root/src/viewer/move.c

/*   */

DEFINITIONS

1. mcview_scroll_to_cursor
2. mcview_movement_fixups
3. mcview_move_up
4. mcview_move_down
5. mcview_move_left
6. mcview_move_right
7. mcview_moveto_top
8. mcview_moveto_bottom
9. mcview_moveto_bol
10. mcview_moveto_eol
11. mcview_moveto_offset
12. mcview_moveto
13. mcview_coord_to_offset
14. mcview_offset_to_coord
15. mcview_place_cursor
16. mcview_moveto_match

   1 /*
   2    Internal file viewer for the Midnight Commander
   3    Functions for handle cursor movement
   4 
   5    Copyright (C) 1994-2021
   6    Free Software Foundation, Inc.
   7 
   8    Written by:
   9    Miguel de Icaza, 1994, 1995, 1998
  10    Janne Kukonlehto, 1994, 1995
  11    Jakub Jelinek, 1995
  12    Joseph M. Hinkle, 1996
  13    Norbert Warmuth, 1997
  14    Pavel Machek, 1998
  15    Roland Illig <roland.illig@gmx.de>, 2004, 2005
  16    Slava Zanko <slavazanko@google.com>, 2009
  17    Andrew Borodin <aborodin@vmail.ru>, 2009, 2013
  18    Ilia Maslakov <il.smind@gmail.com>, 2009, 2010
  19 
  20    This file is part of the Midnight Commander.
  21 
  22    The Midnight Commander is free software: you can redistribute it
  23    and/or modify it under the terms of the GNU General Public License as
  24    published by the Free Software Foundation, either version 3 of the License,
  25    or (at your option) any later version.
  26 
  27    The Midnight Commander is distributed in the hope that it will be useful,
  28    but WITHOUT ANY WARRANTY; without even the implied warranty of
  29    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  30    GNU General Public License for more details.
  31 
  32    You should have received a copy of the GNU General Public License
  33    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  34  */
  35 
  36 /*
  37    The following variables have to do with the current position and are
  38    updated by the cursor movement functions.
  39 
  40    In hex view and wrapped text view mode, dpy_start marks the offset of
  41    the top-left corner on the screen, in non-wrapping text mode it is
  42    the beginning of the current line.  In hex mode, hex_cursor is the
  43    offset of the cursor.  In non-wrapping text mode, dpy_text_column is
  44    the number of columns that are hidden on the left side on the screen.
  45 
  46    In hex mode, dpy_start is updated by the view_fix_cursor_position()
  47    function in order to keep the other functions simple.  In
  48    non-wrapping text mode dpy_start and dpy_text_column are normalized
  49    such that dpy_text_column < view_get_datacolumns().
  50  */
  51 
  52 #include <config.h>
  53 
  54 #include "lib/global.h"
  55 #include "lib/tty/tty.h"
  56 #include "internal.h"
  57 
  58 /*** global variables ****************************************************************************/
  59 
  60 /*** file scope macro definitions ****************************************************************/
  61 
  62 /*** file scope type declarations ****************************************************************/
  63 
  64 /*** file scope variables ************************************************************************/
  65 
  66 /* --------------------------------------------------------------------------------------------- */
  67 /*** file scope functions ************************************************************************/
  68 /* --------------------------------------------------------------------------------------------- */
  69 
  70 static void
  71 mcview_scroll_to_cursor (WView * view)
     /*   */
  72 {
  73     if (view->mode_flags.hex)
  74     {
  75         off_t bytes = view->bytes_per_line;
  76         off_t cursor = view->hex_cursor;
  77         off_t topleft = view->dpy_start;
  78         off_t displaysize;
  79 
  80         displaysize = view->data_area.height * bytes;
  81         if (topleft + displaysize <= cursor)
  82             topleft = mcview_offset_rounddown (cursor, bytes) - (displaysize - bytes);
  83         if (cursor < topleft)
  84             topleft = mcview_offset_rounddown (cursor, bytes);
  85         view->dpy_start = topleft;
  86         view->dpy_paragraph_skip_lines = 0;
  87         view->dpy_wrap_dirty = TRUE;
  88     }
  89 }
  90 
  91 /* --------------------------------------------------------------------------------------------- */
  92 
  93 static void
  94 mcview_movement_fixups (WView * view, gboolean reset_search)
     /*   */
  95 {
  96     mcview_scroll_to_cursor (view);
  97     if (reset_search)
  98     {
  99         view->search_start = view->mode_flags.hex ? view->hex_cursor : view->dpy_start;
 100         view->search_end = view->search_start;
 101     }
 102     view->dirty++;
 103 }
 104 
 105 /* --------------------------------------------------------------------------------------------- */
 106 /*** public functions ****************************************************************************/
 107 /* --------------------------------------------------------------------------------------------- */
 108 
 109 void
 110 mcview_move_up (WView * view, off_t lines)
     /*   */
 111 {
 112     if (view->mode_flags.hex)
 113     {
 114         off_t bytes = lines * view->bytes_per_line;
 115 
 116         if (view->hex_cursor >= bytes)
 117         {
 118             view->hex_cursor -= bytes;
 119             if (view->hex_cursor < view->dpy_start)
 120             {
 121                 view->dpy_start = DOZ (view->dpy_start, bytes);
 122                 view->dpy_paragraph_skip_lines = 0;
 123                 view->dpy_wrap_dirty = TRUE;
 124             }
 125         }
 126         else
 127         {
 128             view->hex_cursor %= view->bytes_per_line;
 129         }
 130     }
 131     else
 132     {
 133         mcview_ascii_move_up (view, lines);
 134     }
 135     mcview_movement_fixups (view, TRUE);
 136 }
 137 
 138 /* --------------------------------------------------------------------------------------------- */
 139 
 140 void
 141 mcview_move_down (WView * view, off_t lines)
     /*   */
 142 {
 143     off_t last_byte;
 144 
 145     last_byte = mcview_get_filesize (view);
 146 
 147     if (view->mode_flags.hex)
 148     {
 149         off_t i, limit;
 150 
 151         limit = DOZ (last_byte, (off_t) view->bytes_per_line);
 152 
 153         for (i = 0; i < lines && view->hex_cursor < limit; i++)
 154         {
 155             view->hex_cursor += view->bytes_per_line;
 156             if (lines != 1)
 157             {
 158                 view->dpy_start += view->bytes_per_line;
 159                 view->dpy_paragraph_skip_lines = 0;
 160                 view->dpy_wrap_dirty = TRUE;
 161             }
 162         }
 163     }
 164     else
 165     {
 166         mcview_ascii_move_down (view, lines);
 167     }
 168     mcview_movement_fixups (view, TRUE);
 169 }
 170 
 171 /* --------------------------------------------------------------------------------------------- */
 172 
 173 void
 174 mcview_move_left (WView * view, off_t columns)
     /*   */
 175 {
 176     if (view->mode_flags.hex)
 177     {
 178         off_t old_cursor = view->hex_cursor;
 179 
 180         g_assert (columns == 1);
 181 
 182         if (view->hexview_in_text || !view->hexedit_lownibble)
 183         {
 184             if (view->hex_cursor > 0)
 185                 view->hex_cursor--;
 186         }
 187         if (!view->hexview_in_text)
 188             if (old_cursor > 0 || view->hexedit_lownibble)
 189                 view->hexedit_lownibble = !view->hexedit_lownibble;
 190     }
 191     else if (!view->mode_flags.wrap)
 192         view->dpy_text_column = DOZ (view->dpy_text_column, columns);
 193     mcview_movement_fixups (view, FALSE);
 194 }
 195 
 196 /* --------------------------------------------------------------------------------------------- */
 197 
 198 void
 199 mcview_move_right (WView * view, off_t columns)
     /*   */
 200 {
 201     if (view->mode_flags.hex)
 202     {
 203         off_t last_byte;
 204         off_t old_cursor = view->hex_cursor;
 205 
 206         last_byte = mcview_get_filesize (view);
 207         last_byte = DOZ (last_byte, 1);
 208 
 209         g_assert (columns == 1);
 210 
 211         if (view->hexview_in_text || view->hexedit_lownibble)
 212         {
 213             if (view->hex_cursor < last_byte)
 214                 view->hex_cursor++;
 215         }
 216         if (!view->hexview_in_text)
 217             if (old_cursor < last_byte || !view->hexedit_lownibble)
 218                 view->hexedit_lownibble = !view->hexedit_lownibble;
 219     }
 220     else if (!view->mode_flags.wrap)
 221     {
 222         view->dpy_text_column += columns;
 223     }
 224     mcview_movement_fixups (view, FALSE);
 225 }
 226 
 227 /* --------------------------------------------------------------------------------------------- */
 228 
 229 void
 230 mcview_moveto_top (WView * view)
     /*   */
 231 {
 232     view->dpy_start = 0;
 233     view->dpy_paragraph_skip_lines = 0;
 234     mcview_state_machine_init (&view->dpy_state_top, 0);
 235     view->hex_cursor = 0;
 236     view->dpy_text_column = 0;
 237     mcview_movement_fixups (view, TRUE);
 238 }
 239 
 240 /* --------------------------------------------------------------------------------------------- */
 241 
 242 void
 243 mcview_moveto_bottom (WView * view)
     /*   */
 244 {
 245     off_t filesize;
 246 
 247     mcview_update_filesize (view);
 248 
 249     if (view->growbuf_in_use)
 250         mcview_growbuf_read_all_data (view);
 251 
 252     filesize = mcview_get_filesize (view);
 253 
 254     if (view->mode_flags.hex)
 255     {
 256         view->hex_cursor = DOZ (filesize, 1);
 257         mcview_movement_fixups (view, TRUE);
 258     }
 259     else
 260     {
 261         const off_t datalines = view->data_area.height;
 262 
 263         view->dpy_start = filesize;
 264         view->dpy_paragraph_skip_lines = 0;
 265         view->dpy_wrap_dirty = TRUE;
 266         mcview_move_up (view, datalines);
 267     }
 268 }
 269 
 270 /* --------------------------------------------------------------------------------------------- */
 271 
 272 void
 273 mcview_moveto_bol (WView * view)
     /*   */
 274 {
 275     if (view->mode_flags.hex)
 276     {
 277         view->hex_cursor -= view->hex_cursor % view->bytes_per_line;
 278         view->dpy_text_column = 0;
 279     }
 280     else
 281     {
 282         mcview_ascii_moveto_bol (view);
 283     }
 284     mcview_movement_fixups (view, TRUE);
 285 }
 286 
 287 /* --------------------------------------------------------------------------------------------- */
 288 
 289 void
 290 mcview_moveto_eol (WView * view)
     /*   */
 291 {
 292     off_t bol;
 293 
 294     if (view->mode_flags.hex)
 295     {
 296         off_t filesize;
 297 
 298         bol = mcview_offset_rounddown (view->hex_cursor, view->bytes_per_line);
 299         if (mcview_get_byte_indexed (view, bol, view->bytes_per_line - 1, NULL) == TRUE)
 300         {
 301             view->hex_cursor = bol + view->bytes_per_line - 1;
 302         }
 303         else
 304         {
 305             filesize = mcview_get_filesize (view);
 306             view->hex_cursor = DOZ (filesize, 1);
 307         }
 308     }
 309     else
 310     {
 311         mcview_ascii_moveto_eol (view);
 312     }
 313     mcview_movement_fixups (view, FALSE);
 314 }
 315 
 316 /* --------------------------------------------------------------------------------------------- */
 317 
 318 void
 319 mcview_moveto_offset (WView * view, off_t offset)
     /*   */
 320 {
 321     if (view->mode_flags.hex)
 322     {
 323         view->hex_cursor = offset;
 324         view->dpy_start = offset - offset % view->bytes_per_line;
 325         view->dpy_paragraph_skip_lines = 0;
 326         view->dpy_wrap_dirty = TRUE;
 327     }
 328     else
 329     {
 330         view->dpy_start = offset;
 331         view->dpy_paragraph_skip_lines = 0;
 332         view->dpy_wrap_dirty = TRUE;
 333     }
 334     mcview_movement_fixups (view, TRUE);
 335 }
 336 
 337 /* --------------------------------------------------------------------------------------------- */
 338 
 339 void
 340 mcview_moveto (WView * view, off_t line, off_t col)
     /*   */
 341 {
 342     off_t offset;
 343 
 344     mcview_coord_to_offset (view, &offset, line, col);
 345     mcview_moveto_offset (view, offset);
 346 }
 347 
 348 /* --------------------------------------------------------------------------------------------- */
 349 
 350 void
 351 mcview_coord_to_offset (WView * view, off_t * ret_offset, off_t line, off_t column)
     /*   */
 352 {
 353     coord_cache_entry_t coord;
 354 
 355     coord.cc_line = line;
 356     coord.cc_column = column;
 357     coord.cc_nroff_column = column;
 358     mcview_ccache_lookup (view, &coord, CCACHE_OFFSET);
 359     *ret_offset = coord.cc_offset;
 360 }
 361 
 362 /* --------------------------------------------------------------------------------------------- */
 363 
 364 void
 365 mcview_offset_to_coord (WView * view, off_t * ret_line, off_t * ret_column, off_t offset)
     /*   */
 366 {
 367     coord_cache_entry_t coord;
 368 
 369     coord.cc_offset = offset;
 370     mcview_ccache_lookup (view, &coord, CCACHE_LINECOL);
 371 
 372     *ret_line = coord.cc_line;
 373     *ret_column = view->mode_flags.nroff ? coord.cc_nroff_column : coord.cc_column;
 374 }
 375 
 376 /* --------------------------------------------------------------------------------------------- */
 377 
 378 void
 379 mcview_place_cursor (WView * view)
     /*   */
 380 {
 381     const screen_dimen top = view->data_area.top;
 382     const screen_dimen left = view->data_area.left;
 383     screen_dimen col = view->cursor_col;
 384     if (!view->hexview_in_text && view->hexedit_lownibble)
 385         col++;
 386     widget_gotoyx (view, top + view->cursor_row, left + col);
 387 }
 388 
 389 /* --------------------------------------------------------------------------------------------- */
 390 /** we have set view->search_start and view->search_end and must set
 391  * view->dpy_text_column and view->dpy_start
 392  * try to display maximum of match */
 393 
 394 void
 395 mcview_moveto_match (WView * view)
     /*   */
 396 {
 397     if (view->mode_flags.hex)
 398     {
 399         view->hex_cursor = view->search_start;
 400         view->hexedit_lownibble = FALSE;
 401         view->dpy_start = view->search_start - view->search_start % view->bytes_per_line;
 402         view->dpy_end = view->search_end - view->search_end % view->bytes_per_line;
 403         view->dpy_paragraph_skip_lines = 0;
 404         view->dpy_wrap_dirty = TRUE;
 405     }
 406     else
 407     {
 408         view->dpy_start = mcview_bol (view, view->search_start, 0);
 409         view->dpy_paragraph_skip_lines = 0;
 410         view->dpy_wrap_dirty = TRUE;
 411     }
 412 
 413     mcview_scroll_to_cursor (view);
 414     view->dirty++;
 415 }
 416 
 417 /* --------------------------------------------------------------------------------------------- */

/*   */