src/viewer/move.c

   1 /*
   2    Internal file viewer for the Midnight Commander
   3    Functions for handle cursor movement
   4
   5    Copyright (C) 1994-2024
   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>, 2009-2022
  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 /*** forward declarations (file scope functions) *************************************************/
  65
  66 /*** file scope variables ************************************************************************/
  67
  68 /* --------------------------------------------------------------------------------------------- */
  69 /*** file scope functions ************************************************************************/
  70 /* --------------------------------------------------------------------------------------------- */
  71
  72 static void
  73 mcview_scroll_to_cursor (WView *view)
  74 {
  75     if (view->mode_flags.hex)
  76     {
  77         off_t bytes = view->bytes_per_line;
  78         off_t cursor = view->hex_cursor;
  79         off_t topleft = view->dpy_start;
  80         off_t displaysize;
  81
  82         displaysize = view->data_area.lines * bytes;
  83         if (topleft + displaysize <= cursor)
  84             topleft = mcview_offset_rounddown (cursor, bytes) - (displaysize - bytes);
  85         if (cursor < topleft)
  86             topleft = mcview_offset_rounddown (cursor, bytes);
  87         view->dpy_start = topleft;
  88         view->dpy_paragraph_skip_lines = 0;
  89         view->dpy_wrap_dirty = TRUE;
  90     }
  91 }
  92
  93 /* --------------------------------------------------------------------------------------------- */
  94
  95 static void
  96 mcview_movement_fixups (WView *view, gboolean reset_search)
  97 {
  98     mcview_scroll_to_cursor (view);
  99
 100     if (reset_search)
 101     {
 102         view->search_start = view->mode_flags.hex ? view->hex_cursor : view->dpy_start;
 103         view->search_end = view->search_start;
 104     }
 105
 106     view->dirty++;
 107 }
 108
 109 /* --------------------------------------------------------------------------------------------- */
 110 /*** public functions ****************************************************************************/
 111 /* --------------------------------------------------------------------------------------------- */
 112
 113 void
 114 mcview_move_up (WView *view, off_t lines)
 115 {
 116     if (!view->mode_flags.hex)
 117         mcview_ascii_move_up (view, lines);
 118     else
 119     {
 120         off_t bytes;
 121
 122         bytes = lines * view->bytes_per_line;
 123
 124         if (view->hex_cursor < bytes)
 125             view->hex_cursor %= view->bytes_per_line;
 126         else
 127         {
 128             view->hex_cursor -= bytes;
 129             if (view->hex_cursor < view->dpy_start)
 130             {
 131                 view->dpy_start = DOZ (view->dpy_start, bytes);
 132                 view->dpy_paragraph_skip_lines = 0;
 133                 view->dpy_wrap_dirty = TRUE;
 134             }
 135         }
 136     }
 137
 138     mcview_movement_fixups (view, TRUE);
 139 }
 140
 141 /* --------------------------------------------------------------------------------------------- */
 142
 143 void
 144 mcview_move_down (WView *view, off_t lines)
 145 {
 146     off_t last_byte;
 147
 148     last_byte = mcview_get_filesize (view);
 149
 150     if (!view->mode_flags.hex)
 151         mcview_ascii_move_down (view, lines);
 152     else
 153     {
 154         off_t i, limit;
 155
 156         limit = DOZ (last_byte, (off_t) view->bytes_per_line);
 157
 158         for (i = 0; i < lines && view->hex_cursor < limit; i++)
 159         {
 160             view->hex_cursor += view->bytes_per_line;
 161
 162             if (lines != 1)
 163             {
 164                 view->dpy_start += view->bytes_per_line;
 165                 view->dpy_paragraph_skip_lines = 0;
 166                 view->dpy_wrap_dirty = TRUE;
 167             }
 168         }
 169     }
 170
 171     mcview_movement_fixups (view, TRUE);
 172 }
 173
 174 /* --------------------------------------------------------------------------------------------- */
 175
 176 void
 177 mcview_move_left (WView *view, off_t columns)
 178 {
 179     if (view->mode_flags.hex)
 180     {
 181         off_t old_cursor = view->hex_cursor;
 182
 183         g_assert (columns == 1);
 184
 185         if (view->hexview_in_text || !view->hexedit_lownibble)
 186             if (view->hex_cursor > 0)
 187                 view->hex_cursor--;
 188
 189         if (!view->hexview_in_text)
 190             if (old_cursor > 0 || view->hexedit_lownibble)
 191                 view->hexedit_lownibble = !view->hexedit_lownibble;
 192     }
 193     else if (!view->mode_flags.wrap)
 194         view->dpy_text_column = DOZ (view->dpy_text_column, columns);
 195
 196     mcview_movement_fixups (view, FALSE);
 197 }
 198
 199 /* --------------------------------------------------------------------------------------------- */
 200
 201 void
 202 mcview_move_right (WView *view, off_t columns)
 203 {
 204     if (view->mode_flags.hex)
 205     {
 206         off_t last_byte;
 207         off_t old_cursor = view->hex_cursor;
 208
 209         last_byte = mcview_get_filesize (view);
 210         last_byte = DOZ (last_byte, 1);
 211
 212         g_assert (columns == 1);
 213
 214         if (view->hexview_in_text || view->hexedit_lownibble)
 215             if (view->hex_cursor < last_byte)
 216                 view->hex_cursor++;
 217
 218         if (!view->hexview_in_text)
 219             if (old_cursor < last_byte || !view->hexedit_lownibble)
 220                 view->hexedit_lownibble = !view->hexedit_lownibble;
 221     }
 222     else if (!view->mode_flags.wrap)
 223         view->dpy_text_column += columns;
 224
 225     mcview_movement_fixups (view, FALSE);
 226 }
 227
 228 /* --------------------------------------------------------------------------------------------- */
 229
 230 void
 231 mcview_moveto_top (WView *view)
 232 {
 233     view->dpy_start = 0;
 234     view->dpy_paragraph_skip_lines = 0;
 235     mcview_state_machine_init (&view->dpy_state_top, 0);
 236     view->hex_cursor = 0;
 237     view->dpy_text_column = 0;
 238     mcview_movement_fixups (view, TRUE);
 239 }
 240
 241 /* --------------------------------------------------------------------------------------------- */
 242
 243 void
 244 mcview_moveto_bottom (WView *view)
 245 {
 246     off_t filesize;
 247
 248     mcview_update_filesize (view);
 249
 250     if (view->growbuf_in_use)
 251         mcview_growbuf_read_all_data (view);
 252
 253     filesize = mcview_get_filesize (view);
 254
 255     if (view->mode_flags.hex)
 256     {
 257         view->hex_cursor = DOZ (filesize, 1);
 258         mcview_movement_fixups (view, TRUE);
 259     }
 260     else
 261     {
 262         view->dpy_start = filesize;
 263         view->dpy_paragraph_skip_lines = 0;
 264         view->dpy_wrap_dirty = TRUE;
 265         mcview_move_up (view, view->data_area.lines);
 266     }
 267 }
 268
 269 /* --------------------------------------------------------------------------------------------- */
 270
 271 void
 272 mcview_moveto_bol (WView *view)
 273 {
 274     if (!view->mode_flags.hex)
 275         mcview_ascii_moveto_bol (view);
 276     else
 277     {
 278         view->hex_cursor -= view->hex_cursor % view->bytes_per_line;
 279         view->dpy_text_column = 0;
 280     }
 281
 282     mcview_movement_fixups (view, TRUE);
 283 }
 284
 285 /* --------------------------------------------------------------------------------------------- */
 286
 287 void
 288 mcview_moveto_eol (WView *view)
 289 {
 290     off_t bol;
 291
 292     if (!view->mode_flags.hex)
 293         mcview_ascii_moveto_eol (view);
 294     else
 295     {
 296         off_t filesize;
 297
 298         bol = mcview_offset_rounddown (view->hex_cursor, view->bytes_per_line);
 299
 300         if (mcview_get_byte_indexed (view, bol, view->bytes_per_line - 1, NULL))
 301             view->hex_cursor = bol + view->bytes_per_line - 1;
 302         else
 303         {
 304             filesize = mcview_get_filesize (view);
 305             view->hex_cursor = DOZ (filesize, 1);
 306         }
 307     }
 308
 309     mcview_movement_fixups (view, FALSE);
 310 }
 311
 312 /* --------------------------------------------------------------------------------------------- */
 313
 314 void
 315 mcview_moveto_offset (WView *view, off_t offset)
 316 {
 317     if (view->mode_flags.hex)
 318     {
 319         view->hex_cursor = offset;
 320         view->dpy_start = offset - offset % view->bytes_per_line;
 321         view->dpy_paragraph_skip_lines = 0;
 322         view->dpy_wrap_dirty = TRUE;
 323     }
 324     else
 325     {
 326         view->dpy_start = offset;
 327         view->dpy_paragraph_skip_lines = 0;
 328         view->dpy_wrap_dirty = TRUE;
 329     }
 330
 331     mcview_movement_fixups (view, TRUE);
 332 }
 333
 334 /* --------------------------------------------------------------------------------------------- */
 335
 336 void
 337 mcview_moveto (WView *view, off_t line, off_t col)
 338 {
 339     off_t offset;
 340
 341     mcview_coord_to_offset (view, &offset, line, col);
 342     mcview_moveto_offset (view, offset);
 343 }
 344
 345 /* --------------------------------------------------------------------------------------------- */
 346
 347 void
 348 mcview_coord_to_offset (WView *view, off_t *ret_offset, off_t line, off_t column)
 349 {
 350     coord_cache_entry_t coord;
 351
 352     coord.cc_line = line;
 353     coord.cc_column = column;
 354     coord.cc_nroff_column = column;
 355     mcview_ccache_lookup (view, &coord, CCACHE_OFFSET);
 356     *ret_offset = coord.cc_offset;
 357 }
 358
 359 /* --------------------------------------------------------------------------------------------- */
 360
 361 void
 362 mcview_offset_to_coord (WView *view, off_t *ret_line, off_t *ret_column, off_t offset)
 363 {
 364     coord_cache_entry_t coord;
 365
 366     coord.cc_offset = offset;
 367     mcview_ccache_lookup (view, &coord, CCACHE_LINECOL);
 368
 369     *ret_line = coord.cc_line;
 370     *ret_column = view->mode_flags.nroff ? coord.cc_nroff_column : coord.cc_column;
 371 }
 372
 373 /* --------------------------------------------------------------------------------------------- */
 374
 375 void
 376 mcview_place_cursor (WView *view)
 377 {
 378     const WRect *r = &view->data_area;
 379     int col = view->cursor_col;
 380
 381     if (!view->hexview_in_text && view->hexedit_lownibble)
 382         col++;
 383
 384     widget_gotoyx (view, r->y + view->cursor_row, r->x + col);
 385 }
 386
 387 /* --------------------------------------------------------------------------------------------- */
 388 /** we have set view->search_start and view->search_end and must set
 389  * view->dpy_text_column and view->dpy_start
 390  * try to display maximum of match */
 391
 392 void
 393 mcview_moveto_match (WView *view)
 394 {
 395     if (view->mode_flags.hex)
 396     {
 397         view->hex_cursor = view->search_start;
 398         view->hexedit_lownibble = FALSE;
 399         view->dpy_start = view->search_start - view->search_start % view->bytes_per_line;
 400         view->dpy_end = view->search_end - view->search_end % view->bytes_per_line;
 401         view->dpy_paragraph_skip_lines = 0;
 402         view->dpy_wrap_dirty = TRUE;
 403     }
 404     else
 405     {
 406         view->dpy_start = mcview_bol (view, view->search_start, 0);
 407         view->dpy_paragraph_skip_lines = 0;
 408         view->dpy_wrap_dirty = TRUE;
 409     }
 410
 411     mcview_scroll_to_cursor (view);
 412     view->dirty++;
 413 }
 414
 415 /* --------------------------------------------------------------------------------------------- */