1 /*
2  *  textbox.c -- implements the text box
3  *
4  *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
5  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
6  *
7  *  This program is free software; you can redistribute it and/or
8  *  modify it under the terms of the GNU General Public License
9  *  as published by the Free Software Foundation; either version 2
10  *  of the License, or (at your option) any later version.
11  *
12  *  This program is distributed in the hope that it will be useful,
13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *  GNU General Public License for more details.
16  *
17  *  You should have received a copy of the GNU General Public License
18  *  along with this program; if not, write to the Free Software
19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22 #include "dialog.h"
23 
24 static void back_lines(int n);
25 static void print_page(WINDOW *win, int height, int width, update_text_fn
26 		       update_text, void *data);
27 static void print_line(WINDOW *win, int row, int width);
28 static char *get_line(void);
29 static void print_position(WINDOW * win);
30 
31 static int hscroll;
32 static int begin_reached, end_reached, page_length;
33 static char *buf;
34 static char *page;
35 
36 /*
37  * refresh window content
38  */
39 static void refresh_text_box(WINDOW *dialog, WINDOW *box, int boxh, int boxw,
40 			     int cur_y, int cur_x, update_text_fn update_text,
41 			     void *data)
42 {
43 	print_page(box, boxh, boxw, update_text, data);
44 	print_position(dialog);
45 	wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
46 	wrefresh(dialog);
47 }
48 
49 
50 /*
51  * Display text from a file in a dialog box.
52  *
53  * keys is a null-terminated array
54  * update_text() may not add or remove any '\n' or '\0' in tbuf
55  */
56 int dialog_textbox(const char *title, char *tbuf, int initial_height,
57 		   int initial_width, int *keys, int *_vscroll, int *_hscroll,
58 		   update_text_fn update_text, void *data)
59 {
60 	int i, x, y, cur_x, cur_y, key = 0;
61 	int height, width, boxh, boxw;
62 	WINDOW *dialog, *box;
63 	bool done = false;
64 
65 	begin_reached = 1;
66 	end_reached = 0;
67 	page_length = 0;
68 	hscroll = 0;
69 	buf = tbuf;
70 	page = buf;	/* page is pointer to start of page to be displayed */
71 
72 	if (_vscroll && *_vscroll) {
73 		begin_reached = 0;
74 
75 		for (i = 0; i < *_vscroll; i++)
76 			get_line();
77 	}
78 	if (_hscroll)
79 		hscroll = *_hscroll;
80 
81 do_resize:
82 	getmaxyx(stdscr, height, width);
83 	if (height < TEXTBOX_HEIGTH_MIN || width < TEXTBOX_WIDTH_MIN)
84 		return -ERRDISPLAYTOOSMALL;
85 	if (initial_height != 0)
86 		height = initial_height;
87 	else
88 		if (height > 4)
89 			height -= 4;
90 		else
91 			height = 0;
92 	if (initial_width != 0)
93 		width = initial_width;
94 	else
95 		if (width > 5)
96 			width -= 5;
97 		else
98 			width = 0;
99 
100 	/* center dialog box on screen */
101 	x = (getmaxx(stdscr) - width) / 2;
102 	y = (getmaxy(stdscr) - height) / 2;
103 
104 	draw_shadow(stdscr, y, x, height, width);
105 
106 	dialog = newwin(height, width, y, x);
107 	keypad(dialog, TRUE);
108 
109 	/* Create window for box region, used for scrolling text */
110 	boxh = height - 4;
111 	boxw = width - 2;
112 	box = subwin(dialog, boxh, boxw, y + 1, x + 1);
113 	wattrset(box, dlg.dialog.atr);
114 	wbkgdset(box, dlg.dialog.atr & A_COLOR);
115 
116 	keypad(box, TRUE);
117 
118 	/* register the new window, along with its borders */
119 	draw_box(dialog, 0, 0, height, width,
120 		 dlg.dialog.atr, dlg.border.atr);
121 
122 	wattrset(dialog, dlg.border.atr);
123 	mvwaddch(dialog, height - 3, 0, ACS_LTEE);
124 	for (i = 0; i < width - 2; i++)
125 		waddch(dialog, ACS_HLINE);
126 	wattrset(dialog, dlg.dialog.atr);
127 	wbkgdset(dialog, dlg.dialog.atr & A_COLOR);
128 	waddch(dialog, ACS_RTEE);
129 
130 	print_title(dialog, title, width);
131 
132 	print_button(dialog, gettext(" Exit "), height - 2, width / 2 - 4, TRUE);
133 	wnoutrefresh(dialog);
134 	getyx(dialog, cur_y, cur_x);	/* Save cursor position */
135 
136 	/* Print first page of text */
137 	attr_clear(box, boxh, boxw, dlg.dialog.atr);
138 	refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x, update_text,
139 			 data);
140 
141 	while (!done) {
142 		key = wgetch(dialog);
143 		switch (key) {
144 		case 'E':	/* Exit */
145 		case 'e':
146 		case 'X':
147 		case 'x':
148 		case 'q':
149 		case '\n':
150 			done = true;
151 			break;
152 		case 'g':	/* First page */
153 		case KEY_HOME:
154 			if (!begin_reached) {
155 				begin_reached = 1;
156 				page = buf;
157 				refresh_text_box(dialog, box, boxh, boxw,
158 						 cur_y, cur_x, update_text,
159 						 data);
160 			}
161 			break;
162 		case 'G':	/* Last page */
163 		case KEY_END:
164 
165 			end_reached = 1;
166 			/* point to last char in buf */
167 			page = buf + strlen(buf);
168 			back_lines(boxh);
169 			refresh_text_box(dialog, box, boxh, boxw, cur_y,
170 					 cur_x, update_text, data);
171 			break;
172 		case 'K':	/* Previous line */
173 		case 'k':
174 		case KEY_UP:
175 			if (begin_reached)
176 				break;
177 
178 			back_lines(page_length + 1);
179 			refresh_text_box(dialog, box, boxh, boxw, cur_y,
180 					 cur_x, update_text, data);
181 			break;
182 		case 'B':	/* Previous page */
183 		case 'b':
184 		case 'u':
185 		case KEY_PPAGE:
186 			if (begin_reached)
187 				break;
188 			back_lines(page_length + boxh);
189 			refresh_text_box(dialog, box, boxh, boxw, cur_y,
190 					 cur_x, update_text, data);
191 			break;
192 		case 'J':	/* Next line */
193 		case 'j':
194 		case KEY_DOWN:
195 			if (end_reached)
196 				break;
197 
198 			back_lines(page_length - 1);
199 			refresh_text_box(dialog, box, boxh, boxw, cur_y,
200 					 cur_x, update_text, data);
201 			break;
202 		case KEY_NPAGE:	/* Next page */
203 		case ' ':
204 		case 'd':
205 			if (end_reached)
206 				break;
207 
208 			begin_reached = 0;
209 			refresh_text_box(dialog, box, boxh, boxw, cur_y,
210 					 cur_x, update_text, data);
211 			break;
212 		case '0':	/* Beginning of line */
213 		case 'H':	/* Scroll left */
214 		case 'h':
215 		case KEY_LEFT:
216 			if (hscroll <= 0)
217 				break;
218 
219 			if (key == '0')
220 				hscroll = 0;
221 			else
222 				hscroll--;
223 			/* Reprint current page to scroll horizontally */
224 			back_lines(page_length);
225 			refresh_text_box(dialog, box, boxh, boxw, cur_y,
226 					 cur_x, update_text, data);
227 			break;
228 		case 'L':	/* Scroll right */
229 		case 'l':
230 		case KEY_RIGHT:
231 			if (hscroll >= MAX_LEN)
232 				break;
233 			hscroll++;
234 			/* Reprint current page to scroll horizontally */
235 			back_lines(page_length);
236 			refresh_text_box(dialog, box, boxh, boxw, cur_y,
237 					 cur_x, update_text, data);
238 			break;
239 		case KEY_ESC:
240 			if (on_key_esc(dialog) == KEY_ESC)
241 				done = true;
242 			break;
243 		case KEY_RESIZE:
244 			back_lines(height);
245 			delwin(box);
246 			delwin(dialog);
247 			on_key_resize();
248 			goto do_resize;
249 		default:
250 			for (i = 0; keys[i]; i++) {
251 				if (key == keys[i]) {
252 					done = true;
253 					break;
254 				}
255 			}
256 		}
257 	}
258 	delwin(box);
259 	delwin(dialog);
260 	if (_vscroll) {
261 		const char *s;
262 
263 		s = buf;
264 		*_vscroll = 0;
265 		back_lines(page_length);
266 		while (s < page && (s = strchr(s, '\n'))) {
267 			(*_vscroll)++;
268 			s++;
269 		}
270 	}
271 	if (_hscroll)
272 		*_hscroll = hscroll;
273 	return key;
274 }
275 
276 /*
277  * Go back 'n' lines in text. Called by dialog_textbox().
278  * 'page' will be updated to point to the desired line in 'buf'.
279  */
280 static void back_lines(int n)
281 {
282 	int i;
283 
284 	begin_reached = 0;
285 	/* Go back 'n' lines */
286 	for (i = 0; i < n; i++) {
287 		if (*page == '\0') {
288 			if (end_reached) {
289 				end_reached = 0;
290 				continue;
291 			}
292 		}
293 		if (page == buf) {
294 			begin_reached = 1;
295 			return;
296 		}
297 		page--;
298 		do {
299 			if (page == buf) {
300 				begin_reached = 1;
301 				return;
302 			}
303 			page--;
304 		} while (*page != '\n');
305 		page++;
306 	}
307 }
308 
309 /*
310  * Print a new page of text.
311  */
312 static void print_page(WINDOW *win, int height, int width, update_text_fn
313 		       update_text, void *data)
314 {
315 	int i, passed_end = 0;
316 
317 	if (update_text) {
318 		char *end;
319 
320 		for (i = 0; i < height; i++)
321 			get_line();
322 		end = page;
323 		back_lines(height);
324 		update_text(buf, page - buf, end - buf, data);
325 	}
326 
327 	page_length = 0;
328 	for (i = 0; i < height; i++) {
329 		print_line(win, i, width);
330 		if (!passed_end)
331 			page_length++;
332 		if (end_reached && !passed_end)
333 			passed_end = 1;
334 	}
335 	wnoutrefresh(win);
336 }
337 
338 /*
339  * Print a new line of text.
340  */
341 static void print_line(WINDOW * win, int row, int width)
342 {
343 	char *line;
344 
345 	line = get_line();
346 	line += MIN(strlen(line), hscroll);	/* Scroll horizontally */
347 	wmove(win, row, 0);	/* move cursor to correct line */
348 	waddch(win, ' ');
349 	waddnstr(win, line, MIN(strlen(line), width - 2));
350 
351 	/* Clear 'residue' of previous line */
352 #if OLD_NCURSES
353 	{
354 		int x = getcurx(win);
355 		int i;
356 		for (i = 0; i < width - x; i++)
357 			waddch(win, ' ');
358 	}
359 #else
360 	wclrtoeol(win);
361 #endif
362 }
363 
364 /*
365  * Return current line of text. Called by dialog_textbox() and print_line().
366  * 'page' should point to start of current line before calling, and will be
367  * updated to point to start of next line.
368  */
369 static char *get_line(void)
370 {
371 	int i = 0;
372 	static char line[MAX_LEN + 1];
373 
374 	end_reached = 0;
375 	while (*page != '\n') {
376 		if (*page == '\0') {
377 			end_reached = 1;
378 			break;
379 		} else if (i < MAX_LEN)
380 			line[i++] = *(page++);
381 		else {
382 			/* Truncate lines longer than MAX_LEN characters */
383 			if (i == MAX_LEN)
384 				line[i++] = '\0';
385 			page++;
386 		}
387 	}
388 	if (i <= MAX_LEN)
389 		line[i] = '\0';
390 	if (!end_reached)
391 		page++;		/* move past '\n' */
392 
393 	return line;
394 }
395 
396 /*
397  * Print current position
398  */
399 static void print_position(WINDOW * win)
400 {
401 	int percent;
402 
403 	wattrset(win, dlg.position_indicator.atr);
404 	wbkgdset(win, dlg.position_indicator.atr & A_COLOR);
405 	percent = (page - buf) * 100 / strlen(buf);
406 	wmove(win, getmaxy(win) - 3, getmaxx(win) - 9);
407 	wprintw(win, "(%3d%%)", percent);
408 }
409