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
31typedef 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 */
44static char *
45get_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 */
83static void
84print_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 */
108static void
109last_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 */
170static void
171print_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
181static void
182print_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
191static void
192repaint_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
207static bool
208handle_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
222static bool
223handle_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 */
283int
284dialog_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}
402