contrib/dialog/tailbox.c

   1 /*
   2  *  $Id: tailbox.c,v 1.68 2012/11/18 15:48:52 tom Exp $
   3  *
   4  *  tailbox.c -- implements the tail box
   5  *
   6  *  Copyright 2000-2011,2012    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 <dialog.h>
  28 #include <dlg_keys.h>
  29 #include <sys/stat.h>
  30
  31 typedef struct {
  32     DIALOG_CALLBACK obj;
  33     WINDOW *text;
  34     const char **buttons;
  35     int hscroll;
  36     int old_hscroll;
  37     char line[MAX_LEN + 2];
  38     off_t last_pos;
  39 } MY_OBJ;
  40
  41 /*
  42  * Return current line of text.
  43  */
  44 static char *
  45 get_line(MY_OBJ * obj)
  46 {
  47     FILE *fp = obj->obj.input;
  48     int col = -(obj->hscroll);
  49     int j, tmpint, ch;
  50
  51     do {
  52         if (((ch = getc(fp)) == EOF) && !feof(fp))
  53             dlg_exiterr("Error moving file pointer in get_line().");
  54         else if (!feof(fp) && (ch != '\n')) {
  55             if ((ch == TAB) && (dialog_vars.tab_correct)) {
  56                 tmpint = dialog_state.tab_len
  57                     - ((col + obj->hscroll) % dialog_state.tab_len);
  58                 for (j = 0; j < tmpint; j++) {
  59                     if (col >= 0 && col < MAX_LEN)
  60                         obj->line[col] = ' ';
  61                     ++col;
  62                 }
  63             } else {
  64                 if (col >= 0)
  65                     obj->line[col] = (char) ch;
  66                 ++col;
  67             }
  68             if (col >= MAX_LEN)
  69                 break;
  70         }
  71     } while (!feof(fp) && (ch != '\n'));
  72
  73     if (col < 0)
  74         col = 0;
  75     obj->line[col] = '\0';
  76
  77     return obj->line;
  78 }
  79
  80 /*
  81  * Print a new line of text.
  82  */
  83 static void
  84 print_line(MY_OBJ * obj, WINDOW *win, int row, int width)
  85 {
  86     int i, y, x;
  87     char *line = get_line(obj);
  88
  89     (void) wmove(win, row, 0);  /* move cursor to correct line */
  90     (void) waddch(win, ' ');
  91 #ifdef NCURSES_VERSION
  92     (void) waddnstr(win, line, MIN((int) strlen(line), width - 2));
  93 #else
  94     line[MIN((int) strlen(line), width - 2)] = '\0';
  95     waddstr(win, line);
  96 #endif
  97
  98     getyx(win, y, x);
  99     (void) y;
 100     /* Clear 'residue' of previous line */
 101     for (i = 0; i < width - x; i++)
 102         (void) waddch(win, ' ');
 103 }
 104
 105 /*
 106  * Go back 'target' lines in text file.  BUFSIZ has to be in 'size_t' range.
 107  */
 108 static void
 109 last_lines(MY_OBJ * obj, int target)
 110 {
 111     FILE *fp = obj->obj.input;
 112     size_t inx;
 113     int count = 0;
 114     char buf[BUFSIZ + 1];
 115     size_t size_to_read;
 116     size_t size_as_read;
 117     long offset = 0;
 118     long fpos = 0;
 119
 120     if (fseek(fp, 0L, SEEK_END) == -1
 121         || (fpos = ftell(fp)) < 0)
 122         dlg_exiterr("Error moving file pointer in last_lines().");
 123
 124     if (fpos != 0) {
 125         ++target;
 126         for (;;) {
 127             if (fpos >= BUFSIZ) {
 128                 size_to_read = BUFSIZ;
 129             } else {
 130                 size_to_read = (size_t) fpos;
 131             }
 132             fpos = fpos - (long) size_to_read;
 133             if (fseek(fp, fpos, SEEK_SET) == -1)
 134                 dlg_exiterr("Error moving file pointer in last_lines().");
 135             size_as_read = fread(buf, sizeof(char), size_to_read, fp);
 136             if (ferror(fp))
 137                 dlg_exiterr("Error reading file in last_lines().");
 138
 139             if (size_as_read == 0) {
 140                 fpos = 0;
 141                 offset = 0;
 142                 break;
 143             }
 144
 145             offset += (long) size_as_read;
 146             for (inx = size_as_read - 1; inx != 0; --inx) {
 147                 if (buf[inx] == '\n') {
 148                     if (++count > target)
 149                         break;
 150                     offset = (long) (inx + 1);
 151                 }
 152             }
 153
 154             if (count > target) {
 155                 break;
 156             } else if (fpos == 0) {
 157                 offset = 0;
 158                 break;
 159             }
 160         }
 161
 162         if (fseek(fp, fpos + offset, SEEK_SET) == -1)
 163             dlg_exiterr("Error moving file pointer in last_lines().");
 164     }
 165 }
 166
 167 /*
 168  * Print a new page of text.
 169  */
 170 static void
 171 print_page(MY_OBJ * obj, int height, int width)
 172 {
 173     int i;
 174
 175     for (i = 0; i < height; i++) {
 176         print_line(obj, obj->text, i, width);
 177     }
 178     (void) wnoutrefresh(obj->text);
 179 }
 180
 181 static void
 182 print_last_page(MY_OBJ * obj)
 183 {
 184     int high = getmaxy(obj->obj.win) - (2 * MARGIN + (obj->obj.bg_task ? 1 : 3));
 185     int wide = getmaxx(obj->text);
 186
 187     last_lines(obj, high);
 188     print_page(obj, high, wide);
 189 }
 190
 191 static void
 192 repaint_text(MY_OBJ * obj)
 193 {
 194     FILE *fp = obj->obj.input;
 195     int cur_y, cur_x;
 196
 197     getyx(obj->obj.win, cur_y, cur_x);
 198     obj->old_hscroll = obj->hscroll;
 199
 200     print_last_page(obj);
 201     obj->last_pos = ftell(fp);
 202
 203     (void) wmove(obj->obj.win, cur_y, cur_x);   /* Restore cursor position */
 204     wrefresh(obj->obj.win);
 205 }
 206
 207 static bool
 208 handle_input(DIALOG_CALLBACK * cb)
 209 {
 210     MY_OBJ *obj = (MY_OBJ *) cb;
 211     FILE *fp = obj->obj.input;
 212     struct stat sb;
 213
 214     if (fstat(fileno(fp), &sb) == 0
 215         && sb.st_size != obj->last_pos) {
 216         repaint_text(obj);
 217     }
 218
 219     return TRUE;
 220 }
 221
 222 static bool
 223 handle_my_getc(DIALOG_CALLBACK * cb, int ch, int fkey, int *result)
 224 {
 225     MY_OBJ *obj = (MY_OBJ *) cb;
 226     bool done = FALSE;
 227
 228     if (!fkey && dlg_char_to_button(ch, obj->buttons) == 0) {
 229         ch = DLGK_ENTER;
 230         fkey = TRUE;
 231     }
 232
 233     if (fkey) {
 234         switch (ch) {
 235         case DLGK_ENTER:
 236             *result = DLG_EXIT_OK;
 237             done = TRUE;
 238             break;
 239         case DLGK_BEGIN:        /* Beginning of line */
 240             obj->hscroll = 0;
 241             break;
 242         case DLGK_GRID_LEFT:    /* Scroll left */
 243             if (obj->hscroll > 0) {
 244                 obj->hscroll -= 1;
 245             }
 246             break;
 247         case DLGK_GRID_RIGHT:   /* Scroll right */
 248             if (obj->hscroll < MAX_LEN)
 249                 obj->hscroll += 1;
 250             break;
 251         default:
 252             beep();
 253             break;
 254         }
 255         if ((obj->hscroll != obj->old_hscroll))
 256             repaint_text(obj);
 257     } else {
 258         switch (ch) {
 259         case ERR:
 260             clearerr(cb->input);
 261             ch = getc(cb->input);
 262             (void) ungetc(ch, cb->input);
 263             if (ch != EOF) {
 264                 handle_input(cb);
 265             }
 266             break;
 267         case ESC:
 268             done = TRUE;
 269             *result = DLG_EXIT_ESC;
 270             break;
 271         default:
 272             beep();
 273             break;
 274         }
 275     }
 276
 277     return !done;
 278 }
 279
 280 /*
 281  * Display text from a file in a dialog box, like in a "tail -f".
 282  */
 283 int
 284 dialog_tailbox(const char *title, const char *file, int height, int width, int bg_task)
 285 {
 286     /* *INDENT-OFF* */
 287     static DLG_KEYS_BINDING binding[] = {
 288         HELPKEY_BINDINGS,
 289         ENTERKEY_BINDINGS,
 290         DLG_KEYS_DATA( DLGK_BEGIN,      '0' ),
 291         DLG_KEYS_DATA( DLGK_BEGIN,      KEY_BEG ),
 292         DLG_KEYS_DATA( DLGK_GRID_LEFT,  'H' ),
 293         DLG_KEYS_DATA( DLGK_GRID_LEFT,  'h' ),
 294         DLG_KEYS_DATA( DLGK_GRID_LEFT,  KEY_LEFT ),
 295         DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'L' ),
 296         DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'l' ),
 297         DLG_KEYS_DATA( DLGK_GRID_RIGHT, KEY_RIGHT ),
 298         END_KEYS_BINDING
 299     };
 300     /* *INDENT-ON* */
 301
 302 #ifdef KEY_RESIZE
 303     int old_height = height;
 304     int old_width = width;
 305 #endif
 306     int fkey;
 307     int x, y, result, thigh;
 308     WINDOW *dialog, *text;
 309     const char **buttons = 0;
 310     MY_OBJ *obj;
 311     FILE *fd;
 312     int min_width = 12;
 313
 314     /* Open input file for reading */
 315     if ((fd = fopen(file, "rb")) == NULL)
 316         dlg_exiterr("Can't open input file in dialog_tailbox().");
 317
 318 #ifdef KEY_RESIZE
 319   retry:
 320 #endif
 321     dlg_auto_sizefile(title, file, &height, &width, 2, min_width);
 322     dlg_print_size(height, width);
 323     dlg_ctl_size(height, width);
 324
 325     x = dlg_box_x_ordinate(width);
 326     y = dlg_box_y_ordinate(height);
 327     thigh = height - ((2 * MARGIN) + (bg_task ? 0 : 2));
 328
 329     dialog = dlg_new_window(height, width, y, x);
 330
 331     dlg_mouse_setbase(x, y);
 332
 333     /* Create window for text region, used for scrolling text */
 334     text = dlg_sub_window(dialog,
 335                           thigh,
 336                           width - (2 * MARGIN),
 337                           y + MARGIN,
 338                           x + MARGIN);
 339
 340     dlg_draw_box2(dialog, 0, 0, height, width, dialog_attr, border_attr, border2_attr);
 341     dlg_draw_bottom_box2(dialog, border_attr, border2_attr, dialog_attr);
 342     dlg_draw_title(dialog, title);
 343     dlg_draw_helpline(dialog, FALSE);
 344
 345     if (!bg_task) {
 346         buttons = dlg_exit_label();
 347         dlg_button_layout(buttons, &min_width);
 348         dlg_draw_buttons(dialog, height - (2 * MARGIN), 0, buttons, FALSE,
 349                          FALSE, width);
 350     }
 351
 352     (void) wmove(dialog, thigh, (MARGIN + 1));
 353     (void) wnoutrefresh(dialog);
 354
 355     obj = dlg_calloc(MY_OBJ, 1);
 356     assert_ptr(obj, "dialog_tailbox");
 357
 358     obj->obj.input = fd;
 359     obj->obj.win = dialog;
 360     obj->obj.handle_getc = handle_my_getc;
 361     obj->obj.handle_input = bg_task ? handle_input : 0;
 362     obj->obj.keep_bg = bg_task && dialog_vars.cant_kill;
 363     obj->obj.bg_task = bg_task;
 364     obj->text = text;
 365     obj->buttons = buttons;
 366     dlg_add_callback(&(obj->obj));
 367
 368     dlg_register_window(dialog, "tailbox", binding);
 369     dlg_register_buttons(dialog, "tailbox", buttons);
 370
 371     /* Print last page of text */
 372     dlg_attr_clear(text, thigh, getmaxx(text), dialog_attr);
 373     repaint_text(obj);
 374
 375     dlg_trace_win(dialog);
 376     if (bg_task) {
 377         result = DLG_EXIT_OK;
 378     } else {
 379         int ch;
 380         do {
 381             ch = dlg_getc(dialog, &fkey);
 382 #ifdef KEY_RESIZE
 383             if (fkey && ch == KEY_RESIZE) {
 384                 /* reset data */
 385                 height = old_height;
 386                 width = old_width;
 387                 /* repaint */
 388                 dlg_clear();
 389                 dlg_del_window(dialog);
 390                 refresh();
 391                 dlg_mouse_free_regions();
 392                 dlg_button_layout(buttons, &min_width);
 393                 goto retry;
 394             }
 395 #endif
 396         }
 397         while (handle_my_getc(&(obj->obj), ch, fkey, &result));
 398     }
 399     dlg_mouse_free_regions();
 400     return result;
 401 }