tailbox.c revision 52bf5abd924bc78494905f16ffbd4bd67062240c
1/*
2 *  $Id: tailbox.c,v 1.63 2011/06/27 08:19:43 tom Exp $
3 *
4 *  tailbox.c -- implements the tail box
5 *
6 *  Copyright 2000-2010,2011	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 + 1];
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    /* Clear 'residue' of previous line */
100    for (i = 0; i < width - x; i++)
101	(void) waddch(win, ' ');
102}
103
104/*
105 * Go back 'target' lines in text file.  BUFSIZ has to be in 'size_t' range.
106 */
107static void
108last_lines(MY_OBJ * obj, int target)
109{
110    FILE *fp = obj->obj.input;
111    size_t inx;
112    int count = 0;
113    char buf[BUFSIZ + 1];
114    size_t size_to_read;
115    size_t size_as_read;
116    long offset = 0;
117    long fpos = 0;
118
119    if (fseek(fp, 0L, SEEK_END) == -1
120	|| (fpos = ftell(fp)) < 0)
121	dlg_exiterr("Error moving file pointer in last_lines().");
122
123    if (fpos != 0) {
124	++target;
125	for (;;) {
126	    if (fpos >= BUFSIZ) {
127		size_to_read = BUFSIZ;
128	    } else {
129		size_to_read = (size_t) fpos;
130	    }
131	    fpos = fpos - (long) size_to_read;
132	    if (fseek(fp, fpos, SEEK_SET) == -1)
133		dlg_exiterr("Error moving file pointer in last_lines().");
134	    size_as_read = fread(buf, sizeof(char), size_to_read, fp);
135	    if (ferror(fp))
136		dlg_exiterr("Error reading file in last_lines().");
137
138	    if (size_as_read == 0) {
139		fpos = 0;
140		offset = 0;
141		break;
142	    }
143
144	    offset += (long) size_as_read;
145	    for (inx = size_as_read - 1; inx != 0; --inx) {
146		if (buf[inx] == '\n') {
147		    if (++count > target)
148			break;
149		    offset = (long) (inx + 1);
150		}
151	    }
152
153	    if (count > target) {
154		break;
155	    } else if (fpos == 0) {
156		offset = 0;
157		break;
158	    }
159	}
160
161	if (fseek(fp, fpos + offset, SEEK_SET) == -1)
162	    dlg_exiterr("Error moving file pointer in last_lines().");
163    }
164}
165
166/*
167 * Print a new page of text.
168 */
169static void
170print_page(MY_OBJ * obj, int height, int width)
171{
172    int i;
173
174    for (i = 0; i < height; i++) {
175	print_line(obj, obj->text, i, width);
176    }
177    (void) wnoutrefresh(obj->text);
178}
179
180static void
181print_last_page(MY_OBJ * obj)
182{
183    int high = getmaxy(obj->obj.win) - (2 * MARGIN + (obj->obj.bg_task ? 1 : 3));
184    int wide = getmaxx(obj->text);
185
186    last_lines(obj, high);
187    print_page(obj, high, wide);
188}
189
190static void
191repaint_text(MY_OBJ * obj)
192{
193    FILE *fp = obj->obj.input;
194    int cur_y, cur_x;
195
196    getyx(obj->obj.win, cur_y, cur_x);
197    obj->old_hscroll = obj->hscroll;
198
199    print_last_page(obj);
200    obj->last_pos = ftell(fp);
201
202    (void) wmove(obj->obj.win, cur_y, cur_x);	/* Restore cursor position */
203    wrefresh(obj->obj.win);
204}
205
206static bool
207handle_input(DIALOG_CALLBACK * cb)
208{
209    MY_OBJ *obj = (MY_OBJ *) cb;
210    FILE *fp = obj->obj.input;
211    struct stat sb;
212
213    if (fstat(fileno(fp), &sb) == 0
214	&& sb.st_size != obj->last_pos) {
215	repaint_text(obj);
216    }
217
218    return TRUE;
219}
220
221static bool
222handle_my_getc(DIALOG_CALLBACK * cb, int ch, int fkey, int *result)
223{
224    MY_OBJ *obj = (MY_OBJ *) cb;
225    bool done = FALSE;
226
227    if (!fkey && dlg_char_to_button(ch, obj->buttons) == 0) {
228	ch = DLGK_ENTER;
229	fkey = TRUE;
230    }
231
232    if (fkey) {
233	switch (ch) {
234	case DLGK_ENTER:
235	    *result = DLG_EXIT_OK;
236	    done = TRUE;
237	    break;
238	case DLGK_BEGIN:	/* Beginning of line */
239	    obj->hscroll = 0;
240	    break;
241	case DLGK_GRID_LEFT:	/* Scroll left */
242	    if (obj->hscroll > 0) {
243		obj->hscroll -= 1;
244	    }
245	    break;
246	case DLGK_GRID_RIGHT:	/* Scroll right */
247	    if (obj->hscroll < MAX_LEN)
248		obj->hscroll += 1;
249	    break;
250	default:
251	    beep();
252	    break;
253	}
254	if ((obj->hscroll != obj->old_hscroll))
255	    repaint_text(obj);
256    } else {
257	switch (ch) {
258	case ERR:
259	    clearerr(cb->input);
260	    ch = getc(cb->input);
261	    (void) ungetc(ch, cb->input);
262	    if (ch != EOF) {
263		handle_input(cb);
264	    }
265	    break;
266	case ESC:
267	    done = TRUE;
268	    *result = DLG_EXIT_ESC;
269	    break;
270	default:
271	    beep();
272	    break;
273	}
274    }
275
276    return !done;
277}
278
279/*
280 * Display text from a file in a dialog box, like in a "tail -f".
281 */
282int
283dialog_tailbox(const char *title, const char *file, int height, int width, int bg_task)
284{
285    /* *INDENT-OFF* */
286    static DLG_KEYS_BINDING binding[] = {
287	HELPKEY_BINDINGS,
288	ENTERKEY_BINDINGS,
289	DLG_KEYS_DATA( DLGK_BEGIN,      '0' ),
290	DLG_KEYS_DATA( DLGK_BEGIN,      KEY_BEG ),
291	DLG_KEYS_DATA( DLGK_GRID_LEFT,  'H' ),
292	DLG_KEYS_DATA( DLGK_GRID_LEFT,  'h' ),
293	DLG_KEYS_DATA( DLGK_GRID_LEFT,  KEY_LEFT ),
294	DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'L' ),
295	DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'l' ),
296	DLG_KEYS_DATA( DLGK_GRID_RIGHT, KEY_RIGHT ),
297	END_KEYS_BINDING
298    };
299    /* *INDENT-ON* */
300
301#ifdef KEY_RESIZE
302    int old_height = height;
303    int old_width = width;
304#endif
305    int fkey;
306    int x, y, result, thigh;
307    WINDOW *dialog, *text;
308    const char **buttons = 0;
309    MY_OBJ *obj;
310    FILE *fd;
311    int min_width = 12;
312
313    /* Open input file for reading */
314    if ((fd = fopen(file, "rb")) == NULL)
315	dlg_exiterr("Can't open input file in dialog_tailbox().");
316
317#ifdef KEY_RESIZE
318  retry:
319#endif
320    dlg_auto_sizefile(title, file, &height, &width, 2, min_width);
321    dlg_print_size(height, width);
322    dlg_ctl_size(height, width);
323
324    x = dlg_box_x_ordinate(width);
325    y = dlg_box_y_ordinate(height);
326    thigh = height - ((2 * MARGIN) + (bg_task ? 0 : 2));
327
328    dialog = dlg_new_window(height, width, y, x);
329
330    dlg_mouse_setbase(x, y);
331
332    /* Create window for text region, used for scrolling text */
333    text = dlg_sub_window(dialog,
334			  thigh,
335			  width - (2 * MARGIN),
336			  y + MARGIN,
337			  x + MARGIN);
338
339    dlg_draw_box(dialog, 0, 0, height, width, dialog_attr, border_attr);
340    dlg_draw_bottom_box(dialog);
341    dlg_draw_title(dialog, title);
342    dlg_draw_helpline(dialog, FALSE);
343
344    if (!bg_task) {
345	buttons = dlg_exit_label();
346	dlg_button_layout(buttons, &min_width);
347	dlg_draw_buttons(dialog, height - (2 * MARGIN), 0, buttons, FALSE,
348			 FALSE, width);
349    }
350
351    (void) wmove(dialog, thigh, (MARGIN + 1));
352    (void) wnoutrefresh(dialog);
353
354    obj = dlg_calloc(MY_OBJ, 1);
355    assert_ptr(obj, "dialog_tailbox");
356
357    obj->obj.input = fd;
358    obj->obj.win = dialog;
359    obj->obj.handle_getc = handle_my_getc;
360    obj->obj.handle_input = bg_task ? handle_input : 0;
361    obj->obj.keep_bg = bg_task && dialog_vars.cant_kill;
362    obj->obj.bg_task = bg_task;
363    obj->text = text;
364    obj->buttons = buttons;
365    dlg_add_callback(&(obj->obj));
366
367    dlg_register_window(dialog, "tailbox", binding);
368    dlg_register_buttons(dialog, "tailbox", buttons);
369
370    /* Print last page of text */
371    dlg_attr_clear(text, thigh, getmaxx(text), dialog_attr);
372    repaint_text(obj);
373
374    if (bg_task) {
375	result = DLG_EXIT_OK;
376    } else {
377	int ch;
378	do {
379	    ch = dlg_getc(dialog, &fkey);
380#ifdef KEY_RESIZE
381	    if (fkey && ch == KEY_RESIZE) {
382		/* reset data */
383		height = old_height;
384		width = old_width;
385		/* repaint */
386		dlg_clear();
387		dlg_del_window(dialog);
388		refresh();
389		dlg_mouse_free_regions();
390		dlg_button_layout(buttons, &min_width);
391		goto retry;
392	    }
393#endif
394	}
395	while (handle_my_getc(&(obj->obj), ch, fkey, &result));
396    }
397    dlg_mouse_free_regions();
398    return result;
399}
400