contrib/dialog/tailbox.c

   1 /*
   2  *  $Id: tailbox.c,v 1.80 2022/04/03 22:38:16 tom Exp $
   3  *
   4  *  tailbox.c -- implements the tail box
   5  *
   6  *  Copyright 2000-2020,2022    Thomas E. Dickey
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU Lesser General Public License, version 2.1
  10  *  as published by the Free Software Foundation.
  11  *
  12  *  This program is distributed in the hope that it will be useful, but
  13  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *  Lesser General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU Lesser General Public
  18  *  License along with this program; if not, write to
  19  *      Free Software Foundation, Inc.
  20  *      51 Franklin St., Fifth Floor
  21  *      Boston, MA 02110, USA.
  22  *
  23  *  An earlier version of this program lists as authors
  24  *      Pasquale De Marco (demarco_p@abramo.it)
  25  */
  26
  27 #include <dlg_internals.h>
  28 #include <dlg_keys.h>
  29
  30 typedef struct {
  31     DIALOG_CALLBACK obj;
  32     WINDOW *text;
  33     const char **buttons;
  34     int hscroll;
  35     int old_hscroll;
  36     char line[MAX_LEN + 2];
  37     off_t last_pos;
  38 } MY_OBJ;
  39
  40 /*
  41  * Return current line of text.
  42  */
  43 static char *
  44 get_line(MY_OBJ * obj)
  45 {
  46     FILE *fp = obj->obj.input;
  47     int col = -(obj->hscroll);
  48     int j, tmpint, ch;
  49
  50     do {
  51         if (((ch = getc(fp)) == EOF) && !feof(fp))
  52             dlg_exiterr("Error moving file pointer in get_line().");
  53         else if (!feof(fp) && (ch != '\n')) {
  54             if ((ch == TAB) && (dialog_vars.tab_correct)) {
  55                 tmpint = dialog_state.tab_len
  56                     - ((col + obj->hscroll) % dialog_state.tab_len);
  57                 for (j = 0; j < tmpint; j++) {
  58                     if (col >= 0 && col < MAX_LEN)
  59                         obj->line[col] = ' ';
  60                     ++col;
  61                 }
  62             } else {
  63                 if (col >= 0)
  64                     obj->line[col] = (char) ch;
  65                 ++col;
  66             }
  67             if (col >= MAX_LEN)
  68                 break;
  69         }
  70     } while (!feof(fp) && (ch != '\n'));
  71
  72     if (col < 0)
  73         col = 0;
  74     obj->line[col] = '\0';
  75
  76     return obj->line;
  77 }
  78
  79 /*
  80  * Print a new line of text.
  81  */
  82 static void
  83 print_line(MY_OBJ * obj, WINDOW *win, int row, int width)
  84 {
  85     int i, y, x;
  86     char *line = get_line(obj);
  87
  88     (void) wmove(win, row, 0);  /* move cursor to correct line */
  89     (void) waddch(win, ' ');
  90     (void) waddnstr(win, line, MIN((int) strlen(line), width - 2));
  91
  92     getyx(win, y, x);
  93     (void) y;
  94     /* Clear 'residue' of previous line */
  95     for (i = 0; i < width - x; i++)
  96         (void) waddch(win, ' ');
  97 }
  98
  99 /*
 100  * Go back 'target' lines in text file.  BUFSIZ has to be in 'size_t' range.
 101  */
 102 static void
 103 last_lines(MY_OBJ * obj, int target)
 104 {
 105     FILE *fp = obj->obj.input;
 106     long fpos = 0;
 107
 108     if (fseek(fp, 0L, SEEK_END) == -1
 109         || (fpos = ftell(fp)) < 0)
 110         dlg_exiterr("Error moving file pointer in last_lines().");
 111
 112     if (fpos != 0) {
 113         long offset = 0;
 114
 115         ++target;
 116         for (;;) {
 117             size_t inx;
 118             size_t size_to_read;
 119             size_t size_as_read;
 120             int count = 0;
 121             char buf[BUFSIZ + 1];
 122
 123             if (fpos >= BUFSIZ) {
 124                 size_to_read = BUFSIZ;
 125             } else {
 126                 size_to_read = (size_t) fpos;
 127             }
 128             fpos = fpos - (long) size_to_read;
 129             if (fseek(fp, fpos, SEEK_SET) == -1)
 130                 dlg_exiterr("Error moving file pointer in last_lines().");
 131             size_as_read = fread(buf, sizeof(char), size_to_read, fp);
 132             if (ferror(fp))
 133                 dlg_exiterr("Error reading file in last_lines().");
 134
 135             if (size_as_read == 0) {
 136                 fpos = 0;
 137                 offset = 0;
 138                 break;
 139             }
 140
 141             offset += (long) size_as_read;
 142             for (inx = size_as_read - 1; inx != 0; --inx) {
 143                 if (buf[inx] == '\n') {
 144                     if (++count > target)
 145                         break;
 146                     offset = (long) (inx + 1);
 147                 }
 148             }
 149
 150             if (count > target) {
 151                 break;
 152             } else if (fpos == 0) {
 153                 offset = 0;
 154                 break;
 155             }
 156         }
 157
 158         if (fseek(fp, fpos + offset, SEEK_SET) == -1)
 159             dlg_exiterr("Error moving file pointer in last_lines().");
 160     }
 161 }
 162
 163 /*
 164  * Print a new page of text.
 165  */
 166 static void
 167 print_page(MY_OBJ * obj, int height, int width)
 168 {
 169     int i;
 170
 171     for (i = 0; i < height; i++) {
 172         print_line(obj, obj->text, i, width);
 173     }
 174     (void) wnoutrefresh(obj->text);
 175 }
 176
 177 static void
 178 print_last_page(MY_OBJ * obj)
 179 {
 180     int high = getmaxy(obj->obj.win) - (2 * MARGIN + (obj->obj.bg_task ? 1 : 3));
 181     int wide = getmaxx(obj->text);
 182
 183     last_lines(obj, high);
 184     print_page(obj, high, wide);
 185 }
 186
 187 static void
 188 repaint_text(MY_OBJ * obj)
 189 {
 190     FILE *fp = obj->obj.input;
 191     int cur_y, cur_x;
 192
 193     getyx(obj->obj.win, cur_y, cur_x);
 194     obj->old_hscroll = obj->hscroll;
 195
 196     print_last_page(obj);
 197     obj->last_pos = ftell(fp);
 198
 199     (void) wmove(obj->obj.win, cur_y, cur_x);   /* Restore cursor position */
 200     wrefresh(obj->obj.win);
 201 }
 202
 203 static bool
 204 handle_input(DIALOG_CALLBACK * cb)
 205 {
 206     MY_OBJ *obj = (MY_OBJ *) cb;
 207     FILE *fp = obj->obj.input;
 208     struct stat sb;
 209
 210     if (fstat(fileno(fp), &sb) == 0
 211         && sb.st_size != obj->last_pos) {
 212         repaint_text(obj);
 213     }
 214
 215     return TRUE;
 216 }
 217
 218 static bool
 219 valid_callback(DIALOG_CALLBACK * cb)
 220 {
 221     bool valid = FALSE;
 222     DIALOG_CALLBACK *p;
 223     for (p = dialog_state.getc_callbacks; p != 0; p = p->next) {
 224         if (p == cb) {
 225             valid = TRUE;
 226             break;
 227         }
 228     }
 229     return valid;
 230 }
 231
 232 static bool
 233 handle_my_getc(DIALOG_CALLBACK * cb, int ch, int fkey, int *result)
 234 {
 235     MY_OBJ *obj = (MY_OBJ *) cb;
 236     bool done = FALSE;
 237
 238     if (!valid_callback(cb))
 239         return FALSE;
 240
 241     if (!fkey && dlg_char_to_button(ch, obj->buttons) == 0) {
 242         ch = DLGK_ENTER;
 243         fkey = TRUE;
 244     }
 245
 246     if (fkey) {
 247         switch (ch) {
 248         case DLGK_ENTER:
 249             *result = DLG_EXIT_OK;
 250             done = TRUE;
 251             break;
 252         case DLGK_BEGIN:        /* Beginning of line */
 253             obj->hscroll = 0;
 254             break;
 255         case DLGK_GRID_LEFT:    /* Scroll left */
 256             if (obj->hscroll > 0) {
 257                 obj->hscroll -= 1;
 258             }
 259             break;
 260         case DLGK_GRID_RIGHT:   /* Scroll right */
 261             if (obj->hscroll < MAX_LEN)
 262                 obj->hscroll += 1;
 263             break;
 264         default:
 265             if (is_DLGK_MOUSE(ch)) {
 266                 *result = dlg_ok_buttoncode(ch - M_EVENT);
 267                 if (*result != DLG_EXIT_ERROR) {
 268                     done = TRUE;
 269                 } else {
 270                     beep();
 271                 }
 272             } else {
 273                 beep();
 274             }
 275             break;
 276         }
 277         if ((obj->hscroll != obj->old_hscroll))
 278             repaint_text(obj);
 279     } else {
 280         switch (ch) {
 281         case ERR:
 282             clearerr(cb->input);
 283             ch = getc(cb->input);
 284             (void) ungetc(ch, cb->input);
 285             if (ch != EOF) {
 286                 handle_input(cb);
 287             }
 288             break;
 289         case ESC:
 290             done = TRUE;
 291             *result = DLG_EXIT_ESC;
 292             break;
 293         default:
 294             beep();
 295             break;
 296         }
 297     }
 298
 299     return !done;
 300 }
 301
 302 /*
 303  * Display text from a file in a dialog box, like in a "tail -f".
 304  */
 305 int
 306 dialog_tailbox(const char *title,
 307                const char *filename,
 308                int height,
 309                int width,
 310                int bg_task)
 311 {
 312     /* *INDENT-OFF* */
 313     static DLG_KEYS_BINDING binding[] = {
 314         HELPKEY_BINDINGS,
 315         ENTERKEY_BINDINGS,
 316         DLG_KEYS_DATA( DLGK_BEGIN,      '0' ),
 317         DLG_KEYS_DATA( DLGK_BEGIN,      KEY_BEG ),
 318         DLG_KEYS_DATA( DLGK_GRID_LEFT,  'H' ),
 319         DLG_KEYS_DATA( DLGK_GRID_LEFT,  'h' ),
 320         DLG_KEYS_DATA( DLGK_GRID_LEFT,  KEY_LEFT ),
 321         DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'L' ),
 322         DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'l' ),
 323         DLG_KEYS_DATA( DLGK_GRID_RIGHT, KEY_RIGHT ),
 324         END_KEYS_BINDING
 325     };
 326     /* *INDENT-ON* */
 327
 328 #ifdef KEY_RESIZE
 329     int old_height = height;
 330     int old_width = width;
 331 #endif
 332     int fkey;
 333     int x, y, result = DLG_EXIT_UNKNOWN, thigh;
 334     WINDOW *dialog, *text;
 335     const char **buttons = 0;
 336     MY_OBJ *obj;
 337     FILE *fd;
 338     int min_width = 12;
 339
 340     DLG_TRACE(("# tailbox args:\n"));
 341     DLG_TRACE2S("title", title);
 342     DLG_TRACE2S("filename", filename);
 343     DLG_TRACE2N("height", height);
 344     DLG_TRACE2N("width", width);
 345     DLG_TRACE2N("bg_task", bg_task);
 346
 347     /* Open input file for reading */
 348     if ((fd = fopen(filename, "rb")) == NULL)
 349         dlg_exiterr("Can't open input file in dialog_tailbox().");
 350
 351 #ifdef KEY_RESIZE
 352   retry:
 353 #endif
 354     dlg_auto_sizefile(title, filename, &height, &width, 2, min_width);
 355     dlg_print_size(height, width);
 356     dlg_ctl_size(height, width);
 357
 358     x = dlg_box_x_ordinate(width);
 359     y = dlg_box_y_ordinate(height);
 360     thigh = height - ((2 * MARGIN) + (bg_task ? 0 : 2));
 361
 362     dialog = dlg_new_window(height, width, y, x);
 363
 364     dlg_mouse_setbase(x, y);
 365
 366     /* Create window for text region, used for scrolling text */
 367     text = dlg_sub_window(dialog,
 368                           thigh,
 369                           width - (2 * MARGIN),
 370                           y + MARGIN,
 371                           x + MARGIN);
 372
 373     dlg_draw_box2(dialog, 0, 0, height, width, dialog_attr, border_attr, border2_attr);
 374     dlg_draw_bottom_box2(dialog, border_attr, border2_attr, dialog_attr);
 375     dlg_draw_title(dialog, title);
 376     dlg_draw_helpline(dialog, FALSE);
 377
 378     if (!bg_task) {
 379         buttons = dlg_exit_label();
 380         dlg_button_layout(buttons, &min_width);
 381         dlg_draw_buttons(dialog, height - (2 * MARGIN), 0, buttons, FALSE,
 382                          FALSE, width);
 383     }
 384
 385     (void) wmove(dialog, thigh, (MARGIN + 1));
 386     (void) wnoutrefresh(dialog);
 387
 388     obj = dlg_calloc(MY_OBJ, 1);
 389     assert_ptr(obj, "dialog_tailbox");
 390
 391     obj->obj.input = fd;
 392     obj->obj.win = dialog;
 393     obj->obj.handle_getc = handle_my_getc;
 394     obj->obj.handle_input = bg_task ? handle_input : 0;
 395     obj->obj.keep_bg = bg_task && dialog_vars.cant_kill;
 396     obj->obj.bg_task = (bool) bg_task;
 397     obj->text = text;
 398     obj->buttons = buttons;
 399     dlg_add_callback(&(obj->obj));
 400
 401     dlg_register_window(dialog, "tailbox", binding);
 402     dlg_register_buttons(dialog, "tailbox", buttons);
 403
 404     /* Print last page of text */
 405     dlg_attr_clear(text, thigh, getmaxx(text), dialog_attr);
 406     repaint_text(obj);
 407
 408     dlg_trace_win(dialog);
 409     if (bg_task) {
 410         result = DLG_EXIT_OK;
 411     } else {
 412         int ch;
 413         do {
 414             ch = dlg_mouse_wgetch(dialog, &fkey);
 415 #ifdef KEY_RESIZE
 416             if (fkey && ch == KEY_RESIZE) {
 417                 dlg_will_resize(dialog);
 418                 /* reset data */
 419                 height = old_height;
 420                 width = old_width;
 421                 /* repaint */
 422                 _dlg_resize_cleanup(dialog);
 423                 dlg_button_layout(buttons, &min_width);
 424                 goto retry;
 425             }
 426 #endif
 427         }
 428         while (handle_my_getc(&(obj->obj), ch, fkey, &result));
 429     }
 430     dlg_mouse_free_regions();
 431     return result;
 432 }