nr_rows;
  83         old_sel = win->sel;
  84         window_changed(win);
  85         win->changed = 1;
  86 }
  87
  88 void window_up(struct window *win, int rows)
  89 {
  90         int i;
  91
  92         for (i = 0; i < rows; i++) {
  93                 struct iter prev = win->sel;
  94
  95                 if (!win->get_prev(&prev))
  96                         break;
  97                 if (iters_equal(&win->sel, &win->top))
  98                         win->top = prev;
  99                 win->sel = prev;
 100         }
 101         if (i)
 102                 sel_changed(win);
 103 }
 104
 105 void window_down(struct window *win, int rows)
 106 {
 107         struct iter iter;
 108         int delta, sel_down, top_down;
 109
 110         /* distance between top and sel */
 111         delta = 0;
 112         iter = win->top;
 113         while (!iters_equal(&iter, &win->sel)) {
 114                 win->get_next(&iter);
 115                 delta++;
 116         }
 117
 118         for (sel_down = 0; sel_down < rows; sel_down++) {
 119                 iter = win->sel;
 120                 if (!win->get_next(&iter))
 121                         break;
 122                 win->sel = iter;
 123         }
 124
 125         top_down = sel_down - (win->nr_rows - delta - 1);
 126         while (top_down > 0) {
 127                 win->get_next(&win->top);
 128                 top_down--;
 129         }
 130         if (sel_down)
 131                 sel_changed(win);
 132 }
 133
 134 /*
 135  * minimize number of empty lines visible
 136  * make sure selection is visible
 137  */
 138 void window_changed(struct window *win)
 139 {
 140         struct iter iter;
 141         int delta, rows;
 142
 143         if (iter_is_null(&win->head)) {
 144                 BUG_ON(!iter_is_null(&win->top));
 145                 BUG_ON(!iter_is_null(&win->sel));
 146                 return;
 147         }
 148         BUG_ON(iter_is_null(&win->top));
 149         BUG_ON(iter_is_null(&win->sel));
 150
 151         /* make sure top and sel point to real row if possible */
 152         if (iter_is_head(&win->top)) {
 153                 win->get_next(&win->top);
 154                 win->sel = win->top;
 155                 sel_changed(win);
 156                 return;
 157         }
 158
 159         /* make sure the selected row is visible */
 160
 161         /* get distance between top and sel */
 162         delta = 0;
 163         iter = win->top;
 164         while (!iters_equal(&iter, &win->sel)) {
 165                 if (!win->get_next(&iter)) {
 166                         /* sel < top, scroll up until top == sel */
 167                         while (!iters_equal(&win->top, &win->sel))
 168                                 win->get_prev(&win->top);
 169                         goto minimize;
 170                 }
 171                 delta++;
 172         }
 173
 174         /* scroll down until sel is visible */
 175         while (delta > win->nr_rows - 1) {
 176                 win->get_next(&win->top);
 177                 delta--;
 178         }
 179 minimize:
 180         /* minimize number of empty lines shown */
 181         iter = win->top;
 182         rows = 1;
 183         while (rows < win->nr_rows) {
 184                 if (!win->get_next(&iter))
 185                         break;
 186                 rows++;
 187         }
 188         while (rows < win->nr_rows) {
 189                 iter = win->top;
 190                 if (!win->get_prev(&iter))
 191                         break;
 192                 win->top = iter;
 193                 rows++;
 194         }
 195         win->changed = 1;
 196 }
 197
 198 void window_row_vanishes(struct window *win, struct iter *iter)
 199 {
 200         struct iter new = *iter;
 201
 202         BUG_ON(iter->data0 != win->head.data0);
 203         if (!win->get_next(&new)) {
 204                 new = *iter;
 205                 win->get_prev(&new);
 206         }
 207         if (iters_equal(&win->top, iter))
 208                 win->top = new;
 209         if (iters_equal(&win->sel, iter)) {
 210                 win->sel = new;
 211                 sel_changed(win);
 212         }
 213         win->changed = 1;
 214 }
 215
 216 int window_get_top(struct window *win, struct iter *iter)
 217 {
 218         *iter = win->top;
 219         return !iter_is_empty(iter);
 220 }
 221
 222 int window_get_sel(struct window *win, struct iter *iter)
 223 {
 224         *iter = win->sel;
 225         return !iter_is_empty(iter);
 226 }
 227
 228 int window_get_prev(struct window *win, struct iter *iter)
 229 {
 230         return win->get_prev(iter);
 231 }
 232
 233 int window_get_next(struct window *win, struct iter *iter)
 234 {
 235         return win->get_next(iter);
 236 }
 237
 238 void window_set_sel(struct window *win, struct iter *iter)
 239 {
 240         int sel_nr, top_nr;
 241         struct iter tmp;
 242
 243         BUG_ON(iter_is_empty(&win->top));
 244         BUG_ON(iter_is_empty(iter));
 245         BUG_ON(iter->data0 != win->head.data0);
 246
 247         if (iters_equal(&win->sel, iter))
 248                 return;
 249         win->sel = *iter;
 250
 251         tmp = win->head;
 252         win->get_next(&tmp);
 253         top_nr = 0;
 254         while (!iters_equal(&tmp, &win->top)) {
 255                 win->get_next(&tmp);
 256                 top_nr++;
 257         }
 258
 259         tmp = win->head;
 260         win->get_next(&tmp);
 261         sel_nr = 0;
 262         while (!iters_equal(&tmp, &win->sel)) {
 263                 BUG_ON(!win->get_next(&tmp));
 264                 sel_nr++;
 265         }
 266
 267         if (sel_nr < top_nr)
 268                 win->top = win->sel;
 269         while (sel_nr - top_nr >= win->nr_rows) {
 270                 win->get_next(&win->top);
 271                 top_nr++;
 272         }
 273         sel_changed(win);
 274 }
 275
 276 void window_goto_top(struct window *win)
 277 {
 278         struct iter old_sel;
 279
 280         old_sel = win->sel;
 281         win->sel = win->head;
 282         win->get_next(&win->sel);
 283         win->top = win->sel;
 284         if (!iters_equal(&old_sel, &win->sel))
 285                 sel_changed(win);
 286 }
 287
 288 void window_goto_bottom(struct window *win)
 289 {
 290         struct iter old_sel;
 291         int count;
 292
 293         old_sel = win->sel;
 294         win->sel = win->head;
 295         win->get_prev(&win->sel);
 296         win->top = win->sel;
 297         count = win->nr_rows - 1;
 298         while (count) {
 299                 struct iter iter = win->top;
 300
 301                 if (!win->get_prev(&iter))
 302                         break;
 303                 win->top = iter;
 304                 count--;
 305         }
 306         if (!iters_equal(&old_sel, &win->sel))
 307                 sel_changed(win);
 308 }
 309
 310 void window_page_up(struct window *win)
 311 {
 312         window_up(win, win->nr_rows - 1);
 313 }
 314
 315 void window_page_down(struct window *win)
 316 {
 317         window_down(win, win->nr_rows - 1);
 318 }
 319
 320 int window_get_nr_rows(struct window *win)
 321 {
 322         return win->nr_rows;
 323 }