xref: /freebsd/contrib/dialog/tailbox.c (revision 10b9d77bf1ccf2f3affafa6261692cb92cf7e992) 
1 /*
2  *  $Id: tailbox.c,v 1.56 2010/04/28 20:52:20 tom Exp $
3  *
4  * tailbox.c -- implements the tail box
5  *
6  * Copyright 2000-2009,2010 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 
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 + 1];
37 } MY_OBJ;
38 
39 /*
40  * Return current line of text.
41  */
42 static char *
43 get_line(MY_OBJ * obj)
44 {
45     FILE *fp = obj->obj.input;
46     int col = -(obj->hscroll);
47     int j, tmpint, ch;
48 
49     do {
50 	if (((ch = getc(fp)) == EOF) && !feof(fp))
51 	    dlg_exiterr("Error moving file pointer in get_line().");
52 	else if (!feof(fp) && (ch != '\n')) {
53 	    if ((ch == TAB) && (dialog_vars.tab_correct)) {
54 		tmpint = dialog_state.tab_len
55 		    - ((col + obj->hscroll) % dialog_state.tab_len);
56 		for (j = 0; j < tmpint; j++) {
57 		    if (col >= 0 && col < MAX_LEN)
58 			obj->line[col] = ' ';
59 		    ++col;
60 		}
61 	    } else {
62 		if (col >= 0)
63 		    obj->line[col] = (char) ch;
64 		++col;
65 	    }
66 	    if (col >= MAX_LEN)
67 		break;
68 	}
69     } while (!feof(fp) && (ch != '\n'));
70 
71     if (col < 0)
72 	col = 0;
73     obj->line[col] = '\0';
74 
75     return obj->line;
76 }
77 
78 /*
79  * Print a new line of text.
80  */
81 static void
82 print_line(MY_OBJ * obj, WINDOW *win, int row, int width)
83 {
84     int i, y, x;
85     char *line = get_line(obj);
86 
87     (void) wmove(win, row, 0);	/* move cursor to correct line */
88     (void) waddch(win, ' ');
89 #ifdef NCURSES_VERSION
90     (void) waddnstr(win, line, MIN((int) strlen(line), width - 2));
91 #else
92     line[MIN((int) strlen(line), width - 2)] = '\0';
93     waddstr(win, line);
94 #endif
95 
96     getyx(win, y, x);
97     /* Clear 'residue' of previous line */
98     for (i = 0; i < width - x; i++)
99 	(void) waddch(win, ' ');
100 }
101 
102 /*
103  * Go back 'target' lines in text file.  BUFSIZ has to be in 'size_t' range.
104  */
105 static void
106 last_lines(MY_OBJ * obj, int target)
107 {
108     FILE *fp = obj->obj.input;
109     long inx;
110     int count = 0;
111     char buf[BUFSIZ + 1];
112     long size_to_read;
113     long offset = 0;
114     long fpos = 0;
115 
116     if (fseek(fp, 0, SEEK_END) == -1
117 	|| (fpos = ftell(fp)) < 0)
118 	dlg_exiterr("Error moving file pointer in last_lines().");
119 
120     if (fpos != 0) {
121 	++target;
122 	for (;;) {
123 	    if (fpos >= BUFSIZ) {
124 		size_to_read = BUFSIZ;
125 	    } else {
126 		size_to_read = fpos;
127 	    }
128 	    fpos = fpos - size_to_read;
129 	    if (fseek(fp, fpos, SEEK_SET) == -1)
130 		dlg_exiterr("Error moving file pointer in last_lines().");
131 	    (void) fread(buf, (size_t) size_to_read, 1, fp);
132 	    if (ferror(fp))
133 		dlg_exiterr("Error reading file in last_lines().");
134 
135 	    offset += size_to_read;
136 	    for (inx = size_to_read - 1; inx >= 0; --inx) {
137 		if (buf[inx] == '\n') {
138 		    if (++count > target)
139 			break;
140 		    offset = inx + 1;
141 		}
142 	    }
143 
144 	    if (count > target) {
145 		break;
146 	    } else if (fpos == 0) {
147 		offset = 0;
148 		break;
149 	    }
150 	}
151 
152 	if (fseek(fp, fpos + offset, SEEK_SET) == -1)
153 	    dlg_exiterr("Error moving file pointer in last_lines().");
154     }
155 }
156 
157 /*
158  * Print a new page of text.
159  */
160 static void
161 print_page(MY_OBJ * obj, int height, int width)
162 {
163     int i;
164 
165     for (i = 0; i < height; i++) {
166 	print_line(obj, obj->text, i, width);
167     }
168     (void) wnoutrefresh(obj->text);
169 }
170 
171 static void
172 print_last_page(MY_OBJ * obj)
173 {
174     int high = getmaxy(obj->obj.win) - (2 * MARGIN + (obj->obj.bg_task ? 1 : 3));
175     int wide = getmaxx(obj->text);
176 
177     last_lines(obj, high);
178     print_page(obj, high, wide);
179 }
180 
181 static void
182 repaint_text(MY_OBJ * obj)
183 {
184     int cur_y, cur_x;
185 
186     getyx(obj->obj.win, cur_y, cur_x);
187     obj->old_hscroll = obj->hscroll;
188     print_last_page(obj);
189     (void) wmove(obj->obj.win, cur_y, cur_x);	/* Restore cursor position */
190     wrefresh(obj->obj.win);
191 }
192 
193 static bool
194 handle_my_getc(DIALOG_CALLBACK * cb, int ch, int fkey, int *result)
195 {
196     MY_OBJ *obj = (MY_OBJ *) cb;
197     bool done = FALSE;
198 
199     if (!fkey && dlg_char_to_button(ch, obj->buttons) == 0) {
200 	ch = DLGK_ENTER;
201 	fkey = TRUE;
202     }
203 
204     if (fkey) {
205 	switch (ch) {
206 	case DLGK_ENTER:
207 	    *result = DLG_EXIT_OK;
208 	    done = TRUE;
209 	    break;
210 	case DLGK_BEGIN:	/* Beginning of line */
211 	    obj->hscroll = 0;
212 	    break;
213 	case DLGK_GRID_LEFT:	/* Scroll left */
214 	    if (obj->hscroll > 0) {
215 		obj->hscroll -= 1;
216 	    }
217 	    break;
218 	case DLGK_GRID_RIGHT:	/* Scroll right */
219 	    if (obj->hscroll < MAX_LEN)
220 		obj->hscroll += 1;
221 	    break;
222 	default:
223 	    beep();
224 	    break;
225 	}
226 	if ((obj->hscroll != obj->old_hscroll))
227 	    repaint_text(obj);
228     } else {
229 	switch (ch) {
230 	case ERR:
231 	    clearerr(cb->input);
232 	    ch = getc(cb->input);
233 	    (void) ungetc(ch, cb->input);
234 	    if ((ch != EOF) || (obj->hscroll != obj->old_hscroll)) {
235 		repaint_text(obj);
236 	    }
237 	    break;
238 	case ESC:
239 	    done = TRUE;
240 	    *result = DLG_EXIT_ESC;
241 	    break;
242 	default:
243 	    beep();
244 	    break;
245 	}
246     }
247 
248     return !done;
249 }
250 
251 /*
252  * Display text from a file in a dialog box, like in a "tail -f".
253  */
254 int
255 dialog_tailbox(const char *title, const char *file, int height, int width, int bg_task)
256 {
257     /* *INDENT-OFF* */
258     static DLG_KEYS_BINDING binding[] = {
259 	ENTERKEY_BINDINGS,
260 	DLG_KEYS_DATA( DLGK_BEGIN,      '0' ),
261 	DLG_KEYS_DATA( DLGK_BEGIN,      KEY_BEG ),
262 	DLG_KEYS_DATA( DLGK_GRID_LEFT,  'H' ),
263 	DLG_KEYS_DATA( DLGK_GRID_LEFT,  'h' ),
264 	DLG_KEYS_DATA( DLGK_GRID_LEFT,  KEY_LEFT ),
265 	DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'L' ),
266 	DLG_KEYS_DATA( DLGK_GRID_RIGHT, 'l' ),
267 	DLG_KEYS_DATA( DLGK_GRID_RIGHT, KEY_RIGHT ),
268 	END_KEYS_BINDING
269     };
270     /* *INDENT-ON* */
271 
272 #ifdef KEY_RESIZE
273     int old_height = height;
274     int old_width = width;
275 #endif
276     int fkey;
277     int x, y, result, thigh;
278     WINDOW *dialog, *text;
279     const char **buttons = 0;
280     MY_OBJ *obj;
281     FILE *fd;
282     int min_width = 12;
283 
284     /* Open input file for reading */
285     if ((fd = fopen(file, "rb")) == NULL)
286 	dlg_exiterr("Can't open input file in dialog_tailbox().");
287 
288 #ifdef KEY_RESIZE
289   retry:
290 #endif
291     dlg_auto_sizefile(title, file, &height, &width, 2, min_width);
292     dlg_print_size(height, width);
293     dlg_ctl_size(height, width);
294 
295     x = dlg_box_x_ordinate(width);
296     y = dlg_box_y_ordinate(height);
297     thigh = height - ((2 * MARGIN) + (bg_task ? 0 : 2));
298 
299     dialog = dlg_new_window(height, width, y, x);
300 
301     dlg_mouse_setbase(x, y);
302 
303     /* Create window for text region, used for scrolling text */
304     text = dlg_sub_window(dialog,
305 			  thigh,
306 			  width - (2 * MARGIN),
307 			  y + MARGIN,
308 			  x + MARGIN);
309 
310     dlg_draw_box(dialog, 0, 0, height, width, dialog_attr, border_attr);
311     dlg_draw_bottom_box(dialog);
312     dlg_draw_title(dialog, title);
313 
314     if (!bg_task) {
315 	buttons = dlg_exit_label();
316 	dlg_button_layout(buttons, &min_width);
317 	dlg_draw_buttons(dialog, height - (2 * MARGIN), 0, buttons, FALSE,
318 			 FALSE, width);
319     }
320 
321     (void) wmove(dialog, thigh, (MARGIN + 1));
322     (void) wnoutrefresh(dialog);
323 
324     obj = dlg_calloc(MY_OBJ, 1);
325     assert_ptr(obj, "dialog_tailbox");
326 
327     obj->obj.input = fd;
328     obj->obj.win = dialog;
329     obj->obj.handle_getc = handle_my_getc;
330     obj->obj.keep_bg = bg_task && dialog_vars.cant_kill;
331     obj->obj.bg_task = bg_task;
332     obj->text = text;
333     obj->buttons = buttons;
334     dlg_add_callback(&(obj->obj));
335 
336     dlg_register_window(dialog, "tailbox", binding);
337     dlg_register_buttons(dialog, "tailbox", buttons);
338 
339     /* Print last page of text */
340     dlg_attr_clear(text, thigh, getmaxx(text), dialog_attr);
341     repaint_text(obj);
342 
343     if (bg_task) {
344 	result = DLG_EXIT_OK;
345     } else {
346 	int ch;
347 	do {
348 	    ch = dlg_getc(dialog, &fkey);
349 #ifdef KEY_RESIZE
350 	    if (fkey && ch == KEY_RESIZE) {
351 		/* reset data */
352 		height = old_height;
353 		width = old_width;
354 		/* repaint */
355 		dlg_clear();
356 		dlg_del_window(dialog);
357 		refresh();
358 		dlg_mouse_free_regions();
359 		dlg_button_layout(buttons, &min_width);
360 		goto retry;
361 	    }
362 #endif
363 	}
364 	while (handle_my_getc(&(obj->obj), ch, fkey, &result));
365     }
366     dlg_mouse_free_regions();
367     return result;
368 }
369