src/viewer/move.c

   1 /*
   2    Internal file viewer for the Midnight Commander
   3    Functions for handle cursor movement
   4
   5    Copyright (C) 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003,
   6    2004, 2005, 2006, 2007, 2009 Free Software Foundation, Inc.
   7
   8    Written by: 1994, 1995, 1998 Miguel de Icaza
   9                1994, 1995 Janne Kukonlehto
  10                1995 Jakub Jelinek
  11                1996 Joseph M. Hinkle
  12                1997 Norbert Warmuth
  13                1998 Pavel Machek
  14                2004 Roland Illig <roland.illig@gmx.de>
  15                2005 Roland Illig <roland.illig@gmx.de>
  16                2009 Slava Zanko <slavazanko@google.com>
  17                2009 Andrew Borodin <aborodin@vmail.ru>
  18                2009 Ilia Maslakov <il.smind@gmail.com>
  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 2 of the
  25    License, or (at your option) any later version.
  26
  27    The Midnight Commander is distributed in the hope that it will be
  28    useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  29    of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  30    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, write to the Free Software
  34    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  35    MA 02110-1301, USA.
  36  */
  37
  38 /*
  39    The following variables have to do with the current position and are
  40    updated by the cursor movement functions.
  41
  42    In hex view and wrapped text view mode, dpy_start marks the offset of
  43    the top-left corner on the screen, in non-wrapping text mode it is
  44    the beginning of the current line.  In hex mode, hex_cursor is the
  45    offset of the cursor.  In non-wrapping text mode, dpy_text_column is
  46    the number of columns that are hidden on the left side on the screen.
  47
  48    In hex mode, dpy_start is updated by the view_fix_cursor_position()
  49    function in order to keep the other functions simple.  In
  50    non-wrapping text mode dpy_start and dpy_text_column are normalized
  51    such that dpy_text_column < view_get_datacolumns().
  52  */
  53
  54 #include <config.h>
  55
  56 #include "../src/global.h"
  57 #include "../src/tty/tty.h"
  58 #include "../src/viewer/internal.h"
  59
  60 /*** global variables ****************************************************************************/
  61
  62 /*** file scope macro definitions ****************************************************************/
  63
  64 /*** file scope type declarations ****************************************************************/
  65
  66 /*** file scope variables ************************************************************************/
  67
  68 /*** file scope functions ************************************************************************/
  69
  70 static void
  71 mcview_movement_fixups (mcview_t * view, gboolean reset_search)
  72 {
  73     mcview_scroll_to_cursor (view);
  74     if (reset_search) {
  75         view->search_start = view->dpy_start;
  76         view->search_end = view->dpy_start;
  77     }
  78     view->dirty++;
  79 }
  80
  81 /* --------------------------------------------------------------------------------------------- */
  82
  83 /*** public functions ****************************************************************************/
  84
  85 /* --------------------------------------------------------------------------------------------- */
  86
  87 void
  88 mcview_move_up (mcview_t * view, off_t lines)
  89 {
  90     if (view->hex_mode) {
  91         off_t bytes = lines * view->bytes_per_line;
  92         if (view->hex_cursor >= bytes) {
  93             view->hex_cursor -= bytes;
  94             if (view->hex_cursor < view->dpy_start)
  95                 view->dpy_start = mcview_offset_doz (view->dpy_start, bytes);
  96         } else {
  97             view->hex_cursor %= view->bytes_per_line;
  98         }
  99     } else if (view->text_wrap_mode) {
 100         const screen_dimen width = view->data_area.width;
 101         off_t i, col, line, linestart;
 102
 103         for (i = 0; i < lines; i++) {
 104             mcview_offset_to_coord (view, &line, &col, view->dpy_start);
 105             if (col >= width) {
 106                 col -= width;
 107             } else if (line >= 1) {
 108                 mcview_coord_to_offset (view, &linestart, line, 0);
 109                 mcview_offset_to_coord (view, &line, &col, linestart - 1);
 110
 111                 /* if the only thing that would be displayed were a
 112                  * single newline character, advance to the previous
 113                  * part of the line. */
 114                 if (col > 0 && col % width == 0)
 115                     col -= width;
 116                 else
 117                     col -= col % width;
 118             } else {
 119                 /* nothing to do */
 120             }
 121             mcview_coord_to_offset (view, &(view->dpy_start), line, col);
 122         }
 123     } else {
 124         off_t line, column;
 125
 126         mcview_offset_to_coord (view, &line, &column, view->dpy_start);
 127         line = mcview_offset_doz (line, lines);
 128         mcview_coord_to_offset (view, &(view->dpy_start), line, column);
 129     }
 130     mcview_movement_fixups (view, (lines != 1));
 131 }
 132
 133 /* --------------------------------------------------------------------------------------------- */
 134
 135 void
 136 mcview_move_down (mcview_t * view, off_t lines)
 137 {
 138     if (view->hex_mode) {
 139         off_t i, limit, last_byte;
 140
 141         last_byte = mcview_get_filesize (view);
 142         if (last_byte >= (off_t) view->bytes_per_line)
 143             limit = last_byte - view->bytes_per_line;
 144         else
 145             limit = 0;
 146         for (i = 0; i < lines && view->hex_cursor < limit; i++) {
 147             view->hex_cursor += view->bytes_per_line;
 148             if (lines != 1)
 149                 view->dpy_start += view->bytes_per_line;
 150         }
 151
 152     } else if (view->dpy_end == mcview_get_filesize (view)) {
 153         /* don't move further down. There's nothing more to see. */
 154
 155     } else if (view->text_wrap_mode) {
 156         off_t line, col, i;
 157
 158         for (i = 0; i < lines; i++) {
 159             off_t new_offset, chk_line, chk_col;
 160
 161             mcview_offset_to_coord (view, &line, &col, view->dpy_start);
 162             col += view->data_area.width;
 163             mcview_coord_to_offset (view, &new_offset, line, col);
 164
 165             /* skip to the next line if the only thing that would be
 166              * displayed is the newline character. */
 167             mcview_offset_to_coord (view, &chk_line, &chk_col, new_offset);
 168             if (chk_line == line && chk_col == col && mcview_get_byte (view, new_offset) == '\n')
 169                 new_offset++;
 170
 171             view->dpy_start = new_offset;
 172         }
 173
 174     } else {
 175         off_t line, col;
 176
 177         mcview_offset_to_coord (view, &line, &col, view->dpy_start);
 178         line += lines;
 179         mcview_coord_to_offset (view, &(view->dpy_start), line, col);
 180     }
 181     mcview_movement_fixups (view, (lines != 1));
 182 }
 183
 184 /* --------------------------------------------------------------------------------------------- */
 185
 186 void
 187 mcview_move_left (mcview_t * view, off_t columns)
 188 {
 189     if (view->hex_mode) {
 190         assert (columns == 1);
 191         if (view->hexview_in_text || !view->hexedit_lownibble) {
 192             if (view->hex_cursor > 0)
 193                 view->hex_cursor--;
 194         }
 195         if (!view->hexview_in_text)
 196             view->hexedit_lownibble = !view->hexedit_lownibble;
 197     } else if (view->text_wrap_mode) {
 198         /* nothing to do */
 199     } else {
 200         if (view->dpy_text_column >= columns)
 201             view->dpy_text_column -= columns;
 202         else
 203             view->dpy_text_column = 0;
 204     }
 205     mcview_movement_fixups (view, FALSE);
 206 }
 207
 208 /* --------------------------------------------------------------------------------------------- */
 209
 210 void
 211 mcview_move_right (mcview_t * view, off_t columns)
 212 {
 213     if (view->hex_mode) {
 214         assert (columns == 1);
 215         if (view->hexview_in_text || view->hexedit_lownibble) {
 216             view->hex_cursor++;
 217         }
 218         if (!view->hexview_in_text)
 219             view->hexedit_lownibble = !view->hexedit_lownibble;
 220     } else if (view->text_wrap_mode) {
 221         /* nothing to do */
 222     } else {
 223         view->dpy_text_column += columns;
 224     }
 225     mcview_movement_fixups (view, FALSE);
 226 }
 227
 228 /* --------------------------------------------------------------------------------------------- */
 229
 230 void
 231 mcview_scroll_to_cursor (mcview_t * view)
 232 {
 233     if (view->hex_mode) {
 234         const off_t bytes = view->bytes_per_line;
 235         const off_t displaysize = view->data_area.height * bytes;
 236         const off_t cursor = view->hex_cursor;
 237         off_t topleft = view->dpy_start;
 238
 239         if (topleft + displaysize <= cursor)
 240             topleft = mcview_offset_rounddown (cursor, bytes)
 241                 - (displaysize - bytes);
 242         if (cursor < topleft)
 243             topleft = mcview_offset_rounddown (cursor, bytes);
 244         view->dpy_start = topleft;
 245     } else if (view->text_wrap_mode) {
 246         off_t line, col, columns;
 247
 248         columns = view->data_area.width;
 249         mcview_offset_to_coord (view, &line, &col, view->dpy_start + view->dpy_text_column);
 250         if (columns != 0)
 251             col = mcview_offset_rounddown (col, columns);
 252         mcview_coord_to_offset (view, &(view->dpy_start), line, col);
 253         view->dpy_text_column = 0;
 254     } else {
 255         /* nothing to do */
 256     }
 257 }
 258
 259 /* --------------------------------------------------------------------------------------------- */
 260
 261 void
 262 mcview_moveto_top (mcview_t * view)
 263 {
 264     view->dpy_start = 0;
 265     view->hex_cursor = 0;
 266     view->dpy_text_column = 0;
 267     mcview_movement_fixups (view, TRUE);
 268 }
 269
 270 /* --------------------------------------------------------------------------------------------- */
 271
 272 void
 273 mcview_moveto_bottom (mcview_t * view)
 274 {
 275     off_t datalines, lines_up, filesize, last_offset;
 276
 277     if (view->growbuf_in_use)
 278         mcview_growbuf_read_until (view, OFFSETTYPE_MAX);
 279
 280     filesize = mcview_get_filesize (view);
 281     last_offset = mcview_offset_doz (filesize, 1);
 282     datalines = view->data_area.height;
 283     lines_up = mcview_offset_doz (datalines, 1);
 284
 285     if (view->hex_mode) {
 286         view->hex_cursor = filesize;
 287         mcview_move_up (view, lines_up);
 288         view->hex_cursor = last_offset;
 289     } else {
 290         view->dpy_start = last_offset;
 291         mcview_moveto_bol (view);
 292         mcview_move_up (view, lines_up);
 293     }
 294     mcview_movement_fixups (view, TRUE);
 295 }
 296
 297 /* --------------------------------------------------------------------------------------------- */
 298
 299 void
 300 mcview_moveto_bol (mcview_t * view)
 301 {
 302     if (view->hex_mode) {
 303         view->hex_cursor -= view->hex_cursor % view->bytes_per_line;
 304     } else if (view->text_wrap_mode) {
 305         /* do nothing */
 306     } else {
 307         off_t line, column;
 308         mcview_offset_to_coord (view, &line, &column, view->dpy_start);
 309         mcview_coord_to_offset (view, &(view->dpy_start), line, 0);
 310         view->dpy_text_column = 0;
 311     }
 312     mcview_movement_fixups (view, TRUE);
 313 }
 314
 315 /* --------------------------------------------------------------------------------------------- */
 316
 317 void
 318 mcview_moveto_eol (mcview_t * view)
 319 {
 320     if (view->hex_mode) {
 321         off_t filesize, bol;
 322
 323         bol = mcview_offset_rounddown (view->hex_cursor, view->bytes_per_line);
 324         if (mcview_get_byte_indexed (view, bol, view->bytes_per_line - 1) != -1) {
 325             view->hex_cursor = bol + view->bytes_per_line - 1;
 326         } else {
 327             filesize = mcview_get_filesize (view);
 328             view->hex_cursor = mcview_offset_doz (filesize, 1);
 329         }
 330     } else if (view->text_wrap_mode) {
 331         /* nothing to do */
 332     } else {
 333         off_t line, col;
 334
 335         mcview_offset_to_coord (view, &line, &col, view->dpy_start);
 336         mcview_coord_to_offset (view, &(view->dpy_start), line, OFFSETTYPE_MAX);
 337     }
 338     mcview_movement_fixups (view, FALSE);
 339 }
 340
 341 /* --------------------------------------------------------------------------------------------- */
 342
 343 void
 344 mcview_moveto_offset (mcview_t * view, off_t offset)
 345 {
 346     if (view->hex_mode) {
 347         view->hex_cursor = offset;
 348         view->dpy_start = offset - offset % view->bytes_per_line;
 349     } else {
 350         view->dpy_start = offset;
 351     }
 352     mcview_movement_fixups (view, TRUE);
 353 }
 354
 355 /* --------------------------------------------------------------------------------------------- */
 356
 357 void
 358 mcview_moveto (mcview_t * view, off_t line, off_t col)
 359 {
 360     off_t offset;
 361
 362     mcview_coord_to_offset (view, &offset, line, col);
 363     mcview_moveto_offset (view, offset);
 364 }
 365
 366 /* --------------------------------------------------------------------------------------------- */
 367
 368 void
 369 mcview_coord_to_offset (mcview_t * view, off_t * ret_offset, off_t line, off_t column)
 370 {
 371     struct coord_cache_entry coord;
 372
 373     coord.cc_line = line;
 374     coord.cc_column = column;
 375     coord.cc_nroff_column = column;
 376     mcview_ccache_lookup (view, &coord, CCACHE_OFFSET);
 377     *ret_offset = coord.cc_offset;
 378 }
 379
 380 /* --------------------------------------------------------------------------------------------- */
 381
 382 void
 383 mcview_offset_to_coord (mcview_t * view, off_t * ret_line, off_t * ret_column, off_t offset)
 384 {
 385     struct coord_cache_entry coord;
 386
 387     coord.cc_offset = offset;
 388     mcview_ccache_lookup (view, &coord, CCACHE_LINECOL);
 389
 390     if (ret_line)
 391         *ret_line = coord.cc_line;
 392
 393     if (ret_column)
 394         *ret_column = (view->text_nroff_mode)
 395             ? coord.cc_nroff_column : coord.cc_column;
 396 }
 397
 398 /* --------------------------------------------------------------------------------------------- */
 399
 400 void
 401 mcview_place_cursor (mcview_t * view)
 402 {
 403     const screen_dimen top = view->data_area.top;
 404     const screen_dimen left = view->data_area.left;
 405     screen_dimen col;
 406
 407     col = view->cursor_col;
 408     if (!view->hexview_in_text && view->hexedit_lownibble)
 409         col++;
 410     widget_move (&view->widget, top + view->cursor_row, left + col);
 411 }
 412
 413 /* --------------------------------------------------------------------------------------------- */
 414
 415 /* we have set view->search_start and view->search_end and must set
 416  * view->dpy_text_column and view->dpy_start
 417  * try to display maximum of match */
 418 void
 419 mcview_moveto_match (mcview_t * view)
 420 {
 421     off_t search_line, offset;
 422
 423     mcview_offset_to_coord (view, &search_line, NULL, view->search_start);
 424     mcview_coord_to_offset (view, &offset, search_line, 0);
 425
 426     if (view->hex_mode) {
 427         view->hex_cursor = offset;
 428         view->dpy_start = offset - offset % view->bytes_per_line;
 429     } else {
 430         view->dpy_start = offset;
 431     }
 432
 433     mcview_scroll_to_cursor (view);
 434     view->dirty++;
 435 }
 436
 437 /* --------------------------------------------------------------------------------------------- */